Installing on bare metal


OpenShift Container Platform 4.18

Installing OpenShift Container Platform on bare metal

Red Hat OpenShift Documentation Team

Abstract

This document describes how to install OpenShift Container Platform on bare metal.

Chapter 1. Preparing for bare metal cluster installation

1.1. Prerequisites

1.2. Planning a bare metal cluster for OpenShift Virtualization

If you will use OpenShift Virtualization, it is important to be aware of several requirements before you install your bare metal cluster.

  • If you want to use live migration features, you must have multiple worker nodes at the time of cluster installation. This is because live migration requires the cluster-level high availability (HA) flag to be set to true. The HA flag is set when a cluster is installed and cannot be changed afterwards. If there are fewer than two worker nodes defined when you install your cluster, the HA flag is set to false for the life of the cluster.

    Note

    You can install OpenShift Virtualization on a single-node cluster, but single-node OpenShift does not support high availability.

  • Live migration requires shared storage. Storage for OpenShift Virtualization must support and use the ReadWriteMany (RWX) access mode.
  • If you plan to use Single Root I/O Virtualization (SR-IOV), ensure that your network interface controllers (NICs) are supported by OpenShift Container Platform.

1.3. NIC partitioning for SR-IOV devices

OpenShift Container Platform can be deployed on a server with a dual port network interface card (NIC). You can partition a single, high-speed dual port NIC into multiple virtual functions (VFs) and enable SR-IOV.

This feature supports the use of bonds for high availability with the Link Aggregation Control Protocol (LACP).

Note

Only one LACP can be declared by physical NIC.

An OpenShift Container Platform cluster can be deployed on a bond interface with 2 VFs on 2 physical functions (PFs) using the following methods:

  • Agent-based installer

    Note

    The minimum required version of nmstate is:

    • 1.4.2-4 for RHEL 8 versions
    • 2.2.7 for RHEL 9 versions
  • Installer-provisioned infrastructure installation
  • User-provisioned infrastructure installation

1.4. Choosing a method to install OpenShift Container Platform on bare metal

The OpenShift Container Platform installation program offers four methods for deploying a cluster:

  • Interactive: You can deploy a cluster with the web-based Assisted Installer. This is the recommended approach for clusters with networks connected to the internet. The Assisted Installer is the easiest way to install OpenShift Container Platform, it provides smart defaults, and it performs pre-flight validations before installing the cluster. It also provides a RESTful API for automation and advanced configuration scenarios.
  • Local Agent-based: You can deploy a cluster locally with the agent-based installer for air-gapped or restricted networks. It provides many of the benefits of the Assisted Installer, but you must download and configure the agent-based installer first. Configuration is done with a commandline interface. This approach is ideal for air-gapped or restricted networks.
  • Automated: You can deploy a cluster on installer-provisioned infrastructure and the cluster it maintains. The installer uses each cluster host’s baseboard management controller (BMC) for provisioning. You can deploy clusters with both connected or air-gapped or restricted networks.
  • Full control: You can deploy a cluster on infrastructure that you prepare and maintain, which provides maximum customizability. You can deploy clusters with both connected or air-gapped or restricted networks.

The clusters have the following characteristics:

  • Highly available infrastructure with no single points of failure is available by default.
  • Administrators maintain control over what updates are applied and when.

See Installation process for more information about installer-provisioned and user-provisioned installation processes.

1.4.1. Installing a cluster on installer-provisioned infrastructure

You can install a cluster on bare metal infrastructure that is provisioned by the OpenShift Container Platform installation program, by using the following method:

1.4.2. Installing a cluster on user-provisioned infrastructure

You can install a cluster on bare metal infrastructure that you provision, by using one of the following methods:

  • Installing a user-provisioned cluster on bare metal: You can install OpenShift Container Platform on bare metal infrastructure that you provision. For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.
  • Installing a user-provisioned bare metal cluster with network customizations: You can install a bare metal cluster on user-provisioned infrastructure with network-customizations. By customizing your network configuration, your cluster can coexist with existing IP address allocations in your environment and integrate with existing MTU and VXLAN configurations. Most of the network customizations must be applied at the installation stage.
  • Installing a user-provisioned bare metal cluster on a restricted network: You can install a user-provisioned bare metal cluster on a restricted or disconnected network by using a mirror registry. You can also use this installation method to ensure that your clusters only use container images that satisfy your organizational controls on external content.

Chapter 2. User-provisioned infrastructure

2.1. Installing a user-provisioned cluster on bare metal

In OpenShift Container Platform 4.18, you can install a cluster on bare metal infrastructure that you provision.

Important

While you might be able to follow this procedure to deploy a cluster on virtualized or cloud environments, you must be aware of additional considerations for non-bare metal platforms. Review the information in the guidelines for deploying OpenShift Container Platform on non-tested platforms before you attempt to install an OpenShift Container Platform cluster in such an environment.

2.1.1. Prerequisites

2.1.2. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.18, you require access to the internet to install your cluster.

You must have internet access to:

  • Access OpenShift Cluster Manager to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.
  • Access Quay.io to obtain the packages that are required to install your cluster.
  • Obtain the packages that are required to perform cluster updates.
Important

If your cluster cannot have direct internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the required content and use it to populate a mirror registry with the installation packages. With some installation types, the environment that you install your cluster in will not require internet access. Before you update the cluster, you update the content of the mirror registry.

Additional resources

2.1.3. Requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

This section describes the requirements for deploying OpenShift Container Platform on user-provisioned infrastructure.

2.1.3.1. Required machines for cluster installation

The smallest OpenShift Container Platform clusters require the following hosts:

Table 2.1. Minimum required hosts
HostsDescription

One temporary bootstrap machine

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Three control plane machines

The control plane machines run the Kubernetes and OpenShift Container Platform services that form the control plane.

At least two compute machines, which are also known as worker machines.

The workloads requested by OpenShift Container Platform users run on the compute machines.

Note

As an exception, you can run zero compute machines in a bare metal cluster that consists of three control plane machines only. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for testing, development, and production. Running one compute machine is not supported.

Important

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS), Red Hat Enterprise Linux (RHEL) 8.6 and later.

Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 9.2 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

2.1.3.2. Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 2.2. Minimum resource requirements
MachineOperating SystemCPU [1]RAMStorageInput/Output Per Second (IOPS)[2]

Bootstrap

RHCOS

4

16 GB

100 GB

300

Control plane

RHCOS

4

16 GB

100 GB

300

Compute

RHCOS, RHEL 8.6 and later [3]

2

8 GB

100 GB

300

  1. One CPU is equivalent to one physical core when simultaneous multithreading (SMT), or Hyper-Threading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = CPUs.
  2. OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
  3. As with all user-provisioned installations, if you choose to use RHEL compute machines in your cluster, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Use of RHEL 7 compute machines is deprecated and has been removed in OpenShift Container Platform 4.10 and later.
Note

For OpenShift Container Platform version 4.18, RHCOS is based on RHEL version 9.4, which updates the micro-architecture requirements. The following list contains the minimum instruction set architectures (ISA) that each architecture requires:

  • x86-64 architecture requires x86-64-v2 ISA
  • ARM64 architecture requires ARMv8.0-A ISA
  • IBM Power architecture requires Power 9 ISA
  • s390x architecture requires z14 ISA

For more information, see Architectures (RHEL documentation).

If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.

Additional resources

2.1.3.3. Certificate signing requests management

Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.

Additional resources

2.1.3.4. Requirements for baremetal clusters on vSphere

Ensure you enable the disk.EnableUUID parameter on all virtual machines in your cluster.

Additional resources

2.1.3.5. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require networking to be configured in initramfs during boot to fetch their Ignition config files.

During the initial boot, the machines require an IP address configuration that is set either through a DHCP server or statically by providing the required boot options. After a network connection is established, the machines download their Ignition config files from an HTTP or HTTPS server. The Ignition config files are then used to set the exact state of each machine. The Machine Config Operator completes more changes to the machines, such as the application of new certificates or keys, after installation.

It is recommended to use a DHCP server for long-term management of the cluster machines. Ensure that the DHCP server is configured to provide persistent IP addresses, DNS server information, and hostnames to the cluster machines.

Note

If a DHCP service is not available for your user-provisioned infrastructure, you can instead provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options.

The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.

2.1.3.5.1. Setting the cluster node hostnames through DHCP

On Red Hat Enterprise Linux CoreOS (RHCOS) machines, the hostname is set through NetworkManager. By default, the machines obtain their hostname through DHCP. If the hostname is not provided by DHCP, set statically through kernel arguments, or another method, it is obtained through a reverse DNS lookup. Reverse DNS lookup occurs after the network has been initialized on a node and can take time to resolve. Other system services can start prior to this and detect the hostname as localhost or similar. You can avoid this by using DHCP to provide the hostname for each cluster node.

Additionally, setting the hostnames through DHCP can bypass any manual DNS record name configuration errors in environments that have a DNS split-horizon implementation.

2.1.3.5.2. Network connectivity requirements

You must configure the network connectivity between machines to allow OpenShift Container Platform cluster components to communicate. Each machine must be able to resolve the hostnames of all other machines in the cluster.

This section provides details about the ports that are required.

Important

In connected OpenShift Container Platform environments, all nodes are required to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Table 2.3. Ports used for all-machine to all-machine communications
ProtocolPortDescription

ICMP

N/A

Network reachability tests

TCP

1936

Metrics

9000-9999

Host level services, including the node exporter on ports 9100-9101 and the Cluster Version Operator on port 9099.

10250-10259

The default ports that Kubernetes reserves

UDP

4789

VXLAN

6081

Geneve

9000-9999

Host level services, including the node exporter on ports 9100-9101.

500

IPsec IKE packets

4500

IPsec NAT-T packets

123

Network Time Protocol (NTP) on UDP port 123

If an external NTP time server is configured, you must open UDP port 123.

TCP/UDP

30000-32767

Kubernetes node port

ESP

N/A

IPsec Encapsulating Security Payload (ESP)

Table 2.4. Ports used for all-machine to control plane communications
ProtocolPortDescription

TCP

6443

Kubernetes API

Table 2.5. Ports used for control plane machine to control plane machine communications
ProtocolPortDescription

TCP

2379-2380

etcd server and peer ports

NTP configuration for user-provisioned infrastructure

OpenShift Container Platform clusters are configured to use a public Network Time Protocol (NTP) server by default. If you want to use a local enterprise NTP server, or if your cluster is being deployed in a disconnected network, you can configure the cluster to use a specific time server. For more information, see the documentation for Configuring chrony time service.

If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

2.1.3.6. User-provisioned DNS requirements

In OpenShift Container Platform deployments, DNS name resolution is required for the following components:

  • The Kubernetes API
  • The OpenShift Container Platform application wildcard
  • The bootstrap, control plane, and compute machines

Reverse DNS resolution is also required for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.

DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Red Hat Enterprise Linux CoreOS (RHCOS) uses the reverse records to set the hostnames for all the nodes, unless the hostnames are provided by DHCP. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OpenShift Container Platform needs to operate.

Note

It is recommended to use a DHCP server to provide the hostnames to each cluster node. See the DHCP recommendations for user-provisioned infrastructure section for more information.

The following DNS records are required for a user-provisioned OpenShift Container Platform cluster and they must be in place before installation. In each record, <cluster_name> is the cluster name and <base_domain> is the base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 2.6. Required DNS records
ComponentRecordDescription

Kubernetes API

api.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the API load balancer. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

api-int.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to internally identify the API load balancer. These records must be resolvable from all the nodes within the cluster.

Important

The API server must be able to resolve the worker nodes by the hostnames that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

*.apps.<cluster_name>.<base_domain>.

A wildcard DNS A/AAAA or CNAME record that refers to the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

For example, console-openshift-console.apps.<cluster_name>.<base_domain> is used as a wildcard route to the OpenShift Container Platform console.

Bootstrap machine

bootstrap.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.

Control plane machines

<control_plane><n>.<cluster_name>.<base_domain>.

DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes. These records must be resolvable by the nodes within the cluster.

Compute machines

<compute><n>.<cluster_name>.<base_domain>.

DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Note

In OpenShift Container Platform 4.4 and later, you do not need to specify etcd host and SRV records in your DNS configuration.

Tip

You can use the dig command to verify name and reverse name resolution. See the section on Validating DNS resolution for user-provisioned infrastructure for detailed validation steps.

2.1.3.6.1. Example DNS configuration for user-provisioned clusters

This section provides A and PTR record configuration samples that meet the DNS requirements for deploying OpenShift Container Platform on user-provisioned infrastructure. The samples are not meant to provide advice for choosing one DNS solution over another.

In the examples, the cluster name is ocp4 and the base domain is example.com.

Example DNS A record configuration for a user-provisioned cluster

The following example is a BIND zone file that shows sample A records for name resolution in a user-provisioned cluster.

Example 2.1. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1.example.com.		IN	A	192.168.1.5
smtp.example.com.		IN	A	192.168.1.5
;
helper.example.com.		IN	A	192.168.1.5
helper.ocp4.example.com.	IN	A	192.168.1.5
;
api.ocp4.example.com.		IN	A	192.168.1.5 1
api-int.ocp4.example.com.	IN	A	192.168.1.5 2
;
*.apps.ocp4.example.com.	IN	A	192.168.1.5 3
;
bootstrap.ocp4.example.com.	IN	A	192.168.1.96 4
;
control-plane0.ocp4.example.com.	IN	A	192.168.1.97 5
control-plane1.ocp4.example.com.	IN	A	192.168.1.98 6
control-plane2.ocp4.example.com.	IN	A	192.168.1.99 7
;
compute0.ocp4.example.com.	IN	A	192.168.1.11 8
compute1.ocp4.example.com.	IN	A	192.168.1.7 9
;
;EOF
1
Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer.
2
Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer and is used for internal cluster communications.
3
Provides name resolution for the wildcard routes. The record refers to the IP address of the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
Note

In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

4
Provides name resolution for the bootstrap machine.
5 6 7
Provides name resolution for the control plane machines.
8 9
Provides name resolution for the compute machines.

Example DNS PTR record configuration for a user-provisioned cluster

The following example BIND zone file shows sample PTR records for reverse name resolution in a user-provisioned cluster.

Example 2.2. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
5.1.168.192.in-addr.arpa.	IN	PTR	api.ocp4.example.com. 1
5.1.168.192.in-addr.arpa.	IN	PTR	api-int.ocp4.example.com. 2
;
96.1.168.192.in-addr.arpa.	IN	PTR	bootstrap.ocp4.example.com. 3
;
97.1.168.192.in-addr.arpa.	IN	PTR	control-plane0.ocp4.example.com. 4
98.1.168.192.in-addr.arpa.	IN	PTR	control-plane1.ocp4.example.com. 5
99.1.168.192.in-addr.arpa.	IN	PTR	control-plane2.ocp4.example.com. 6
;
11.1.168.192.in-addr.arpa.	IN	PTR	compute0.ocp4.example.com. 7
7.1.168.192.in-addr.arpa.	IN	PTR	compute1.ocp4.example.com. 8
;
;EOF
1
Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer.
2
Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer and is used for internal cluster communications.
3
Provides reverse DNS resolution for the bootstrap machine.
4 5 6
Provides reverse DNS resolution for the control plane machines.
7 8
Provides reverse DNS resolution for the compute machines.
Note

A PTR record is not required for the OpenShift Container Platform application wildcard.

2.1.3.7. Load balancing requirements for user-provisioned infrastructure

Before you install OpenShift Container Platform, you must provision the API and application Ingress load balancing infrastructure. In production scenarios, you can deploy the API and application Ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

Note

If you want to deploy the API and application Ingress load balancers with a Red Hat Enterprise Linux (RHEL) instance, you must purchase the RHEL subscription separately.

The load balancing infrastructure must meet the following requirements:

  1. API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
    • A stateless load balancing algorithm. The options vary based on the load balancer implementation.
    Important

    Do not configure session persistence for an API load balancer. Configuring session persistence for a Kubernetes API server might cause performance issues from excess application traffic for your OpenShift Container Platform cluster and the Kubernetes API that runs inside the cluster.

    Configure the following ports on both the front and back of the load balancers:

    Table 2.7. API load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    6443

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the /readyz endpoint for the API server health check probe.

    X

    X

    Kubernetes API server

    22623

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.

    X

     

    Machine config server

    Note

    The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the /readyz endpoint to the removal of the API server instance from the pool. Within the time frame after /readyz returns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values.

  2. Application Ingress load balancer: Provides an ingress point for application traffic flowing in from outside the cluster. A working configuration for the Ingress router is required for an OpenShift Container Platform cluster.

    Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
    • A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.
    Tip

    If the true IP address of the client can be seen by the application Ingress load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

    Configure the following ports on both the front and back of the load balancers:

    Table 2.8. Application Ingress load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    443

    The machines that run the Ingress Controller pods, compute, or worker, by default.

    X

    X

    HTTPS traffic

    80

    The machines that run the Ingress Controller pods, compute, or worker, by default.

    X

    X

    HTTP traffic

    Note

    If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application Ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.

2.1.3.7.1. Example load balancer configuration for user-provisioned clusters

This section provides an example API and application Ingress load balancer configuration that meets the load balancing requirements for user-provisioned clusters. The sample is an /etc/haproxy/haproxy.cfg configuration for an HAProxy load balancer. The example is not meant to provide advice for choosing one load balancing solution over another.

In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

Note

If you are using HAProxy as a load balancer and SELinux is set to enforcing, you must ensure that the HAProxy service can bind to the configured TCP port by running setsebool -P haproxy_connect_any=1.

Example 2.3. Sample API and application Ingress load balancer configuration

global
  log         127.0.0.1 local2
  pidfile     /var/run/haproxy.pid
  maxconn     4000
  daemon
defaults
  mode                    http
  log                     global
  option                  dontlognull
  option http-server-close
  option                  redispatch
  retries                 3
  timeout http-request    10s
  timeout queue           1m
  timeout connect         10s
  timeout client          1m
  timeout server          1m
  timeout http-keep-alive 10s
  timeout check           10s
  maxconn                 3000
listen api-server-6443 1
  bind *:6443
  mode tcp
  option  httpchk GET /readyz HTTP/1.0
  option  log-health-checks
  balance roundrobin
  server bootstrap bootstrap.ocp4.example.com:6443 verify none check check-ssl inter 10s fall 2 rise 3 backup 2
  server master0 master0.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
  server master1 master1.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
  server master2 master2.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
listen machine-config-server-22623 3
  bind *:22623
  mode tcp
  server bootstrap bootstrap.ocp4.example.com:22623 check inter 1s backup 4
  server master0 master0.ocp4.example.com:22623 check inter 1s
  server master1 master1.ocp4.example.com:22623 check inter 1s
  server master2 master2.ocp4.example.com:22623 check inter 1s
listen ingress-router-443 5
  bind *:443
  mode tcp
  balance source
  server compute0 compute0.ocp4.example.com:443 check inter 1s
  server compute1 compute1.ocp4.example.com:443 check inter 1s
listen ingress-router-80 6
  bind *:80
  mode tcp
  balance source
  server compute0 compute0.ocp4.example.com:80 check inter 1s
  server compute1 compute1.ocp4.example.com:80 check inter 1s
1
Port 6443 handles the Kubernetes API traffic and points to the control plane machines.
2 4
The bootstrap entries must be in place before the OpenShift Container Platform cluster installation and they must be removed after the bootstrap process is complete.
3
Port 22623 handles the machine config server traffic and points to the control plane machines.
5
Port 443 handles the HTTPS traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
6
Port 80 handles the HTTP traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
Note

If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application Ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.

Tip

If you are using HAProxy as a load balancer, you can check that the haproxy process is listening on ports 6443, 22623, 443, and 80 by running netstat -nltupe on the HAProxy node.

2.1.4. Creating a manifest object that includes a customized br-ex bridge

As an alternative to using the configure-ovs.sh shell script to set a br-ex bridge on a bare-metal platform, you can create a MachineConfig object that includes an NMState configuration file. The NMState configuration file creates a customized br-ex bridge network configuration on each node in your cluster.

Consider the following use cases for creating a manifest object that includes a customized br-ex bridge:

  • You want to make postinstallation changes to the bridge, such as changing the Open vSwitch (OVS) or OVN-Kubernetes br-ex bridge network. The configure-ovs.sh shell script does not support making postinstallation changes to the bridge.
  • You want to deploy the bridge on a different interface than the interface available on a host or server IP address.
  • You want to make advanced configurations to the bridge that are not possible with the configure-ovs.sh shell script. Using the script for these configurations might result in the bridge failing to connect multiple network interfaces and facilitating data forwarding between the interfaces.
Note

If you require an environment with a single network interface controller (NIC) and default network settings, use the configure-ovs.sh shell script.

After you install Red Hat Enterprise Linux CoreOS (RHCOS) and the system reboots, the Machine Config Operator injects Ignition configuration files into each node in your cluster, so that each node received the br-ex bridge network configuration. To prevent configuration conflicts, the configure-ovs.sh shell script receives a signal to not configure the br-ex bridge.

Prerequisites

  • Optional: You have installed the nmstate API so that you can validate the NMState configuration.

Procedure

  1. Create a NMState configuration file that has decoded base64 information for your customized br-ex bridge network:

    Example of an NMState configuration for a customized br-ex bridge network

    interfaces:
    - name: enp2s0 1
      type: ethernet 2
      state: up 3
      ipv4:
        enabled: false 4
      ipv6:
        enabled: false
    - name: br-ex
      type: ovs-bridge
      state: up
      ipv4:
        enabled: false
        dhcp: false
      ipv6:
        enabled: false
        dhcp: false
      bridge:
        port:
        - name: enp2s0 5
        - name: br-ex
    - name: br-ex
      type: ovs-interface
      state: up
      copy-mac-from: enp2s0
      ipv4:
        enabled: true
        dhcp: true
      ipv6:
        enabled: false
        dhcp: false
    # ...

    1
    Name of the interface.
    2
    The type of ethernet.
    3
    The requested state for the interface after creation.
    4
    Disables IPv4 and IPv6 in this example.
    5
    The node NIC to which the bridge attaches.
  2. Use the cat command to base64-encode the contents of the NMState configuration:

    $ cat <nmstate_configuration>.yaml | base64 1
    1
    Replace <nmstate_configuration> with the name of your NMState resource YAML file.
  3. Create a MachineConfig manifest file and define a customized br-ex bridge network configuration analogous to the following example:

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker 1
      name: 10-br-ex-worker 2
    spec:
      config:
        ignition:
          version: 3.2.0
        storage:
          files:
          - contents:
              source: data:text/plain;charset=utf-8;base64,<base64_encoded_nmstate_configuration> 3
            mode: 0644
            overwrite: true
            path: /etc/nmstate/openshift/cluster.yml
    # ...
    1
    For each node in your cluster, specify the hostname path to your node and the base-64 encoded Ignition configuration file data for the machine type. If you have a single global configuration specified in an /etc/nmstate/openshift/cluster.yml configuration file that you want to apply to all nodes in your cluster, you do not need to specify the hostname path for each node. The worker role is the default role for nodes in your cluster. The .yaml extension does not work when specifying the hostname path for each node or all nodes in the MachineConfig manifest file.
    2
    The name of the policy.
    3
    Writes the encoded base64 information to the specified path.
2.1.4.1. Scaling each machine set to compute nodes

To apply a customized br-ex bridge configuration to all compute nodes in your OpenShift Container Platform cluster, you must edit your MachineConfig custom resource (CR) and modify its roles. Additionally, you must create a BareMetalHost CR that defines information for your bare-metal machine, such as hostname, credentials, and so on.

After you configure these resources, you must scale machine sets, so that the machine sets can apply the resource configuration to each compute node and reboot the nodes.

Prerequisites

  • You created a MachineConfig manifest object that includes a customized br-ex bridge configuration.

Procedure

  1. Edit the MachineConfig CR by entering the following command:

    $ oc edit mc <machineconfig_custom_resource_name>
  2. Add each compute node configuration to the CR, so that the CR can manage roles for each defined compute node in your cluster.
  3. Create a Secret object named extraworker-secret that has a minimal static IP configuration.
  4. Apply the extraworker-secret secret to each node in your cluster by entering the following command. This step provides each compute node access to the Ignition config file.

    $ oc apply -f ./extraworker-secret.yaml
  5. Create a BareMetalHost resource and specify the network secret in the preprovisioningNetworkDataName parameter:

    Example BareMetalHost resource with an attached network secret

    apiVersion: metal3.io/v1alpha1
    kind: BareMetalHost
    spec:
    # ...
      preprovisioningNetworkDataName: ostest-extraworker-0-network-config-secret
    # ...

  6. To manage the BareMetalHost object within the openshift-machine-api namespace of your cluster, change to the namespace by entering the following command:

    $ oc project openshift-machine-api
  7. Get the machine sets:

    $ oc get machinesets
  8. Scale each machine set by entering the following command. You must run this command for each machine set.

    $ oc scale machineset <machineset_name> --replicas=<n> 1
    1
    Where <machineset_name> is the name of the machine set and <n> is the number of compute nodes.

2.1.5. Preparing the user-provisioned infrastructure

Before you install OpenShift Container Platform on user-provisioned infrastructure, you must prepare the underlying infrastructure.

This section provides details about the high-level steps required to set up your cluster infrastructure in preparation for an OpenShift Container Platform installation. This includes configuring IP networking and network connectivity for your cluster nodes, enabling the required ports through your firewall, and setting up the required DNS and load balancing infrastructure.

After preparation, your cluster infrastructure must meet the requirements outlined in the Requirements for a cluster with user-provisioned infrastructure section.

Prerequisites

Procedure

  1. If you are using DHCP to provide the IP networking configuration to your cluster nodes, configure your DHCP service.

    1. Add persistent IP addresses for the nodes to your DHCP server configuration. In your configuration, match the MAC address of the relevant network interface to the intended IP address for each node.
    2. When you use DHCP to configure IP addressing for the cluster machines, the machines also obtain the DNS server information through DHCP. Define the persistent DNS server address that is used by the cluster nodes through your DHCP server configuration.

      Note

      If you are not using a DHCP service, you must provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options.

    3. Define the hostnames of your cluster nodes in your DHCP server configuration. See the Setting the cluster node hostnames through DHCP section for details about hostname considerations.

      Note

      If you are not using a DHCP service, the cluster nodes obtain their hostname through a reverse DNS lookup.

  2. Ensure that your network infrastructure provides the required network connectivity between the cluster components. See the Networking requirements for user-provisioned infrastructure section for details about the requirements.
  3. Configure your firewall to enable the ports required for the OpenShift Container Platform cluster components to communicate. See Networking requirements for user-provisioned infrastructure section for details about the ports that are required.

    Important

    By default, port 1936 is accessible for an OpenShift Container Platform cluster, because each control plane node needs access to this port.

    Avoid using the Ingress load balancer to expose this port, because doing so might result in the exposure of sensitive information, such as statistics and metrics, related to Ingress Controllers.

  4. Setup the required DNS infrastructure for your cluster.

    1. Configure DNS name resolution for the Kubernetes API, the application wildcard, the bootstrap machine, the control plane machines, and the compute machines.
    2. Configure reverse DNS resolution for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.

      See the User-provisioned DNS requirements section for more information about the OpenShift Container Platform DNS requirements.

  5. Validate your DNS configuration.

    1. From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses in the responses correspond to the correct components.
    2. From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names in the responses correspond to the correct components.

      See the Validating DNS resolution for user-provisioned infrastructure section for detailed DNS validation steps.

  6. Provision the required API and application ingress load balancing infrastructure. See the Load balancing requirements for user-provisioned infrastructure section for more information about the requirements.
Note

Some load balancing solutions require the DNS name resolution for the cluster nodes to be in place before the load balancing is initialized.

2.1.6. Validating DNS resolution for user-provisioned infrastructure

You can validate your DNS configuration before installing OpenShift Container Platform on user-provisioned infrastructure.

Important

The validation steps detailed in this section must succeed before you install your cluster.

Prerequisites

  • You have configured the required DNS records for your user-provisioned infrastructure.

Procedure

  1. From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses contained in the responses correspond to the correct components.

    1. Perform a lookup against the Kubernetes API record name. Check that the result points to the IP address of the API load balancer:

      $ dig +noall +answer @<nameserver_ip> api.<cluster_name>.<base_domain> 1
      1
      Replace <nameserver_ip> with the IP address of the nameserver, <cluster_name> with your cluster name, and <base_domain> with your base domain name.

      Example output

      api.ocp4.example.com.		604800	IN	A	192.168.1.5

    2. Perform a lookup against the Kubernetes internal API record name. Check that the result points to the IP address of the API load balancer:

      $ dig +noall +answer @<nameserver_ip> api-int.<cluster_name>.<base_domain>

      Example output

      api-int.ocp4.example.com.		604800	IN	A	192.168.1.5

    3. Test an example *.apps.<cluster_name>.<base_domain> DNS wildcard lookup. All of the application wildcard lookups must resolve to the IP address of the application ingress load balancer:

      $ dig +noall +answer @<nameserver_ip> random.apps.<cluster_name>.<base_domain>

      Example output

      random.apps.ocp4.example.com.		604800	IN	A	192.168.1.5

      Note

      In the example outputs, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

      You can replace random with another wildcard value. For example, you can query the route to the OpenShift Container Platform console:

      $ dig +noall +answer @<nameserver_ip> console-openshift-console.apps.<cluster_name>.<base_domain>

      Example output

      console-openshift-console.apps.ocp4.example.com. 604800 IN	A 192.168.1.5

    4. Run a lookup against the bootstrap DNS record name. Check that the result points to the IP address of the bootstrap node:

      $ dig +noall +answer @<nameserver_ip> bootstrap.<cluster_name>.<base_domain>

      Example output

      bootstrap.ocp4.example.com.		604800	IN	A	192.168.1.96

    5. Use this method to perform lookups against the DNS record names for the control plane and compute nodes. Check that the results correspond to the IP addresses of each node.
  2. From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names contained in the responses correspond to the correct components.

    1. Perform a reverse lookup against the IP address of the API load balancer. Check that the response includes the record names for the Kubernetes API and the Kubernetes internal API:

      $ dig +noall +answer @<nameserver_ip> -x 192.168.1.5

      Example output

      5.1.168.192.in-addr.arpa. 604800	IN	PTR	api-int.ocp4.example.com. 1
      5.1.168.192.in-addr.arpa. 604800	IN	PTR	api.ocp4.example.com. 2

      1
      Provides the record name for the Kubernetes internal API.
      2
      Provides the record name for the Kubernetes API.
      Note

      A PTR record is not required for the OpenShift Container Platform application wildcard. No validation step is needed for reverse DNS resolution against the IP address of the application ingress load balancer.

    2. Perform a reverse lookup against the IP address of the bootstrap node. Check that the result points to the DNS record name of the bootstrap node:

      $ dig +noall +answer @<nameserver_ip> -x 192.168.1.96

      Example output

      96.1.168.192.in-addr.arpa. 604800	IN	PTR	bootstrap.ocp4.example.com.

    3. Use this method to perform reverse lookups against the IP addresses for the control plane and compute nodes. Check that the results correspond to the DNS record names of each node.

2.1.7. Generating a key pair for cluster node SSH access

During an OpenShift Container Platform installation, you can provide an SSH public key to the installation program. The key is passed to the Red Hat Enterprise Linux CoreOS (RHCOS) nodes through their Ignition config files and is used to authenticate SSH access to the nodes. The key is added to the ~/.ssh/authorized_keys list for the core user on each node, which enables password-less authentication.

After the key is passed to the nodes, you can use the key pair to SSH in to the RHCOS nodes as the user core. To access the nodes through SSH, the private key identity must be managed by SSH for your local user.

If you want to SSH in to your cluster nodes to perform installation debugging or disaster recovery, you must provide the SSH public key during the installation process. The ./openshift-install gather command also requires the SSH public key to be in place on the cluster nodes.

Important

Do not skip this procedure in production environments, where disaster recovery and debugging is required.

Note

You must use a local key, not one that you configured with platform-specific approaches.

Procedure

  1. If you do not have an existing SSH key pair on your local machine to use for authentication onto your cluster nodes, create one. For example, on a computer that uses a Linux operating system, run the following command:

    $ ssh-keygen -t ed25519 -N '' -f <path>/<file_name> 1
    1
    Specify the path and file name, such as ~/.ssh/id_ed25519, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
    Note

    If you plan to install an OpenShift Container Platform cluster that uses the RHEL cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. View the public SSH key:

    $ cat <path>/<file_name>.pub

    For example, run the following to view the ~/.ssh/id_ed25519.pub public key:

    $ cat ~/.ssh/id_ed25519.pub
  3. Add the SSH private key identity to the SSH agent for your local user, if it has not already been added. SSH agent management of the key is required for password-less SSH authentication onto your cluster nodes, or if you want to use the ./openshift-install gather command.

    Note

    On some distributions, default SSH private key identities such as ~/.ssh/id_rsa and ~/.ssh/id_dsa are managed automatically.

    1. If the ssh-agent process is not already running for your local user, start it as a background task:

      $ eval "$(ssh-agent -s)"

      Example output

      Agent pid 31874

      Note

      If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

  4. Add your SSH private key to the ssh-agent:

    $ ssh-add <path>/<file_name> 1
    1
    Specify the path and file name for your SSH private key, such as ~/.ssh/id_ed25519

    Example output

    Identity added: /home/<you>/<path>/<file_name> (<computer_name>)

Next steps

  • When you install OpenShift Container Platform, provide the SSH public key to the installation program. If you install a cluster on infrastructure that you provision, you must provide the key to the installation program.

Additional resources

2.1.8. Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on the host you are using for installation.

Prerequisites

  • You have a computer that runs Linux or macOS, with 500 MB of local disk space.

Procedure

  1. Go to the Cluster Type page on the Red Hat Hybrid Cloud Console. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
  2. Select your infrastructure provider from the Run it yourself section of the page.
  3. Select your host operating system and architecture from the dropdown menus under OpenShift Installer and click Download Installer.
  4. Place the downloaded file in the directory where you want to store the installation configuration files.

    Important
    • The installation program creates several files on the computer that you use to install your cluster. You must keep the installation program and the files that the installation program creates after you finish installing the cluster. Both of the files are required to delete the cluster.
    • Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OpenShift Container Platform uninstallation procedures for your specific cloud provider.
  5. Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:

    $ tar -xvf openshift-install-linux.tar.gz
  6. Download your installation pull secret from Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.
Tip

Alternatively, you can retrieve the installation program from the Red Hat Customer Portal, where you can specify a version of the installation program to download. However, you must have an active subscription to access this page.

2.1.9. Installing the OpenShift CLI

You can install the OpenShift CLI (oc) to interact with OpenShift Container Platform from a command-line interface. You can install oc on Linux, Windows, or macOS.

Important

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.18. Download and install the new version of oc.

Installing the OpenShift CLI on Linux

You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the architecture from the Product Variant drop-down list.
  3. Select the appropriate version from the Version drop-down list.
  4. Click Download Now next to the OpenShift v4.18 Linux Clients entry and save the file.
  5. Unpack the archive:

    $ tar xvf <file>
  6. Place the oc binary in a directory that is on your PATH.

    To check your PATH, execute the following command:

    $ echo $PATH

Verification

  • After you install the OpenShift CLI, it is available using the oc command:

    $ oc <command>
Installing the OpenShift CLI on Windows

You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the appropriate version from the Version drop-down list.
  3. Click Download Now next to the OpenShift v4.18 Windows Client entry and save the file.
  4. Unzip the archive with a ZIP program.
  5. Move the oc binary to a directory that is on your PATH.

    To check your PATH, open the command prompt and execute the following command:

    C:\> path

Verification

  • After you install the OpenShift CLI, it is available using the oc command:

    C:\> oc <command>
Installing the OpenShift CLI on macOS

You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the appropriate version from the Version drop-down list.
  3. Click Download Now next to the OpenShift v4.18 macOS Clients entry and save the file.

    Note

    For macOS arm64, choose the OpenShift v4.18 macOS arm64 Client entry.

  4. Unpack and unzip the archive.
  5. Move the oc binary to a directory on your PATH.

    To check your PATH, open a terminal and execute the following command:

    $ echo $PATH

Verification

  • Verify your installation by using an oc command:

    $ oc <command>

2.1.10. Manually creating the installation configuration file

Installing the cluster requires that you manually create the installation configuration file.

Prerequisites

  • You have an SSH public key on your local machine to provide to the installation program. The key will be used for SSH authentication onto your cluster nodes for debugging and disaster recovery.
  • You have obtained the OpenShift Container Platform installation program and the pull secret for your cluster.

Procedure

  1. Create an installation directory to store your required installation assets in:

    $ mkdir <installation_directory>
    Important

    You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.

  2. Customize the sample install-config.yaml file template that is provided and save it in the <installation_directory>.

    Note

    You must name this configuration file install-config.yaml.

  3. Back up the install-config.yaml file so that you can use it to install multiple clusters.

    Important

    The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

2.1.10.1. Sample install-config.yaml file for bare metal

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OVNKubernetes 11
  serviceNetwork: 12
  - 172.30.0.0/16
platform:
  none: {} 13
fips: false 14
pullSecret: '{"auths": ...}' 15
sshKey: 'ssh-ed25519 AAAA...' 16
1
The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 5
The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Only one control plane pool is used.
3 6
Specifies whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of the cores in your machines. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note

Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.

Important

If you disable hyperthreading, whether in the BIOS or in the install-config.yaml file, ensure that your capacity planning accounts for the dramatically decreased machine performance.

4
You must set this value to 0 when you install OpenShift Container Platform on user-provisioned infrastructure. In installer-provisioned installations, the parameter controls the number of compute machines that the cluster creates and manages for you. In user-provisioned installations, you must manually deploy the compute machines before you finish installing the cluster.
Note

If you are installing a three-node cluster, do not deploy any compute machines when you install the Red Hat Enterprise Linux CoreOS (RHCOS) machines.

7
The number of control plane machines that you add to the cluster. Because the cluster uses these values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8
The cluster name that you specified in your DNS records.
9
A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
Note

Class E CIDR range is reserved for a future use. To use the Class E CIDR range, you must ensure your networking environment accepts the IP addresses within the Class E CIDR range.

10
The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IP addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.
11
The cluster network plugin to install. The default value OVNKubernetes is the only supported value.
12
The IP address pool to use for service IP addresses. You can enter only one IP address pool. This block must not overlap with existing physical networks. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
13
You must set the platform to none. You cannot provide additional platform configuration variables for your platform.
Important

Clusters that are installed with the platform type none are unable to use some features, such as managing compute machines with the Machine API. This limitation applies even if the compute machines that are attached to the cluster are installed on a platform that would normally support the feature. This parameter cannot be changed after installation.

14
Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
Important

To enable FIPS mode for your cluster, you must run the installation program from a Red Hat Enterprise Linux (RHEL) computer configured to operate in FIPS mode. For more information about configuring FIPS mode on RHEL, see Switching RHEL to FIPS mode.

When running Red Hat Enterprise Linux (RHEL) or Red Hat Enterprise Linux CoreOS (RHCOS) booted in FIPS mode, OpenShift Container Platform core components use the RHEL cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures.

15
The pull secret from Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.
16
The SSH public key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

Additional resources

2.1.10.2. Configuring the cluster-wide proxy during installation

Production environments can deny direct access to the internet and instead have an HTTP or HTTPS proxy available. You can configure a new OpenShift Container Platform cluster to use a proxy by configuring the proxy settings in the install-config.yaml file.

Note

For bare metal installations, if you do not assign node IP addresses from the range that is specified in the networking.machineNetwork[].cidr field in the install-config.yaml file, you must include them in the proxy.noProxy field.

Prerequisites

  • You have an existing install-config.yaml file.
  • You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.

    Note

    The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.

    For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

  1. Edit your install-config.yaml file and add the proxy settings. For example:

    apiVersion: v1
    baseDomain: my.domain.com
    proxy:
      httpProxy: http://<username>:<pswd>@<ip>:<port> 1
      httpsProxy: https://<username>:<pswd>@<ip>:<port> 2
      noProxy: example.com 3
    additionalTrustBundle: | 4
        -----BEGIN CERTIFICATE-----
        <MY_TRUSTED_CA_CERT>
        -----END CERTIFICATE-----
    additionalTrustBundlePolicy: <policy_to_add_additionalTrustBundle> 5
    1
    A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
    2
    A proxy URL to use for creating HTTPS connections outside the cluster.
    3
    A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations.
    4
    If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the trustedCA field of the Proxy object. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
    5
    Optional: The policy to determine the configuration of the Proxy object to reference the user-ca-bundle config map in the trustedCA field. The allowed values are Proxyonly and Always. Use Proxyonly to reference the user-ca-bundle config map only when http/https proxy is configured. Use Always to always reference the user-ca-bundle config map. The default value is Proxyonly.
    Note

    The installation program does not support the proxy readinessEndpoints field.

    Note

    If the installer times out, restart and then complete the deployment by using the wait-for command of the installer. For example:

    $ ./openshift-install wait-for install-complete --log-level debug
  2. Save the file and reference it when installing OpenShift Container Platform.

The installation program creates a cluster-wide proxy that is named cluster that uses the proxy settings in the provided install-config.yaml file. If no proxy settings are provided, a cluster Proxy object is still created, but it will have a nil spec.

Note

Only the Proxy object named cluster is supported, and no additional proxies can be created.

2.1.10.3. Configuring a three-node cluster

Optionally, you can deploy zero compute machines in a bare metal cluster that consists of three control plane machines only. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for testing, development, and production.

In three-node OpenShift Container Platform environments, the three control plane machines are schedulable, which means that your application workloads are scheduled to run on them.

Prerequisites

  • You have an existing install-config.yaml file.

Procedure

  • Ensure that the number of compute replicas is set to 0 in your install-config.yaml file, as shown in the following compute stanza:

    compute:
    - name: worker
      platform: {}
      replicas: 0
    Note

    You must set the value of the replicas parameter for the compute machines to 0 when you install OpenShift Container Platform on user-provisioned infrastructure, regardless of the number of compute machines you are deploying. In installer-provisioned installations, the parameter controls the number of compute machines that the cluster creates and manages for you. This does not apply to user-provisioned installations, where the compute machines are deployed manually.

For three-node cluster installations, follow these next steps:

  • If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes. See the Load balancing requirements for user-provisioned infrastructure section for more information.
  • When you create the Kubernetes manifest files in the following procedure, ensure that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml file is set to true. This enables your application workloads to run on the control plane nodes.
  • Do not deploy any compute nodes when you create the Red Hat Enterprise Linux CoreOS (RHCOS) machines.

2.1.11. Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to configure the machines.

The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to configure the cluster machines.

Important
  • The Ignition config files that the OpenShift Container Platform installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
  • It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.

Prerequisites

  • You obtained the OpenShift Container Platform installation program.
  • You created the install-config.yaml installation configuration file.

Procedure

  1. Change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster:

    $ ./openshift-install create manifests --dir <installation_directory> 1
    1
    For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
    Warning

    If you are installing a three-node cluster, skip the following step to allow the control plane nodes to be schedulable.

    Important

    When you configure control plane nodes from the default unschedulable to schedulable, additional subscriptions are required. This is because control plane nodes then become compute nodes.

  2. Check that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file is set to false. This setting prevents pods from being scheduled on the control plane machines:

    1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
    2. Locate the mastersSchedulable parameter and ensure that it is set to false.
    3. Save and exit the file.
  3. To create the Ignition configuration files, run the following command from the directory that contains the installation program:

    $ ./openshift-install create ignition-configs --dir <installation_directory> 1
    1
    For <installation_directory>, specify the same installation directory.

    Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory. The kubeadmin-password and kubeconfig files are created in the ./<installation_directory>/auth directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign

Additional resources

2.1.12. Installing RHCOS and starting the OpenShift Container Platform bootstrap process

To install OpenShift Container Platform on bare metal infrastructure that you provision, you must install Red Hat Enterprise Linux CoreOS (RHCOS) on the machines. When you install RHCOS, you must provide the Ignition config file that was generated by the OpenShift Container Platform installation program for the type of machine you are installing. If you have configured suitable networking, DNS, and load balancing infrastructure, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS machines have rebooted.

To install RHCOS on the machines, follow either the steps to use an ISO image or network PXE booting.

Note

The compute node deployment steps included in this installation document are RHCOS-specific. If you choose instead to deploy RHEL-based compute nodes, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Only RHEL 8 compute machines are supported.

You can configure RHCOS during ISO and PXE installations by using the following methods:

  • Kernel arguments: You can use kernel arguments to provide installation-specific information. For example, you can specify the locations of the RHCOS installation files that you uploaded to your HTTP server and the location of the Ignition config file for the type of node you are installing. For a PXE installation, you can use the APPEND parameter to pass the arguments to the kernel of the live installer. For an ISO installation, you can interrupt the live installation boot process to add the kernel arguments. In both installation cases, you can use special coreos.inst.* arguments to direct the live installer, as well as standard installation boot arguments for turning standard kernel services on or off.
  • Ignition configs: OpenShift Container Platform Ignition config files (*.ign) are specific to the type of node you are installing. You pass the location of a bootstrap, control plane, or compute node Ignition config file during the RHCOS installation so that it takes effect on first boot. In special cases, you can create a separate, limited Ignition config to pass to the live system. That Ignition config could do a certain set of tasks, such as reporting success to a provisioning system after completing installation. This special Ignition config is consumed by the coreos-installer to be applied on first boot of the installed system. Do not provide the standard control plane and compute node Ignition configs to the live ISO directly.
  • coreos-installer: You can boot the live ISO installer to a shell prompt, which allows you to prepare the permanent system in a variety of ways before first boot. In particular, you can run the coreos-installer command to identify various artifacts to include, work with disk partitions, and set up networking. In some cases, you can configure features on the live system and copy them to the installed system.

Whether to use an ISO or PXE install depends on your situation. A PXE install requires an available DHCP service and more preparation, but can make the installation process more automated. An ISO install is a more manual process and can be inconvenient if you are setting up more than a few machines.

2.1.12.1. Installing RHCOS by using an ISO image

You can use an ISO image to install RHCOS on the machines.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have an HTTP server that can be accessed from your computer, and from the machines that you create.
  • You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.

Procedure

  1. Obtain the SHA512 digest for each of your Ignition config files. For example, you can use the following on a system running Linux to get the SHA512 digest for your bootstrap.ign Ignition config file:

    $ sha512sum <installation_directory>/bootstrap.ign

    The digests are provided to the coreos-installer in a later step to validate the authenticity of the Ignition config files on the cluster nodes.

  2. Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

    You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  3. From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node:

    $ curl -k http://<HTTP_server>/bootstrap.ign 1

    Example output

      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
      0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...

    Replace bootstrap.ign with master.ign or worker.ign in the command to validate that the Ignition config files for the control plane and compute nodes are also available.

  4. Although it is possible to obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS images are from the output of openshift-install command:

    $ openshift-install coreos print-stream-json | grep '\.iso[^.]'

    Example output

    "location": "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live.x86_64.iso",

    Important

    The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Use only ISO images for this procedure. RHCOS qcow2 images are not supported for this installation type.

    ISO file names resemble the following example:

    rhcos-<version>-live.<architecture>.iso

  5. Use the ISO to start the RHCOS installation. Use one of the following installation options:

    • Burn the ISO image to a disk and boot it directly.
    • Use ISO redirection by using a lights-out management (LOM) interface.
  6. Boot the RHCOS ISO image without specifying any options or interrupting the live boot sequence. Wait for the installer to boot into a shell prompt in the RHCOS live environment.

    Note

    It is possible to interrupt the RHCOS installation boot process to add kernel arguments. However, for this ISO procedure you should use the coreos-installer command as outlined in the following steps, instead of adding kernel arguments.

  7. Run the coreos-installer command and specify the options that meet your installation requirements. At a minimum, you must specify the URL that points to the Ignition config file for the node type, and the device that you are installing to:

    $ sudo coreos-installer install --ignition-url=http://<HTTP_server>/<node_type>.ign <device> --ignition-hash=sha512-<digest> 12
    1 1
    You must run the coreos-installer command by using sudo, because the core user does not have the required root privileges to perform the installation.
    2
    The --ignition-hash option is required when the Ignition config file is obtained through an HTTP URL to validate the authenticity of the Ignition config file on the cluster node. <digest> is the Ignition config file SHA512 digest obtained in a preceding step.
    Note

    If you want to provide your Ignition config files through an HTTPS server that uses TLS, you can add the internal certificate authority (CA) to the system trust store before running coreos-installer.

    The following example initializes a bootstrap node installation to the /dev/sda device. The Ignition config file for the bootstrap node is obtained from an HTTP web server with the IP address 192.168.1.2:

    $ sudo coreos-installer install --ignition-url=http://192.168.1.2:80/installation_directory/bootstrap.ign /dev/sda --ignition-hash=sha512-a5a2d43879223273c9b60af66b44202a1d1248fc01cf156c46d4a79f552b6bad47bc8cc78ddf0116e80c59d2ea9e32ba53bc807afbca581aa059311def2c3e3b
  8. Monitor the progress of the RHCOS installation on the console of the machine.

    Important

    Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise.

  9. After RHCOS installs, you must reboot the system. During the system reboot, it applies the Ignition config file that you specified.
  10. Check the console output to verify that Ignition ran.

    Example command

    Ignition: ran on 2022/03/14 14:48:33 UTC (this boot)
    Ignition: user-provided config was applied

  11. Continue to create the other machines for your cluster.

    Important

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, also create at least two compute machines before you install OpenShift Container Platform.

    If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted.

    Note

    RHCOS nodes do not include a default password for the core user. You can access the nodes by running ssh core@<node>.<cluster_name>.<base_domain> as a user with access to the SSH private key that is paired to the public key that you specified in your install_config.yaml file. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.

2.1.12.2. Installing RHCOS by using PXE or iPXE booting

You can use PXE or iPXE booting to install RHCOS on the machines.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have configured suitable PXE or iPXE infrastructure.
  • You have an HTTP server that can be accessed from your computer, and from the machines that you create.
  • You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.

Procedure

  1. Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

    You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  2. From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node:

    $ curl -k http://<HTTP_server>/bootstrap.ign 1

    Example output

      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
      0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...

    Replace bootstrap.ign with master.ign or worker.ign in the command to validate that the Ignition config files for the control plane and compute nodes are also available.

  3. Although it is possible to obtain the RHCOS kernel, initramfs and rootfs files that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS files are from the output of openshift-install command:

    $ openshift-install coreos print-stream-json | grep -Eo '"https.*(kernel-|initramfs.|rootfs.)\w+(\.img)?"'

    Example output

    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-kernel-aarch64"
    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-initramfs.aarch64.img"
    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-rootfs.aarch64.img"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/49.84.202110081256-0/ppc64le/rhcos-<release>-live-kernel-ppc64le"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live-initramfs.ppc64le.img"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live-rootfs.ppc64le.img"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-kernel-s390x"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-initramfs.s390x.img"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-rootfs.s390x.img"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-kernel-x86_64"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-initramfs.x86_64.img"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-rootfs.x86_64.img"

    Important

    The RHCOS artifacts might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate kernel, initramfs, and rootfs artifacts described below for this procedure. RHCOS QCOW2 images are not supported for this installation type.

    The file names contain the OpenShift Container Platform version number. They resemble the following examples:

    • kernel: rhcos-<version>-live-kernel-<architecture>
    • initramfs: rhcos-<version>-live-initramfs.<architecture>.img
    • rootfs: rhcos-<version>-live-rootfs.<architecture>.img
  4. Upload the rootfs, kernel, and initramfs files to your HTTP server.

    Important

    If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  5. Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
  6. Configure PXE or iPXE installation for the RHCOS images and begin the installation.

    Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:

    • For PXE (x86_64):

      DEFAULT pxeboot
      TIMEOUT 20
      PROMPT 0
      LABEL pxeboot
          KERNEL http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> 1
          APPEND initrd=http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 2 3
      1 1
      Specify the location of the live kernel file that you uploaded to your HTTP server. The URL must be HTTP, TFTP, or FTP; HTTPS and NFS are not supported.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the locations of the RHCOS files that you uploaded to your HTTP server. The initrd parameter value is the location of the initramfs file, the coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file. You can also add more kernel arguments to the APPEND line to configure networking or other boot options.
      Note

      This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the APPEND line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux? and "Enabling the serial console for PXE and ISO installation" in the "Advanced RHCOS installation configuration" section.

    • For iPXE (x86_64 + aarch64 ):

      kernel http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> initrd=main coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
      initrd --name main http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img 3
      boot
      1
      Specify the locations of the RHCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd=main argument is needed for booting on UEFI systems, the coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the location of the initramfs file that you uploaded to your HTTP server.
      Note

      This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the kernel line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux? and "Enabling the serial console for PXE and ISO installation" in the "Advanced RHCOS installation configuration" section.

      Note

      To network boot the CoreOS kernel on aarch64 architecture, you need to use a version of iPXE build with the IMAGE_GZIP option enabled. See IMAGE_GZIP option in iPXE.

    • For PXE (with UEFI and Grub as second stage) on aarch64:

      menuentry 'Install CoreOS' {
          linux rhcos-<version>-live-kernel-<architecture>  coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
          initrd rhcos-<version>-live-initramfs.<architecture>.img 3
      }
      1
      Specify the locations of the RHCOS files that you uploaded to your HTTP/TFTP server. The kernel parameter value is the location of the kernel file on your TFTP server. The coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file on your HTTP Server.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the location of the initramfs file that you uploaded to your TFTP server.
  7. Monitor the progress of the RHCOS installation on the console of the machine.

    Important

    Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise.

  8. After RHCOS installs, the system reboots. During reboot, the system applies the Ignition config file that you specified.
  9. Check the console output to verify that Ignition ran.

    Example command

    Ignition: ran on 2022/03/14 14:48:33 UTC (this boot)
    Ignition: user-provided config was applied

  10. Continue to create the machines for your cluster.

    Important

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, also create at least two compute machines before you install the cluster.

    If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted.

    Note

    RHCOS nodes do not include a default password for the core user. You can access the nodes by running ssh core@<node>.<cluster_name>.<base_domain> as a user with access to the SSH private key that is paired to the public key that you specified in your install_config.yaml file. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.

2.1.12.3. Advanced RHCOS installation configuration

A key benefit for manually provisioning the Red Hat Enterprise Linux CoreOS (RHCOS) nodes for OpenShift Container Platform is to be able to do configuration that is not available through default OpenShift Container Platform installation methods. This section describes some of the configurations that you can do using techniques that include:

  • Passing kernel arguments to the live installer
  • Running coreos-installer manually from the live system
  • Customizing a live ISO or PXE boot image

The advanced configuration topics for manual Red Hat Enterprise Linux CoreOS (RHCOS) installations detailed in this section relate to disk partitioning, networking, and using Ignition configs in different ways.

2.1.12.3.1. Using advanced networking options for PXE and ISO installations

Networking for OpenShift Container Platform nodes uses DHCP by default to gather all necessary configuration settings. To set up static IP addresses or configure special settings, such as bonding, you can do one of the following:

  • Pass special kernel parameters when you boot the live installer.
  • Use a machine config to copy networking files to the installed system.
  • Configure networking from a live installer shell prompt, then copy those settings to the installed system so that they take effect when the installed system first boots.

To configure a PXE or iPXE installation, use one of the following options:

  • See the "Advanced RHCOS installation reference" tables.
  • Use a machine config to copy networking files to the installed system.

To configure an ISO installation, use the following procedure.

Procedure

  1. Boot the ISO installer.
  2. From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.
  3. Run the coreos-installer command to install the system, adding the --copy-network option to copy networking configuration. For example:

    $ sudo coreos-installer install --copy-network \
         --ignition-url=http://host/worker.ign /dev/disk/by-id/scsi-<serial_number>
    Important

    The --copy-network option only copies networking configuration found under /etc/NetworkManager/system-connections. In particular, it does not copy the system hostname.

  4. Reboot into the installed system.

Additional resources

2.1.12.3.2. Disk partitioning

Disk partitions are created on OpenShift Container Platform cluster nodes during the Red Hat Enterprise Linux CoreOS (RHCOS) installation. Each RHCOS node of a particular architecture uses the same partition layout, unless you override the default partitioning configuration. During the RHCOS installation, the size of the root file system is increased to use any remaining available space on the target device.

Important

The use of a custom partition scheme on your node might result in OpenShift Container Platform not monitoring or alerting on some node partitions. If you override the default partitioning, see Understanding OpenShift File System Monitoring (eviction conditions) for more information about how OpenShift Container Platform monitors your host file systems.

OpenShift Container Platform monitors the following two filesystem identifiers:

  • nodefs, which is the filesystem that contains /var/lib/kubelet
  • imagefs, which is the filesystem that contains /var/lib/containers

For the default partition scheme, nodefs and imagefs monitor the same root filesystem, /.

To override the default partitioning when installing RHCOS on an OpenShift Container Platform cluster node, you must create separate partitions. Consider a situation where you want to add a separate storage partition for your containers and container images. For example, by mounting /var/lib/containers in a separate partition, the kubelet separately monitors /var/lib/containers as the imagefs directory and the root file system as the nodefs directory.

Important

If you have resized your disk size to host a larger file system, consider creating a separate /var/lib/containers partition. Consider resizing a disk that has an xfs format to reduce CPU time issues caused by a high number of allocation groups.

2.1.12.3.2.1. Creating a separate /var partition

In general, you should use the default disk partitioning that is created during the RHCOS installation. However, there are cases where you might want to create a separate partition for a directory that you expect to grow.

OpenShift Container Platform supports the addition of a single partition to attach storage to either the /var directory or a subdirectory of /var. For example:

  • /var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system.
  • /var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage.
  • /var: Holds data that you might want to keep separate for purposes such as auditing.

    Important

    For disk sizes larger than 100GB, and especially larger than 1TB, create a separate /var partition.

Storing the contents of a /var directory separately makes it easier to grow storage for those areas as needed and reinstall OpenShift Container Platform at a later date and keep that data intact. With this method, you will not have to pull all your containers again, nor will you have to copy massive log files when you update systems.

The use of a separate partition for the /var directory or a subdirectory of /var also prevents data growth in the partitioned directory from filling up the root file system.

The following procedure sets up a separate /var partition by adding a machine config manifest that is wrapped into the Ignition config file for a node type during the preparation phase of an installation.

Procedure

  1. On your installation host, change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster:

    $ openshift-install create manifests --dir <installation_directory>
  2. Create a Butane config that configures the additional partition. For example, name the file $HOME/clusterconfig/98-var-partition.bu, change the disk device name to the name of the storage device on the worker systems, and set the storage size as appropriate. This example places the /var directory on a separate partition:

    variant: openshift
    version: 4.18.0
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker
      name: 98-var-partition
    storage:
      disks:
      - device: /dev/disk/by-id/<device_name> 1
        partitions:
        - label: var
          start_mib: <partition_start_offset> 2
          size_mib: <partition_size> 3
          number: 5
      filesystems:
        - device: /dev/disk/by-partlabel/var
          path: /var
          format: xfs
          mount_options: [defaults, prjquota] 4
          with_mount_unit: true
    1
    The storage device name of the disk that you want to partition.
    2
    When adding a data partition to the boot disk, a minimum offset value of 25000 mebibytes is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no offset value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of RHCOS might overwrite the beginning of the data partition.
    3
    The size of the data partition in mebibytes.
    4
    The prjquota mount option must be enabled for filesystems used for container storage.
    Note

    When creating a separate /var partition, you cannot use different instance types for compute nodes, if the different instance types do not have the same device name.

  3. Create a manifest from the Butane config and save it to the clusterconfig/openshift directory. For example, run the following command:

    $ butane $HOME/clusterconfig/98-var-partition.bu -o $HOME/clusterconfig/openshift/98-var-partition.yaml
  4. Create the Ignition config files:

    $ openshift-install create ignition-configs --dir <installation_directory> 1
    1
    For <installation_directory>, specify the same installation directory.

    Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign

    The files in the <installation_directory>/manifest and <installation_directory>/openshift directories are wrapped into the Ignition config files, including the file that contains the 98-var-partition custom MachineConfig object.

Next steps

  • You can apply the custom disk partitioning by referencing the Ignition config files during the RHCOS installations.
2.1.12.3.2.2. Retaining existing partitions

For an ISO installation, you can add options to the coreos-installer command that cause the installer to maintain one or more existing partitions. For a PXE installation, you can add coreos.inst.* options to the APPEND parameter to preserve partitions.

Saved partitions might be data partitions from an existing OpenShift Container Platform system. You can identify the disk partitions you want to keep either by partition label or by number.

Note

If you save existing partitions, and those partitions do not leave enough space for RHCOS, the installation will fail without damaging the saved partitions.

Retaining existing partitions during an ISO installation

This example preserves any partition in which the partition label begins with data (data*):

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partlabel 'data*' /dev/disk/by-id/scsi-<serial_number>

The following example illustrates running the coreos-installer in a way that preserves the sixth (6) partition on the disk:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partindex 6 /dev/disk/by-id/scsi-<serial_number>

This example preserves partitions 5 and higher:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign
        --save-partindex 5- /dev/disk/by-id/scsi-<serial_number>

In the previous examples where partition saving is used, coreos-installer recreates the partition immediately.

Retaining existing partitions during a PXE installation

This APPEND option preserves any partition in which the partition label begins with 'data' ('data*'):

coreos.inst.save_partlabel=data*

This APPEND option preserves partitions 5 and higher:

coreos.inst.save_partindex=5-

This APPEND option preserves partition 6:

coreos.inst.save_partindex=6
2.1.12.3.3. Identifying Ignition configs

When doing an RHCOS manual installation, there are two types of Ignition configs that you can provide, with different reasons for providing each one:

  • Permanent install Ignition config: Every manual RHCOS installation needs to pass one of the Ignition config files generated by openshift-installer, such as bootstrap.ign, master.ign and worker.ign, to carry out the installation.

    Important

    It is not recommended to modify these Ignition config files directly. You can update the manifest files that are wrapped into the Ignition config files, as outlined in examples in the preceding sections.

    For PXE installations, you pass the Ignition configs on the APPEND line using the coreos.inst.ignition_url= option. For ISO installations, after the ISO boots to the shell prompt, you identify the Ignition config on the coreos-installer command line with the --ignition-url= option. In both cases, only HTTP and HTTPS protocols are supported.

  • Live install Ignition config: This type can be created by using the coreos-installer customize subcommand and its various options. With this method, the Ignition config passes to the live install medium, runs immediately upon booting, and performs setup tasks before or after the RHCOS system installs to disk. This method should only be used for performing tasks that must be done once and not applied again later, such as with advanced partitioning that cannot be done using a machine config.

    For PXE or ISO boots, you can create the Ignition config and APPEND the ignition.config.url= option to identify the location of the Ignition config. You also need to append ignition.firstboot ignition.platform.id=metal or the ignition.config.url option will be ignored.

2.1.12.3.4. Default console configuration

Red Hat Enterprise Linux CoreOS (RHCOS) nodes installed from an OpenShift Container Platform 4.18 boot image use a default console that is meant to accomodate most virtualized and bare metal setups. Different cloud and virtualization platforms may use different default settings depending on the chosen architecture. Bare metal installations use the kernel default settings which typically means the graphical console is the primary console and the serial console is disabled.

The default consoles may not match your specific hardware configuration or you might have specific needs that require you to adjust the default console. For example:

  • You want to access the emergency shell on the console for debugging purposes.
  • Your cloud platform does not provide interactive access to the graphical console, but provides a serial console.
  • You want to enable multiple consoles.

Console configuration is inherited from the boot image. This means that new nodes in existing clusters are unaffected by changes to the default console.

You can configure the console for bare metal installations in the following ways:

  • Using coreos-installer manually on the command line.
  • Using the coreos-installer iso customize or coreos-installer pxe customize subcommands with the --dest-console option to create a custom image that automates the process.
Note

For advanced customization, perform console configuration using the coreos-installer iso or coreos-installer pxe subcommands, and not kernel arguments.

2.1.12.3.5. Enabling the serial console for PXE and ISO installations

By default, the Red Hat Enterprise Linux CoreOS (RHCOS) serial console is disabled and all output is written to the graphical console. You can enable the serial console for an ISO installation and reconfigure the bootloader so that output is sent to both the serial console and the graphical console.

Procedure

  1. Boot the ISO installer.
  2. Run the coreos-installer command to install the system, adding the --console option once to specify the graphical console, and a second time to specify the serial console:

    $ coreos-installer install \
      --console=tty0 \1
      --console=ttyS0,<options> \2
      --ignition-url=http://host/worker.ign /dev/disk/by-id/scsi-<serial_number>
    1
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    2
    The desired primary console. In this case the serial console. The options field defines the baud rate and other settings. A common value for this field is 11520n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see Linux kernel serial console documentation.
  3. Reboot into the installed system.

    Note

    A similar outcome can be obtained by using the coreos-installer install --append-karg option, and specifying the console with console=. However, this will only set the console for the kernel and not the bootloader.

To configure a PXE installation, make sure the coreos.inst.install_dev kernel command line option is omitted, and use the shell prompt to run coreos-installer manually using the above ISO installation procedure.

2.1.12.3.6. Customizing a live RHCOS ISO or PXE install

You can use the live ISO image or PXE environment to install RHCOS by injecting an Ignition config file directly into the image. This creates a customized image that you can use to provision your system.

For an ISO image, the mechanism to do this is the coreos-installer iso customize subcommand, which modifies the .iso file with your configuration. Similarly, the mechanism for a PXE environment is the coreos-installer pxe customize subcommand, which creates a new initramfs file that includes your customizations.

The customize subcommand is a general purpose tool that can embed other types of customizations as well. The following tasks are examples of some of the more common customizations:

  • Inject custom CA certificates for when corporate security policy requires their use.
  • Configure network settings without the need for kernel arguments.
  • Embed arbitrary preinstall and post-install scripts or binaries.
2.1.12.3.7. Customizing a live RHCOS ISO image

You can customize a live RHCOS ISO image directly with the coreos-installer iso customize subcommand. When you boot the ISO image, the customizations are applied automatically.

You can use this feature to configure the ISO image to automatically install RHCOS.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and the Ignition config file, and then run the following command to inject the Ignition config directly into the ISO image:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
        --dest-ignition bootstrap.ign \ 1
        --dest-device /dev/disk/by-id/scsi-<serial_number> 2
    1
    The Ignition config file that is generated from the openshift-installer installation program.
    2
    When you specify this option, the ISO image automatically runs an installation. Otherwise, the image remains configured for installation, but does not install automatically unless you specify the coreos.inst.install_dev kernel argument.
  3. Optional: To remove the ISO image customizations and return the image to its pristine state, run:

    $ coreos-installer iso reset rhcos-<version>-live.x86_64.iso

    You can now re-customize the live ISO image or use it in its pristine state.

Applying your customizations affects every subsequent boot of RHCOS.

2.1.12.3.7.1. Modifying a live install ISO image to enable the serial console

On clusters installed with OpenShift Container Platform 4.12 and above, the serial console is disabled by default and all output is written to the graphical console. You can enable the serial console with the following procedure.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image to enable the serial console to receive output:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
      --dest-ignition <path> \1
      --dest-console tty0 \2
      --dest-console ttyS0,<options> \3
      --dest-device /dev/disk/by-id/scsi-<serial_number> 4
    1
    The location of the Ignition config to install.
    2
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    3
    The desired primary console. In this case, the serial console. The options field defines the baud rate and other settings. A common value for this field is 115200n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see the Linux kernel serial console documentation.
    4
    The specified disk to install to. If you omit this option, the ISO image automatically runs the installation program which will fail unless you also specify the coreos.inst.install_dev kernel argument.
    Note

    The --dest-console option affects the installed system and not the live ISO system. To modify the console for a live ISO system, use the --live-karg-append option and specify the console with console=.

    Your customizations are applied and affect every subsequent boot of the ISO image.

  3. Optional: To remove the ISO image customizations and return the image to its original state, run the following command:

    $ coreos-installer iso reset rhcos-<version>-live.x86_64.iso

    You can now recustomize the live ISO image or use it in its original state.

2.1.12.3.7.2. Modifying a live install ISO image to use a custom certificate authority

You can provide certificate authority (CA) certificates to Ignition with the --ignition-ca flag of the customize subcommand. You can use the CA certificates during both the installation boot and when provisioning the installed system.

Note

Custom CA certificates affect how Ignition fetches remote resources but they do not affect the certificates installed onto the system.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image for use with a custom CA:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso --ignition-ca cert.pem
Important

The coreos.inst.ignition_url kernel parameter does not work with the --ignition-ca flag. You must use the --dest-ignition flag to create a customized image for each cluster.

Applying your custom CA certificate affects every subsequent boot of RHCOS.

2.1.12.3.7.3. Modifying a live install ISO image with customized network settings

You can embed a NetworkManager keyfile into the live ISO image and pass it through to the installed system with the --network-keyfile flag of the customize subcommand.

Warning

When creating a connection profile, you must use a .nmconnection filename extension in the filename of the connection profile. If you do not use a .nmconnection filename extension, the cluster will apply the connection profile to the live environment, but it will not apply the configuration when the cluster first boots up the nodes, resulting in a setup that does not work.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Create a connection profile for a bonded interface. For example, create the bond0.nmconnection file in your local directory with the following content:

    [connection]
    id=bond0
    type=bond
    interface-name=bond0
    multi-connect=1
    
    [bond]
    miimon=100
    mode=active-backup
    
    [ipv4]
    method=auto
    
    [ipv6]
    method=auto
  3. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em1.nmconnection file in your local directory with the following content:

    [connection]
    id=em1
    type=ethernet
    interface-name=em1
    master=bond0
    multi-connect=1
    slave-type=bond
  4. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em2.nmconnection file in your local directory with the following content:

    [connection]
    id=em2
    type=ethernet
    interface-name=em2
    master=bond0
    multi-connect=1
    slave-type=bond
  5. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with your configured networking:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
        --network-keyfile bond0.nmconnection \
        --network-keyfile bond0-proxy-em1.nmconnection \
        --network-keyfile bond0-proxy-em2.nmconnection

    Network settings are applied to the live system and are carried over to the destination system.

2.1.12.3.7.4. Customizing a live install ISO image for an iSCSI boot device

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with the following information:

    $ coreos-installer iso customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/disk/by-path/<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.initiator=<initiator_iqn> \ 5
        --dest-karg-append netroot=<target_iqn> \ 6
        -o custom.iso rhcos-<version>-live.x86_64.iso
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The location of the destination system. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    6
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.1.12.3.7.5. Customizing a live install ISO image for an iSCSI boot device with iBFT

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.
  2. Optional: you have multipathed your iSCSI target.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with the following information:

    $ coreos-installer iso customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/mapper/mpatha \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.firmware=1 \ 5
        --dest-karg-append rd.multipath=default \ 6
        -o custom.iso rhcos-<version>-live.x86_64.iso
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The path to the device. If you are using multipath, the multipath device, /dev/mapper/mpatha, If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI parameter is read from the BIOS firmware.
    6
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.1.12.3.8. Customizing a live RHCOS PXE environment

You can customize a live RHCOS PXE environment directly with the coreos-installer pxe customize subcommand. When you boot the PXE environment, the customizations are applied automatically.

You can use this feature to configure the PXE environment to automatically install RHCOS.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and the Ignition config file, and then run the following command to create a new initramfs file that contains the customizations from your Ignition config:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --dest-ignition bootstrap.ign \ 1
        --dest-device /dev/disk/by-id/scsi-<serial_number> \ 2
        -o rhcos-<version>-custom-initramfs.x86_64.img 3
    1
    The Ignition config file that is generated from openshift-installer.
    2
    When you specify this option, the PXE environment automatically runs an install. Otherwise, the image remains configured for installing, but does not do so automatically unless you specify the coreos.inst.install_dev kernel argument.
    3
    Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

Applying your customizations affects every subsequent boot of RHCOS.

2.1.12.3.8.1. Modifying a live install PXE environment to enable the serial console

On clusters installed with OpenShift Container Platform 4.12 and above, the serial console is disabled by default and all output is written to the graphical console. You can enable the serial console with the following procedure.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and the Ignition config file, and then run the following command to create a new customized initramfs file that enables the serial console to receive output:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
      --dest-ignition <path> \1
      --dest-console tty0 \2
      --dest-console ttyS0,<options> \3
      --dest-device /dev/disk/by-id/scsi-<serial_number> \4
      -o rhcos-<version>-custom-initramfs.x86_64.img 5
    1
    The location of the Ignition config to install.
    2
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    3
    The desired primary console. In this case, the serial console. The options field defines the baud rate and other settings. A common value for this field is 115200n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see the Linux kernel serial console documentation.
    4
    The specified disk to install to. If you omit this option, the PXE environment automatically runs the installer which will fail unless you also specify the coreos.inst.install_dev kernel argument.
    5
    Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

    Your customizations are applied and affect every subsequent boot of the PXE environment.

2.1.12.3.8.2. Modifying a live install PXE environment to use a custom certificate authority

You can provide certificate authority (CA) certificates to Ignition with the --ignition-ca flag of the customize subcommand. You can use the CA certificates during both the installation boot and when provisioning the installed system.

Note

Custom CA certificates affect how Ignition fetches remote resources but they do not affect the certificates installed onto the system.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file for use with a custom CA:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --ignition-ca cert.pem \
        -o rhcos-<version>-custom-initramfs.x86_64.img
  3. Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.
Important

The coreos.inst.ignition_url kernel parameter does not work with the --ignition-ca flag. You must use the --dest-ignition flag to create a customized image for each cluster.

Applying your custom CA certificate affects every subsequent boot of RHCOS.

2.1.12.3.8.3. Modifying a live install PXE environment with customized network settings

You can embed a NetworkManager keyfile into the live PXE environment and pass it through to the installed system with the --network-keyfile flag of the customize subcommand.

Warning

When creating a connection profile, you must use a .nmconnection filename extension in the filename of the connection profile. If you do not use a .nmconnection filename extension, the cluster will apply the connection profile to the live environment, but it will not apply the configuration when the cluster first boots up the nodes, resulting in a setup that does not work.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Create a connection profile for a bonded interface. For example, create the bond0.nmconnection file in your local directory with the following content:

    [connection]
    id=bond0
    type=bond
    interface-name=bond0
    multi-connect=1
    
    [bond]
    miimon=100
    mode=active-backup
    
    [ipv4]
    method=auto
    
    [ipv6]
    method=auto
  3. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em1.nmconnection file in your local directory with the following content:

    [connection]
    id=em1
    type=ethernet
    interface-name=em1
    master=bond0
    multi-connect=1
    slave-type=bond
  4. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em2.nmconnection file in your local directory with the following content:

    [connection]
    id=em2
    type=ethernet
    interface-name=em2
    master=bond0
    multi-connect=1
    slave-type=bond
  5. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file that contains your configured networking:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --network-keyfile bond0.nmconnection \
        --network-keyfile bond0-proxy-em1.nmconnection \
        --network-keyfile bond0-proxy-em2.nmconnection \
        -o rhcos-<version>-custom-initramfs.x86_64.img
  6. Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

    Network settings are applied to the live system and are carried over to the destination system.

2.1.12.3.8.4. Customizing a live install PXE environment for an iSCSI boot device

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file with the following information:

    $ coreos-installer pxe customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/disk/by-path/<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.initiator=<initiator_iqn> \ 5
        --dest-karg-append netroot=<target_iqn> \ 6
        -o custom.img rhcos-<version>-live-initramfs.x86_64.img
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The location of the destination system. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    6
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.1.12.3.8.5. Customizing a live install PXE environment for an iSCSI boot device with iBFT

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.
  2. Optional: you have multipathed your iSCSI target.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file with the following information:

    $ coreos-installer pxe customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/mapper/mpatha \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.firmware=1 \ 5
        --dest-karg-append rd.multipath=default \ 6
        -o custom.img rhcos-<version>-live-initramfs.x86_64.img
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The path to the device. If you are using multipath, the multipath device, /dev/mapper/mpatha, If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI parameter is read from the BIOS firmware.
    6
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.1.12.3.9. Advanced RHCOS installation reference

This section illustrates the networking configuration and other advanced options that allow you to modify the Red Hat Enterprise Linux CoreOS (RHCOS) manual installation process. The following tables describe the kernel arguments and command-line options you can use with the RHCOS live installer and the coreos-installer command.

2.1.12.3.9.1. Networking and bonding options for ISO installations

If you install RHCOS from an ISO image, you can add kernel arguments manually when you boot the image to configure networking for a node. If no networking arguments are specified, DHCP is activated in the initramfs when RHCOS detects that networking is required to fetch the Ignition config file.

Important

When adding networking arguments manually, you must also add the rd.neednet=1 kernel argument to bring the network up in the initramfs.

The following information provides examples for configuring networking and bonding on your RHCOS nodes for ISO installations. The examples describe how to use the ip=, nameserver=, and bond= kernel arguments.

Note

Ordering is important when adding the kernel arguments: ip=, nameserver=, and then bond=.

The networking options are passed to the dracut tool during system boot. For more information about the networking options supported by dracut, see the dracut.cmdline manual page.

The following examples are the networking options for ISO installation.

Configuring DHCP or static IP addresses

To configure an IP address, either use DHCP (ip=dhcp) or set an individual static IP address (ip=<host_ip>). If setting a static IP, you must then identify the DNS server IP address (nameserver=<dns_ip>) on each node. The following example sets:

  • The node’s IP address to 10.10.10.2
  • The gateway address to 10.10.10.254
  • The netmask to 255.255.255.0
  • The hostname to core0.example.com
  • The DNS server address to 4.4.4.41
  • The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
nameserver=4.4.4.41
Note

When you use DHCP to configure IP addressing for the RHCOS machines, the machines also obtain the DNS server information through DHCP. For DHCP-based deployments, you can define the DNS server address that is used by the RHCOS nodes through your DHCP server configuration.

Configuring an IP address without a static hostname

You can configure an IP address without assigning a static hostname. If a static hostname is not set by the user, it will be picked up and automatically set by a reverse DNS lookup. To configure an IP address without a static hostname refer to the following example:

  • The node’s IP address to 10.10.10.2
  • The gateway address to 10.10.10.254
  • The netmask to 255.255.255.0
  • The DNS server address to 4.4.4.41
  • The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0::enp1s0:none
nameserver=4.4.4.41
Specifying multiple network interfaces

You can specify multiple network interfaces by setting multiple ip= entries.

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
Configuring default gateway and route

Optional: You can configure routes to additional networks by setting an rd.route= value.

Note

When you configure one or multiple networks, one default gateway is required. If the additional network gateway is different from the primary network gateway, the default gateway must be the primary network gateway.

  • Run the following command to configure the default gateway:

    ip=::10.10.10.254::::
  • Enter the following command to configure the route for the additional network:

    rd.route=20.20.20.0/24:20.20.20.254:enp2s0
Disabling DHCP on a single interface

You can disable DHCP on a single interface, such as when there are two or more network interfaces and only one interface is being used. In the example, the enp1s0 interface has a static networking configuration and DHCP is disabled for enp2s0, which is not used:

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=::::core0.example.com:enp2s0:none
Combining DHCP and static IP configurations

You can combine DHCP and static IP configurations on systems with multiple network interfaces, for example:

ip=enp1s0:dhcp
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
Configuring VLANs on individual interfaces

Optional: You can configure VLANs on individual interfaces by using the vlan= parameter.

  • To configure a VLAN on a network interface and use a static IP address, run the following command:

    ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0.100:none
    vlan=enp2s0.100:enp2s0
  • To configure a VLAN on a network interface and to use DHCP, run the following command:

    ip=enp2s0.100:dhcp
    vlan=enp2s0.100:enp2s0
Providing multiple DNS servers

You can provide multiple DNS servers by adding a nameserver= entry for each server, for example:

nameserver=1.1.1.1
nameserver=8.8.8.8
Bonding multiple network interfaces to a single interface

Optional: You can bond multiple network interfaces to a single interface by using the bond= option. Refer to the following examples:

  • The syntax for configuring a bonded interface is: bond=<name>[:<network_interfaces>][:options]

    <name> is the bonding device name (bond0), <network_interfaces> represents a comma-separated list of physical (ethernet) interfaces (em1,em2), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.

  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

    • To configure the bonded interface to use DHCP, set the bond’s IP address to dhcp. For example:

      bond=bond0:em1,em2:mode=active-backup
      ip=bond0:dhcp
    • To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:

      bond=bond0:em1,em2:mode=active-backup
      ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Bonding multiple SR-IOV network interfaces to a dual port NIC interface

Optional: You can bond multiple SR-IOV network interfaces to a dual port NIC interface by using the bond= option.

On each node, you must perform the following tasks:

  1. Create the SR-IOV virtual functions (VFs) following the guidance in Managing SR-IOV devices. Follow the procedure in the "Attaching SR-IOV networking devices to virtual machines" section.
  2. Create the bond, attach the desired VFs to the bond and set the bond link state up following the guidance in Configuring network bonding. Follow any of the described procedures to create the bond.

The following examples illustrate the syntax you must use:

  • The syntax for configuring a bonded interface is bond=<name>[:<network_interfaces>][:options].

    <name> is the bonding device name (bond0), <network_interfaces> represents the virtual functions (VFs) by their known name in the kernel and shown in the output of the ip link command(eno1f0, eno2f0), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.

  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

    • To configure the bonded interface to use DHCP, set the bond’s IP address to dhcp. For example:

      bond=bond0:eno1f0,eno2f0:mode=active-backup
      ip=bond0:dhcp
    • To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:

      bond=bond0:eno1f0,eno2f0:mode=active-backup
      ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Using network teaming

Optional: You can use a network teaming as an alternative to bonding by using the team= parameter:

  • The syntax for configuring a team interface is: team=name[:network_interfaces]

    name is the team device name (team0) and network_interfaces represents a comma-separated list of physical (ethernet) interfaces (em1, em2).

Note

Teaming is planned to be deprecated when RHCOS switches to an upcoming version of RHEL. For more information, see this Red Hat Knowledgebase Article.

Use the following example to configure a network team:

team=team0:em1,em2
ip=team0:dhcp
2.1.12.3.9.2. coreos-installer options for ISO and PXE installations

You can install RHCOS by running coreos-installer install <options> <device> at the command prompt, after booting into the RHCOS live environment from an ISO image.

The following table shows the subcommands, options, and arguments you can pass to the coreos-installer command.

Table 2.9. coreos-installer subcommands, command-line options, and arguments

coreos-installer install subcommand

Subcommand

Description

$ coreos-installer install <options> <device>

Embed an Ignition config in an ISO image.

coreos-installer install subcommand options

Option

Description

-u, --image-url <url>

Specify the image URL manually.

-f, --image-file <path>

Specify a local image file manually. Used for debugging.

-i, --ignition-file <path>

Embed an Ignition config from a file.

-I, --ignition-url <URL>

Embed an Ignition config from a URL.

--ignition-hash <digest>

Digest type-value of the Ignition config.

-p, --platform <name>

Override the Ignition platform ID for the installed system.

--console <spec>

Set the kernel and bootloader console for the installed system. For more information about the format of <spec>, see the Linux kernel serial console documentation.

--append-karg <arg>…​

Append a default kernel argument to the installed system.

--delete-karg <arg>…​

Delete a default kernel argument from the installed system.

-n, --copy-network

Copy the network configuration from the install environment.

Important

The --copy-network option only copies networking configuration found under /etc/NetworkManager/system-connections. In particular, it does not copy the system hostname.

--network-dir <path>

For use with -n. Default is /etc/NetworkManager/system-connections/.

--save-partlabel <lx>..

Save partitions with this label glob.

--save-partindex <id>…​

Save partitions with this number or range.

--insecure

Skip RHCOS image signature verification.

--insecure-ignition

Allow Ignition URL without HTTPS or hash.

--architecture <name>

Target CPU architecture. Valid values are x86_64 and aarch64.

--preserve-on-error

Do not clear partition table on error.

-h, --help

Print help information.

coreos-installer install subcommand argument

Argument

Description

<device>

The destination device.

coreos-installer ISO subcommands

Subcommand

Description

$ coreos-installer iso customize <options> <ISO_image>

Customize a RHCOS live ISO image.

coreos-installer iso reset <options> <ISO_image>

Restore a RHCOS live ISO image to default settings.

coreos-installer iso ignition remove <options> <ISO_image>

Remove the embedded Ignition config from an ISO image.

coreos-installer ISO customize subcommand options

Option

Description

--dest-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the destination system.

--dest-console <spec>

Specify the kernel and bootloader console for the destination system.

--dest-device <path>

Install and overwrite the specified destination device.

--dest-karg-append <arg>

Add a kernel argument to each boot of the destination system.

--dest-karg-delete <arg>

Delete a kernel argument from each boot of the destination system.

--network-keyfile <path>

Configure networking by using the specified NetworkManager keyfile for live and destination systems.

--ignition-ca <path>

Specify an additional TLS certificate authority to be trusted by Ignition.

--pre-install <path>

Run the specified script before installation.

--post-install <path>

Run the specified script after installation.

--installer-config <path>

Apply the specified installer configuration file.

--live-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the live environment.

--live-karg-append <arg>

Add a kernel argument to each boot of the live environment.

--live-karg-delete <arg>

Delete a kernel argument from each boot of the live environment.

--live-karg-replace <k=o=n>

Replace a kernel argument in each boot of the live environment, in the form key=old=new.

-f, --force

Overwrite an existing Ignition config.

-o, --output <path>

Write the ISO to a new output file.

-h, --help

Print help information.

coreos-installer PXE subcommands

Subcommand

Description

Note that not all of these options are accepted by all subcommands.

coreos-installer pxe customize <options> <path>

Customize a RHCOS live PXE boot config.

coreos-installer pxe ignition wrap <options>

Wrap an Ignition config in an image.

coreos-installer pxe ignition unwrap <options> <image_name>

Show the wrapped Ignition config in an image.

coreos-installer PXE customize subcommand options

Option

Description

Note that not all of these options are accepted by all subcommands.

--dest-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the destination system.

--dest-console <spec>

Specify the kernel and bootloader console for the destination system.

--dest-device <path>

Install and overwrite the specified destination device.

--network-keyfile <path>

Configure networking by using the specified NetworkManager keyfile for live and destination systems.

--ignition-ca <path>

Specify an additional TLS certificate authority to be trusted by Ignition.

--pre-install <path>

Run the specified script before installation.

post-install <path>

Run the specified script after installation.

--installer-config <path>

Apply the specified installer configuration file.

--live-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the live environment.

-o, --output <path>

Write the initramfs to a new output file.

Note

This option is required for PXE environments.

-h, --help

Print help information.

2.1.12.3.9.3. coreos.inst boot options for ISO or PXE installations

You can automatically invoke coreos-installer options at boot time by passing coreos.inst boot arguments to the RHCOS live installer. These are provided in addition to the standard boot arguments.

  • For ISO installations, the coreos.inst options can be added by interrupting the automatic boot at the bootloader menu. You can interrupt the automatic boot by pressing TAB while the RHEL CoreOS (Live) menu option is highlighted.
  • For PXE or iPXE installations, the coreos.inst options must be added to the APPEND line before the RHCOS live installer is booted.

The following table shows the RHCOS live installer coreos.inst boot options for ISO and PXE installations.

Table 2.10. coreos.inst boot options
ArgumentDescription

coreos.inst.install_dev

Required. The block device on the system to install to. It is recommended to use the full path, such as /dev/sda, although sda is allowed.

coreos.inst.ignition_url

Optional: The URL of the Ignition config to embed into the installed system. If no URL is specified, no Ignition config is embedded. Only HTTP and HTTPS protocols are supported.

coreos.inst.save_partlabel

Optional: Comma-separated labels of partitions to preserve during the install. Glob-style wildcards are permitted. The specified partitions do not need to exist.

coreos.inst.save_partindex

Optional: Comma-separated indexes of partitions to preserve during the install. Ranges m-n are permitted, and either m or n can be omitted. The specified partitions do not need to exist.

coreos.inst.insecure

Optional: Permits the OS image that is specified by coreos.inst.image_url to be unsigned.

coreos.inst.image_url

Optional: Download and install the specified RHCOS image.

  • This argument should not be used in production environments and is intended for debugging purposes only.
  • While this argument can be used to install a version of RHCOS that does not match the live media, it is recommended that you instead use the media that matches the version you want to install.
  • If you are using coreos.inst.image_url, you must also use coreos.inst.insecure. This is because the bare-metal media are not GPG-signed for OpenShift Container Platform.
  • Only HTTP and HTTPS protocols are supported.

coreos.inst.skip_reboot

Optional: The system will not reboot after installing. After the install finishes, you will receive a prompt that allows you to inspect what is happening during installation. This argument should not be used in production environments and is intended for debugging purposes only.

coreos.inst.platform_id

Optional: The Ignition platform ID of the platform the RHCOS image is being installed on. Default is metal. This option determines whether or not to request an Ignition config from the cloud provider, such as VMware. For example: coreos.inst.platform_id=vmware.

ignition.config.url

Optional: The URL of the Ignition config for the live boot. For example, this can be used to customize how coreos-installer is invoked, or to run code before or after the installation. This is different from coreos.inst.ignition_url, which is the Ignition config for the installed system.

2.1.12.4. Enabling multipathing with kernel arguments on RHCOS

RHCOS supports multipathing on the primary disk, allowing stronger resilience to hardware failure to achieve higher host availability.

You can enable multipathing at installation time for nodes that were provisioned in OpenShift Container Platform 4.8 or later. While postinstallation support is available by activating multipathing via the machine config, enabling multipathing during installation is recommended.

In setups where any I/O to non-optimized paths results in I/O system errors, you must enable multipathing at installation time.

Important

On IBM Z® and IBM® LinuxONE, you can enable multipathing only if you configured your cluster for it during installation. For more information, see "Installing RHCOS and starting the OpenShift Container Platform bootstrap process" in Installing a cluster with z/VM on IBM Z® and IBM® LinuxONE.

The following procedure enables multipath at installation time and appends kernel arguments to the coreos-installer install command so that the installed system itself will use multipath beginning from the first boot.

Note

OpenShift Container Platform does not support enabling multipathing as a day-2 activity on nodes that have been upgraded from 4.6 or earlier.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have reviewed Installing RHCOS and starting the OpenShift Container Platform bootstrap process.

Procedure

  1. To enable multipath and start the multipathd daemon, run the following command on the installation host:

    $ mpathconf --enable && systemctl start multipathd.service
    • Optional: If booting the PXE or ISO, you can instead enable multipath by adding rd.multipath=default from the kernel command line.
  2. Append the kernel arguments by invoking the coreos-installer program:

    • If there is only one multipath device connected to the machine, it should be available at path /dev/mapper/mpatha. For example:

      $ coreos-installer install /dev/mapper/mpatha \1
      --ignition-url=http://host/worker.ign \
      --append-karg rd.multipath=default \
      --append-karg root=/dev/disk/by-label/dm-mpath-root \
      --append-karg rw
      1
      Indicates the path of the single multipathed device.
    • If there are multiple multipath devices connected to the machine, or to be more explicit, instead of using /dev/mapper/mpatha, it is recommended to use the World Wide Name (WWN) symlink available in /dev/disk/by-id. For example:

      $ coreos-installer install /dev/disk/by-id/wwn-<wwn_ID> \1
      --ignition-url=http://host/worker.ign \
      --append-karg rd.multipath=default \
      --append-karg root=/dev/disk/by-label/dm-mpath-root \
      --append-karg rw
      1
      Indicates the WWN ID of the target multipathed device. For example, 0xx194e957fcedb4841.

      This symlink can also be used as the coreos.inst.install_dev kernel argument when using special coreos.inst.* arguments to direct the live installer. For more information, see "Installing RHCOS and starting the OpenShift Container Platform bootstrap process".

  3. Reboot into the installed system.
  4. Check that the kernel arguments worked by going to one of the worker nodes and listing the kernel command line arguments (in /proc/cmdline on the host):

    $ oc debug node/ip-10-0-141-105.ec2.internal

    Example output

    Starting pod/ip-10-0-141-105ec2internal-debug ...
    To use host binaries, run `chroot /host`
    
    sh-4.2# cat /host/proc/cmdline
    ...
    rd.multipath=default root=/dev/disk/by-label/dm-mpath-root
    ...
    
    sh-4.2# exit

    You should see the added kernel arguments.

2.1.12.4.1. Enabling multipathing on secondary disks

RHCOS also supports multipathing on a secondary disk. Instead of kernel arguments, you use Ignition to enable multipathing for the secondary disk at installation time.

Prerequisites

  • You have read the section Disk partitioning.
  • You have read Enabling multipathing with kernel arguments on RHCOS.
  • You have installed the Butane utility.

Procedure

  1. Create a Butane config with information similar to the following:

    Example multipath-config.bu

    variant: openshift
    version: 4.18.0
    systemd:
      units:
        - name: mpath-configure.service
          enabled: true
          contents: |
            [Unit]
            Description=Configure Multipath on Secondary Disk
            ConditionFirstBoot=true
            ConditionPathExists=!/etc/multipath.conf
            Before=multipathd.service 1
            DefaultDependencies=no
    
            [Service]
            Type=oneshot
            ExecStart=/usr/sbin/mpathconf --enable 2
    
            [Install]
            WantedBy=multi-user.target
        - name: mpath-var-lib-container.service
          enabled: true
          contents: |
            [Unit]
            Description=Set Up Multipath On /var/lib/containers
            ConditionFirstBoot=true 3
            Requires=dev-mapper-mpatha.device
            After=dev-mapper-mpatha.device
            After=ostree-remount.service
            Before=kubelet.service
            DefaultDependencies=no
    
            [Service] 4
            Type=oneshot
            ExecStart=/usr/sbin/mkfs.xfs -L containers -m reflink=1 /dev/mapper/mpatha
            ExecStart=/usr/bin/mkdir -p /var/lib/containers
    
            [Install]
            WantedBy=multi-user.target
        - name: var-lib-containers.mount
          enabled: true
          contents: |
            [Unit]
            Description=Mount /var/lib/containers
            After=mpath-var-lib-containers.service
            Before=kubelet.service 5
    
            [Mount] 6
            What=/dev/disk/by-label/dm-mpath-containers
            Where=/var/lib/containers
            Type=xfs
    
            [Install]
            WantedBy=multi-user.target

    1
    The configuration must be set before launching the multipath daemon.
    2
    Starts the mpathconf utility.
    3
    This field must be set to the value true.
    4
    Creates the filesystem and directory /var/lib/containers.
    5
    The device must be mounted before starting any nodes.
    6
    Mounts the device to the /var/lib/containers mount point. This location cannot be a symlink.
  2. Create the Ignition configuration by running the following command:

    $ butane --pretty --strict multipath-config.bu > multipath-config.ign
  3. Continue with the rest of the first boot RHCOS installation process.

    Important

    Do not add the rd.multipath or root kernel arguments on the command-line during installation unless the primary disk is also multipathed.

2.1.12.5. Installing RHCOS manually on an iSCSI boot device

You can manually install RHCOS on an iSCSI target.

Prerequisites

  1. You are in the RHCOS live environment.
  2. You have an iSCSI target that you want to install RHCOS on.

Procedure

  1. Mount the iSCSI target from the live environment by running the following command:

    $ iscsiadm \
        --mode discovery \
        --type sendtargets
        --portal <IP_address> \ 1
        --login
    1
    The IP address of the target portal.
  2. Install RHCOS onto the iSCSI target by running the following command and using the necessary kernel arguments, for example:

    $ coreos-installer install \
        /dev/disk/by-path/ip-<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 1
        --append-karg rd.iscsi.initiator=<initiator_iqn> \ 2
        --append.karg netroot=<target_iqn> \ 3
        --console ttyS0,115200n8
        --ignition-file <path_to_file>
    1
    The location you are installing to. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    2
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    3
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

  3. Unmount the iSCSI disk with the following command:

    $ iscsiadm --mode node --logoutall=all

This procedure can also be performed using the coreos-installer iso customize or coreos-installer pxe customize subcommands.

2.1.12.6. Installing RHCOS on an iSCSI boot device using iBFT

On a completely diskless machine, the iSCSI target and initiator values can be passed through iBFT. iSCSI multipathing is also supported.

Prerequisites

  1. You are in the RHCOS live environment.
  2. You have an iSCSI target you want to install RHCOS on.
  3. Optional: you have multipathed your iSCSI target.

Procedure

  1. Mount the iSCSI target from the live environment by running the following command:

    $ iscsiadm \
        --mode discovery \
        --type sendtargets
        --portal <IP_address> \ 1
        --login
    1
    The IP address of the target portal.
  2. Optional: enable multipathing and start the daemon with the following command:

    $ mpathconf --enable && systemctl start multipathd.service
  3. Install RHCOS onto the iSCSI target by running the following command and using the necessary kernel arguments, for example:

    $ coreos-installer install \
        /dev/mapper/mpatha \ 1
        --append-karg rd.iscsi.firmware=1 \ 2
        --append-karg rd.multipath=default \ 3
        --console ttyS0 \
        --ignition-file <path_to_file>
    1
    The path of a single multipathed device. If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    2
    The iSCSI parameter is read from the BIOS firmware.
    3
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

  4. Unmount the iSCSI disk:

    $ iscsiadm --mode node --logout=all

This procedure can also be performed using the coreos-installer iso customize or coreos-installer pxe customize subcommands.

Additional resources

2.1.13. Waiting for the bootstrap process to complete

The OpenShift Container Platform bootstrap process begins after the cluster nodes first boot into the persistent RHCOS environment that has been installed to disk. The configuration information provided through the Ignition config files is used to initialize the bootstrap process and install OpenShift Container Platform on the machines. You must wait for the bootstrap process to complete.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have obtained the installation program and generated the Ignition config files for your cluster.
  • You installed RHCOS on your cluster machines and provided the Ignition config files that the OpenShift Container Platform installation program generated.
  • Your machines have direct internet access or have an HTTP or HTTPS proxy available.

Procedure

  1. Monitor the bootstrap process:

    $ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ 1
        --log-level=info 2
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.
    2
    To view different installation details, specify warn, debug, or error instead of info.

    Example output

    INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
    INFO API v1.31.3 up
    INFO Waiting up to 30m0s for bootstrapping to complete...
    INFO It is now safe to remove the bootstrap resources

    The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.

  2. After the bootstrap process is complete, remove the bootstrap machine from the load balancer.

    Important

    You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the bootstrap machine itself.

Additional resources

2.1.14. Logging in to the cluster by using the CLI

You can log in to your cluster as a default system user by exporting the cluster kubeconfig file. The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server. The file is specific to a cluster and is created during OpenShift Container Platform installation.

Prerequisites

  • You deployed an OpenShift Container Platform cluster.
  • You installed the oc CLI.

Procedure

  1. Export the kubeadmin credentials:

    $ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.
  2. Verify you can run oc commands successfully using the exported configuration:

    $ oc whoami

    Example output

    system:admin

2.1.15. Approving the certificate signing requests for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.

Prerequisites

  • You added machines to your cluster.

Procedure

  1. Confirm that the cluster recognizes the machines:

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
    master-0  Ready     master  63m  v1.31.3
    master-1  Ready     master  63m  v1.31.3
    master-2  Ready     master  64m  v1.31.3

    The output lists all of the machines that you created.

    Note

    The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.

  2. Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

    $ oc get csr

    Example output

    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    ...

    In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

  3. If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:

    Note

    Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. After the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.

    Note

    For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the oc exec, oc rsh, and oc logs commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the node-bootstrapper service account in the system:node or system:admin groups, and confirm the identity of the node.

    • To approve them individually, run the following command for each valid CSR:

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
      Note

      Some Operators might not become available until some CSRs are approved.

  4. Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

    $ oc get csr

    Example output

    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
    csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
    ...

  5. If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:

    • To approve them individually, run the following command for each valid CSR:

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
  6. After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
    master-0  Ready     master  73m  v1.31.3
    master-1  Ready     master  73m  v1.31.3
    master-2  Ready     master  74m  v1.31.3
    worker-0  Ready     worker  11m  v1.31.3
    worker-1  Ready     worker  11m  v1.31.3

    Note

    It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

2.1.16. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

  • Your control plane has initialized.

Procedure

  1. Watch the cluster components come online:

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.18.0    True        False         False      19m
    baremetal                                  4.18.0    True        False         False      37m
    cloud-credential                           4.18.0    True        False         False      40m
    cluster-autoscaler                         4.18.0    True        False         False      37m
    config-operator                            4.18.0    True        False         False      38m
    console                                    4.18.0    True        False         False      26m
    csi-snapshot-controller                    4.18.0    True        False         False      37m
    dns                                        4.18.0    True        False         False      37m
    etcd                                       4.18.0    True        False         False      36m
    image-registry                             4.18.0    True        False         False      31m
    ingress                                    4.18.0    True        False         False      30m
    insights                                   4.18.0    True        False         False      31m
    kube-apiserver                             4.18.0    True        False         False      26m
    kube-controller-manager                    4.18.0    True        False         False      36m
    kube-scheduler                             4.18.0    True        False         False      36m
    kube-storage-version-migrator              4.18.0    True        False         False      37m
    machine-api                                4.18.0    True        False         False      29m
    machine-approver                           4.18.0    True        False         False      37m
    machine-config                             4.18.0    True        False         False      36m
    marketplace                                4.18.0    True        False         False      37m
    monitoring                                 4.18.0    True        False         False      29m
    network                                    4.18.0    True        False         False      38m
    node-tuning                                4.18.0    True        False         False      37m
    openshift-apiserver                        4.18.0    True        False         False      32m
    openshift-controller-manager               4.18.0    True        False         False      30m
    openshift-samples                          4.18.0    True        False         False      32m
    operator-lifecycle-manager                 4.18.0    True        False         False      37m
    operator-lifecycle-manager-catalog         4.18.0    True        False         False      37m
    operator-lifecycle-manager-packageserver   4.18.0    True        False         False      32m
    service-ca                                 4.18.0    True        False         False      38m
    storage                                    4.18.0    True        False         False      37m

  2. Configure the Operators that are not available.

Additional resources

2.1.16.1. Image registry removed during installation

On platforms that do not provide shareable object storage, the OpenShift Image Registry Operator bootstraps itself as Removed. This allows openshift-installer to complete installations on these platform types.

After installation, you must edit the Image Registry Operator configuration to switch the managementState from Removed to Managed. When this has completed, you must configure storage.

2.1.16.2. Image registry storage configuration

The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.

Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

2.1.16.2.1. Configuring registry storage for bare metal and other manual installations

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites

  • You have access to the cluster as a user with the cluster-admin role.
  • You have a cluster that uses manually-provisioned Red Hat Enterprise Linux CoreOS (RHCOS) nodes, such as bare metal.
  • You have provisioned persistent storage for your cluster, such as Red Hat OpenShift Data Foundation.

    Important

    OpenShift Container Platform supports ReadWriteOnce access for image registry storage when you have only one replica. ReadWriteOnce access also requires that the registry uses the Recreate rollout strategy. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.

  • Must have 100Gi capacity.

Procedure

  1. To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.

    Note

    When you use shared storage, review your security settings to prevent outside access.

  2. Verify that you do not have a registry pod:

    $ oc get pod -n openshift-image-registry -l docker-registry=default

    Example output

    No resources found in openshift-image-registry namespace

    Note

    If you do have a registry pod in your output, you do not need to continue with this procedure.

  3. Check the registry configuration:

    $ oc edit configs.imageregistry.operator.openshift.io

    Example output

    storage:
      pvc:
        claim:

    Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.

  4. Check the clusteroperator status:

    $ oc get clusteroperator image-registry

    Example output

    NAME             VERSION              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
    image-registry   4.18                 True        False         False      6h50m

  5. Ensure that your registry is set to managed to enable building and pushing of images.

    • Run:

      $ oc edit configs.imageregistry/cluster

      Then, change the line

      managementState: Removed

      to

      managementState: Managed
2.1.16.2.2. Configuring storage for the image registry in non-production clusters

You must configure storage for the Image Registry Operator. For non-production clusters, you can set the image registry to an empty directory. If you do so, all images are lost if you restart the registry.

Procedure

  • To set the image registry storage to an empty directory:

    $ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'
    Warning

    Configure this option for only non-production clusters.

    If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:

    Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found

    Wait a few minutes and run the command again.

2.1.16.2.3. Configuring block registry storage for bare metal

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Important

Block storage volumes, or block persistent volumes, are supported but not recommended for use with the image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica.

If you choose to use a block storage volume with the image registry, you must use a filesystem persistent volume claim (PVC).

Procedure

  1. Enter the following command to set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy, and runs with only one (1) replica:

    $ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
  2. Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.

    1. Create a pvc.yaml file with the following contents to define a VMware vSphere PersistentVolumeClaim object:

      kind: PersistentVolumeClaim
      apiVersion: v1
      metadata:
        name: image-registry-storage 1
        namespace: openshift-image-registry 2
      spec:
        accessModes:
        - ReadWriteOnce 3
        resources:
          requests:
            storage: 100Gi 4
      1
      A unique name that represents the PersistentVolumeClaim object.
      2
      The namespace for the PersistentVolumeClaim object, which is openshift-image-registry.
      3
      The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node.
      4
      The size of the persistent volume claim.
    2. Enter the following command to create the PersistentVolumeClaim object from the file:

      $ oc create -f pvc.yaml -n openshift-image-registry
  3. Enter the following command to edit the registry configuration so that it references the correct PVC:

    $ oc edit config.imageregistry.operator.openshift.io -o yaml

    Example output

    storage:
      pvc:
        claim: 1

    1
    By creating a custom PVC, you can leave the claim field blank for the default automatic creation of an image-registry-storage PVC.

2.1.17. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

  • Your control plane has initialized.
  • You have completed the initial Operator configuration.

Procedure

  1. Confirm that all the cluster components are online with the following command:

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.18.0    True        False         False      19m
    baremetal                                  4.18.0    True        False         False      37m
    cloud-credential                           4.18.0    True        False         False      40m
    cluster-autoscaler                         4.18.0    True        False         False      37m
    config-operator                            4.18.0    True        False         False      38m
    console                                    4.18.0    True        False         False      26m
    csi-snapshot-controller                    4.18.0    True        False         False      37m
    dns                                        4.18.0    True        False         False      37m
    etcd                                       4.18.0    True        False         False      36m
    image-registry                             4.18.0    True        False         False      31m
    ingress                                    4.18.0    True        False         False      30m
    insights                                   4.18.0    True        False         False      31m
    kube-apiserver                             4.18.0    True        False         False      26m
    kube-controller-manager                    4.18.0    True        False         False      36m
    kube-scheduler                             4.18.0    True        False         False      36m
    kube-storage-version-migrator              4.18.0    True        False         False      37m
    machine-api                                4.18.0    True        False         False      29m
    machine-approver                           4.18.0    True        False         False      37m
    machine-config                             4.18.0    True        False         False      36m
    marketplace                                4.18.0    True        False         False      37m
    monitoring                                 4.18.0    True        False         False      29m
    network                                    4.18.0    True        False         False      38m
    node-tuning                                4.18.0    True        False         False      37m
    openshift-apiserver                        4.18.0    True        False         False      32m
    openshift-controller-manager               4.18.0    True        False         False      30m
    openshift-samples                          4.18.0    True        False         False      32m
    operator-lifecycle-manager                 4.18.0    True        False         False      37m
    operator-lifecycle-manager-catalog         4.18.0    True        False         False      37m
    operator-lifecycle-manager-packageserver   4.18.0    True        False         False      32m
    service-ca                                 4.18.0    True        False         False      38m
    storage                                    4.18.0    True        False         False      37m

    Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

    $ ./openshift-install --dir <installation_directory> wait-for install-complete 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.

    Example output

    INFO Waiting up to 30m0s for the cluster to initialize...

    The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

    Important
    • The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
    • It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.
  2. Confirm that the Kubernetes API server is communicating with the pods.

    1. To view a list of all pods, use the following command:

      $ oc get pods --all-namespaces

      Example output

      NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
      openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
      openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
      openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
      openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
      openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
      ...

    2. View the logs for a pod that is listed in the output of the previous command by using the following command:

      $ oc logs <pod_name> -n <namespace> 1
      1
      Specify the pod name and namespace, as shown in the output of the previous command.

      If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

  3. For an installation with Fibre Channel Protocol (FCP), additional steps are required to enable multipathing. Do not enable multipathing during installation.

    See "Enabling multipathing with kernel arguments on RHCOS" in the Postinstallation machine configuration tasks documentation for more information.

2.1.18. Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.18, the Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to OpenShift Cluster Manager.

After you confirm that your OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually by using OpenShift Cluster Manager, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.

Additional resources

2.1.19. Next steps

2.2. Installing a user-provisioned bare metal cluster with network customizations

In OpenShift Container Platform 4.18, you can install a cluster on bare metal infrastructure that you provision with customized network configuration options. By customizing your network configuration, your cluster can coexist with existing IP address allocations in your environment and integrate with existing MTU and VXLAN configurations.

When you customize OpenShift Container Platform networking, you must set most of the network configuration parameters during installation. You can modify only kubeProxy network configuration parameters in a running cluster.

2.2.1. Prerequisites

2.2.2. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.18, you require access to the internet to install your cluster.

You must have internet access to:

  • Access OpenShift Cluster Manager to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.
  • Access Quay.io to obtain the packages that are required to install your cluster.
  • Obtain the packages that are required to perform cluster updates.
Important

If your cluster cannot have direct internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the required content and use it to populate a mirror registry with the installation packages. With some installation types, the environment that you install your cluster in will not require internet access. Before you update the cluster, you update the content of the mirror registry.

Additional resources

2.2.3. Requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

This section describes the requirements for deploying OpenShift Container Platform on user-provisioned infrastructure.

2.2.3.1. Required machines for cluster installation

The smallest OpenShift Container Platform clusters require the following hosts:

Table 2.11. Minimum required hosts
HostsDescription

One temporary bootstrap machine

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Three control plane machines

The control plane machines run the Kubernetes and OpenShift Container Platform services that form the control plane.

At least two compute machines, which are also known as worker machines.

The workloads requested by OpenShift Container Platform users run on the compute machines.

Note

As an exception, you can run zero compute machines in a bare metal cluster that consists of three control plane machines only. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for testing, development, and production. Running one compute machine is not supported.

Important

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS), Red Hat Enterprise Linux (RHEL) 8.6 and later.

Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 9.2 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

2.2.3.2. Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 2.12. Minimum resource requirements
MachineOperating SystemCPU [1]RAMStorageInput/Output Per Second (IOPS)[2]

Bootstrap

RHCOS

4

16 GB

100 GB

300

Control plane

RHCOS

4

16 GB

100 GB

300

Compute

RHCOS, RHEL 8.6 and later [3]

2

8 GB

100 GB

300

  1. One CPU is equivalent to one physical core when simultaneous multithreading (SMT), or Hyper-Threading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = CPUs.
  2. OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
  3. As with all user-provisioned installations, if you choose to use RHEL compute machines in your cluster, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Use of RHEL 7 compute machines is deprecated and has been removed in OpenShift Container Platform 4.10 and later.
Note

For OpenShift Container Platform version 4.18, RHCOS is based on RHEL version 9.4, which updates the micro-architecture requirements. The following list contains the minimum instruction set architectures (ISA) that each architecture requires:

  • x86-64 architecture requires x86-64-v2 ISA
  • ARM64 architecture requires ARMv8.0-A ISA
  • IBM Power architecture requires Power 9 ISA
  • s390x architecture requires z14 ISA

For more information, see Architectures (RHEL documentation).

If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.

Additional resources

2.2.3.3. Certificate signing requests management

Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.

Additional resources

2.2.3.4. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require networking to be configured in initramfs during boot to fetch their Ignition config files.

During the initial boot, the machines require an IP address configuration that is set either through a DHCP server or statically by providing the required boot options. After a network connection is established, the machines download their Ignition config files from an HTTP or HTTPS server. The Ignition config files are then used to set the exact state of each machine. The Machine Config Operator completes more changes to the machines, such as the application of new certificates or keys, after installation.

It is recommended to use a DHCP server for long-term management of the cluster machines. Ensure that the DHCP server is configured to provide persistent IP addresses, DNS server information, and hostnames to the cluster machines.

Note

If a DHCP service is not available for your user-provisioned infrastructure, you can instead provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options.

The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.

2.2.3.4.1. Setting the cluster node hostnames through DHCP

On Red Hat Enterprise Linux CoreOS (RHCOS) machines, the hostname is set through NetworkManager. By default, the machines obtain their hostname through DHCP. If the hostname is not provided by DHCP, set statically through kernel arguments, or another method, it is obtained through a reverse DNS lookup. Reverse DNS lookup occurs after the network has been initialized on a node and can take time to resolve. Other system services can start prior to this and detect the hostname as localhost or similar. You can avoid this by using DHCP to provide the hostname for each cluster node.

Additionally, setting the hostnames through DHCP can bypass any manual DNS record name configuration errors in environments that have a DNS split-horizon implementation.

2.2.3.4.2. Network connectivity requirements

You must configure the network connectivity between machines to allow OpenShift Container Platform cluster components to communicate. Each machine must be able to resolve the hostnames of all other machines in the cluster.

This section provides details about the ports that are required.

Important

In connected OpenShift Container Platform environments, all nodes are required to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Table 2.13. Ports used for all-machine to all-machine communications
ProtocolPortDescription

ICMP

N/A

Network reachability tests

TCP

1936

Metrics

9000-9999

Host level services, including the node exporter on ports 9100-9101 and the Cluster Version Operator on port 9099.

10250-10259

The default ports that Kubernetes reserves

UDP

4789

VXLAN

6081

Geneve

9000-9999

Host level services, including the node exporter on ports 9100-9101.

500

IPsec IKE packets

4500

IPsec NAT-T packets

123

Network Time Protocol (NTP) on UDP port 123

If an external NTP time server is configured, you must open UDP port 123.

TCP/UDP

30000-32767

Kubernetes node port

ESP

N/A

IPsec Encapsulating Security Payload (ESP)

Table 2.14. Ports used for all-machine to control plane communications
ProtocolPortDescription

TCP

6443

Kubernetes API

Table 2.15. Ports used for control plane machine to control plane machine communications
ProtocolPortDescription

TCP

2379-2380

etcd server and peer ports

NTP configuration for user-provisioned infrastructure

OpenShift Container Platform clusters are configured to use a public Network Time Protocol (NTP) server by default. If you want to use a local enterprise NTP server, or if your cluster is being deployed in a disconnected network, you can configure the cluster to use a specific time server. For more information, see the documentation for Configuring chrony time service.

If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

2.2.3.5. User-provisioned DNS requirements

In OpenShift Container Platform deployments, DNS name resolution is required for the following components:

  • The Kubernetes API
  • The OpenShift Container Platform application wildcard
  • The bootstrap, control plane, and compute machines

Reverse DNS resolution is also required for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.

DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Red Hat Enterprise Linux CoreOS (RHCOS) uses the reverse records to set the hostnames for all the nodes, unless the hostnames are provided by DHCP. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OpenShift Container Platform needs to operate.

Note

It is recommended to use a DHCP server to provide the hostnames to each cluster node. See the DHCP recommendations for user-provisioned infrastructure section for more information.

The following DNS records are required for a user-provisioned OpenShift Container Platform cluster and they must be in place before installation. In each record, <cluster_name> is the cluster name and <base_domain> is the base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 2.16. Required DNS records
ComponentRecordDescription

Kubernetes API

api.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the API load balancer. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

api-int.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to internally identify the API load balancer. These records must be resolvable from all the nodes within the cluster.

Important

The API server must be able to resolve the worker nodes by the hostnames that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

*.apps.<cluster_name>.<base_domain>.

A wildcard DNS A/AAAA or CNAME record that refers to the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

For example, console-openshift-console.apps.<cluster_name>.<base_domain> is used as a wildcard route to the OpenShift Container Platform console.

Bootstrap machine

bootstrap.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.

Control plane machines

<control_plane><n>.<cluster_name>.<base_domain>.

DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes. These records must be resolvable by the nodes within the cluster.

Compute machines

<compute><n>.<cluster_name>.<base_domain>.

DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Note

In OpenShift Container Platform 4.4 and later, you do not need to specify etcd host and SRV records in your DNS configuration.

Tip

You can use the dig command to verify name and reverse name resolution. See the section on Validating DNS resolution for user-provisioned infrastructure for detailed validation steps.

2.2.3.5.1. Example DNS configuration for user-provisioned clusters

This section provides A and PTR record configuration samples that meet the DNS requirements for deploying OpenShift Container Platform on user-provisioned infrastructure. The samples are not meant to provide advice for choosing one DNS solution over another.

In the examples, the cluster name is ocp4 and the base domain is example.com.

Example DNS A record configuration for a user-provisioned cluster

The following example is a BIND zone file that shows sample A records for name resolution in a user-provisioned cluster.

Example 2.4. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1.example.com.		IN	A	192.168.1.5
smtp.example.com.		IN	A	192.168.1.5
;
helper.example.com.		IN	A	192.168.1.5
helper.ocp4.example.com.	IN	A	192.168.1.5
;
api.ocp4.example.com.		IN	A	192.168.1.5 1
api-int.ocp4.example.com.	IN	A	192.168.1.5 2
;
*.apps.ocp4.example.com.	IN	A	192.168.1.5 3
;
bootstrap.ocp4.example.com.	IN	A	192.168.1.96 4
;
control-plane0.ocp4.example.com.	IN	A	192.168.1.97 5
control-plane1.ocp4.example.com.	IN	A	192.168.1.98 6
control-plane2.ocp4.example.com.	IN	A	192.168.1.99 7
;
compute0.ocp4.example.com.	IN	A	192.168.1.11 8
compute1.ocp4.example.com.	IN	A	192.168.1.7 9
;
;EOF
1
Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer.
2
Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer and is used for internal cluster communications.
3
Provides name resolution for the wildcard routes. The record refers to the IP address of the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
Note

In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

4
Provides name resolution for the bootstrap machine.
5 6 7
Provides name resolution for the control plane machines.
8 9
Provides name resolution for the compute machines.

Example DNS PTR record configuration for a user-provisioned cluster

The following example BIND zone file shows sample PTR records for reverse name resolution in a user-provisioned cluster.

Example 2.5. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
5.1.168.192.in-addr.arpa.	IN	PTR	api.ocp4.example.com. 1
5.1.168.192.in-addr.arpa.	IN	PTR	api-int.ocp4.example.com. 2
;
96.1.168.192.in-addr.arpa.	IN	PTR	bootstrap.ocp4.example.com. 3
;
97.1.168.192.in-addr.arpa.	IN	PTR	control-plane0.ocp4.example.com. 4
98.1.168.192.in-addr.arpa.	IN	PTR	control-plane1.ocp4.example.com. 5
99.1.168.192.in-addr.arpa.	IN	PTR	control-plane2.ocp4.example.com. 6
;
11.1.168.192.in-addr.arpa.	IN	PTR	compute0.ocp4.example.com. 7
7.1.168.192.in-addr.arpa.	IN	PTR	compute1.ocp4.example.com. 8
;
;EOF
1
Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer.
2
Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer and is used for internal cluster communications.
3
Provides reverse DNS resolution for the bootstrap machine.
4 5 6
Provides reverse DNS resolution for the control plane machines.
7 8
Provides reverse DNS resolution for the compute machines.
Note

A PTR record is not required for the OpenShift Container Platform application wildcard.

2.2.3.6. Load balancing requirements for user-provisioned infrastructure

Before you install OpenShift Container Platform, you must provision the API and application Ingress load balancing infrastructure. In production scenarios, you can deploy the API and application Ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

Note

If you want to deploy the API and application Ingress load balancers with a Red Hat Enterprise Linux (RHEL) instance, you must purchase the RHEL subscription separately.

The load balancing infrastructure must meet the following requirements:

  1. API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
    • A stateless load balancing algorithm. The options vary based on the load balancer implementation.
    Important

    Do not configure session persistence for an API load balancer. Configuring session persistence for a Kubernetes API server might cause performance issues from excess application traffic for your OpenShift Container Platform cluster and the Kubernetes API that runs inside the cluster.

    Configure the following ports on both the front and back of the load balancers:

    Table 2.17. API load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    6443

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the /readyz endpoint for the API server health check probe.

    X

    X

    Kubernetes API server

    22623

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.

    X

     

    Machine config server

    Note

    The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the /readyz endpoint to the removal of the API server instance from the pool. Within the time frame after /readyz returns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values.

  2. Application Ingress load balancer: Provides an ingress point for application traffic flowing in from outside the cluster. A working configuration for the Ingress router is required for an OpenShift Container Platform cluster.

    Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
    • A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.
    Tip

    If the true IP address of the client can be seen by the application Ingress load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

    Configure the following ports on both the front and back of the load balancers:

    Table 2.18. Application Ingress load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    443

    The machines that run the Ingress Controller pods, compute, or worker, by default.

    X

    X

    HTTPS traffic

    80

    The machines that run the Ingress Controller pods, compute, or worker, by default.

    X

    X

    HTTP traffic

    Note

    If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application Ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.

2.2.3.6.1. Example load balancer configuration for user-provisioned clusters

This section provides an example API and application Ingress load balancer configuration that meets the load balancing requirements for user-provisioned clusters. The sample is an /etc/haproxy/haproxy.cfg configuration for an HAProxy load balancer. The example is not meant to provide advice for choosing one load balancing solution over another.

In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

Note

If you are using HAProxy as a load balancer and SELinux is set to enforcing, you must ensure that the HAProxy service can bind to the configured TCP port by running setsebool -P haproxy_connect_any=1.

Example 2.6. Sample API and application Ingress load balancer configuration

global
  log         127.0.0.1 local2
  pidfile     /var/run/haproxy.pid
  maxconn     4000
  daemon
defaults
  mode                    http
  log                     global
  option                  dontlognull
  option http-server-close
  option                  redispatch
  retries                 3
  timeout http-request    10s
  timeout queue           1m
  timeout connect         10s
  timeout client          1m
  timeout server          1m
  timeout http-keep-alive 10s
  timeout check           10s
  maxconn                 3000
listen api-server-6443 1
  bind *:6443
  mode tcp
  option  httpchk GET /readyz HTTP/1.0
  option  log-health-checks
  balance roundrobin
  server bootstrap bootstrap.ocp4.example.com:6443 verify none check check-ssl inter 10s fall 2 rise 3 backup 2
  server master0 master0.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
  server master1 master1.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
  server master2 master2.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
listen machine-config-server-22623 3
  bind *:22623
  mode tcp
  server bootstrap bootstrap.ocp4.example.com:22623 check inter 1s backup 4
  server master0 master0.ocp4.example.com:22623 check inter 1s
  server master1 master1.ocp4.example.com:22623 check inter 1s
  server master2 master2.ocp4.example.com:22623 check inter 1s
listen ingress-router-443 5
  bind *:443
  mode tcp
  balance source
  server compute0 compute0.ocp4.example.com:443 check inter 1s
  server compute1 compute1.ocp4.example.com:443 check inter 1s
listen ingress-router-80 6
  bind *:80
  mode tcp
  balance source
  server compute0 compute0.ocp4.example.com:80 check inter 1s
  server compute1 compute1.ocp4.example.com:80 check inter 1s
1
Port 6443 handles the Kubernetes API traffic and points to the control plane machines.
2 4
The bootstrap entries must be in place before the OpenShift Container Platform cluster installation and they must be removed after the bootstrap process is complete.
3
Port 22623 handles the machine config server traffic and points to the control plane machines.
5
Port 443 handles the HTTPS traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
6
Port 80 handles the HTTP traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
Note

If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application Ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.

Tip

If you are using HAProxy as a load balancer, you can check that the haproxy process is listening on ports 6443, 22623, 443, and 80 by running netstat -nltupe on the HAProxy node.

2.2.4. Creating a manifest object that includes a customized br-ex bridge

As an alternative to using the configure-ovs.sh shell script to set a br-ex bridge on a bare-metal platform, you can create a MachineConfig object that includes an NMState configuration file. The NMState configuration file creates a customized br-ex bridge network configuration on each node in your cluster.

Consider the following use cases for creating a manifest object that includes a customized br-ex bridge:

  • You want to make postinstallation changes to the bridge, such as changing the Open vSwitch (OVS) or OVN-Kubernetes br-ex bridge network. The configure-ovs.sh shell script does not support making postinstallation changes to the bridge.
  • You want to deploy the bridge on a different interface than the interface available on a host or server IP address.
  • You want to make advanced configurations to the bridge that are not possible with the configure-ovs.sh shell script. Using the script for these configurations might result in the bridge failing to connect multiple network interfaces and facilitating data forwarding between the interfaces.
Note

If you require an environment with a single network interface controller (NIC) and default network settings, use the configure-ovs.sh shell script.

After you install Red Hat Enterprise Linux CoreOS (RHCOS) and the system reboots, the Machine Config Operator injects Ignition configuration files into each node in your cluster, so that each node received the br-ex bridge network configuration. To prevent configuration conflicts, the configure-ovs.sh shell script receives a signal to not configure the br-ex bridge.

Prerequisites

  • Optional: You have installed the nmstate API so that you can validate the NMState configuration.

Procedure

  1. Create a NMState configuration file that has decoded base64 information for your customized br-ex bridge network:

    Example of an NMState configuration for a customized br-ex bridge network

    interfaces:
    - name: enp2s0 1
      type: ethernet 2
      state: up 3
      ipv4:
        enabled: false 4
      ipv6:
        enabled: false
    - name: br-ex
      type: ovs-bridge
      state: up
      ipv4:
        enabled: false
        dhcp: false
      ipv6:
        enabled: false
        dhcp: false
      bridge:
        port:
        - name: enp2s0 5
        - name: br-ex
    - name: br-ex
      type: ovs-interface
      state: up
      copy-mac-from: enp2s0
      ipv4:
        enabled: true
        dhcp: true
      ipv6:
        enabled: false
        dhcp: false
    # ...

    1
    Name of the interface.
    2
    The type of ethernet.
    3
    The requested state for the interface after creation.
    4
    Disables IPv4 and IPv6 in this example.
    5
    The node NIC to which the bridge attaches.
  2. Use the cat command to base64-encode the contents of the NMState configuration:

    $ cat <nmstate_configuration>.yaml | base64 1
    1
    Replace <nmstate_configuration> with the name of your NMState resource YAML file.
  3. Create a MachineConfig manifest file and define a customized br-ex bridge network configuration analogous to the following example:

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker 1
      name: 10-br-ex-worker 2
    spec:
      config:
        ignition:
          version: 3.2.0
        storage:
          files:
          - contents:
              source: data:text/plain;charset=utf-8;base64,<base64_encoded_nmstate_configuration> 3
            mode: 0644
            overwrite: true
            path: /etc/nmstate/openshift/cluster.yml
    # ...
    1
    For each node in your cluster, specify the hostname path to your node and the base-64 encoded Ignition configuration file data for the machine type. If you have a single global configuration specified in an /etc/nmstate/openshift/cluster.yml configuration file that you want to apply to all nodes in your cluster, you do not need to specify the hostname path for each node. The worker role is the default role for nodes in your cluster. The .yaml extension does not work when specifying the hostname path for each node or all nodes in the MachineConfig manifest file.
    2
    The name of the policy.
    3
    Writes the encoded base64 information to the specified path.
2.2.4.1. Scaling each machine set to compute nodes

To apply a customized br-ex bridge configuration to all compute nodes in your OpenShift Container Platform cluster, you must edit your MachineConfig custom resource (CR) and modify its roles. Additionally, you must create a BareMetalHost CR that defines information for your bare-metal machine, such as hostname, credentials, and so on.

After you configure these resources, you must scale machine sets, so that the machine sets can apply the resource configuration to each compute node and reboot the nodes.

Prerequisites

  • You created a MachineConfig manifest object that includes a customized br-ex bridge configuration.

Procedure

  1. Edit the MachineConfig CR by entering the following command:

    $ oc edit mc <machineconfig_custom_resource_name>
  2. Add each compute node configuration to the CR, so that the CR can manage roles for each defined compute node in your cluster.
  3. Create a Secret object named extraworker-secret that has a minimal static IP configuration.
  4. Apply the extraworker-secret secret to each node in your cluster by entering the following command. This step provides each compute node access to the Ignition config file.

    $ oc apply -f ./extraworker-secret.yaml
  5. Create a BareMetalHost resource and specify the network secret in the preprovisioningNetworkDataName parameter:

    Example BareMetalHost resource with an attached network secret

    apiVersion: metal3.io/v1alpha1
    kind: BareMetalHost
    spec:
    # ...
      preprovisioningNetworkDataName: ostest-extraworker-0-network-config-secret
    # ...

  6. To manage the BareMetalHost object within the openshift-machine-api namespace of your cluster, change to the namespace by entering the following command:

    $ oc project openshift-machine-api
  7. Get the machine sets:

    $ oc get machinesets
  8. Scale each machine set by entering the following command. You must run this command for each machine set.

    $ oc scale machineset <machineset_name> --replicas=<n> 1
    1
    Where <machineset_name> is the name of the machine set and <n> is the number of compute nodes.

2.2.5. Preparing the user-provisioned infrastructure

Before you install OpenShift Container Platform on user-provisioned infrastructure, you must prepare the underlying infrastructure.

This section provides details about the high-level steps required to set up your cluster infrastructure in preparation for an OpenShift Container Platform installation. This includes configuring IP networking and network connectivity for your cluster nodes, enabling the required ports through your firewall, and setting up the required DNS and load balancing infrastructure.

After preparation, your cluster infrastructure must meet the requirements outlined in the Requirements for a cluster with user-provisioned infrastructure section.

Prerequisites

Procedure

  1. If you are using DHCP to provide the IP networking configuration to your cluster nodes, configure your DHCP service.

    1. Add persistent IP addresses for the nodes to your DHCP server configuration. In your configuration, match the MAC address of the relevant network interface to the intended IP address for each node.
    2. When you use DHCP to configure IP addressing for the cluster machines, the machines also obtain the DNS server information through DHCP. Define the persistent DNS server address that is used by the cluster nodes through your DHCP server configuration.

      Note

      If you are not using a DHCP service, you must provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options.

    3. Define the hostnames of your cluster nodes in your DHCP server configuration. See the Setting the cluster node hostnames through DHCP section for details about hostname considerations.

      Note

      If you are not using a DHCP service, the cluster nodes obtain their hostname through a reverse DNS lookup.

  2. Ensure that your network infrastructure provides the required network connectivity between the cluster components. See the Networking requirements for user-provisioned infrastructure section for details about the requirements.
  3. Configure your firewall to enable the ports required for the OpenShift Container Platform cluster components to communicate. See Networking requirements for user-provisioned infrastructure section for details about the ports that are required.

    Important

    By default, port 1936 is accessible for an OpenShift Container Platform cluster, because each control plane node needs access to this port.

    Avoid using the Ingress load balancer to expose this port, because doing so might result in the exposure of sensitive information, such as statistics and metrics, related to Ingress Controllers.

  4. Setup the required DNS infrastructure for your cluster.

    1. Configure DNS name resolution for the Kubernetes API, the application wildcard, the bootstrap machine, the control plane machines, and the compute machines.
    2. Configure reverse DNS resolution for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.

      See the User-provisioned DNS requirements section for more information about the OpenShift Container Platform DNS requirements.

  5. Validate your DNS configuration.

    1. From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses in the responses correspond to the correct components.
    2. From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names in the responses correspond to the correct components.

      See the Validating DNS resolution for user-provisioned infrastructure section for detailed DNS validation steps.

  6. Provision the required API and application ingress load balancing infrastructure. See the Load balancing requirements for user-provisioned infrastructure section for more information about the requirements.
Note

Some load balancing solutions require the DNS name resolution for the cluster nodes to be in place before the load balancing is initialized.

2.2.6. Validating DNS resolution for user-provisioned infrastructure

You can validate your DNS configuration before installing OpenShift Container Platform on user-provisioned infrastructure.

Important

The validation steps detailed in this section must succeed before you install your cluster.

Prerequisites

  • You have configured the required DNS records for your user-provisioned infrastructure.

Procedure

  1. From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses contained in the responses correspond to the correct components.

    1. Perform a lookup against the Kubernetes API record name. Check that the result points to the IP address of the API load balancer:

      $ dig +noall +answer @<nameserver_ip> api.<cluster_name>.<base_domain> 1
      1
      Replace <nameserver_ip> with the IP address of the nameserver, <cluster_name> with your cluster name, and <base_domain> with your base domain name.

      Example output

      api.ocp4.example.com.		604800	IN	A	192.168.1.5

    2. Perform a lookup against the Kubernetes internal API record name. Check that the result points to the IP address of the API load balancer:

      $ dig +noall +answer @<nameserver_ip> api-int.<cluster_name>.<base_domain>

      Example output

      api-int.ocp4.example.com.		604800	IN	A	192.168.1.5

    3. Test an example *.apps.<cluster_name>.<base_domain> DNS wildcard lookup. All of the application wildcard lookups must resolve to the IP address of the application ingress load balancer:

      $ dig +noall +answer @<nameserver_ip> random.apps.<cluster_name>.<base_domain>

      Example output

      random.apps.ocp4.example.com.		604800	IN	A	192.168.1.5

      Note

      In the example outputs, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

      You can replace random with another wildcard value. For example, you can query the route to the OpenShift Container Platform console:

      $ dig +noall +answer @<nameserver_ip> console-openshift-console.apps.<cluster_name>.<base_domain>

      Example output

      console-openshift-console.apps.ocp4.example.com. 604800 IN	A 192.168.1.5

    4. Run a lookup against the bootstrap DNS record name. Check that the result points to the IP address of the bootstrap node:

      $ dig +noall +answer @<nameserver_ip> bootstrap.<cluster_name>.<base_domain>

      Example output

      bootstrap.ocp4.example.com.		604800	IN	A	192.168.1.96

    5. Use this method to perform lookups against the DNS record names for the control plane and compute nodes. Check that the results correspond to the IP addresses of each node.
  2. From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names contained in the responses correspond to the correct components.

    1. Perform a reverse lookup against the IP address of the API load balancer. Check that the response includes the record names for the Kubernetes API and the Kubernetes internal API:

      $ dig +noall +answer @<nameserver_ip> -x 192.168.1.5

      Example output

      5.1.168.192.in-addr.arpa. 604800	IN	PTR	api-int.ocp4.example.com. 1
      5.1.168.192.in-addr.arpa. 604800	IN	PTR	api.ocp4.example.com. 2

      1
      Provides the record name for the Kubernetes internal API.
      2
      Provides the record name for the Kubernetes API.
      Note

      A PTR record is not required for the OpenShift Container Platform application wildcard. No validation step is needed for reverse DNS resolution against the IP address of the application ingress load balancer.

    2. Perform a reverse lookup against the IP address of the bootstrap node. Check that the result points to the DNS record name of the bootstrap node:

      $ dig +noall +answer @<nameserver_ip> -x 192.168.1.96

      Example output

      96.1.168.192.in-addr.arpa. 604800	IN	PTR	bootstrap.ocp4.example.com.

    3. Use this method to perform reverse lookups against the IP addresses for the control plane and compute nodes. Check that the results correspond to the DNS record names of each node.

2.2.7. Generating a key pair for cluster node SSH access

During an OpenShift Container Platform installation, you can provide an SSH public key to the installation program. The key is passed to the Red Hat Enterprise Linux CoreOS (RHCOS) nodes through their Ignition config files and is used to authenticate SSH access to the nodes. The key is added to the ~/.ssh/authorized_keys list for the core user on each node, which enables password-less authentication.

After the key is passed to the nodes, you can use the key pair to SSH in to the RHCOS nodes as the user core. To access the nodes through SSH, the private key identity must be managed by SSH for your local user.

If you want to SSH in to your cluster nodes to perform installation debugging or disaster recovery, you must provide the SSH public key during the installation process. The ./openshift-install gather command also requires the SSH public key to be in place on the cluster nodes.

Important

Do not skip this procedure in production environments, where disaster recovery and debugging is required.

Note

You must use a local key, not one that you configured with platform-specific approaches.

Procedure

  1. If you do not have an existing SSH key pair on your local machine to use for authentication onto your cluster nodes, create one. For example, on a computer that uses a Linux operating system, run the following command:

    $ ssh-keygen -t ed25519 -N '' -f <path>/<file_name> 1
    1
    Specify the path and file name, such as ~/.ssh/id_ed25519, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
    Note

    If you plan to install an OpenShift Container Platform cluster that uses the RHEL cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. View the public SSH key:

    $ cat <path>/<file_name>.pub

    For example, run the following to view the ~/.ssh/id_ed25519.pub public key:

    $ cat ~/.ssh/id_ed25519.pub
  3. Add the SSH private key identity to the SSH agent for your local user, if it has not already been added. SSH agent management of the key is required for password-less SSH authentication onto your cluster nodes, or if you want to use the ./openshift-install gather command.

    Note

    On some distributions, default SSH private key identities such as ~/.ssh/id_rsa and ~/.ssh/id_dsa are managed automatically.

    1. If the ssh-agent process is not already running for your local user, start it as a background task:

      $ eval "$(ssh-agent -s)"

      Example output

      Agent pid 31874

      Note

      If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

  4. Add your SSH private key to the ssh-agent:

    $ ssh-add <path>/<file_name> 1
    1
    Specify the path and file name for your SSH private key, such as ~/.ssh/id_ed25519

    Example output

    Identity added: /home/<you>/<path>/<file_name> (<computer_name>)

Next steps

  • When you install OpenShift Container Platform, provide the SSH public key to the installation program.

Additional resources

2.2.8. Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on the host you are using for installation.

Prerequisites

  • You have a computer that runs Linux or macOS, with 500 MB of local disk space.

Procedure

  1. Go to the Cluster Type page on the Red Hat Hybrid Cloud Console. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
  2. Select your infrastructure provider from the Run it yourself section of the page.
  3. Select your host operating system and architecture from the dropdown menus under OpenShift Installer and click Download Installer.
  4. Place the downloaded file in the directory where you want to store the installation configuration files.

    Important
    • The installation program creates several files on the computer that you use to install your cluster. You must keep the installation program and the files that the installation program creates after you finish installing the cluster. Both of the files are required to delete the cluster.
    • Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OpenShift Container Platform uninstallation procedures for your specific cloud provider.
  5. Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:

    $ tar -xvf openshift-install-linux.tar.gz
  6. Download your installation pull secret from Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.
Tip

Alternatively, you can retrieve the installation program from the Red Hat Customer Portal, where you can specify a version of the installation program to download. However, you must have an active subscription to access this page.

2.2.9. Installing the OpenShift CLI

You can install the OpenShift CLI (oc) to interact with OpenShift Container Platform from a command-line interface. You can install oc on Linux, Windows, or macOS.

Important

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.18. Download and install the new version of oc.

Installing the OpenShift CLI on Linux

You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the architecture from the Product Variant drop-down list.
  3. Select the appropriate version from the Version drop-down list.
  4. Click Download Now next to the OpenShift v4.18 Linux Clients entry and save the file.
  5. Unpack the archive:

    $ tar xvf <file>
  6. Place the oc binary in a directory that is on your PATH.

    To check your PATH, execute the following command:

    $ echo $PATH

Verification

  • After you install the OpenShift CLI, it is available using the oc command:

    $ oc <command>
Installing the OpenShift CLI on Windows

You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the appropriate version from the Version drop-down list.
  3. Click Download Now next to the OpenShift v4.18 Windows Client entry and save the file.
  4. Unzip the archive with a ZIP program.
  5. Move the oc binary to a directory that is on your PATH.

    To check your PATH, open the command prompt and execute the following command:

    C:\> path

Verification

  • After you install the OpenShift CLI, it is available using the oc command:

    C:\> oc <command>
Installing the OpenShift CLI on macOS

You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the appropriate version from the Version drop-down list.
  3. Click Download Now next to the OpenShift v4.18 macOS Clients entry and save the file.

    Note

    For macOS arm64, choose the OpenShift v4.18 macOS arm64 Client entry.

  4. Unpack and unzip the archive.
  5. Move the oc binary to a directory on your PATH.

    To check your PATH, open a terminal and execute the following command:

    $ echo $PATH

Verification

  • Verify your installation by using an oc command:

    $ oc <command>

2.2.10. Manually creating the installation configuration file

Installing the cluster requires that you manually create the installation configuration file.

Prerequisites

  • You have an SSH public key on your local machine to provide to the installation program. The key will be used for SSH authentication onto your cluster nodes for debugging and disaster recovery.
  • You have obtained the OpenShift Container Platform installation program and the pull secret for your cluster.

Procedure

  1. Create an installation directory to store your required installation assets in:

    $ mkdir <installation_directory>
    Important

    You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.

  2. Customize the sample install-config.yaml file template that is provided and save it in the <installation_directory>.

    Note

    You must name this configuration file install-config.yaml.

  3. Back up the install-config.yaml file so that you can use it to install multiple clusters.

    Important

    The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

2.2.10.1. Sample install-config.yaml file for bare metal

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OVNKubernetes 11
  serviceNetwork: 12
  - 172.30.0.0/16
platform:
  none: {} 13
fips: false 14
pullSecret: '{"auths": ...}' 15
sshKey: 'ssh-ed25519 AAAA...' 16
1
The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 5
The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Only one control plane pool is used.
3 6
Specifies whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of the cores in your machines. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note

Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.

Important

If you disable hyperthreading, whether in the BIOS or in the install-config.yaml file, ensure that your capacity planning accounts for the dramatically decreased machine performance.

4
You must set this value to 0 when you install OpenShift Container Platform on user-provisioned infrastructure. In installer-provisioned installations, the parameter controls the number of compute machines that the cluster creates and manages for you. In user-provisioned installations, you must manually deploy the compute machines before you finish installing the cluster.
Note

If you are installing a three-node cluster, do not deploy any compute machines when you install the Red Hat Enterprise Linux CoreOS (RHCOS) machines.

7
The number of control plane machines that you add to the cluster. Because the cluster uses these values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8
The cluster name that you specified in your DNS records.
9
A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
Note

Class E CIDR range is reserved for a future use. To use the Class E CIDR range, you must ensure your networking environment accepts the IP addresses within the Class E CIDR range.

10
The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IP addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.
11
The cluster network plugin to install. The default value OVNKubernetes is the only supported value.
12
The IP address pool to use for service IP addresses. You can enter only one IP address pool. This block must not overlap with existing physical networks. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
13
You must set the platform to none. You cannot provide additional platform configuration variables for your platform.
Important

Clusters that are installed with the platform type none are unable to use some features, such as managing compute machines with the Machine API. This limitation applies even if the compute machines that are attached to the cluster are installed on a platform that would normally support the feature. This parameter cannot be changed after installation.

14
Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
Important

To enable FIPS mode for your cluster, you must run the installation program from a Red Hat Enterprise Linux (RHEL) computer configured to operate in FIPS mode. For more information about configuring FIPS mode on RHEL, see Switching RHEL to FIPS mode.

When running Red Hat Enterprise Linux (RHEL) or Red Hat Enterprise Linux CoreOS (RHCOS) booted in FIPS mode, OpenShift Container Platform core components use the RHEL cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures.

15
The pull secret from Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.
16
The SSH public key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

Additional resources

2.2.11. Network configuration phases

There are two phases prior to OpenShift Container Platform installation where you can customize the network configuration.

Phase 1

You can customize the following network-related fields in the install-config.yaml file before you create the manifest files:

  • networking.networkType
  • networking.clusterNetwork
  • networking.serviceNetwork
  • networking.machineNetwork
  • nodeNetworking

    For more information, see "Installation configuration parameters".

    Note

    Set the networking.machineNetwork to match the Classless Inter-Domain Routing (CIDR) where the preferred subnet is located.

    Important

    The CIDR range 172.17.0.0/16 is reserved by libVirt. You cannot use any other CIDR range that overlaps with the 172.17.0.0/16 CIDR range for networks in your cluster.

Phase 2
After creating the manifest files by running openshift-install create manifests, you can define a customized Cluster Network Operator manifest with only the fields you want to modify. You can use the manifest to specify an advanced network configuration.

During phase 2, you cannot override the values that you specified in phase 1 in the install-config.yaml file. However, you can customize the network plugin during phase 2.

2.2.12. Specifying advanced network configuration

You can use advanced network configuration for your network plugin to integrate your cluster into your existing network environment.

You can specify advanced network configuration only before you install the cluster.

Important

Customizing your network configuration by modifying the OpenShift Container Platform manifest files created by the installation program is not supported. Applying a manifest file that you create, as in the following procedure, is supported.

Prerequisites

  • You have created the install-config.yaml file and completed any modifications to it.

Procedure

  1. Change to the directory that contains the installation program and create the manifests:

    $ ./openshift-install create manifests --dir <installation_directory> 1
    1
    <installation_directory> specifies the name of the directory that contains the install-config.yaml file for your cluster.
  2. Create a stub manifest file for the advanced network configuration that is named cluster-network-03-config.yml in the <installation_directory>/manifests/ directory:

    apiVersion: operator.openshift.io/v1
    kind: Network
    metadata:
      name: cluster
    spec:
  3. Specify the advanced network configuration for your cluster in the cluster-network-03-config.yml file, such as in the following example:

    Enable IPsec for the OVN-Kubernetes network provider

    apiVersion: operator.openshift.io/v1
    kind: Network
    metadata:
      name: cluster
    spec:
      defaultNetwork:
        ovnKubernetesConfig:
          ipsecConfig:
            mode: Full

  4. Optional: Back up the manifests/cluster-network-03-config.yml file. The installation program consumes the manifests/ directory when you create the Ignition config files.
  5. Remove the Kubernetes manifest files that define the control plane machines and compute MachineSets:

    $ rm -f openshift/99_openshift-cluster-api_master-machines-*.yaml openshift/99_openshift-cluster-api_worker-machineset-*.yaml

    Because you create and manage these resources yourself, you do not have to initialize them.

    • You can preserve the MachineSet files to create compute machines by using the machine API, but you must update references to them to match your environment.

2.2.13. Cluster Network Operator configuration

The configuration for the cluster network is specified as part of the Cluster Network Operator (CNO) configuration and stored in a custom resource (CR) object that is named cluster. The CR specifies the fields for the Network API in the operator.openshift.io API group.

The CNO configuration inherits the following fields during cluster installation from the Network API in the Network.config.openshift.io API group:

clusterNetwork
IP address pools from which pod IP addresses are allocated.
serviceNetwork
IP address pool for services.
defaultNetwork.type
Cluster network plugin. OVNKubernetes is the only supported plugin during installation.

You can specify the cluster network plugin configuration for your cluster by setting the fields for the defaultNetwork object in the CNO object named cluster.

2.2.13.1. Cluster Network Operator configuration object

The fields for the Cluster Network Operator (CNO) are described in the following table:

Table 2.19. Cluster Network Operator configuration object
FieldTypeDescription

metadata.name

string

The name of the CNO object. This name is always cluster.

spec.clusterNetwork

array

A list specifying the blocks of IP addresses from which pod IP addresses are allocated and the subnet prefix length assigned to each individual node in the cluster. For example:

spec:
  clusterNetwork:
  - cidr: 10.128.0.0/19
    hostPrefix: 23
  - cidr: 10.128.32.0/19
    hostPrefix: 23

spec.serviceNetwork

array

A block of IP addresses for services. The OVN-Kubernetes network plugin supports only a single IP address block for the service network. For example:

spec:
  serviceNetwork:
  - 172.30.0.0/14

You can customize this field only in the install-config.yaml file before you create the manifests. The value is read-only in the manifest file.

spec.defaultNetwork

object

Configures the network plugin for the cluster network.

spec.kubeProxyConfig

object

The fields for this object specify the kube-proxy configuration. If you are using the OVN-Kubernetes cluster network plugin, the kube-proxy configuration has no effect.

Important

For a cluster that needs to deploy objects across multiple networks, ensure that you specify the same value for the clusterNetwork.hostPrefix parameter for each network type that is defined in the install-config.yaml file. Setting a different value for each clusterNetwork.hostPrefix parameter can impact the OVN-Kubernetes network plugin, where the plugin cannot effectively route object traffic among different nodes.

defaultNetwork object configuration

The values for the defaultNetwork object are defined in the following table:

Table 2.20. defaultNetwork object
FieldTypeDescription

type

string

OVNKubernetes. The Red Hat OpenShift Networking network plugin is selected during installation. This value cannot be changed after cluster installation.

Note

OpenShift Container Platform uses the OVN-Kubernetes network plugin by default.

ovnKubernetesConfig

object

This object is only valid for the OVN-Kubernetes network plugin.

Configuration for the OVN-Kubernetes network plugin

The following table describes the configuration fields for the OVN-Kubernetes network plugin:

Table 2.21. ovnKubernetesConfig object
FieldTypeDescription

mtu

integer

The maximum transmission unit (MTU) for the Geneve (Generic Network Virtualization Encapsulation) overlay network. This is detected automatically based on the MTU of the primary network interface. You do not normally need to override the detected MTU.

If the auto-detected value is not what you expect it to be, confirm that the MTU on the primary network interface on your nodes is correct. You cannot use this option to change the MTU value of the primary network interface on the nodes.

If your cluster requires different MTU values for different nodes, you must set this value to 100 less than the lowest MTU value in your cluster. For example, if some nodes in your cluster have an MTU of 9001, and some have an MTU of 1500, you must set this value to 1400.

genevePort

integer

The port to use for all Geneve packets. The default value is 6081. This value cannot be changed after cluster installation.

ipsecConfig

object

Specify a configuration object for customizing the IPsec configuration.

ipv4

object

Specifies a configuration object for IPv4 settings.

ipv6

object

Specifies a configuration object for IPv6 settings.

policyAuditConfig

object

Specify a configuration object for customizing network policy audit logging. If unset, the defaults audit log settings are used.

gatewayConfig

object

Optional: Specify a configuration object for customizing how egress traffic is sent to the node gateway.

Note

While migrating egress traffic, you can expect some disruption to workloads and service traffic until the Cluster Network Operator (CNO) successfully rolls out the changes.

Table 2.22. ovnKubernetesConfig.ipv4 object
FieldTypeDescription

internalTransitSwitchSubnet

string

If your existing network infrastructure overlaps with the 100.88.0.0/16 IPv4 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. The subnet for the distributed transit switch that enables east-west traffic. This subnet cannot overlap with any other subnets used by OVN-Kubernetes or on the host itself. It must be large enough to accommodate one IP address per node in your cluster.

The default value is 100.88.0.0/16.

internalJoinSubnet

string

If your existing network infrastructure overlaps with the 100.64.0.0/16 IPv4 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. You must ensure that the IP address range does not overlap with any other subnet used by your OpenShift Container Platform installation. The IP address range must be larger than the maximum number of nodes that can be added to the cluster. For example, if the clusterNetwork.cidr value is 10.128.0.0/14 and the clusterNetwork.hostPrefix value is /23, then the maximum number of nodes is 2^(23-14)=512.

The default value is 100.64.0.0/16.

Table 2.23. ovnKubernetesConfig.ipv6 object
FieldTypeDescription

internalTransitSwitchSubnet

string

If your existing network infrastructure overlaps with the fd97::/64 IPv6 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. The subnet for the distributed transit switch that enables east-west traffic. This subnet cannot overlap with any other subnets used by OVN-Kubernetes or on the host itself. It must be large enough to accommodate one IP address per node in your cluster.

The default value is fd97::/64.

internalJoinSubnet

string

If your existing network infrastructure overlaps with the fd98::/64 IPv6 subnet, you can specify a different IP address range for internal use by OVN-Kubernetes. You must ensure that the IP address range does not overlap with any other subnet used by your OpenShift Container Platform installation. The IP address range must be larger than the maximum number of nodes that can be added to the cluster.

The default value is fd98::/64.

Table 2.24. policyAuditConfig object
FieldTypeDescription

rateLimit

integer

The maximum number of messages to generate every second per node. The default value is 20 messages per second.

maxFileSize

integer

The maximum size for the audit log in bytes. The default value is 50000000 or 50 MB.

maxLogFiles

integer

The maximum number of log files that are retained.

destination

string

One of the following additional audit log targets:

libc
The libc syslog() function of the journald process on the host.
udp:<host>:<port>
A syslog server. Replace <host>:<port> with the host and port of the syslog server.
unix:<file>
A Unix Domain Socket file specified by <file>.
null
Do not send the audit logs to any additional target.

syslogFacility

string

The syslog facility, such as kern, as defined by RFC5424. The default value is local0.

Table 2.25. gatewayConfig object
FieldTypeDescription

routingViaHost

boolean

Set this field to true to send egress traffic from pods to the host networking stack. For highly-specialized installations and applications that rely on manually configured routes in the kernel routing table, you might want to route egress traffic to the host networking stack. By default, egress traffic is processed in OVN to exit the cluster and is not affected by specialized routes in the kernel routing table. The default value is false.

This field has an interaction with the Open vSwitch hardware offloading feature. If you set this field to true, you do not receive the performance benefits of the offloading because egress traffic is processed by the host networking stack.

ipForwarding

object

You can control IP forwarding for all traffic on OVN-Kubernetes managed interfaces by using the ipForwarding specification in the Network resource. Specify Restricted to only allow IP forwarding for Kubernetes related traffic. Specify Global to allow forwarding of all IP traffic. For new installations, the default is Restricted. For updates to OpenShift Container Platform 4.14 or later, the default is Global.

Note

The default value of Restricted sets the IP forwarding to drop.

ipv4

object

Optional: Specify an object to configure the internal OVN-Kubernetes masquerade address for host to service traffic for IPv4 addresses.

ipv6

object

Optional: Specify an object to configure the internal OVN-Kubernetes masquerade address for host to service traffic for IPv6 addresses.

Table 2.26. gatewayConfig.ipv4 object
FieldTypeDescription

internalMasqueradeSubnet

string

The masquerade IPv4 addresses that are used internally to enable host to service traffic. The host is configured with these IP addresses as well as the shared gateway bridge interface. The default value is 169.254.169.0/29.

Important

For OpenShift Container Platform 4.17 and later versions, clusters use 169.254.0.0/17 as the default masquerade subnet. For upgraded clusters, there is no change to the default masquerade subnet.

Table 2.27. gatewayConfig.ipv6 object
FieldTypeDescription

internalMasqueradeSubnet

string

The masquerade IPv6 addresses that are used internally to enable host to service traffic. The host is configured with these IP addresses as well as the shared gateway bridge interface. The default value is fd69::/125.

Important

For OpenShift Container Platform 4.17 and later versions, clusters use fd69::/112 as the default masquerade subnet. For upgraded clusters, there is no change to the default masquerade subnet.

Table 2.28. ipsecConfig object
FieldTypeDescription

mode

string

Specifies the behavior of the IPsec implementation. Must be one of the following values:

  • Disabled: IPsec is not enabled on cluster nodes.
  • External: IPsec is enabled for network traffic with external hosts.
  • Full: IPsec is enabled for pod traffic and network traffic with external hosts.

Example OVN-Kubernetes configuration with IPSec enabled

defaultNetwork:
  type: OVNKubernetes
  ovnKubernetesConfig:
    mtu: 1400
    genevePort: 6081
    ipsecConfig:
      mode: Full

2.2.14. Creating the Ignition config files

Because you must manually start the cluster machines, you must generate the Ignition config files that the cluster needs to make its machines.

Important
  • The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
  • It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.

Prerequisites

  • Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.

Procedure

  • Obtain the Ignition config files:

    $ ./openshift-install create ignition-configs --dir <installation_directory> 1
    1
    For <installation_directory>, specify the directory name to store the files that the installation program creates.
    Important

    If you created an install-config.yaml file, specify the directory that contains it. Otherwise, specify an empty directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.

    The following files are generated in the directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign

2.2.15. Installing RHCOS and starting the OpenShift Container Platform bootstrap process

To install OpenShift Container Platform on bare metal infrastructure that you provision, you must install Red Hat Enterprise Linux CoreOS (RHCOS) on the machines. When you install RHCOS, you must provide the Ignition config file that was generated by the OpenShift Container Platform installation program for the type of machine you are installing. If you have configured suitable networking, DNS, and load balancing infrastructure, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS machines have rebooted.

To install RHCOS on the machines, follow either the steps to use an ISO image or network PXE booting.

Note

The compute node deployment steps included in this installation document are RHCOS-specific. If you choose instead to deploy RHEL-based compute nodes, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Only RHEL 8 compute machines are supported.

You can configure RHCOS during ISO and PXE installations by using the following methods:

  • Kernel arguments: You can use kernel arguments to provide installation-specific information. For example, you can specify the locations of the RHCOS installation files that you uploaded to your HTTP server and the location of the Ignition config file for the type of node you are installing. For a PXE installation, you can use the APPEND parameter to pass the arguments to the kernel of the live installer. For an ISO installation, you can interrupt the live installation boot process to add the kernel arguments. In both installation cases, you can use special coreos.inst.* arguments to direct the live installer, as well as standard installation boot arguments for turning standard kernel services on or off.
  • Ignition configs: OpenShift Container Platform Ignition config files (*.ign) are specific to the type of node you are installing. You pass the location of a bootstrap, control plane, or compute node Ignition config file during the RHCOS installation so that it takes effect on first boot. In special cases, you can create a separate, limited Ignition config to pass to the live system. That Ignition config could do a certain set of tasks, such as reporting success to a provisioning system after completing installation. This special Ignition config is consumed by the coreos-installer to be applied on first boot of the installed system. Do not provide the standard control plane and compute node Ignition configs to the live ISO directly.
  • coreos-installer: You can boot the live ISO installer to a shell prompt, which allows you to prepare the permanent system in a variety of ways before first boot. In particular, you can run the coreos-installer command to identify various artifacts to include, work with disk partitions, and set up networking. In some cases, you can configure features on the live system and copy them to the installed system.

Whether to use an ISO or PXE install depends on your situation. A PXE install requires an available DHCP service and more preparation, but can make the installation process more automated. An ISO install is a more manual process and can be inconvenient if you are setting up more than a few machines.

2.2.15.1. Installing RHCOS by using an ISO image

You can use an ISO image to install RHCOS on the machines.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have an HTTP server that can be accessed from your computer, and from the machines that you create.
  • You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.

Procedure

  1. Obtain the SHA512 digest for each of your Ignition config files. For example, you can use the following on a system running Linux to get the SHA512 digest for your bootstrap.ign Ignition config file:

    $ sha512sum <installation_directory>/bootstrap.ign

    The digests are provided to the coreos-installer in a later step to validate the authenticity of the Ignition config files on the cluster nodes.

  2. Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

    You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  3. From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node:

    $ curl -k http://<HTTP_server>/bootstrap.ign 1

    Example output

      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
      0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...

    Replace bootstrap.ign with master.ign or worker.ign in the command to validate that the Ignition config files for the control plane and compute nodes are also available.

  4. Although it is possible to obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS images are from the output of openshift-install command:

    $ openshift-install coreos print-stream-json | grep '\.iso[^.]'

    Example output

    "location": "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live.x86_64.iso",

    Important

    The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Use only ISO images for this procedure. RHCOS qcow2 images are not supported for this installation type.

    ISO file names resemble the following example:

    rhcos-<version>-live.<architecture>.iso

  5. Use the ISO to start the RHCOS installation. Use one of the following installation options:

    • Burn the ISO image to a disk and boot it directly.
    • Use ISO redirection by using a lights-out management (LOM) interface.
  6. Boot the RHCOS ISO image without specifying any options or interrupting the live boot sequence. Wait for the installer to boot into a shell prompt in the RHCOS live environment.

    Note

    It is possible to interrupt the RHCOS installation boot process to add kernel arguments. However, for this ISO procedure you should use the coreos-installer command as outlined in the following steps, instead of adding kernel arguments.

  7. Run the coreos-installer command and specify the options that meet your installation requirements. At a minimum, you must specify the URL that points to the Ignition config file for the node type, and the device that you are installing to:

    $ sudo coreos-installer install --ignition-url=http://<HTTP_server>/<node_type>.ign <device> --ignition-hash=sha512-<digest> 12
    1 1
    You must run the coreos-installer command by using sudo, because the core user does not have the required root privileges to perform the installation.
    2
    The --ignition-hash option is required when the Ignition config file is obtained through an HTTP URL to validate the authenticity of the Ignition config file on the cluster node. <digest> is the Ignition config file SHA512 digest obtained in a preceding step.
    Note

    If you want to provide your Ignition config files through an HTTPS server that uses TLS, you can add the internal certificate authority (CA) to the system trust store before running coreos-installer.

    The following example initializes a bootstrap node installation to the /dev/sda device. The Ignition config file for the bootstrap node is obtained from an HTTP web server with the IP address 192.168.1.2:

    $ sudo coreos-installer install --ignition-url=http://192.168.1.2:80/installation_directory/bootstrap.ign /dev/sda --ignition-hash=sha512-a5a2d43879223273c9b60af66b44202a1d1248fc01cf156c46d4a79f552b6bad47bc8cc78ddf0116e80c59d2ea9e32ba53bc807afbca581aa059311def2c3e3b
  8. Monitor the progress of the RHCOS installation on the console of the machine.

    Important

    Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise.

  9. After RHCOS installs, you must reboot the system. During the system reboot, it applies the Ignition config file that you specified.
  10. Check the console output to verify that Ignition ran.

    Example command

    Ignition: ran on 2022/03/14 14:48:33 UTC (this boot)
    Ignition: user-provided config was applied

  11. Continue to create the other machines for your cluster.

    Important

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, also create at least two compute machines before you install OpenShift Container Platform.

    If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted.

    Note

    RHCOS nodes do not include a default password for the core user. You can access the nodes by running ssh core@<node>.<cluster_name>.<base_domain> as a user with access to the SSH private key that is paired to the public key that you specified in your install_config.yaml file. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.

2.2.15.2. Installing RHCOS by using PXE or iPXE booting

You can use PXE or iPXE booting to install RHCOS on the machines.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have configured suitable PXE or iPXE infrastructure.
  • You have an HTTP server that can be accessed from your computer, and from the machines that you create.
  • You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.

Procedure

  1. Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

    You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  2. From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node:

    $ curl -k http://<HTTP_server>/bootstrap.ign 1

    Example output

      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
      0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...

    Replace bootstrap.ign with master.ign or worker.ign in the command to validate that the Ignition config files for the control plane and compute nodes are also available.

  3. Although it is possible to obtain the RHCOS kernel, initramfs and rootfs files that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS files are from the output of openshift-install command:

    $ openshift-install coreos print-stream-json | grep -Eo '"https.*(kernel-|initramfs.|rootfs.)\w+(\.img)?"'

    Example output

    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-kernel-aarch64"
    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-initramfs.aarch64.img"
    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-rootfs.aarch64.img"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/49.84.202110081256-0/ppc64le/rhcos-<release>-live-kernel-ppc64le"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live-initramfs.ppc64le.img"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live-rootfs.ppc64le.img"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-kernel-s390x"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-initramfs.s390x.img"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-rootfs.s390x.img"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-kernel-x86_64"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-initramfs.x86_64.img"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-rootfs.x86_64.img"

    Important

    The RHCOS artifacts might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate kernel, initramfs, and rootfs artifacts described below for this procedure. RHCOS QCOW2 images are not supported for this installation type.

    The file names contain the OpenShift Container Platform version number. They resemble the following examples:

    • kernel: rhcos-<version>-live-kernel-<architecture>
    • initramfs: rhcos-<version>-live-initramfs.<architecture>.img
    • rootfs: rhcos-<version>-live-rootfs.<architecture>.img
  4. Upload the rootfs, kernel, and initramfs files to your HTTP server.

    Important

    If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  5. Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
  6. Configure PXE or iPXE installation for the RHCOS images and begin the installation.

    Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:

    • For PXE (x86_64):

      DEFAULT pxeboot
      TIMEOUT 20
      PROMPT 0
      LABEL pxeboot
          KERNEL http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> 1
          APPEND initrd=http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 2 3
      1 1
      Specify the location of the live kernel file that you uploaded to your HTTP server. The URL must be HTTP, TFTP, or FTP; HTTPS and NFS are not supported.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the locations of the RHCOS files that you uploaded to your HTTP server. The initrd parameter value is the location of the initramfs file, the coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file. You can also add more kernel arguments to the APPEND line to configure networking or other boot options.
      Note

      This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the APPEND line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux? and "Enabling the serial console for PXE and ISO installation" in the "Advanced RHCOS installation configuration" section.

    • For iPXE (x86_64 + aarch64 ):

      kernel http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> initrd=main coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
      initrd --name main http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img 3
      boot
      1
      Specify the locations of the RHCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd=main argument is needed for booting on UEFI systems, the coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the location of the initramfs file that you uploaded to your HTTP server.
      Note

      This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the kernel line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux? and "Enabling the serial console for PXE and ISO installation" in the "Advanced RHCOS installation configuration" section.

      Note

      To network boot the CoreOS kernel on aarch64 architecture, you need to use a version of iPXE build with the IMAGE_GZIP option enabled. See IMAGE_GZIP option in iPXE.

    • For PXE (with UEFI and Grub as second stage) on aarch64:

      menuentry 'Install CoreOS' {
          linux rhcos-<version>-live-kernel-<architecture>  coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
          initrd rhcos-<version>-live-initramfs.<architecture>.img 3
      }
      1
      Specify the locations of the RHCOS files that you uploaded to your HTTP/TFTP server. The kernel parameter value is the location of the kernel file on your TFTP server. The coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file on your HTTP Server.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the location of the initramfs file that you uploaded to your TFTP server.
  7. Monitor the progress of the RHCOS installation on the console of the machine.

    Important

    Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise.

  8. After RHCOS installs, the system reboots. During reboot, the system applies the Ignition config file that you specified.
  9. Check the console output to verify that Ignition ran.

    Example command

    Ignition: ran on 2022/03/14 14:48:33 UTC (this boot)
    Ignition: user-provided config was applied

  10. Continue to create the machines for your cluster.

    Important

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, also create at least two compute machines before you install the cluster.

    If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted.

    Note

    RHCOS nodes do not include a default password for the core user. You can access the nodes by running ssh core@<node>.<cluster_name>.<base_domain> as a user with access to the SSH private key that is paired to the public key that you specified in your install_config.yaml file. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.

2.2.15.3. Advanced RHCOS installation configuration

A key benefit for manually provisioning the Red Hat Enterprise Linux CoreOS (RHCOS) nodes for OpenShift Container Platform is to be able to do configuration that is not available through default OpenShift Container Platform installation methods. This section describes some of the configurations that you can do using techniques that include:

  • Passing kernel arguments to the live installer
  • Running coreos-installer manually from the live system
  • Customizing a live ISO or PXE boot image

The advanced configuration topics for manual Red Hat Enterprise Linux CoreOS (RHCOS) installations detailed in this section relate to disk partitioning, networking, and using Ignition configs in different ways.

2.2.15.3.1. Using advanced networking options for PXE and ISO installations

Networking for OpenShift Container Platform nodes uses DHCP by default to gather all necessary configuration settings. To set up static IP addresses or configure special settings, such as bonding, you can do one of the following:

  • Pass special kernel parameters when you boot the live installer.
  • Use a machine config to copy networking files to the installed system.
  • Configure networking from a live installer shell prompt, then copy those settings to the installed system so that they take effect when the installed system first boots.

To configure a PXE or iPXE installation, use one of the following options:

  • See the "Advanced RHCOS installation reference" tables.
  • Use a machine config to copy networking files to the installed system.

To configure an ISO installation, use the following procedure.

Procedure

  1. Boot the ISO installer.
  2. From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.
  3. Run the coreos-installer command to install the system, adding the --copy-network option to copy networking configuration. For example:

    $ sudo coreos-installer install --copy-network \
         --ignition-url=http://host/worker.ign /dev/disk/by-id/scsi-<serial_number>
    Important

    The --copy-network option only copies networking configuration found under /etc/NetworkManager/system-connections. In particular, it does not copy the system hostname.

  4. Reboot into the installed system.

Additional resources

2.2.15.3.2. Disk partitioning

Disk partitions are created on OpenShift Container Platform cluster nodes during the Red Hat Enterprise Linux CoreOS (RHCOS) installation. Each RHCOS node of a particular architecture uses the same partition layout, unless you override the default partitioning configuration. During the RHCOS installation, the size of the root file system is increased to use any remaining available space on the target device.

Important

The use of a custom partition scheme on your node might result in OpenShift Container Platform not monitoring or alerting on some node partitions. If you override the default partitioning, see Understanding OpenShift File System Monitoring (eviction conditions) for more information about how OpenShift Container Platform monitors your host file systems.

OpenShift Container Platform monitors the following two filesystem identifiers:

  • nodefs, which is the filesystem that contains /var/lib/kubelet
  • imagefs, which is the filesystem that contains /var/lib/containers

For the default partition scheme, nodefs and imagefs monitor the same root filesystem, /.

To override the default partitioning when installing RHCOS on an OpenShift Container Platform cluster node, you must create separate partitions. Consider a situation where you want to add a separate storage partition for your containers and container images. For example, by mounting /var/lib/containers in a separate partition, the kubelet separately monitors /var/lib/containers as the imagefs directory and the root file system as the nodefs directory.

Important

If you have resized your disk size to host a larger file system, consider creating a separate /var/lib/containers partition. Consider resizing a disk that has an xfs format to reduce CPU time issues caused by a high number of allocation groups.

2.2.15.3.2.1. Creating a separate /var partition

In general, you should use the default disk partitioning that is created during the RHCOS installation. However, there are cases where you might want to create a separate partition for a directory that you expect to grow.

OpenShift Container Platform supports the addition of a single partition to attach storage to either the /var directory or a subdirectory of /var. For example:

  • /var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system.
  • /var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage.
  • /var: Holds data that you might want to keep separate for purposes such as auditing.

    Important

    For disk sizes larger than 100GB, and especially larger than 1TB, create a separate /var partition.

Storing the contents of a /var directory separately makes it easier to grow storage for those areas as needed and reinstall OpenShift Container Platform at a later date and keep that data intact. With this method, you will not have to pull all your containers again, nor will you have to copy massive log files when you update systems.

The use of a separate partition for the /var directory or a subdirectory of /var also prevents data growth in the partitioned directory from filling up the root file system.

The following procedure sets up a separate /var partition by adding a machine config manifest that is wrapped into the Ignition config file for a node type during the preparation phase of an installation.

Procedure

  1. On your installation host, change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster:

    $ openshift-install create manifests --dir <installation_directory>
  2. Create a Butane config that configures the additional partition. For example, name the file $HOME/clusterconfig/98-var-partition.bu, change the disk device name to the name of the storage device on the worker systems, and set the storage size as appropriate. This example places the /var directory on a separate partition:

    variant: openshift
    version: 4.18.0
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker
      name: 98-var-partition
    storage:
      disks:
      - device: /dev/disk/by-id/<device_name> 1
        partitions:
        - label: var
          start_mib: <partition_start_offset> 2
          size_mib: <partition_size> 3
          number: 5
      filesystems:
        - device: /dev/disk/by-partlabel/var
          path: /var
          format: xfs
          mount_options: [defaults, prjquota] 4
          with_mount_unit: true
    1
    The storage device name of the disk that you want to partition.
    2
    When adding a data partition to the boot disk, a minimum offset value of 25000 mebibytes is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no offset value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of RHCOS might overwrite the beginning of the data partition.
    3
    The size of the data partition in mebibytes.
    4
    The prjquota mount option must be enabled for filesystems used for container storage.
    Note

    When creating a separate /var partition, you cannot use different instance types for compute nodes, if the different instance types do not have the same device name.

  3. Create a manifest from the Butane config and save it to the clusterconfig/openshift directory. For example, run the following command:

    $ butane $HOME/clusterconfig/98-var-partition.bu -o $HOME/clusterconfig/openshift/98-var-partition.yaml
  4. Create the Ignition config files:

    $ openshift-install create ignition-configs --dir <installation_directory> 1
    1
    For <installation_directory>, specify the same installation directory.

    Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign

    The files in the <installation_directory>/manifest and <installation_directory>/openshift directories are wrapped into the Ignition config files, including the file that contains the 98-var-partition custom MachineConfig object.

Next steps

  • You can apply the custom disk partitioning by referencing the Ignition config files during the RHCOS installations.
2.2.15.3.2.2. Retaining existing partitions

For an ISO installation, you can add options to the coreos-installer command that cause the installer to maintain one or more existing partitions. For a PXE installation, you can add coreos.inst.* options to the APPEND parameter to preserve partitions.

Saved partitions might be data partitions from an existing OpenShift Container Platform system. You can identify the disk partitions you want to keep either by partition label or by number.

Note

If you save existing partitions, and those partitions do not leave enough space for RHCOS, the installation will fail without damaging the saved partitions.

Retaining existing partitions during an ISO installation

This example preserves any partition in which the partition label begins with data (data*):

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partlabel 'data*' /dev/disk/by-id/scsi-<serial_number>

The following example illustrates running the coreos-installer in a way that preserves the sixth (6) partition on the disk:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partindex 6 /dev/disk/by-id/scsi-<serial_number>

This example preserves partitions 5 and higher:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign
        --save-partindex 5- /dev/disk/by-id/scsi-<serial_number>

In the previous examples where partition saving is used, coreos-installer recreates the partition immediately.

Retaining existing partitions during a PXE installation

This APPEND option preserves any partition in which the partition label begins with 'data' ('data*'):

coreos.inst.save_partlabel=data*

This APPEND option preserves partitions 5 and higher:

coreos.inst.save_partindex=5-

This APPEND option preserves partition 6:

coreos.inst.save_partindex=6
2.2.15.3.3. Identifying Ignition configs

When doing an RHCOS manual installation, there are two types of Ignition configs that you can provide, with different reasons for providing each one:

  • Permanent install Ignition config: Every manual RHCOS installation needs to pass one of the Ignition config files generated by openshift-installer, such as bootstrap.ign, master.ign and worker.ign, to carry out the installation.

    Important

    It is not recommended to modify these Ignition config files directly. You can update the manifest files that are wrapped into the Ignition config files, as outlined in examples in the preceding sections.

    For PXE installations, you pass the Ignition configs on the APPEND line using the coreos.inst.ignition_url= option. For ISO installations, after the ISO boots to the shell prompt, you identify the Ignition config on the coreos-installer command line with the --ignition-url= option. In both cases, only HTTP and HTTPS protocols are supported.

  • Live install Ignition config: This type can be created by using the coreos-installer customize subcommand and its various options. With this method, the Ignition config passes to the live install medium, runs immediately upon booting, and performs setup tasks before or after the RHCOS system installs to disk. This method should only be used for performing tasks that must be done once and not applied again later, such as with advanced partitioning that cannot be done using a machine config.

    For PXE or ISO boots, you can create the Ignition config and APPEND the ignition.config.url= option to identify the location of the Ignition config. You also need to append ignition.firstboot ignition.platform.id=metal or the ignition.config.url option will be ignored.

2.2.15.3.4. Default console configuration

Red Hat Enterprise Linux CoreOS (RHCOS) nodes installed from an OpenShift Container Platform 4.18 boot image use a default console that is meant to accomodate most virtualized and bare metal setups. Different cloud and virtualization platforms may use different default settings depending on the chosen architecture. Bare metal installations use the kernel default settings which typically means the graphical console is the primary console and the serial console is disabled.

The default consoles may not match your specific hardware configuration or you might have specific needs that require you to adjust the default console. For example:

  • You want to access the emergency shell on the console for debugging purposes.
  • Your cloud platform does not provide interactive access to the graphical console, but provides a serial console.
  • You want to enable multiple consoles.

Console configuration is inherited from the boot image. This means that new nodes in existing clusters are unaffected by changes to the default console.

You can configure the console for bare metal installations in the following ways:

  • Using coreos-installer manually on the command line.
  • Using the coreos-installer iso customize or coreos-installer pxe customize subcommands with the --dest-console option to create a custom image that automates the process.
Note

For advanced customization, perform console configuration using the coreos-installer iso or coreos-installer pxe subcommands, and not kernel arguments.

2.2.15.3.5. Enabling the serial console for PXE and ISO installations

By default, the Red Hat Enterprise Linux CoreOS (RHCOS) serial console is disabled and all output is written to the graphical console. You can enable the serial console for an ISO installation and reconfigure the bootloader so that output is sent to both the serial console and the graphical console.

Procedure

  1. Boot the ISO installer.
  2. Run the coreos-installer command to install the system, adding the --console option once to specify the graphical console, and a second time to specify the serial console:

    $ coreos-installer install \
      --console=tty0 \1
      --console=ttyS0,<options> \2
      --ignition-url=http://host/worker.ign /dev/disk/by-id/scsi-<serial_number>
    1
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    2
    The desired primary console. In this case the serial console. The options field defines the baud rate and other settings. A common value for this field is 11520n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see Linux kernel serial console documentation.
  3. Reboot into the installed system.

    Note

    A similar outcome can be obtained by using the coreos-installer install --append-karg option, and specifying the console with console=. However, this will only set the console for the kernel and not the bootloader.

To configure a PXE installation, make sure the coreos.inst.install_dev kernel command line option is omitted, and use the shell prompt to run coreos-installer manually using the above ISO installation procedure.

2.2.15.3.6. Customizing a live RHCOS ISO or PXE install

You can use the live ISO image or PXE environment to install RHCOS by injecting an Ignition config file directly into the image. This creates a customized image that you can use to provision your system.

For an ISO image, the mechanism to do this is the coreos-installer iso customize subcommand, which modifies the .iso file with your configuration. Similarly, the mechanism for a PXE environment is the coreos-installer pxe customize subcommand, which creates a new initramfs file that includes your customizations.

The customize subcommand is a general purpose tool that can embed other types of customizations as well. The following tasks are examples of some of the more common customizations:

  • Inject custom CA certificates for when corporate security policy requires their use.
  • Configure network settings without the need for kernel arguments.
  • Embed arbitrary preinstall and post-install scripts or binaries.
2.2.15.3.7. Customizing a live RHCOS ISO image

You can customize a live RHCOS ISO image directly with the coreos-installer iso customize subcommand. When you boot the ISO image, the customizations are applied automatically.

You can use this feature to configure the ISO image to automatically install RHCOS.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and the Ignition config file, and then run the following command to inject the Ignition config directly into the ISO image:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
        --dest-ignition bootstrap.ign \ 1
        --dest-device /dev/disk/by-id/scsi-<serial_number> 2
    1
    The Ignition config file that is generated from the openshift-installer installation program.
    2
    When you specify this option, the ISO image automatically runs an installation. Otherwise, the image remains configured for installation, but does not install automatically unless you specify the coreos.inst.install_dev kernel argument.
  3. Optional: To remove the ISO image customizations and return the image to its pristine state, run:

    $ coreos-installer iso reset rhcos-<version>-live.x86_64.iso

    You can now re-customize the live ISO image or use it in its pristine state.

Applying your customizations affects every subsequent boot of RHCOS.

2.2.15.3.7.1. Modifying a live install ISO image to enable the serial console

On clusters installed with OpenShift Container Platform 4.12 and above, the serial console is disabled by default and all output is written to the graphical console. You can enable the serial console with the following procedure.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image to enable the serial console to receive output:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
      --dest-ignition <path> \1
      --dest-console tty0 \2
      --dest-console ttyS0,<options> \3
      --dest-device /dev/disk/by-id/scsi-<serial_number> 4
    1
    The location of the Ignition config to install.
    2
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    3
    The desired primary console. In this case, the serial console. The options field defines the baud rate and other settings. A common value for this field is 115200n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see the Linux kernel serial console documentation.
    4
    The specified disk to install to. If you omit this option, the ISO image automatically runs the installation program which will fail unless you also specify the coreos.inst.install_dev kernel argument.
    Note

    The --dest-console option affects the installed system and not the live ISO system. To modify the console for a live ISO system, use the --live-karg-append option and specify the console with console=.

    Your customizations are applied and affect every subsequent boot of the ISO image.

  3. Optional: To remove the ISO image customizations and return the image to its original state, run the following command:

    $ coreos-installer iso reset rhcos-<version>-live.x86_64.iso

    You can now recustomize the live ISO image or use it in its original state.

2.2.15.3.7.2. Modifying a live install ISO image to use a custom certificate authority

You can provide certificate authority (CA) certificates to Ignition with the --ignition-ca flag of the customize subcommand. You can use the CA certificates during both the installation boot and when provisioning the installed system.

Note

Custom CA certificates affect how Ignition fetches remote resources but they do not affect the certificates installed onto the system.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image for use with a custom CA:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso --ignition-ca cert.pem
Important

The coreos.inst.ignition_url kernel parameter does not work with the --ignition-ca flag. You must use the --dest-ignition flag to create a customized image for each cluster.

Applying your custom CA certificate affects every subsequent boot of RHCOS.

2.2.15.3.7.3. Modifying a live install ISO image with customized network settings

You can embed a NetworkManager keyfile into the live ISO image and pass it through to the installed system with the --network-keyfile flag of the customize subcommand.

Warning

When creating a connection profile, you must use a .nmconnection filename extension in the filename of the connection profile. If you do not use a .nmconnection filename extension, the cluster will apply the connection profile to the live environment, but it will not apply the configuration when the cluster first boots up the nodes, resulting in a setup that does not work.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Create a connection profile for a bonded interface. For example, create the bond0.nmconnection file in your local directory with the following content:

    [connection]
    id=bond0
    type=bond
    interface-name=bond0
    multi-connect=1
    
    [bond]
    miimon=100
    mode=active-backup
    
    [ipv4]
    method=auto
    
    [ipv6]
    method=auto
  3. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em1.nmconnection file in your local directory with the following content:

    [connection]
    id=em1
    type=ethernet
    interface-name=em1
    master=bond0
    multi-connect=1
    slave-type=bond
  4. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em2.nmconnection file in your local directory with the following content:

    [connection]
    id=em2
    type=ethernet
    interface-name=em2
    master=bond0
    multi-connect=1
    slave-type=bond
  5. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with your configured networking:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
        --network-keyfile bond0.nmconnection \
        --network-keyfile bond0-proxy-em1.nmconnection \
        --network-keyfile bond0-proxy-em2.nmconnection

    Network settings are applied to the live system and are carried over to the destination system.

2.2.15.3.7.4. Customizing a live install ISO image for an iSCSI boot device

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with the following information:

    $ coreos-installer iso customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/disk/by-path/<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.initiator=<initiator_iqn> \ 5
        --dest-karg-append netroot=<target_iqn> \ 6
        -o custom.iso rhcos-<version>-live.x86_64.iso
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The location of the destination system. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    6
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.2.15.3.7.5. Customizing a live install ISO image for an iSCSI boot device with iBFT

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.
  2. Optional: you have multipathed your iSCSI target.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with the following information:

    $ coreos-installer iso customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/mapper/mpatha \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.firmware=1 \ 5
        --dest-karg-append rd.multipath=default \ 6
        -o custom.iso rhcos-<version>-live.x86_64.iso
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The path to the device. If you are using multipath, the multipath device, /dev/mapper/mpatha, If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI parameter is read from the BIOS firmware.
    6
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.2.15.3.8. Customizing a live RHCOS PXE environment

You can customize a live RHCOS PXE environment directly with the coreos-installer pxe customize subcommand. When you boot the PXE environment, the customizations are applied automatically.

You can use this feature to configure the PXE environment to automatically install RHCOS.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and the Ignition config file, and then run the following command to create a new initramfs file that contains the customizations from your Ignition config:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --dest-ignition bootstrap.ign \ 1
        --dest-device /dev/disk/by-id/scsi-<serial_number> \ 2
        -o rhcos-<version>-custom-initramfs.x86_64.img 3
    1
    The Ignition config file that is generated from openshift-installer.
    2
    When you specify this option, the PXE environment automatically runs an install. Otherwise, the image remains configured for installing, but does not do so automatically unless you specify the coreos.inst.install_dev kernel argument.
    3
    Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

Applying your customizations affects every subsequent boot of RHCOS.

2.2.15.3.8.1. Modifying a live install PXE environment to enable the serial console

On clusters installed with OpenShift Container Platform 4.12 and above, the serial console is disabled by default and all output is written to the graphical console. You can enable the serial console with the following procedure.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and the Ignition config file, and then run the following command to create a new customized initramfs file that enables the serial console to receive output:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
      --dest-ignition <path> \1
      --dest-console tty0 \2
      --dest-console ttyS0,<options> \3
      --dest-device /dev/disk/by-id/scsi-<serial_number> \4
      -o rhcos-<version>-custom-initramfs.x86_64.img 5
    1
    The location of the Ignition config to install.
    2
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    3
    The desired primary console. In this case, the serial console. The options field defines the baud rate and other settings. A common value for this field is 115200n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see the Linux kernel serial console documentation.
    4
    The specified disk to install to. If you omit this option, the PXE environment automatically runs the installer which will fail unless you also specify the coreos.inst.install_dev kernel argument.
    5
    Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

    Your customizations are applied and affect every subsequent boot of the PXE environment.

2.2.15.3.8.2. Modifying a live install PXE environment to use a custom certificate authority

You can provide certificate authority (CA) certificates to Ignition with the --ignition-ca flag of the customize subcommand. You can use the CA certificates during both the installation boot and when provisioning the installed system.

Note

Custom CA certificates affect how Ignition fetches remote resources but they do not affect the certificates installed onto the system.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file for use with a custom CA:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --ignition-ca cert.pem \
        -o rhcos-<version>-custom-initramfs.x86_64.img
  3. Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.
Important

The coreos.inst.ignition_url kernel parameter does not work with the --ignition-ca flag. You must use the --dest-ignition flag to create a customized image for each cluster.

Applying your custom CA certificate affects every subsequent boot of RHCOS.

2.2.15.3.8.3. Modifying a live install PXE environment with customized network settings

You can embed a NetworkManager keyfile into the live PXE environment and pass it through to the installed system with the --network-keyfile flag of the customize subcommand.

Warning

When creating a connection profile, you must use a .nmconnection filename extension in the filename of the connection profile. If you do not use a .nmconnection filename extension, the cluster will apply the connection profile to the live environment, but it will not apply the configuration when the cluster first boots up the nodes, resulting in a setup that does not work.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Create a connection profile for a bonded interface. For example, create the bond0.nmconnection file in your local directory with the following content:

    [connection]
    id=bond0
    type=bond
    interface-name=bond0
    multi-connect=1
    
    [bond]
    miimon=100
    mode=active-backup
    
    [ipv4]
    method=auto
    
    [ipv6]
    method=auto
  3. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em1.nmconnection file in your local directory with the following content:

    [connection]
    id=em1
    type=ethernet
    interface-name=em1
    master=bond0
    multi-connect=1
    slave-type=bond
  4. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em2.nmconnection file in your local directory with the following content:

    [connection]
    id=em2
    type=ethernet
    interface-name=em2
    master=bond0
    multi-connect=1
    slave-type=bond
  5. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file that contains your configured networking:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --network-keyfile bond0.nmconnection \
        --network-keyfile bond0-proxy-em1.nmconnection \
        --network-keyfile bond0-proxy-em2.nmconnection \
        -o rhcos-<version>-custom-initramfs.x86_64.img
  6. Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

    Network settings are applied to the live system and are carried over to the destination system.

2.2.15.3.8.4. Customizing a live install PXE environment for an iSCSI boot device

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file with the following information:

    $ coreos-installer pxe customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/disk/by-path/<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.initiator=<initiator_iqn> \ 5
        --dest-karg-append netroot=<target_iqn> \ 6
        -o custom.img rhcos-<version>-live-initramfs.x86_64.img
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The location of the destination system. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    6
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.2.15.3.8.5. Customizing a live install PXE environment for an iSCSI boot device with iBFT

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.
  2. Optional: you have multipathed your iSCSI target.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file with the following information:

    $ coreos-installer pxe customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/mapper/mpatha \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.firmware=1 \ 5
        --dest-karg-append rd.multipath=default \ 6
        -o custom.img rhcos-<version>-live-initramfs.x86_64.img
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The path to the device. If you are using multipath, the multipath device, /dev/mapper/mpatha, If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI parameter is read from the BIOS firmware.
    6
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.2.15.3.9. Advanced RHCOS installation reference

This section illustrates the networking configuration and other advanced options that allow you to modify the Red Hat Enterprise Linux CoreOS (RHCOS) manual installation process. The following tables describe the kernel arguments and command-line options you can use with the RHCOS live installer and the coreos-installer command.

2.2.15.3.9.1. Networking and bonding options for ISO installations

If you install RHCOS from an ISO image, you can add kernel arguments manually when you boot the image to configure networking for a node. If no networking arguments are specified, DHCP is activated in the initramfs when RHCOS detects that networking is required to fetch the Ignition config file.

Important

When adding networking arguments manually, you must also add the rd.neednet=1 kernel argument to bring the network up in the initramfs.

The following information provides examples for configuring networking and bonding on your RHCOS nodes for ISO installations. The examples describe how to use the ip=, nameserver=, and bond= kernel arguments.

Note

Ordering is important when adding the kernel arguments: ip=, nameserver=, and then bond=.

The networking options are passed to the dracut tool during system boot. For more information about the networking options supported by dracut, see the dracut.cmdline manual page.

The following examples are the networking options for ISO installation.

Configuring DHCP or static IP addresses

To configure an IP address, either use DHCP (ip=dhcp) or set an individual static IP address (ip=<host_ip>). If setting a static IP, you must then identify the DNS server IP address (nameserver=<dns_ip>) on each node. The following example sets:

  • The node’s IP address to 10.10.10.2
  • The gateway address to 10.10.10.254
  • The netmask to 255.255.255.0
  • The hostname to core0.example.com
  • The DNS server address to 4.4.4.41
  • The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
nameserver=4.4.4.41
Note

When you use DHCP to configure IP addressing for the RHCOS machines, the machines also obtain the DNS server information through DHCP. For DHCP-based deployments, you can define the DNS server address that is used by the RHCOS nodes through your DHCP server configuration.

Configuring an IP address without a static hostname

You can configure an IP address without assigning a static hostname. If a static hostname is not set by the user, it will be picked up and automatically set by a reverse DNS lookup. To configure an IP address without a static hostname refer to the following example:

  • The node’s IP address to 10.10.10.2
  • The gateway address to 10.10.10.254
  • The netmask to 255.255.255.0
  • The DNS server address to 4.4.4.41
  • The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0::enp1s0:none
nameserver=4.4.4.41
Specifying multiple network interfaces

You can specify multiple network interfaces by setting multiple ip= entries.

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
Configuring default gateway and route

Optional: You can configure routes to additional networks by setting an rd.route= value.

Note

When you configure one or multiple networks, one default gateway is required. If the additional network gateway is different from the primary network gateway, the default gateway must be the primary network gateway.

  • Run the following command to configure the default gateway:

    ip=::10.10.10.254::::
  • Enter the following command to configure the route for the additional network:

    rd.route=20.20.20.0/24:20.20.20.254:enp2s0
Disabling DHCP on a single interface

You can disable DHCP on a single interface, such as when there are two or more network interfaces and only one interface is being used. In the example, the enp1s0 interface has a static networking configuration and DHCP is disabled for enp2s0, which is not used:

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=::::core0.example.com:enp2s0:none
Combining DHCP and static IP configurations

You can combine DHCP and static IP configurations on systems with multiple network interfaces, for example:

ip=enp1s0:dhcp
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
Configuring VLANs on individual interfaces

Optional: You can configure VLANs on individual interfaces by using the vlan= parameter.

  • To configure a VLAN on a network interface and use a static IP address, run the following command:

    ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0.100:none
    vlan=enp2s0.100:enp2s0
  • To configure a VLAN on a network interface and to use DHCP, run the following command:

    ip=enp2s0.100:dhcp
    vlan=enp2s0.100:enp2s0
Providing multiple DNS servers

You can provide multiple DNS servers by adding a nameserver= entry for each server, for example:

nameserver=1.1.1.1
nameserver=8.8.8.8
Bonding multiple network interfaces to a single interface

Optional: You can bond multiple network interfaces to a single interface by using the bond= option. Refer to the following examples:

  • The syntax for configuring a bonded interface is: bond=<name>[:<network_interfaces>][:options]

    <name> is the bonding device name (bond0), <network_interfaces> represents a comma-separated list of physical (ethernet) interfaces (em1,em2), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.

  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

    • To configure the bonded interface to use DHCP, set the bond’s IP address to dhcp. For example:

      bond=bond0:em1,em2:mode=active-backup
      ip=bond0:dhcp
    • To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:

      bond=bond0:em1,em2:mode=active-backup
      ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Bonding multiple SR-IOV network interfaces to a dual port NIC interface

Optional: You can bond multiple SR-IOV network interfaces to a dual port NIC interface by using the bond= option.

On each node, you must perform the following tasks:

  1. Create the SR-IOV virtual functions (VFs) following the guidance in Managing SR-IOV devices. Follow the procedure in the "Attaching SR-IOV networking devices to virtual machines" section.
  2. Create the bond, attach the desired VFs to the bond and set the bond link state up following the guidance in Configuring network bonding. Follow any of the described procedures to create the bond.

The following examples illustrate the syntax you must use:

  • The syntax for configuring a bonded interface is bond=<name>[:<network_interfaces>][:options].

    <name> is the bonding device name (bond0), <network_interfaces> represents the virtual functions (VFs) by their known name in the kernel and shown in the output of the ip link command(eno1f0, eno2f0), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.

  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

    • To configure the bonded interface to use DHCP, set the bond’s IP address to dhcp. For example:

      bond=bond0:eno1f0,eno2f0:mode=active-backup
      ip=bond0:dhcp
    • To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:

      bond=bond0:eno1f0,eno2f0:mode=active-backup
      ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Using network teaming

Optional: You can use a network teaming as an alternative to bonding by using the team= parameter:

  • The syntax for configuring a team interface is: team=name[:network_interfaces]

    name is the team device name (team0) and network_interfaces represents a comma-separated list of physical (ethernet) interfaces (em1, em2).

Note

Teaming is planned to be deprecated when RHCOS switches to an upcoming version of RHEL. For more information, see this Red Hat Knowledgebase Article.

Use the following example to configure a network team:

team=team0:em1,em2
ip=team0:dhcp
2.2.15.3.9.2. coreos-installer options for ISO and PXE installations

You can install RHCOS by running coreos-installer install <options> <device> at the command prompt, after booting into the RHCOS live environment from an ISO image.

The following table shows the subcommands, options, and arguments you can pass to the coreos-installer command.

Table 2.29. coreos-installer subcommands, command-line options, and arguments

coreos-installer install subcommand

Subcommand

Description

$ coreos-installer install <options> <device>

Embed an Ignition config in an ISO image.

coreos-installer install subcommand options

Option

Description

-u, --image-url <url>

Specify the image URL manually.

-f, --image-file <path>

Specify a local image file manually. Used for debugging.

-i, --ignition-file <path>

Embed an Ignition config from a file.

-I, --ignition-url <URL>

Embed an Ignition config from a URL.

--ignition-hash <digest>

Digest type-value of the Ignition config.

-p, --platform <name>

Override the Ignition platform ID for the installed system.

--console <spec>

Set the kernel and bootloader console for the installed system. For more information about the format of <spec>, see the Linux kernel serial console documentation.

--append-karg <arg>…​

Append a default kernel argument to the installed system.

--delete-karg <arg>…​

Delete a default kernel argument from the installed system.

-n, --copy-network

Copy the network configuration from the install environment.

Important

The --copy-network option only copies networking configuration found under /etc/NetworkManager/system-connections. In particular, it does not copy the system hostname.

--network-dir <path>

For use with -n. Default is /etc/NetworkManager/system-connections/.

--save-partlabel <lx>..

Save partitions with this label glob.

--save-partindex <id>…​

Save partitions with this number or range.

--insecure

Skip RHCOS image signature verification.

--insecure-ignition

Allow Ignition URL without HTTPS or hash.

--architecture <name>

Target CPU architecture. Valid values are x86_64 and aarch64.

--preserve-on-error

Do not clear partition table on error.

-h, --help

Print help information.

coreos-installer install subcommand argument

Argument

Description

<device>

The destination device.

coreos-installer ISO subcommands

Subcommand

Description

$ coreos-installer iso customize <options> <ISO_image>

Customize a RHCOS live ISO image.

coreos-installer iso reset <options> <ISO_image>

Restore a RHCOS live ISO image to default settings.

coreos-installer iso ignition remove <options> <ISO_image>

Remove the embedded Ignition config from an ISO image.

coreos-installer ISO customize subcommand options

Option

Description

--dest-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the destination system.

--dest-console <spec>

Specify the kernel and bootloader console for the destination system.

--dest-device <path>

Install and overwrite the specified destination device.

--dest-karg-append <arg>

Add a kernel argument to each boot of the destination system.

--dest-karg-delete <arg>

Delete a kernel argument from each boot of the destination system.

--network-keyfile <path>

Configure networking by using the specified NetworkManager keyfile for live and destination systems.

--ignition-ca <path>

Specify an additional TLS certificate authority to be trusted by Ignition.

--pre-install <path>

Run the specified script before installation.

--post-install <path>

Run the specified script after installation.

--installer-config <path>

Apply the specified installer configuration file.

--live-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the live environment.

--live-karg-append <arg>

Add a kernel argument to each boot of the live environment.

--live-karg-delete <arg>

Delete a kernel argument from each boot of the live environment.

--live-karg-replace <k=o=n>

Replace a kernel argument in each boot of the live environment, in the form key=old=new.

-f, --force

Overwrite an existing Ignition config.

-o, --output <path>

Write the ISO to a new output file.

-h, --help

Print help information.

coreos-installer PXE subcommands

Subcommand

Description

Note that not all of these options are accepted by all subcommands.

coreos-installer pxe customize <options> <path>

Customize a RHCOS live PXE boot config.

coreos-installer pxe ignition wrap <options>

Wrap an Ignition config in an image.

coreos-installer pxe ignition unwrap <options> <image_name>

Show the wrapped Ignition config in an image.

coreos-installer PXE customize subcommand options

Option

Description

Note that not all of these options are accepted by all subcommands.

--dest-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the destination system.

--dest-console <spec>

Specify the kernel and bootloader console for the destination system.

--dest-device <path>

Install and overwrite the specified destination device.

--network-keyfile <path>

Configure networking by using the specified NetworkManager keyfile for live and destination systems.

--ignition-ca <path>

Specify an additional TLS certificate authority to be trusted by Ignition.

--pre-install <path>

Run the specified script before installation.

post-install <path>

Run the specified script after installation.

--installer-config <path>

Apply the specified installer configuration file.

--live-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the live environment.

-o, --output <path>

Write the initramfs to a new output file.

Note

This option is required for PXE environments.

-h, --help

Print help information.

2.2.15.3.9.3. coreos.inst boot options for ISO or PXE installations

You can automatically invoke coreos-installer options at boot time by passing coreos.inst boot arguments to the RHCOS live installer. These are provided in addition to the standard boot arguments.

  • For ISO installations, the coreos.inst options can be added by interrupting the automatic boot at the bootloader menu. You can interrupt the automatic boot by pressing TAB while the RHEL CoreOS (Live) menu option is highlighted.
  • For PXE or iPXE installations, the coreos.inst options must be added to the APPEND line before the RHCOS live installer is booted.

The following table shows the RHCOS live installer coreos.inst boot options for ISO and PXE installations.

Table 2.30. coreos.inst boot options
ArgumentDescription

coreos.inst.install_dev

Required. The block device on the system to install to. It is recommended to use the full path, such as /dev/sda, although sda is allowed.

coreos.inst.ignition_url

Optional: The URL of the Ignition config to embed into the installed system. If no URL is specified, no Ignition config is embedded. Only HTTP and HTTPS protocols are supported.

coreos.inst.save_partlabel

Optional: Comma-separated labels of partitions to preserve during the install. Glob-style wildcards are permitted. The specified partitions do not need to exist.

coreos.inst.save_partindex

Optional: Comma-separated indexes of partitions to preserve during the install. Ranges m-n are permitted, and either m or n can be omitted. The specified partitions do not need to exist.

coreos.inst.insecure

Optional: Permits the OS image that is specified by coreos.inst.image_url to be unsigned.

coreos.inst.image_url

Optional: Download and install the specified RHCOS image.

  • This argument should not be used in production environments and is intended for debugging purposes only.
  • While this argument can be used to install a version of RHCOS that does not match the live media, it is recommended that you instead use the media that matches the version you want to install.
  • If you are using coreos.inst.image_url, you must also use coreos.inst.insecure. This is because the bare-metal media are not GPG-signed for OpenShift Container Platform.
  • Only HTTP and HTTPS protocols are supported.

coreos.inst.skip_reboot

Optional: The system will not reboot after installing. After the install finishes, you will receive a prompt that allows you to inspect what is happening during installation. This argument should not be used in production environments and is intended for debugging purposes only.

coreos.inst.platform_id

Optional: The Ignition platform ID of the platform the RHCOS image is being installed on. Default is metal. This option determines whether or not to request an Ignition config from the cloud provider, such as VMware. For example: coreos.inst.platform_id=vmware.

ignition.config.url

Optional: The URL of the Ignition config for the live boot. For example, this can be used to customize how coreos-installer is invoked, or to run code before or after the installation. This is different from coreos.inst.ignition_url, which is the Ignition config for the installed system.

2.2.15.4. Enabling multipathing with kernel arguments on RHCOS

RHCOS supports multipathing on the primary disk, allowing stronger resilience to hardware failure to achieve higher host availability.

You can enable multipathing at installation time for nodes that were provisioned in OpenShift Container Platform 4.8 or later. While postinstallation support is available by activating multipathing via the machine config, enabling multipathing during installation is recommended.

In setups where any I/O to non-optimized paths results in I/O system errors, you must enable multipathing at installation time.

Important

On IBM Z® and IBM® LinuxONE, you can enable multipathing only if you configured your cluster for it during installation. For more information, see "Installing RHCOS and starting the OpenShift Container Platform bootstrap process" in Installing a cluster with z/VM on IBM Z® and IBM® LinuxONE.

The following procedure enables multipath at installation time and appends kernel arguments to the coreos-installer install command so that the installed system itself will use multipath beginning from the first boot.

Note

OpenShift Container Platform does not support enabling multipathing as a day-2 activity on nodes that have been upgraded from 4.6 or earlier.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have reviewed Installing RHCOS and starting the OpenShift Container Platform bootstrap process.

Procedure

  1. To enable multipath and start the multipathd daemon, run the following command on the installation host:

    $ mpathconf --enable && systemctl start multipathd.service
    • Optional: If booting the PXE or ISO, you can instead enable multipath by adding rd.multipath=default from the kernel command line.
  2. Append the kernel arguments by invoking the coreos-installer program:

    • If there is only one multipath device connected to the machine, it should be available at path /dev/mapper/mpatha. For example:

      $ coreos-installer install /dev/mapper/mpatha \1
      --ignition-url=http://host/worker.ign \
      --append-karg rd.multipath=default \
      --append-karg root=/dev/disk/by-label/dm-mpath-root \
      --append-karg rw
      1
      Indicates the path of the single multipathed device.
    • If there are multiple multipath devices connected to the machine, or to be more explicit, instead of using /dev/mapper/mpatha, it is recommended to use the World Wide Name (WWN) symlink available in /dev/disk/by-id. For example:

      $ coreos-installer install /dev/disk/by-id/wwn-<wwn_ID> \1
      --ignition-url=http://host/worker.ign \
      --append-karg rd.multipath=default \
      --append-karg root=/dev/disk/by-label/dm-mpath-root \
      --append-karg rw
      1
      Indicates the WWN ID of the target multipathed device. For example, 0xx194e957fcedb4841.

      This symlink can also be used as the coreos.inst.install_dev kernel argument when using special coreos.inst.* arguments to direct the live installer. For more information, see "Installing RHCOS and starting the OpenShift Container Platform bootstrap process".

  3. Reboot into the installed system.
  4. Check that the kernel arguments worked by going to one of the worker nodes and listing the kernel command line arguments (in /proc/cmdline on the host):

    $ oc debug node/ip-10-0-141-105.ec2.internal

    Example output

    Starting pod/ip-10-0-141-105ec2internal-debug ...
    To use host binaries, run `chroot /host`
    
    sh-4.2# cat /host/proc/cmdline
    ...
    rd.multipath=default root=/dev/disk/by-label/dm-mpath-root
    ...
    
    sh-4.2# exit

    You should see the added kernel arguments.

2.2.15.4.1. Enabling multipathing on secondary disks

RHCOS also supports multipathing on a secondary disk. Instead of kernel arguments, you use Ignition to enable multipathing for the secondary disk at installation time.

Prerequisites

  • You have read the section Disk partitioning.
  • You have read Enabling multipathing with kernel arguments on RHCOS.
  • You have installed the Butane utility.

Procedure

  1. Create a Butane config with information similar to the following:

    Example multipath-config.bu

    variant: openshift
    version: 4.18.0
    systemd:
      units:
        - name: mpath-configure.service
          enabled: true
          contents: |
            [Unit]
            Description=Configure Multipath on Secondary Disk
            ConditionFirstBoot=true
            ConditionPathExists=!/etc/multipath.conf
            Before=multipathd.service 1
            DefaultDependencies=no
    
            [Service]
            Type=oneshot
            ExecStart=/usr/sbin/mpathconf --enable 2
    
            [Install]
            WantedBy=multi-user.target
        - name: mpath-var-lib-container.service
          enabled: true
          contents: |
            [Unit]
            Description=Set Up Multipath On /var/lib/containers
            ConditionFirstBoot=true 3
            Requires=dev-mapper-mpatha.device
            After=dev-mapper-mpatha.device
            After=ostree-remount.service
            Before=kubelet.service
            DefaultDependencies=no
    
            [Service] 4
            Type=oneshot
            ExecStart=/usr/sbin/mkfs.xfs -L containers -m reflink=1 /dev/mapper/mpatha
            ExecStart=/usr/bin/mkdir -p /var/lib/containers
    
            [Install]
            WantedBy=multi-user.target
        - name: var-lib-containers.mount
          enabled: true
          contents: |
            [Unit]
            Description=Mount /var/lib/containers
            After=mpath-var-lib-containers.service
            Before=kubelet.service 5
    
            [Mount] 6
            What=/dev/disk/by-label/dm-mpath-containers
            Where=/var/lib/containers
            Type=xfs
    
            [Install]
            WantedBy=multi-user.target

    1
    The configuration must be set before launching the multipath daemon.
    2
    Starts the mpathconf utility.
    3
    This field must be set to the value true.
    4
    Creates the filesystem and directory /var/lib/containers.
    5
    The device must be mounted before starting any nodes.
    6
    Mounts the device to the /var/lib/containers mount point. This location cannot be a symlink.
  2. Create the Ignition configuration by running the following command:

    $ butane --pretty --strict multipath-config.bu > multipath-config.ign
  3. Continue with the rest of the first boot RHCOS installation process.

    Important

    Do not add the rd.multipath or root kernel arguments on the command-line during installation unless the primary disk is also multipathed.

2.2.15.5. Installing RHCOS manually on an iSCSI boot device

You can manually install RHCOS on an iSCSI target.

Prerequisites

  1. You are in the RHCOS live environment.
  2. You have an iSCSI target that you want to install RHCOS on.

Procedure

  1. Mount the iSCSI target from the live environment by running the following command:

    $ iscsiadm \
        --mode discovery \
        --type sendtargets
        --portal <IP_address> \ 1
        --login
    1
    The IP address of the target portal.
  2. Install RHCOS onto the iSCSI target by running the following command and using the necessary kernel arguments, for example:

    $ coreos-installer install \
        /dev/disk/by-path/ip-<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 1
        --append-karg rd.iscsi.initiator=<initiator_iqn> \ 2
        --append.karg netroot=<target_iqn> \ 3
        --console ttyS0,115200n8
        --ignition-file <path_to_file>
    1
    The location you are installing to. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    2
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    3
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

  3. Unmount the iSCSI disk with the following command:

    $ iscsiadm --mode node --logoutall=all

This procedure can also be performed using the coreos-installer iso customize or coreos-installer pxe customize subcommands.

2.2.15.6. Installing RHCOS on an iSCSI boot device using iBFT

On a completely diskless machine, the iSCSI target and initiator values can be passed through iBFT. iSCSI multipathing is also supported.

Prerequisites

  1. You are in the RHCOS live environment.
  2. You have an iSCSI target you want to install RHCOS on.
  3. Optional: you have multipathed your iSCSI target.

Procedure

  1. Mount the iSCSI target from the live environment by running the following command:

    $ iscsiadm \
        --mode discovery \
        --type sendtargets
        --portal <IP_address> \ 1
        --login
    1
    The IP address of the target portal.
  2. Optional: enable multipathing and start the daemon with the following command:

    $ mpathconf --enable && systemctl start multipathd.service
  3. Install RHCOS onto the iSCSI target by running the following command and using the necessary kernel arguments, for example:

    $ coreos-installer install \
        /dev/mapper/mpatha \ 1
        --append-karg rd.iscsi.firmware=1 \ 2
        --append-karg rd.multipath=default \ 3
        --console ttyS0 \
        --ignition-file <path_to_file>
    1
    The path of a single multipathed device. If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    2
    The iSCSI parameter is read from the BIOS firmware.
    3
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

  4. Unmount the iSCSI disk:

    $ iscsiadm --mode node --logout=all

This procedure can also be performed using the coreos-installer iso customize or coreos-installer pxe customize subcommands.

2.2.16. Waiting for the bootstrap process to complete

The OpenShift Container Platform bootstrap process begins after the cluster nodes first boot into the persistent RHCOS environment that has been installed to disk. The configuration information provided through the Ignition config files is used to initialize the bootstrap process and install OpenShift Container Platform on the machines. You must wait for the bootstrap process to complete.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have obtained the installation program and generated the Ignition config files for your cluster.
  • You installed RHCOS on your cluster machines and provided the Ignition config files that the OpenShift Container Platform installation program generated.
  • Your machines have direct internet access or have an HTTP or HTTPS proxy available.

Procedure

  1. Monitor the bootstrap process:

    $ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ 1
        --log-level=info 2
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.
    2
    To view different installation details, specify warn, debug, or error instead of info.

    Example output

    INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
    INFO API v1.31.3 up
    INFO Waiting up to 30m0s for bootstrapping to complete...
    INFO It is now safe to remove the bootstrap resources

    The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.

  2. After the bootstrap process is complete, remove the bootstrap machine from the load balancer.

    Important

    You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the bootstrap machine itself.

Additional resources

2.2.17. Logging in to the cluster by using the CLI

You can log in to your cluster as a default system user by exporting the cluster kubeconfig file. The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server. The file is specific to a cluster and is created during OpenShift Container Platform installation.

Prerequisites

  • You deployed an OpenShift Container Platform cluster.
  • You installed the oc CLI.

Procedure

  1. Export the kubeadmin credentials:

    $ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.
  2. Verify you can run oc commands successfully using the exported configuration:

    $ oc whoami

    Example output

    system:admin

2.2.18. Approving the certificate signing requests for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.

Prerequisites

  • You added machines to your cluster.

Procedure

  1. Confirm that the cluster recognizes the machines:

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
    master-0  Ready     master  63m  v1.31.3
    master-1  Ready     master  63m  v1.31.3
    master-2  Ready     master  64m  v1.31.3

    The output lists all of the machines that you created.

    Note

    The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.

  2. Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

    $ oc get csr

    Example output

    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    ...

    In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

  3. If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:

    Note

    Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. After the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.

    Note

    For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the oc exec, oc rsh, and oc logs commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the node-bootstrapper service account in the system:node or system:admin groups, and confirm the identity of the node.

    • To approve them individually, run the following command for each valid CSR:

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
      Note

      Some Operators might not become available until some CSRs are approved.

  4. Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

    $ oc get csr

    Example output

    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
    csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
    ...

  5. If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:

    • To approve them individually, run the following command for each valid CSR:

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
  6. After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
    master-0  Ready     master  73m  v1.31.3
    master-1  Ready     master  73m  v1.31.3
    master-2  Ready     master  74m  v1.31.3
    worker-0  Ready     worker  11m  v1.31.3
    worker-1  Ready     worker  11m  v1.31.3

    Note

    It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

2.2.19. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

  • Your control plane has initialized.

Procedure

  1. Watch the cluster components come online:

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.18.0    True        False         False      19m
    baremetal                                  4.18.0    True        False         False      37m
    cloud-credential                           4.18.0    True        False         False      40m
    cluster-autoscaler                         4.18.0    True        False         False      37m
    config-operator                            4.18.0    True        False         False      38m
    console                                    4.18.0    True        False         False      26m
    csi-snapshot-controller                    4.18.0    True        False         False      37m
    dns                                        4.18.0    True        False         False      37m
    etcd                                       4.18.0    True        False         False      36m
    image-registry                             4.18.0    True        False         False      31m
    ingress                                    4.18.0    True        False         False      30m
    insights                                   4.18.0    True        False         False      31m
    kube-apiserver                             4.18.0    True        False         False      26m
    kube-controller-manager                    4.18.0    True        False         False      36m
    kube-scheduler                             4.18.0    True        False         False      36m
    kube-storage-version-migrator              4.18.0    True        False         False      37m
    machine-api                                4.18.0    True        False         False      29m
    machine-approver                           4.18.0    True        False         False      37m
    machine-config                             4.18.0    True        False         False      36m
    marketplace                                4.18.0    True        False         False      37m
    monitoring                                 4.18.0    True        False         False      29m
    network                                    4.18.0    True        False         False      38m
    node-tuning                                4.18.0    True        False         False      37m
    openshift-apiserver                        4.18.0    True        False         False      32m
    openshift-controller-manager               4.18.0    True        False         False      30m
    openshift-samples                          4.18.0    True        False         False      32m
    operator-lifecycle-manager                 4.18.0    True        False         False      37m
    operator-lifecycle-manager-catalog         4.18.0    True        False         False      37m
    operator-lifecycle-manager-packageserver   4.18.0    True        False         False      32m
    service-ca                                 4.18.0    True        False         False      38m
    storage                                    4.18.0    True        False         False      37m

  2. Configure the Operators that are not available.

Additional resources

2.2.19.1. Image registry removed during installation

On platforms that do not provide shareable object storage, the OpenShift Image Registry Operator bootstraps itself as Removed. This allows openshift-installer to complete installations on these platform types.

After installation, you must edit the Image Registry Operator configuration to switch the managementState from Removed to Managed. When this has completed, you must configure storage.

2.2.19.2. Image registry storage configuration

The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.

Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

2.2.19.3. Configuring block registry storage for bare metal

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Important

Block storage volumes, or block persistent volumes, are supported but not recommended for use with the image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica.

If you choose to use a block storage volume with the image registry, you must use a filesystem persistent volume claim (PVC).

Procedure

  1. Enter the following command to set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy, and runs with only one (1) replica:

    $ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
  2. Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.

    1. Create a pvc.yaml file with the following contents to define a VMware vSphere PersistentVolumeClaim object:

      kind: PersistentVolumeClaim
      apiVersion: v1
      metadata:
        name: image-registry-storage 1
        namespace: openshift-image-registry 2
      spec:
        accessModes:
        - ReadWriteOnce 3
        resources:
          requests:
            storage: 100Gi 4
      1
      A unique name that represents the PersistentVolumeClaim object.
      2
      The namespace for the PersistentVolumeClaim object, which is openshift-image-registry.
      3
      The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node.
      4
      The size of the persistent volume claim.
    2. Enter the following command to create the PersistentVolumeClaim object from the file:

      $ oc create -f pvc.yaml -n openshift-image-registry
  3. Enter the following command to edit the registry configuration so that it references the correct PVC:

    $ oc edit config.imageregistry.operator.openshift.io -o yaml

    Example output

    storage:
      pvc:
        claim: 1

    1
    By creating a custom PVC, you can leave the claim field blank for the default automatic creation of an image-registry-storage PVC.

2.2.20. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

  • Your control plane has initialized.
  • You have completed the initial Operator configuration.

Procedure

  1. Confirm that all the cluster components are online with the following command:

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.18.0    True        False         False      19m
    baremetal                                  4.18.0    True        False         False      37m
    cloud-credential                           4.18.0    True        False         False      40m
    cluster-autoscaler                         4.18.0    True        False         False      37m
    config-operator                            4.18.0    True        False         False      38m
    console                                    4.18.0    True        False         False      26m
    csi-snapshot-controller                    4.18.0    True        False         False      37m
    dns                                        4.18.0    True        False         False      37m
    etcd                                       4.18.0    True        False         False      36m
    image-registry                             4.18.0    True        False         False      31m
    ingress                                    4.18.0    True        False         False      30m
    insights                                   4.18.0    True        False         False      31m
    kube-apiserver                             4.18.0    True        False         False      26m
    kube-controller-manager                    4.18.0    True        False         False      36m
    kube-scheduler                             4.18.0    True        False         False      36m
    kube-storage-version-migrator              4.18.0    True        False         False      37m
    machine-api                                4.18.0    True        False         False      29m
    machine-approver                           4.18.0    True        False         False      37m
    machine-config                             4.18.0    True        False         False      36m
    marketplace                                4.18.0    True        False         False      37m
    monitoring                                 4.18.0    True        False         False      29m
    network                                    4.18.0    True        False         False      38m
    node-tuning                                4.18.0    True        False         False      37m
    openshift-apiserver                        4.18.0    True        False         False      32m
    openshift-controller-manager               4.18.0    True        False         False      30m
    openshift-samples                          4.18.0    True        False         False      32m
    operator-lifecycle-manager                 4.18.0    True        False         False      37m
    operator-lifecycle-manager-catalog         4.18.0    True        False         False      37m
    operator-lifecycle-manager-packageserver   4.18.0    True        False         False      32m
    service-ca                                 4.18.0    True        False         False      38m
    storage                                    4.18.0    True        False         False      37m

    Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

    $ ./openshift-install --dir <installation_directory> wait-for install-complete 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.

    Example output

    INFO Waiting up to 30m0s for the cluster to initialize...

    The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

    Important
    • The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
    • It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.
  2. Confirm that the Kubernetes API server is communicating with the pods.

    1. To view a list of all pods, use the following command:

      $ oc get pods --all-namespaces

      Example output

      NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
      openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
      openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
      openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
      openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
      openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
      ...

    2. View the logs for a pod that is listed in the output of the previous command by using the following command:

      $ oc logs <pod_name> -n <namespace> 1
      1
      Specify the pod name and namespace, as shown in the output of the previous command.

      If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

  3. For an installation with Fibre Channel Protocol (FCP), additional steps are required to enable multipathing. Do not enable multipathing during installation.

    See "Enabling multipathing with kernel arguments on RHCOS" in the Postinstallation machine configuration tasks documentation for more information.

2.2.21. Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.18, the Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to OpenShift Cluster Manager.

After you confirm that your OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually by using OpenShift Cluster Manager, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.

Additional resources

2.2.22. Next steps

2.3. Installing a user-provisioned bare metal cluster on a disconnected environment

In OpenShift Container Platform 4.18, you can install a cluster on bare metal infrastructure that you provision in a restricted network.

Important

While you might be able to follow this procedure to deploy a cluster on virtualized or cloud environments, you must be aware of additional considerations for non-bare metal platforms. Review the information in the guidelines for deploying OpenShift Container Platform on non-tested platforms before you attempt to install an OpenShift Container Platform cluster in such an environment.

2.3.1. Prerequisites

2.3.2. About installations in restricted networks

In OpenShift Container Platform 4.18, you can perform an installation that does not require an active connection to the internet to obtain software components. Restricted network installations can be completed using installer-provisioned infrastructure or user-provisioned infrastructure, depending on the cloud platform to which you are installing the cluster.

If you choose to perform a restricted network installation on a cloud platform, you still require access to its cloud APIs. Some cloud functions, like Amazon Web Service’s Route 53 DNS and IAM services, require internet access. Depending on your network, you might require less internet access for an installation on bare metal hardware, Nutanix, or on VMware vSphere.

To complete a restricted network installation, you must create a registry that mirrors the contents of the OpenShift image registry and contains the installation media. You can create this registry on a mirror host, which can access both the internet and your closed network, or by using other methods that meet your restrictions.

Important

Because of the complexity of the configuration for user-provisioned installations, consider completing a standard user-provisioned infrastructure installation before you attempt a restricted network installation using user-provisioned infrastructure. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network.

2.3.2.1. Additional limits

Clusters in restricted networks have the following additional limitations and restrictions:

  • The ClusterVersion status includes an Unable to retrieve available updates error.
  • By default, you cannot use the contents of the Developer Catalog because you cannot access the required image stream tags.

2.3.3. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.18, you require access to the internet to obtain the images that are necessary to install your cluster.

You must have internet access to:

  • Access OpenShift Cluster Manager to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.
  • Access Quay.io to obtain the packages that are required to install your cluster.
  • Obtain the packages that are required to perform cluster updates.

2.3.4. Requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

This section describes the requirements for deploying OpenShift Container Platform on user-provisioned infrastructure.

2.3.4.1. Required machines for cluster installation

The smallest OpenShift Container Platform clusters require the following hosts:

Table 2.31. Minimum required hosts
HostsDescription

One temporary bootstrap machine

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Three control plane machines

The control plane machines run the Kubernetes and OpenShift Container Platform services that form the control plane.

At least two compute machines, which are also known as worker machines.

The workloads requested by OpenShift Container Platform users run on the compute machines.

Note

As an exception, you can run zero compute machines in a bare metal cluster that consists of three control plane machines only. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for testing, development, and production. Running one compute machine is not supported.

Important

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS), Red Hat Enterprise Linux (RHEL) 8.6 and later.

Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 9.2 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

2.3.4.2. Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 2.32. Minimum resource requirements
MachineOperating SystemCPU [1]RAMStorageInput/Output Per Second (IOPS)[2]

Bootstrap

RHCOS

4

16 GB

100 GB

300

Control plane

RHCOS

4

16 GB

100 GB

300

Compute

RHCOS, RHEL 8.6 and later [3]

2

8 GB

100 GB

300

  1. One CPU is equivalent to one physical core when simultaneous multithreading (SMT), or Hyper-Threading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = CPUs.
  2. OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
  3. As with all user-provisioned installations, if you choose to use RHEL compute machines in your cluster, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Use of RHEL 7 compute machines is deprecated and has been removed in OpenShift Container Platform 4.10 and later.
Note

For OpenShift Container Platform version 4.18, RHCOS is based on RHEL version 9.4, which updates the micro-architecture requirements. The following list contains the minimum instruction set architectures (ISA) that each architecture requires:

  • x86-64 architecture requires x86-64-v2 ISA
  • ARM64 architecture requires ARMv8.0-A ISA
  • IBM Power architecture requires Power 9 ISA
  • s390x architecture requires z14 ISA

For more information, see Architectures (RHEL documentation).

If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.

Additional resources

2.3.4.3. Certificate signing requests management

Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.

Additional resources

2.3.4.4. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require networking to be configured in initramfs during boot to fetch their Ignition config files.

During the initial boot, the machines require an IP address configuration that is set either through a DHCP server or statically by providing the required boot options. After a network connection is established, the machines download their Ignition config files from an HTTP or HTTPS server. The Ignition config files are then used to set the exact state of each machine. The Machine Config Operator completes more changes to the machines, such as the application of new certificates or keys, after installation.

It is recommended to use a DHCP server for long-term management of the cluster machines. Ensure that the DHCP server is configured to provide persistent IP addresses, DNS server information, and hostnames to the cluster machines.

Note

If a DHCP service is not available for your user-provisioned infrastructure, you can instead provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options.

The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.

2.3.4.4.1. Setting the cluster node hostnames through DHCP

On Red Hat Enterprise Linux CoreOS (RHCOS) machines, the hostname is set through NetworkManager. By default, the machines obtain their hostname through DHCP. If the hostname is not provided by DHCP, set statically through kernel arguments, or another method, it is obtained through a reverse DNS lookup. Reverse DNS lookup occurs after the network has been initialized on a node and can take time to resolve. Other system services can start prior to this and detect the hostname as localhost or similar. You can avoid this by using DHCP to provide the hostname for each cluster node.

Additionally, setting the hostnames through DHCP can bypass any manual DNS record name configuration errors in environments that have a DNS split-horizon implementation.

2.3.4.4.2. Network connectivity requirements

You must configure the network connectivity between machines to allow OpenShift Container Platform cluster components to communicate. Each machine must be able to resolve the hostnames of all other machines in the cluster.

This section provides details about the ports that are required.

Table 2.33. Ports used for all-machine to all-machine communications
ProtocolPortDescription

ICMP

N/A

Network reachability tests

TCP

1936

Metrics

9000-9999

Host level services, including the node exporter on ports 9100-9101 and the Cluster Version Operator on port 9099.

10250-10259

The default ports that Kubernetes reserves

UDP

4789

VXLAN

6081

Geneve

9000-9999

Host level services, including the node exporter on ports 9100-9101.

500

IPsec IKE packets

4500

IPsec NAT-T packets

123

Network Time Protocol (NTP) on UDP port 123

If an external NTP time server is configured, you must open UDP port 123.

TCP/UDP

30000-32767

Kubernetes node port

ESP

N/A

IPsec Encapsulating Security Payload (ESP)

Table 2.34. Ports used for all-machine to control plane communications
ProtocolPortDescription

TCP

6443

Kubernetes API

Table 2.35. Ports used for control plane machine to control plane machine communications
ProtocolPortDescription

TCP

2379-2380

etcd server and peer ports

NTP configuration for user-provisioned infrastructure

OpenShift Container Platform clusters are configured to use a public Network Time Protocol (NTP) server by default. If you want to use a local enterprise NTP server, or if your cluster is being deployed in a disconnected network, you can configure the cluster to use a specific time server. For more information, see the documentation for Configuring chrony time service.

If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

2.3.4.5. User-provisioned DNS requirements

In OpenShift Container Platform deployments, DNS name resolution is required for the following components:

  • The Kubernetes API
  • The OpenShift Container Platform application wildcard
  • The bootstrap, control plane, and compute machines

Reverse DNS resolution is also required for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.

DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Red Hat Enterprise Linux CoreOS (RHCOS) uses the reverse records to set the hostnames for all the nodes, unless the hostnames are provided by DHCP. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OpenShift Container Platform needs to operate.

Note

It is recommended to use a DHCP server to provide the hostnames to each cluster node. See the DHCP recommendations for user-provisioned infrastructure section for more information.

The following DNS records are required for a user-provisioned OpenShift Container Platform cluster and they must be in place before installation. In each record, <cluster_name> is the cluster name and <base_domain> is the base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 2.36. Required DNS records
ComponentRecordDescription

Kubernetes API

api.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the API load balancer. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

api-int.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to internally identify the API load balancer. These records must be resolvable from all the nodes within the cluster.

Important

The API server must be able to resolve the worker nodes by the hostnames that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

*.apps.<cluster_name>.<base_domain>.

A wildcard DNS A/AAAA or CNAME record that refers to the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

For example, console-openshift-console.apps.<cluster_name>.<base_domain> is used as a wildcard route to the OpenShift Container Platform console.

Bootstrap machine

bootstrap.<cluster_name>.<base_domain>.

A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.

Control plane machines

<control_plane><n>.<cluster_name>.<base_domain>.

DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes. These records must be resolvable by the nodes within the cluster.

Compute machines

<compute><n>.<cluster_name>.<base_domain>.

DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Note

In OpenShift Container Platform 4.4 and later, you do not need to specify etcd host and SRV records in your DNS configuration.

Tip

You can use the dig command to verify name and reverse name resolution. See the section on Validating DNS resolution for user-provisioned infrastructure for detailed validation steps.

2.3.4.5.1. Example DNS configuration for user-provisioned clusters

This section provides A and PTR record configuration samples that meet the DNS requirements for deploying OpenShift Container Platform on user-provisioned infrastructure. The samples are not meant to provide advice for choosing one DNS solution over another.

In the examples, the cluster name is ocp4 and the base domain is example.com.

Example DNS A record configuration for a user-provisioned cluster

The following example is a BIND zone file that shows sample A records for name resolution in a user-provisioned cluster.

Example 2.7. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1.example.com.		IN	A	192.168.1.5
smtp.example.com.		IN	A	192.168.1.5
;
helper.example.com.		IN	A	192.168.1.5
helper.ocp4.example.com.	IN	A	192.168.1.5
;
api.ocp4.example.com.		IN	A	192.168.1.5 1
api-int.ocp4.example.com.	IN	A	192.168.1.5 2
;
*.apps.ocp4.example.com.	IN	A	192.168.1.5 3
;
bootstrap.ocp4.example.com.	IN	A	192.168.1.96 4
;
control-plane0.ocp4.example.com.	IN	A	192.168.1.97 5
control-plane1.ocp4.example.com.	IN	A	192.168.1.98 6
control-plane2.ocp4.example.com.	IN	A	192.168.1.99 7
;
compute0.ocp4.example.com.	IN	A	192.168.1.11 8
compute1.ocp4.example.com.	IN	A	192.168.1.7 9
;
;EOF
1
Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer.
2
Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer and is used for internal cluster communications.
3
Provides name resolution for the wildcard routes. The record refers to the IP address of the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
Note

In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

4
Provides name resolution for the bootstrap machine.
5 6 7
Provides name resolution for the control plane machines.
8 9
Provides name resolution for the compute machines.

Example DNS PTR record configuration for a user-provisioned cluster

The following example BIND zone file shows sample PTR records for reverse name resolution in a user-provisioned cluster.

Example 2.8. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
5.1.168.192.in-addr.arpa.	IN	PTR	api.ocp4.example.com. 1
5.1.168.192.in-addr.arpa.	IN	PTR	api-int.ocp4.example.com. 2
;
96.1.168.192.in-addr.arpa.	IN	PTR	bootstrap.ocp4.example.com. 3
;
97.1.168.192.in-addr.arpa.	IN	PTR	control-plane0.ocp4.example.com. 4
98.1.168.192.in-addr.arpa.	IN	PTR	control-plane1.ocp4.example.com. 5
99.1.168.192.in-addr.arpa.	IN	PTR	control-plane2.ocp4.example.com. 6
;
11.1.168.192.in-addr.arpa.	IN	PTR	compute0.ocp4.example.com. 7
7.1.168.192.in-addr.arpa.	IN	PTR	compute1.ocp4.example.com. 8
;
;EOF
1
Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer.
2
Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer and is used for internal cluster communications.
3
Provides reverse DNS resolution for the bootstrap machine.
4 5 6
Provides reverse DNS resolution for the control plane machines.
7 8
Provides reverse DNS resolution for the compute machines.
Note

A PTR record is not required for the OpenShift Container Platform application wildcard.

2.3.4.6. Load balancing requirements for user-provisioned infrastructure

Before you install OpenShift Container Platform, you must provision the API and application Ingress load balancing infrastructure. In production scenarios, you can deploy the API and application Ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

Note

If you want to deploy the API and application Ingress load balancers with a Red Hat Enterprise Linux (RHEL) instance, you must purchase the RHEL subscription separately.

The load balancing infrastructure must meet the following requirements:

  1. API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
    • A stateless load balancing algorithm. The options vary based on the load balancer implementation.
    Important

    Do not configure session persistence for an API load balancer. Configuring session persistence for a Kubernetes API server might cause performance issues from excess application traffic for your OpenShift Container Platform cluster and the Kubernetes API that runs inside the cluster.

    Configure the following ports on both the front and back of the load balancers:

    Table 2.37. API load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    6443

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the /readyz endpoint for the API server health check probe.

    X

    X

    Kubernetes API server

    22623

    Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.

    X

     

    Machine config server

    Note

    The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the /readyz endpoint to the removal of the API server instance from the pool. Within the time frame after /readyz returns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values.

  2. Application Ingress load balancer: Provides an ingress point for application traffic flowing in from outside the cluster. A working configuration for the Ingress router is required for an OpenShift Container Platform cluster.

    Configure the following conditions:

    • Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
    • A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.
    Tip

    If the true IP address of the client can be seen by the application Ingress load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

    Configure the following ports on both the front and back of the load balancers:

    Table 2.38. Application Ingress load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    443

    The machines that run the Ingress Controller pods, compute, or worker, by default.

    X

    X

    HTTPS traffic

    80

    The machines that run the Ingress Controller pods, compute, or worker, by default.

    X

    X

    HTTP traffic

    Note

    If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application Ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.

2.3.4.6.1. Example load balancer configuration for user-provisioned clusters

This section provides an example API and application Ingress load balancer configuration that meets the load balancing requirements for user-provisioned clusters. The sample is an /etc/haproxy/haproxy.cfg configuration for an HAProxy load balancer. The example is not meant to provide advice for choosing one load balancing solution over another.

In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

Note

If you are using HAProxy as a load balancer and SELinux is set to enforcing, you must ensure that the HAProxy service can bind to the configured TCP port by running setsebool -P haproxy_connect_any=1.

Example 2.9. Sample API and application Ingress load balancer configuration

global
  log         127.0.0.1 local2
  pidfile     /var/run/haproxy.pid
  maxconn     4000
  daemon
defaults
  mode                    http
  log                     global
  option                  dontlognull
  option http-server-close
  option                  redispatch
  retries                 3
  timeout http-request    10s
  timeout queue           1m
  timeout connect         10s
  timeout client          1m
  timeout server          1m
  timeout http-keep-alive 10s
  timeout check           10s
  maxconn                 3000
listen api-server-6443 1
  bind *:6443
  mode tcp
  option  httpchk GET /readyz HTTP/1.0
  option  log-health-checks
  balance roundrobin
  server bootstrap bootstrap.ocp4.example.com:6443 verify none check check-ssl inter 10s fall 2 rise 3 backup 2
  server master0 master0.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
  server master1 master1.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
  server master2 master2.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
listen machine-config-server-22623 3
  bind *:22623
  mode tcp
  server bootstrap bootstrap.ocp4.example.com:22623 check inter 1s backup 4
  server master0 master0.ocp4.example.com:22623 check inter 1s
  server master1 master1.ocp4.example.com:22623 check inter 1s
  server master2 master2.ocp4.example.com:22623 check inter 1s
listen ingress-router-443 5
  bind *:443
  mode tcp
  balance source
  server compute0 compute0.ocp4.example.com:443 check inter 1s
  server compute1 compute1.ocp4.example.com:443 check inter 1s
listen ingress-router-80 6
  bind *:80
  mode tcp
  balance source
  server compute0 compute0.ocp4.example.com:80 check inter 1s
  server compute1 compute1.ocp4.example.com:80 check inter 1s
1
Port 6443 handles the Kubernetes API traffic and points to the control plane machines.
2 4
The bootstrap entries must be in place before the OpenShift Container Platform cluster installation and they must be removed after the bootstrap process is complete.
3
Port 22623 handles the machine config server traffic and points to the control plane machines.
5
Port 443 handles the HTTPS traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
6
Port 80 handles the HTTP traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
Note

If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application Ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.

Tip

If you are using HAProxy as a load balancer, you can check that the haproxy process is listening on ports 6443, 22623, 443, and 80 by running netstat -nltupe on the HAProxy node.

2.3.5. Creating a manifest object that includes a customized br-ex bridge

As an alternative to using the configure-ovs.sh shell script to set a br-ex bridge on a bare-metal platform, you can create a MachineConfig object that includes an NMState configuration file. The NMState configuration file creates a customized br-ex bridge network configuration on each node in your cluster.

Consider the following use cases for creating a manifest object that includes a customized br-ex bridge:

  • You want to make postinstallation changes to the bridge, such as changing the Open vSwitch (OVS) or OVN-Kubernetes br-ex bridge network. The configure-ovs.sh shell script does not support making postinstallation changes to the bridge.
  • You want to deploy the bridge on a different interface than the interface available on a host or server IP address.
  • You want to make advanced configurations to the bridge that are not possible with the configure-ovs.sh shell script. Using the script for these configurations might result in the bridge failing to connect multiple network interfaces and facilitating data forwarding between the interfaces.
Note

If you require an environment with a single network interface controller (NIC) and default network settings, use the configure-ovs.sh shell script.

After you install Red Hat Enterprise Linux CoreOS (RHCOS) and the system reboots, the Machine Config Operator injects Ignition configuration files into each node in your cluster, so that each node received the br-ex bridge network configuration. To prevent configuration conflicts, the configure-ovs.sh shell script receives a signal to not configure the br-ex bridge.

Prerequisites

  • Optional: You have installed the nmstate API so that you can validate the NMState configuration.

Procedure

  1. Create a NMState configuration file that has decoded base64 information for your customized br-ex bridge network:

    Example of an NMState configuration for a customized br-ex bridge network

    interfaces:
    - name: enp2s0 1
      type: ethernet 2
      state: up 3
      ipv4:
        enabled: false 4
      ipv6:
        enabled: false
    - name: br-ex
      type: ovs-bridge
      state: up
      ipv4:
        enabled: false
        dhcp: false
      ipv6:
        enabled: false
        dhcp: false
      bridge:
        port:
        - name: enp2s0 5
        - name: br-ex
    - name: br-ex
      type: ovs-interface
      state: up
      copy-mac-from: enp2s0
      ipv4:
        enabled: true
        dhcp: true
      ipv6:
        enabled: false
        dhcp: false
    # ...

    1
    Name of the interface.
    2
    The type of ethernet.
    3
    The requested state for the interface after creation.
    4
    Disables IPv4 and IPv6 in this example.
    5
    The node NIC to which the bridge attaches.
  2. Use the cat command to base64-encode the contents of the NMState configuration:

    $ cat <nmstate_configuration>.yaml | base64 1
    1
    Replace <nmstate_configuration> with the name of your NMState resource YAML file.
  3. Create a MachineConfig manifest file and define a customized br-ex bridge network configuration analogous to the following example:

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker 1
      name: 10-br-ex-worker 2
    spec:
      config:
        ignition:
          version: 3.2.0
        storage:
          files:
          - contents:
              source: data:text/plain;charset=utf-8;base64,<base64_encoded_nmstate_configuration> 3
            mode: 0644
            overwrite: true
            path: /etc/nmstate/openshift/cluster.yml
    # ...
    1
    For each node in your cluster, specify the hostname path to your node and the base-64 encoded Ignition configuration file data for the machine type. If you have a single global configuration specified in an /etc/nmstate/openshift/cluster.yml configuration file that you want to apply to all nodes in your cluster, you do not need to specify the hostname path for each node. The worker role is the default role for nodes in your cluster. The .yaml extension does not work when specifying the hostname path for each node or all nodes in the MachineConfig manifest file.
    2
    The name of the policy.
    3
    Writes the encoded base64 information to the specified path.
2.3.5.1. Scaling each machine set to compute nodes

To apply a customized br-ex bridge configuration to all compute nodes in your OpenShift Container Platform cluster, you must edit your MachineConfig custom resource (CR) and modify its roles. Additionally, you must create a BareMetalHost CR that defines information for your bare-metal machine, such as hostname, credentials, and so on.

After you configure these resources, you must scale machine sets, so that the machine sets can apply the resource configuration to each compute node and reboot the nodes.

Prerequisites

  • You created a MachineConfig manifest object that includes a customized br-ex bridge configuration.

Procedure

  1. Edit the MachineConfig CR by entering the following command:

    $ oc edit mc <machineconfig_custom_resource_name>
  2. Add each compute node configuration to the CR, so that the CR can manage roles for each defined compute node in your cluster.
  3. Create a Secret object named extraworker-secret that has a minimal static IP configuration.
  4. Apply the extraworker-secret secret to each node in your cluster by entering the following command. This step provides each compute node access to the Ignition config file.

    $ oc apply -f ./extraworker-secret.yaml
  5. Create a BareMetalHost resource and specify the network secret in the preprovisioningNetworkDataName parameter:

    Example BareMetalHost resource with an attached network secret

    apiVersion: metal3.io/v1alpha1
    kind: BareMetalHost
    spec:
    # ...
      preprovisioningNetworkDataName: ostest-extraworker-0-network-config-secret
    # ...

  6. To manage the BareMetalHost object within the openshift-machine-api namespace of your cluster, change to the namespace by entering the following command:

    $ oc project openshift-machine-api
  7. Get the machine sets:

    $ oc get machinesets
  8. Scale each machine set by entering the following command. You must run this command for each machine set.

    $ oc scale machineset <machineset_name> --replicas=<n> 1
    1
    Where <machineset_name> is the name of the machine set and <n> is the number of compute nodes.

2.3.6. Preparing the user-provisioned infrastructure

Before you install OpenShift Container Platform on user-provisioned infrastructure, you must prepare the underlying infrastructure.

This section provides details about the high-level steps required to set up your cluster infrastructure in preparation for an OpenShift Container Platform installation. This includes configuring IP networking and network connectivity for your cluster nodes, enabling the required ports through your firewall, and setting up the required DNS and load balancing infrastructure.

After preparation, your cluster infrastructure must meet the requirements outlined in the Requirements for a cluster with user-provisioned infrastructure section.

Prerequisites

Procedure

  1. If you are using DHCP to provide the IP networking configuration to your cluster nodes, configure your DHCP service.

    1. Add persistent IP addresses for the nodes to your DHCP server configuration. In your configuration, match the MAC address of the relevant network interface to the intended IP address for each node.
    2. When you use DHCP to configure IP addressing for the cluster machines, the machines also obtain the DNS server information through DHCP. Define the persistent DNS server address that is used by the cluster nodes through your DHCP server configuration.

      Note

      If you are not using a DHCP service, you must provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options.

    3. Define the hostnames of your cluster nodes in your DHCP server configuration. See the Setting the cluster node hostnames through DHCP section for details about hostname considerations.

      Note

      If you are not using a DHCP service, the cluster nodes obtain their hostname through a reverse DNS lookup.

  2. Ensure that your network infrastructure provides the required network connectivity between the cluster components. See the Networking requirements for user-provisioned infrastructure section for details about the requirements.
  3. Configure your firewall to enable the ports required for the OpenShift Container Platform cluster components to communicate. See Networking requirements for user-provisioned infrastructure section for details about the ports that are required.

    Important

    By default, port 1936 is accessible for an OpenShift Container Platform cluster, because each control plane node needs access to this port.

    Avoid using the Ingress load balancer to expose this port, because doing so might result in the exposure of sensitive information, such as statistics and metrics, related to Ingress Controllers.

  4. Setup the required DNS infrastructure for your cluster.

    1. Configure DNS name resolution for the Kubernetes API, the application wildcard, the bootstrap machine, the control plane machines, and the compute machines.
    2. Configure reverse DNS resolution for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.

      See the User-provisioned DNS requirements section for more information about the OpenShift Container Platform DNS requirements.

  5. Validate your DNS configuration.

    1. From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses in the responses correspond to the correct components.
    2. From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names in the responses correspond to the correct components.

      See the Validating DNS resolution for user-provisioned infrastructure section for detailed DNS validation steps.

  6. Provision the required API and application ingress load balancing infrastructure. See the Load balancing requirements for user-provisioned infrastructure section for more information about the requirements.
Note

Some load balancing solutions require the DNS name resolution for the cluster nodes to be in place before the load balancing is initialized.

2.3.7. Validating DNS resolution for user-provisioned infrastructure

You can validate your DNS configuration before installing OpenShift Container Platform on user-provisioned infrastructure.

Important

The validation steps detailed in this section must succeed before you install your cluster.

Prerequisites

  • You have configured the required DNS records for your user-provisioned infrastructure.

Procedure

  1. From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses contained in the responses correspond to the correct components.

    1. Perform a lookup against the Kubernetes API record name. Check that the result points to the IP address of the API load balancer:

      $ dig +noall +answer @<nameserver_ip> api.<cluster_name>.<base_domain> 1
      1
      Replace <nameserver_ip> with the IP address of the nameserver, <cluster_name> with your cluster name, and <base_domain> with your base domain name.

      Example output

      api.ocp4.example.com.		604800	IN	A	192.168.1.5

    2. Perform a lookup against the Kubernetes internal API record name. Check that the result points to the IP address of the API load balancer:

      $ dig +noall +answer @<nameserver_ip> api-int.<cluster_name>.<base_domain>

      Example output

      api-int.ocp4.example.com.		604800	IN	A	192.168.1.5

    3. Test an example *.apps.<cluster_name>.<base_domain> DNS wildcard lookup. All of the application wildcard lookups must resolve to the IP address of the application ingress load balancer:

      $ dig +noall +answer @<nameserver_ip> random.apps.<cluster_name>.<base_domain>

      Example output

      random.apps.ocp4.example.com.		604800	IN	A	192.168.1.5

      Note

      In the example outputs, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.

      You can replace random with another wildcard value. For example, you can query the route to the OpenShift Container Platform console:

      $ dig +noall +answer @<nameserver_ip> console-openshift-console.apps.<cluster_name>.<base_domain>

      Example output

      console-openshift-console.apps.ocp4.example.com. 604800 IN	A 192.168.1.5

    4. Run a lookup against the bootstrap DNS record name. Check that the result points to the IP address of the bootstrap node:

      $ dig +noall +answer @<nameserver_ip> bootstrap.<cluster_name>.<base_domain>

      Example output

      bootstrap.ocp4.example.com.		604800	IN	A	192.168.1.96

    5. Use this method to perform lookups against the DNS record names for the control plane and compute nodes. Check that the results correspond to the IP addresses of each node.
  2. From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names contained in the responses correspond to the correct components.

    1. Perform a reverse lookup against the IP address of the API load balancer. Check that the response includes the record names for the Kubernetes API and the Kubernetes internal API:

      $ dig +noall +answer @<nameserver_ip> -x 192.168.1.5

      Example output

      5.1.168.192.in-addr.arpa. 604800	IN	PTR	api-int.ocp4.example.com. 1
      5.1.168.192.in-addr.arpa. 604800	IN	PTR	api.ocp4.example.com. 2

      1
      Provides the record name for the Kubernetes internal API.
      2
      Provides the record name for the Kubernetes API.
      Note

      A PTR record is not required for the OpenShift Container Platform application wildcard. No validation step is needed for reverse DNS resolution against the IP address of the application ingress load balancer.

    2. Perform a reverse lookup against the IP address of the bootstrap node. Check that the result points to the DNS record name of the bootstrap node:

      $ dig +noall +answer @<nameserver_ip> -x 192.168.1.96

      Example output

      96.1.168.192.in-addr.arpa. 604800	IN	PTR	bootstrap.ocp4.example.com.

    3. Use this method to perform reverse lookups against the IP addresses for the control plane and compute nodes. Check that the results correspond to the DNS record names of each node.

2.3.8. Generating a key pair for cluster node SSH access

During an OpenShift Container Platform installation, you can provide an SSH public key to the installation program. The key is passed to the Red Hat Enterprise Linux CoreOS (RHCOS) nodes through their Ignition config files and is used to authenticate SSH access to the nodes. The key is added to the ~/.ssh/authorized_keys list for the core user on each node, which enables password-less authentication.

After the key is passed to the nodes, you can use the key pair to SSH in to the RHCOS nodes as the user core. To access the nodes through SSH, the private key identity must be managed by SSH for your local user.

If you want to SSH in to your cluster nodes to perform installation debugging or disaster recovery, you must provide the SSH public key during the installation process. The ./openshift-install gather command also requires the SSH public key to be in place on the cluster nodes.

Important

Do not skip this procedure in production environments, where disaster recovery and debugging is required.

Note

You must use a local key, not one that you configured with platform-specific approaches.

Procedure

  1. If you do not have an existing SSH key pair on your local machine to use for authentication onto your cluster nodes, create one. For example, on a computer that uses a Linux operating system, run the following command:

    $ ssh-keygen -t ed25519 -N '' -f <path>/<file_name> 1
    1
    Specify the path and file name, such as ~/.ssh/id_ed25519, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
    Note

    If you plan to install an OpenShift Container Platform cluster that uses the RHEL cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. View the public SSH key:

    $ cat <path>/<file_name>.pub

    For example, run the following to view the ~/.ssh/id_ed25519.pub public key:

    $ cat ~/.ssh/id_ed25519.pub
  3. Add the SSH private key identity to the SSH agent for your local user, if it has not already been added. SSH agent management of the key is required for password-less SSH authentication onto your cluster nodes, or if you want to use the ./openshift-install gather command.

    Note

    On some distributions, default SSH private key identities such as ~/.ssh/id_rsa and ~/.ssh/id_dsa are managed automatically.

    1. If the ssh-agent process is not already running for your local user, start it as a background task:

      $ eval "$(ssh-agent -s)"

      Example output

      Agent pid 31874

      Note

      If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

  4. Add your SSH private key to the ssh-agent:

    $ ssh-add <path>/<file_name> 1
    1
    Specify the path and file name for your SSH private key, such as ~/.ssh/id_ed25519

    Example output

    Identity added: /home/<you>/<path>/<file_name> (<computer_name>)

Next steps

  • When you install OpenShift Container Platform, provide the SSH public key to the installation program. If you install a cluster on infrastructure that you provision, you must provide the key to the installation program.

Additional resources

2.3.9. Manually creating the installation configuration file

Installing the cluster requires that you manually create the installation configuration file.

Prerequisites

  • You have an SSH public key on your local machine to provide to the installation program. The key will be used for SSH authentication onto your cluster nodes for debugging and disaster recovery.
  • You have obtained the OpenShift Container Platform installation program and the pull secret for your cluster.
  • Obtain the imageContentSources section from the output of the command to mirror the repository.
  • Obtain the contents of the certificate for your mirror registry.

Procedure

  1. Create an installation directory to store your required installation assets in:

    $ mkdir <installation_directory>
    Important

    You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.

  2. Customize the sample install-config.yaml file template that is provided and save it in the <installation_directory>.

    Note

    You must name this configuration file install-config.yaml.

    • Unless you use a registry that RHCOS trusts by default, such as docker.io, you must provide the contents of the certificate for your mirror repository in the additionalTrustBundle section. In most cases, you must provide the certificate for your mirror.
    • You must include the imageContentSources section from the output of the command to mirror the repository.
    Important
    • The ImageContentSourcePolicy file is generated as an output of oc mirror after the mirroring process is finished.
    • The oc mirror command generates an ImageContentSourcePolicy file which contains the YAML needed to define ImageContentSourcePolicy. Copy the text from this file and paste it into your install-config.yaml file.
    • You must run the 'oc mirror' command twice. The first time you run the oc mirror command, you get a full ImageContentSourcePolicy file. The second time you run the oc mirror command, you only get the difference between the first and second run. Because of this behavior, you must always keep a backup of these files in case you need to merge them into one complete ImageContentSourcePolicy file. Keeping a backup of these two output files ensures that you have a complete ImageContentSourcePolicy file.
  3. Back up the install-config.yaml file so that you can use it to install multiple clusters.

    Important

    The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

2.3.9.1. Sample install-config.yaml file for bare metal

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OVNKubernetes 11
  serviceNetwork: 12
  - 172.30.0.0/16
platform:
  none: {} 13
fips: false 14
pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' 15
sshKey: 'ssh-ed25519 AAAA...' 16
additionalTrustBundle: | 17
  -----BEGIN CERTIFICATE-----
  ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
  -----END CERTIFICATE-----
imageContentSources: 18
- mirrors:
  - <local_registry>/<local_repository_name>/release
  source: quay.io/openshift-release-dev/ocp-release
- mirrors:
  - <local_registry>/<local_repository_name>/release
  source: quay.io/openshift-release-dev/ocp-v4.0-art-dev
1
The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 5
The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Only one control plane pool is used.
3 6
Specifies whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of the cores in your machines. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note

Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.

Important

If you disable hyperthreading, whether in the BIOS or in the install-config.yaml file, ensure that your capacity planning accounts for the dramatically decreased machine performance.

4
You must set this value to 0 when you install OpenShift Container Platform on user-provisioned infrastructure. In installer-provisioned installations, the parameter controls the number of compute machines that the cluster creates and manages for you. In user-provisioned installations, you must manually deploy the compute machines before you finish installing the cluster.
Note

If you are installing a three-node cluster, do not deploy any compute machines when you install the Red Hat Enterprise Linux CoreOS (RHCOS) machines.

7
The number of control plane machines that you add to the cluster. Because the cluster uses these values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8
The cluster name that you specified in your DNS records.
9
A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
Note

Class E CIDR range is reserved for a future use. To use the Class E CIDR range, you must ensure your networking environment accepts the IP addresses within the Class E CIDR range.

10
The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IP addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.
11
The cluster network plugin to install. The default value OVNKubernetes is the only supported value.
12
The IP address pool to use for service IP addresses. You can enter only one IP address pool. This block must not overlap with existing physical networks. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
13
You must set the platform to none. You cannot provide additional platform configuration variables for your platform.
Important

Clusters that are installed with the platform type none are unable to use some features, such as managing compute machines with the Machine API. This limitation applies even if the compute machines that are attached to the cluster are installed on a platform that would normally support the feature. This parameter cannot be changed after installation.

14
Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
Important

To enable FIPS mode for your cluster, you must run the installation program from a Red Hat Enterprise Linux (RHEL) computer configured to operate in FIPS mode. For more information about configuring FIPS mode on RHEL, see Switching RHEL to FIPS mode.

When running Red Hat Enterprise Linux (RHEL) or Red Hat Enterprise Linux CoreOS (RHCOS) booted in FIPS mode, OpenShift Container Platform core components use the RHEL cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures.

15
For <local_registry>, specify the registry domain name, and optionally the port, that your mirror registry uses to serve content. For example, registry.example.com or registry.example.com:5000. For <credentials>, specify the base64-encoded user name and password for your mirror registry.
16
The SSH public key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

17
Provide the contents of the certificate file that you used for your mirror registry.
18
Provide the imageContentSources section according to the output of the command that you used to mirror the repository.
Important
  • When using the oc adm release mirror command, use the output from the imageContentSources section.
  • When using oc mirror command, use the repositoryDigestMirrors section of the ImageContentSourcePolicy file that results from running the command.
  • ImageContentSourcePolicy is deprecated. For more information see Configuring image registry repository mirroring.

Additional resources

2.3.9.2. Configuring the cluster-wide proxy during installation

Production environments can deny direct access to the internet and instead have an HTTP or HTTPS proxy available. You can configure a new OpenShift Container Platform cluster to use a proxy by configuring the proxy settings in the install-config.yaml file.

Note

For bare metal installations, if you do not assign node IP addresses from the range that is specified in the networking.machineNetwork[].cidr field in the install-config.yaml file, you must include them in the proxy.noProxy field.

Prerequisites

  • You have an existing install-config.yaml file.
  • You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.

    Note

    The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.

    For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

  1. Edit your install-config.yaml file and add the proxy settings. For example:

    apiVersion: v1
    baseDomain: my.domain.com
    proxy:
      httpProxy: http://<username>:<pswd>@<ip>:<port> 1
      httpsProxy: https://<username>:<pswd>@<ip>:<port> 2
      noProxy: example.com 3
    additionalTrustBundle: | 4
        -----BEGIN CERTIFICATE-----
        <MY_TRUSTED_CA_CERT>
        -----END CERTIFICATE-----
    additionalTrustBundlePolicy: <policy_to_add_additionalTrustBundle> 5
    1
    A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
    2
    A proxy URL to use for creating HTTPS connections outside the cluster.
    3
    A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations.
    4
    If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the trustedCA field of the Proxy object. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
    5
    Optional: The policy to determine the configuration of the Proxy object to reference the user-ca-bundle config map in the trustedCA field. The allowed values are Proxyonly and Always. Use Proxyonly to reference the user-ca-bundle config map only when http/https proxy is configured. Use Always to always reference the user-ca-bundle config map. The default value is Proxyonly.
    Note

    The installation program does not support the proxy readinessEndpoints field.

    Note

    If the installer times out, restart and then complete the deployment by using the wait-for command of the installer. For example:

    $ ./openshift-install wait-for install-complete --log-level debug
  2. Save the file and reference it when installing OpenShift Container Platform.

The installation program creates a cluster-wide proxy that is named cluster that uses the proxy settings in the provided install-config.yaml file. If no proxy settings are provided, a cluster Proxy object is still created, but it will have a nil spec.

Note

Only the Proxy object named cluster is supported, and no additional proxies can be created.

2.3.9.3. Configuring a three-node cluster

Optionally, you can deploy zero compute machines in a bare metal cluster that consists of three control plane machines only. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for testing, development, and production.

In three-node OpenShift Container Platform environments, the three control plane machines are schedulable, which means that your application workloads are scheduled to run on them.

Prerequisites

  • You have an existing install-config.yaml file.

Procedure

  • Ensure that the number of compute replicas is set to 0 in your install-config.yaml file, as shown in the following compute stanza:

    compute:
    - name: worker
      platform: {}
      replicas: 0
    Note

    You must set the value of the replicas parameter for the compute machines to 0 when you install OpenShift Container Platform on user-provisioned infrastructure, regardless of the number of compute machines you are deploying. In installer-provisioned installations, the parameter controls the number of compute machines that the cluster creates and manages for you. This does not apply to user-provisioned installations, where the compute machines are deployed manually.

For three-node cluster installations, follow these next steps:

  • If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes. See the Load balancing requirements for user-provisioned infrastructure section for more information.
  • When you create the Kubernetes manifest files in the following procedure, ensure that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml file is set to true. This enables your application workloads to run on the control plane nodes.
  • Do not deploy any compute nodes when you create the Red Hat Enterprise Linux CoreOS (RHCOS) machines.

2.3.10. Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to configure the machines.

The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to configure the cluster machines.

Important
  • The Ignition config files that the OpenShift Container Platform installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
  • It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.

Prerequisites

  • You obtained the OpenShift Container Platform installation program. For a restricted network installation, these files are on your mirror host.
  • You created the install-config.yaml installation configuration file.

Procedure

  1. Change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster:

    $ ./openshift-install create manifests --dir <installation_directory> 1
    1
    For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
    Warning

    If you are installing a three-node cluster, skip the following step to allow the control plane nodes to be schedulable.

    Important

    When you configure control plane nodes from the default unschedulable to schedulable, additional subscriptions are required. This is because control plane nodes then become compute nodes.

  2. Check that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file is set to false. This setting prevents pods from being scheduled on the control plane machines:

    1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
    2. Locate the mastersSchedulable parameter and ensure that it is set to false.
    3. Save and exit the file.
  3. To create the Ignition configuration files, run the following command from the directory that contains the installation program:

    $ ./openshift-install create ignition-configs --dir <installation_directory> 1
    1
    For <installation_directory>, specify the same installation directory.

    Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory. The kubeadmin-password and kubeconfig files are created in the ./<installation_directory>/auth directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign

Additional resources

2.3.11. Configuring chrony time service

You must set the time server and related settings used by the chrony time service (chronyd) by modifying the contents of the chrony.conf file and passing those contents to your nodes as a machine config.

Procedure

  1. Create a Butane config including the contents of the chrony.conf file. For example, to configure chrony on worker nodes, create a 99-worker-chrony.bu file.

    Note

    See "Creating machine configs with Butane" for information about Butane.

    variant: openshift
    version: 4.18.0
    metadata:
      name: 99-worker-chrony 1
      labels:
        machineconfiguration.openshift.io/role: worker 2
    storage:
      files:
      - path: /etc/chrony.conf
        mode: 0644 3
        overwrite: true
        contents:
          inline: |
            pool 0.rhel.pool.ntp.org iburst 4
            driftfile /var/lib/chrony/drift
            makestep 1.0 3
            rtcsync
            logdir /var/log/chrony
    1 2
    On control plane nodes, substitute master for worker in both of these locations.
    3
    Specify an octal value mode for the mode field in the machine config file. After creating the file and applying the changes, the mode is converted to a decimal value. You can check the YAML file with the command oc get mc <mc-name> -o yaml.
    4
    Specify any valid, reachable time source, such as the one provided by your DHCP server.
  2. Use Butane to generate a MachineConfig object file, 99-worker-chrony.yaml, containing the configuration to be delivered to the nodes:

    $ butane 99-worker-chrony.bu -o 99-worker-chrony.yaml
  3. Apply the configurations in one of two ways:

    • If the cluster is not running yet, after you generate manifest files, add the MachineConfig object file to the <installation_directory>/openshift directory, and then continue to create the cluster.
    • If the cluster is already running, apply the file:

      $ oc apply -f ./99-worker-chrony.yaml

2.3.12. Installing RHCOS and starting the OpenShift Container Platform bootstrap process

To install OpenShift Container Platform on bare metal infrastructure that you provision, you must install Red Hat Enterprise Linux CoreOS (RHCOS) on the machines. When you install RHCOS, you must provide the Ignition config file that was generated by the OpenShift Container Platform installation program for the type of machine you are installing. If you have configured suitable networking, DNS, and load balancing infrastructure, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS machines have rebooted.

To install RHCOS on the machines, follow either the steps to use an ISO image or network PXE booting.

Note

The compute node deployment steps included in this installation document are RHCOS-specific. If you choose instead to deploy RHEL-based compute nodes, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Only RHEL 8 compute machines are supported.

You can configure RHCOS during ISO and PXE installations by using the following methods:

  • Kernel arguments: You can use kernel arguments to provide installation-specific information. For example, you can specify the locations of the RHCOS installation files that you uploaded to your HTTP server and the location of the Ignition config file for the type of node you are installing. For a PXE installation, you can use the APPEND parameter to pass the arguments to the kernel of the live installer. For an ISO installation, you can interrupt the live installation boot process to add the kernel arguments. In both installation cases, you can use special coreos.inst.* arguments to direct the live installer, as well as standard installation boot arguments for turning standard kernel services on or off.
  • Ignition configs: OpenShift Container Platform Ignition config files (*.ign) are specific to the type of node you are installing. You pass the location of a bootstrap, control plane, or compute node Ignition config file during the RHCOS installation so that it takes effect on first boot. In special cases, you can create a separate, limited Ignition config to pass to the live system. That Ignition config could do a certain set of tasks, such as reporting success to a provisioning system after completing installation. This special Ignition config is consumed by the coreos-installer to be applied on first boot of the installed system. Do not provide the standard control plane and compute node Ignition configs to the live ISO directly.
  • coreos-installer: You can boot the live ISO installer to a shell prompt, which allows you to prepare the permanent system in a variety of ways before first boot. In particular, you can run the coreos-installer command to identify various artifacts to include, work with disk partitions, and set up networking. In some cases, you can configure features on the live system and copy them to the installed system.

Whether to use an ISO or PXE install depends on your situation. A PXE install requires an available DHCP service and more preparation, but can make the installation process more automated. An ISO install is a more manual process and can be inconvenient if you are setting up more than a few machines.

2.3.12.1. Installing RHCOS by using an ISO image

You can use an ISO image to install RHCOS on the machines.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have an HTTP server that can be accessed from your computer, and from the machines that you create.
  • You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.

Procedure

  1. Obtain the SHA512 digest for each of your Ignition config files. For example, you can use the following on a system running Linux to get the SHA512 digest for your bootstrap.ign Ignition config file:

    $ sha512sum <installation_directory>/bootstrap.ign

    The digests are provided to the coreos-installer in a later step to validate the authenticity of the Ignition config files on the cluster nodes.

  2. Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

    You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  3. From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node:

    $ curl -k http://<HTTP_server>/bootstrap.ign 1

    Example output

      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
      0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...

    Replace bootstrap.ign with master.ign or worker.ign in the command to validate that the Ignition config files for the control plane and compute nodes are also available.

  4. Although it is possible to obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS images are from the output of openshift-install command:

    $ openshift-install coreos print-stream-json | grep '\.iso[^.]'

    Example output

    "location": "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso",
    "location": "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live.x86_64.iso",

    Important

    The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Use only ISO images for this procedure. RHCOS qcow2 images are not supported for this installation type.

    ISO file names resemble the following example:

    rhcos-<version>-live.<architecture>.iso

  5. Use the ISO to start the RHCOS installation. Use one of the following installation options:

    • Burn the ISO image to a disk and boot it directly.
    • Use ISO redirection by using a lights-out management (LOM) interface.
  6. Boot the RHCOS ISO image without specifying any options or interrupting the live boot sequence. Wait for the installer to boot into a shell prompt in the RHCOS live environment.

    Note

    It is possible to interrupt the RHCOS installation boot process to add kernel arguments. However, for this ISO procedure you should use the coreos-installer command as outlined in the following steps, instead of adding kernel arguments.

  7. Run the coreos-installer command and specify the options that meet your installation requirements. At a minimum, you must specify the URL that points to the Ignition config file for the node type, and the device that you are installing to:

    $ sudo coreos-installer install --ignition-url=http://<HTTP_server>/<node_type>.ign <device> --ignition-hash=sha512-<digest> 12
    1 1
    You must run the coreos-installer command by using sudo, because the core user does not have the required root privileges to perform the installation.
    2
    The --ignition-hash option is required when the Ignition config file is obtained through an HTTP URL to validate the authenticity of the Ignition config file on the cluster node. <digest> is the Ignition config file SHA512 digest obtained in a preceding step.
    Note

    If you want to provide your Ignition config files through an HTTPS server that uses TLS, you can add the internal certificate authority (CA) to the system trust store before running coreos-installer.

    The following example initializes a bootstrap node installation to the /dev/sda device. The Ignition config file for the bootstrap node is obtained from an HTTP web server with the IP address 192.168.1.2:

    $ sudo coreos-installer install --ignition-url=http://192.168.1.2:80/installation_directory/bootstrap.ign /dev/sda --ignition-hash=sha512-a5a2d43879223273c9b60af66b44202a1d1248fc01cf156c46d4a79f552b6bad47bc8cc78ddf0116e80c59d2ea9e32ba53bc807afbca581aa059311def2c3e3b
  8. Monitor the progress of the RHCOS installation on the console of the machine.

    Important

    Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise.

  9. After RHCOS installs, you must reboot the system. During the system reboot, it applies the Ignition config file that you specified.
  10. Check the console output to verify that Ignition ran.

    Example command

    Ignition: ran on 2022/03/14 14:48:33 UTC (this boot)
    Ignition: user-provided config was applied

  11. Continue to create the other machines for your cluster.

    Important

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, also create at least two compute machines before you install OpenShift Container Platform.

    If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted.

    Note

    RHCOS nodes do not include a default password for the core user. You can access the nodes by running ssh core@<node>.<cluster_name>.<base_domain> as a user with access to the SSH private key that is paired to the public key that you specified in your install_config.yaml file. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.

2.3.12.2. Installing RHCOS by using PXE or iPXE booting

You can use PXE or iPXE booting to install RHCOS on the machines.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have configured suitable PXE or iPXE infrastructure.
  • You have an HTTP server that can be accessed from your computer, and from the machines that you create.
  • You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.

Procedure

  1. Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

    You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  2. From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node:

    $ curl -k http://<HTTP_server>/bootstrap.ign 1

    Example output

      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
      0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...

    Replace bootstrap.ign with master.ign or worker.ign in the command to validate that the Ignition config files for the control plane and compute nodes are also available.

  3. Although it is possible to obtain the RHCOS kernel, initramfs and rootfs files that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS files are from the output of openshift-install command:

    $ openshift-install coreos print-stream-json | grep -Eo '"https.*(kernel-|initramfs.|rootfs.)\w+(\.img)?"'

    Example output

    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-kernel-aarch64"
    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-initramfs.aarch64.img"
    "<url>/art/storage/releases/rhcos-4.18-aarch64/<release>/aarch64/rhcos-<release>-live-rootfs.aarch64.img"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/49.84.202110081256-0/ppc64le/rhcos-<release>-live-kernel-ppc64le"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live-initramfs.ppc64le.img"
    "<url>/art/storage/releases/rhcos-4.18-ppc64le/<release>/ppc64le/rhcos-<release>-live-rootfs.ppc64le.img"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-kernel-s390x"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-initramfs.s390x.img"
    "<url>/art/storage/releases/rhcos-4.18-s390x/<release>/s390x/rhcos-<release>-live-rootfs.s390x.img"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-kernel-x86_64"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-initramfs.x86_64.img"
    "<url>/art/storage/releases/rhcos-4.18/<release>/x86_64/rhcos-<release>-live-rootfs.x86_64.img"

    Important

    The RHCOS artifacts might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate kernel, initramfs, and rootfs artifacts described below for this procedure. RHCOS QCOW2 images are not supported for this installation type.

    The file names contain the OpenShift Container Platform version number. They resemble the following examples:

    • kernel: rhcos-<version>-live-kernel-<architecture>
    • initramfs: rhcos-<version>-live-initramfs.<architecture>.img
    • rootfs: rhcos-<version>-live-rootfs.<architecture>.img
  4. Upload the rootfs, kernel, and initramfs files to your HTTP server.

    Important

    If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

  5. Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
  6. Configure PXE or iPXE installation for the RHCOS images and begin the installation.

    Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:

    • For PXE (x86_64):

      DEFAULT pxeboot
      TIMEOUT 20
      PROMPT 0
      LABEL pxeboot
          KERNEL http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> 1
          APPEND initrd=http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 2 3
      1 1
      Specify the location of the live kernel file that you uploaded to your HTTP server. The URL must be HTTP, TFTP, or FTP; HTTPS and NFS are not supported.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the locations of the RHCOS files that you uploaded to your HTTP server. The initrd parameter value is the location of the initramfs file, the coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file. You can also add more kernel arguments to the APPEND line to configure networking or other boot options.
      Note

      This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the APPEND line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux? and "Enabling the serial console for PXE and ISO installation" in the "Advanced RHCOS installation configuration" section.

    • For iPXE (x86_64 + aarch64 ):

      kernel http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> initrd=main coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
      initrd --name main http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img 3
      boot
      1
      Specify the locations of the RHCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd=main argument is needed for booting on UEFI systems, the coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the location of the initramfs file that you uploaded to your HTTP server.
      Note

      This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the kernel line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux? and "Enabling the serial console for PXE and ISO installation" in the "Advanced RHCOS installation configuration" section.

      Note

      To network boot the CoreOS kernel on aarch64 architecture, you need to use a version of iPXE build with the IMAGE_GZIP option enabled. See IMAGE_GZIP option in iPXE.

    • For PXE (with UEFI and Grub as second stage) on aarch64:

      menuentry 'Install CoreOS' {
          linux rhcos-<version>-live-kernel-<architecture>  coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
          initrd rhcos-<version>-live-initramfs.<architecture>.img 3
      }
      1
      Specify the locations of the RHCOS files that you uploaded to your HTTP/TFTP server. The kernel parameter value is the location of the kernel file on your TFTP server. The coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file on your HTTP Server.
      2
      If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
      3
      Specify the location of the initramfs file that you uploaded to your TFTP server.
  7. Monitor the progress of the RHCOS installation on the console of the machine.

    Important

    Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise.

  8. After RHCOS installs, the system reboots. During reboot, the system applies the Ignition config file that you specified.
  9. Check the console output to verify that Ignition ran.

    Example command

    Ignition: ran on 2022/03/14 14:48:33 UTC (this boot)
    Ignition: user-provided config was applied

  10. Continue to create the machines for your cluster.

    Important

    You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, also create at least two compute machines before you install the cluster.

    If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted.

    Note

    RHCOS nodes do not include a default password for the core user. You can access the nodes by running ssh core@<node>.<cluster_name>.<base_domain> as a user with access to the SSH private key that is paired to the public key that you specified in your install_config.yaml file. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.

2.3.12.3. Advanced RHCOS installation configuration

A key benefit for manually provisioning the Red Hat Enterprise Linux CoreOS (RHCOS) nodes for OpenShift Container Platform is to be able to do configuration that is not available through default OpenShift Container Platform installation methods. This section describes some of the configurations that you can do using techniques that include:

  • Passing kernel arguments to the live installer
  • Running coreos-installer manually from the live system
  • Customizing a live ISO or PXE boot image

The advanced configuration topics for manual Red Hat Enterprise Linux CoreOS (RHCOS) installations detailed in this section relate to disk partitioning, networking, and using Ignition configs in different ways.

2.3.12.3.1. Using advanced networking options for PXE and ISO installations

Networking for OpenShift Container Platform nodes uses DHCP by default to gather all necessary configuration settings. To set up static IP addresses or configure special settings, such as bonding, you can do one of the following:

  • Pass special kernel parameters when you boot the live installer.
  • Use a machine config to copy networking files to the installed system.
  • Configure networking from a live installer shell prompt, then copy those settings to the installed system so that they take effect when the installed system first boots.

To configure a PXE or iPXE installation, use one of the following options:

  • See the "Advanced RHCOS installation reference" tables.
  • Use a machine config to copy networking files to the installed system.

To configure an ISO installation, use the following procedure.

Procedure

  1. Boot the ISO installer.
  2. From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.
  3. Run the coreos-installer command to install the system, adding the --copy-network option to copy networking configuration. For example:

    $ sudo coreos-installer install --copy-network \
         --ignition-url=http://host/worker.ign /dev/disk/by-id/scsi-<serial_number>
    Important

    The --copy-network option only copies networking configuration found under /etc/NetworkManager/system-connections. In particular, it does not copy the system hostname.

  4. Reboot into the installed system.

Additional resources

2.3.12.3.2. Disk partitioning

Disk partitions are created on OpenShift Container Platform cluster nodes during the Red Hat Enterprise Linux CoreOS (RHCOS) installation. Each RHCOS node of a particular architecture uses the same partition layout, unless you override the default partitioning configuration. During the RHCOS installation, the size of the root file system is increased to use any remaining available space on the target device.

Important

The use of a custom partition scheme on your node might result in OpenShift Container Platform not monitoring or alerting on some node partitions. If you override the default partitioning, see Understanding OpenShift File System Monitoring (eviction conditions) for more information about how OpenShift Container Platform monitors your host file systems.

OpenShift Container Platform monitors the following two filesystem identifiers:

  • nodefs, which is the filesystem that contains /var/lib/kubelet
  • imagefs, which is the filesystem that contains /var/lib/containers

For the default partition scheme, nodefs and imagefs monitor the same root filesystem, /.

To override the default partitioning when installing RHCOS on an OpenShift Container Platform cluster node, you must create separate partitions. Consider a situation where you want to add a separate storage partition for your containers and container images. For example, by mounting /var/lib/containers in a separate partition, the kubelet separately monitors /var/lib/containers as the imagefs directory and the root file system as the nodefs directory.

Important

If you have resized your disk size to host a larger file system, consider creating a separate /var/lib/containers partition. Consider resizing a disk that has an xfs format to reduce CPU time issues caused by a high number of allocation groups.

2.3.12.3.2.1. Creating a separate /var partition

In general, you should use the default disk partitioning that is created during the RHCOS installation. However, there are cases where you might want to create a separate partition for a directory that you expect to grow.

OpenShift Container Platform supports the addition of a single partition to attach storage to either the /var directory or a subdirectory of /var. For example:

  • /var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system.
  • /var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage.
  • /var: Holds data that you might want to keep separate for purposes such as auditing.

    Important

    For disk sizes larger than 100GB, and especially larger than 1TB, create a separate /var partition.

Storing the contents of a /var directory separately makes it easier to grow storage for those areas as needed and reinstall OpenShift Container Platform at a later date and keep that data intact. With this method, you will not have to pull all your containers again, nor will you have to copy massive log files when you update systems.

The use of a separate partition for the /var directory or a subdirectory of /var also prevents data growth in the partitioned directory from filling up the root file system.

The following procedure sets up a separate /var partition by adding a machine config manifest that is wrapped into the Ignition config file for a node type during the preparation phase of an installation.

Procedure

  1. On your installation host, change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster:

    $ openshift-install create manifests --dir <installation_directory>
  2. Create a Butane config that configures the additional partition. For example, name the file $HOME/clusterconfig/98-var-partition.bu, change the disk device name to the name of the storage device on the worker systems, and set the storage size as appropriate. This example places the /var directory on a separate partition:

    variant: openshift
    version: 4.18.0
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker
      name: 98-var-partition
    storage:
      disks:
      - device: /dev/disk/by-id/<device_name> 1
        partitions:
        - label: var
          start_mib: <partition_start_offset> 2
          size_mib: <partition_size> 3
          number: 5
      filesystems:
        - device: /dev/disk/by-partlabel/var
          path: /var
          format: xfs
          mount_options: [defaults, prjquota] 4
          with_mount_unit: true
    1
    The storage device name of the disk that you want to partition.
    2
    When adding a data partition to the boot disk, a minimum offset value of 25000 mebibytes is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no offset value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of RHCOS might overwrite the beginning of the data partition.
    3
    The size of the data partition in mebibytes.
    4
    The prjquota mount option must be enabled for filesystems used for container storage.
    Note

    When creating a separate /var partition, you cannot use different instance types for compute nodes, if the different instance types do not have the same device name.

  3. Create a manifest from the Butane config and save it to the clusterconfig/openshift directory. For example, run the following command:

    $ butane $HOME/clusterconfig/98-var-partition.bu -o $HOME/clusterconfig/openshift/98-var-partition.yaml
  4. Create the Ignition config files:

    $ openshift-install create ignition-configs --dir <installation_directory> 1
    1
    For <installation_directory>, specify the same installation directory.

    Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign

    The files in the <installation_directory>/manifest and <installation_directory>/openshift directories are wrapped into the Ignition config files, including the file that contains the 98-var-partition custom MachineConfig object.

Next steps

  • You can apply the custom disk partitioning by referencing the Ignition config files during the RHCOS installations.
2.3.12.3.2.2. Retaining existing partitions

For an ISO installation, you can add options to the coreos-installer command that cause the installer to maintain one or more existing partitions. For a PXE installation, you can add coreos.inst.* options to the APPEND parameter to preserve partitions.

Saved partitions might be data partitions from an existing OpenShift Container Platform system. You can identify the disk partitions you want to keep either by partition label or by number.

Note

If you save existing partitions, and those partitions do not leave enough space for RHCOS, the installation will fail without damaging the saved partitions.

Retaining existing partitions during an ISO installation

This example preserves any partition in which the partition label begins with data (data*):

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partlabel 'data*' /dev/disk/by-id/scsi-<serial_number>

The following example illustrates running the coreos-installer in a way that preserves the sixth (6) partition on the disk:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partindex 6 /dev/disk/by-id/scsi-<serial_number>

This example preserves partitions 5 and higher:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign
        --save-partindex 5- /dev/disk/by-id/scsi-<serial_number>

In the previous examples where partition saving is used, coreos-installer recreates the partition immediately.

Retaining existing partitions during a PXE installation

This APPEND option preserves any partition in which the partition label begins with 'data' ('data*'):

coreos.inst.save_partlabel=data*

This APPEND option preserves partitions 5 and higher:

coreos.inst.save_partindex=5-

This APPEND option preserves partition 6:

coreos.inst.save_partindex=6
2.3.12.3.3. Identifying Ignition configs

When doing an RHCOS manual installation, there are two types of Ignition configs that you can provide, with different reasons for providing each one:

  • Permanent install Ignition config: Every manual RHCOS installation needs to pass one of the Ignition config files generated by openshift-installer, such as bootstrap.ign, master.ign and worker.ign, to carry out the installation.

    Important

    It is not recommended to modify these Ignition config files directly. You can update the manifest files that are wrapped into the Ignition config files, as outlined in examples in the preceding sections.

    For PXE installations, you pass the Ignition configs on the APPEND line using the coreos.inst.ignition_url= option. For ISO installations, after the ISO boots to the shell prompt, you identify the Ignition config on the coreos-installer command line with the --ignition-url= option. In both cases, only HTTP and HTTPS protocols are supported.

  • Live install Ignition config: This type can be created by using the coreos-installer customize subcommand and its various options. With this method, the Ignition config passes to the live install medium, runs immediately upon booting, and performs setup tasks before or after the RHCOS system installs to disk. This method should only be used for performing tasks that must be done once and not applied again later, such as with advanced partitioning that cannot be done using a machine config.

    For PXE or ISO boots, you can create the Ignition config and APPEND the ignition.config.url= option to identify the location of the Ignition config. You also need to append ignition.firstboot ignition.platform.id=metal or the ignition.config.url option will be ignored.

2.3.12.3.4. Default console configuration

Red Hat Enterprise Linux CoreOS (RHCOS) nodes installed from an OpenShift Container Platform 4.18 boot image use a default console that is meant to accomodate most virtualized and bare metal setups. Different cloud and virtualization platforms may use different default settings depending on the chosen architecture. Bare metal installations use the kernel default settings which typically means the graphical console is the primary console and the serial console is disabled.

The default consoles may not match your specific hardware configuration or you might have specific needs that require you to adjust the default console. For example:

  • You want to access the emergency shell on the console for debugging purposes.
  • Your cloud platform does not provide interactive access to the graphical console, but provides a serial console.
  • You want to enable multiple consoles.

Console configuration is inherited from the boot image. This means that new nodes in existing clusters are unaffected by changes to the default console.

You can configure the console for bare metal installations in the following ways:

  • Using coreos-installer manually on the command line.
  • Using the coreos-installer iso customize or coreos-installer pxe customize subcommands with the --dest-console option to create a custom image that automates the process.
Note

For advanced customization, perform console configuration using the coreos-installer iso or coreos-installer pxe subcommands, and not kernel arguments.

2.3.12.3.5. Enabling the serial console for PXE and ISO installations

By default, the Red Hat Enterprise Linux CoreOS (RHCOS) serial console is disabled and all output is written to the graphical console. You can enable the serial console for an ISO installation and reconfigure the bootloader so that output is sent to both the serial console and the graphical console.

Procedure

  1. Boot the ISO installer.
  2. Run the coreos-installer command to install the system, adding the --console option once to specify the graphical console, and a second time to specify the serial console:

    $ coreos-installer install \
      --console=tty0 \1
      --console=ttyS0,<options> \2
      --ignition-url=http://host/worker.ign /dev/disk/by-id/scsi-<serial_number>
    1
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    2
    The desired primary console. In this case the serial console. The options field defines the baud rate and other settings. A common value for this field is 11520n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see Linux kernel serial console documentation.
  3. Reboot into the installed system.

    Note

    A similar outcome can be obtained by using the coreos-installer install --append-karg option, and specifying the console with console=. However, this will only set the console for the kernel and not the bootloader.

To configure a PXE installation, make sure the coreos.inst.install_dev kernel command line option is omitted, and use the shell prompt to run coreos-installer manually using the above ISO installation procedure.

2.3.12.3.6. Customizing a live RHCOS ISO or PXE install

You can use the live ISO image or PXE environment to install RHCOS by injecting an Ignition config file directly into the image. This creates a customized image that you can use to provision your system.

For an ISO image, the mechanism to do this is the coreos-installer iso customize subcommand, which modifies the .iso file with your configuration. Similarly, the mechanism for a PXE environment is the coreos-installer pxe customize subcommand, which creates a new initramfs file that includes your customizations.

The customize subcommand is a general purpose tool that can embed other types of customizations as well. The following tasks are examples of some of the more common customizations:

  • Inject custom CA certificates for when corporate security policy requires their use.
  • Configure network settings without the need for kernel arguments.
  • Embed arbitrary preinstall and post-install scripts or binaries.
2.3.12.3.7. Customizing a live RHCOS ISO image

You can customize a live RHCOS ISO image directly with the coreos-installer iso customize subcommand. When you boot the ISO image, the customizations are applied automatically.

You can use this feature to configure the ISO image to automatically install RHCOS.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and the Ignition config file, and then run the following command to inject the Ignition config directly into the ISO image:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
        --dest-ignition bootstrap.ign \ 1
        --dest-device /dev/disk/by-id/scsi-<serial_number> 2
    1
    The Ignition config file that is generated from the openshift-installer installation program.
    2
    When you specify this option, the ISO image automatically runs an installation. Otherwise, the image remains configured for installation, but does not install automatically unless you specify the coreos.inst.install_dev kernel argument.
  3. Optional: To remove the ISO image customizations and return the image to its pristine state, run:

    $ coreos-installer iso reset rhcos-<version>-live.x86_64.iso

    You can now re-customize the live ISO image or use it in its pristine state.

Applying your customizations affects every subsequent boot of RHCOS.

2.3.12.3.7.1. Modifying a live install ISO image to enable the serial console

On clusters installed with OpenShift Container Platform 4.12 and above, the serial console is disabled by default and all output is written to the graphical console. You can enable the serial console with the following procedure.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image to enable the serial console to receive output:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
      --dest-ignition <path> \1
      --dest-console tty0 \2
      --dest-console ttyS0,<options> \3
      --dest-device /dev/disk/by-id/scsi-<serial_number> 4
    1
    The location of the Ignition config to install.
    2
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    3
    The desired primary console. In this case, the serial console. The options field defines the baud rate and other settings. A common value for this field is 115200n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see the Linux kernel serial console documentation.
    4
    The specified disk to install to. If you omit this option, the ISO image automatically runs the installation program which will fail unless you also specify the coreos.inst.install_dev kernel argument.
    Note

    The --dest-console option affects the installed system and not the live ISO system. To modify the console for a live ISO system, use the --live-karg-append option and specify the console with console=.

    Your customizations are applied and affect every subsequent boot of the ISO image.

  3. Optional: To remove the ISO image customizations and return the image to its original state, run the following command:

    $ coreos-installer iso reset rhcos-<version>-live.x86_64.iso

    You can now recustomize the live ISO image or use it in its original state.

2.3.12.3.7.2. Modifying a live install ISO image to use a custom certificate authority

You can provide certificate authority (CA) certificates to Ignition with the --ignition-ca flag of the customize subcommand. You can use the CA certificates during both the installation boot and when provisioning the installed system.

Note

Custom CA certificates affect how Ignition fetches remote resources but they do not affect the certificates installed onto the system.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image for use with a custom CA:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso --ignition-ca cert.pem
Important

The coreos.inst.ignition_url kernel parameter does not work with the --ignition-ca flag. You must use the --dest-ignition flag to create a customized image for each cluster.

Applying your custom CA certificate affects every subsequent boot of RHCOS.

2.3.12.3.7.3. Modifying a live install ISO image with customized network settings

You can embed a NetworkManager keyfile into the live ISO image and pass it through to the installed system with the --network-keyfile flag of the customize subcommand.

Warning

When creating a connection profile, you must use a .nmconnection filename extension in the filename of the connection profile. If you do not use a .nmconnection filename extension, the cluster will apply the connection profile to the live environment, but it will not apply the configuration when the cluster first boots up the nodes, resulting in a setup that does not work.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Create a connection profile for a bonded interface. For example, create the bond0.nmconnection file in your local directory with the following content:

    [connection]
    id=bond0
    type=bond
    interface-name=bond0
    multi-connect=1
    
    [bond]
    miimon=100
    mode=active-backup
    
    [ipv4]
    method=auto
    
    [ipv6]
    method=auto
  3. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em1.nmconnection file in your local directory with the following content:

    [connection]
    id=em1
    type=ethernet
    interface-name=em1
    master=bond0
    multi-connect=1
    slave-type=bond
  4. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em2.nmconnection file in your local directory with the following content:

    [connection]
    id=em2
    type=ethernet
    interface-name=em2
    master=bond0
    multi-connect=1
    slave-type=bond
  5. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with your configured networking:

    $ coreos-installer iso customize rhcos-<version>-live.x86_64.iso \
        --network-keyfile bond0.nmconnection \
        --network-keyfile bond0-proxy-em1.nmconnection \
        --network-keyfile bond0-proxy-em2.nmconnection

    Network settings are applied to the live system and are carried over to the destination system.

2.3.12.3.7.4. Customizing a live install ISO image for an iSCSI boot device

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with the following information:

    $ coreos-installer iso customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/disk/by-path/<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.initiator=<initiator_iqn> \ 5
        --dest-karg-append netroot=<target_iqn> \ 6
        -o custom.iso rhcos-<version>-live.x86_64.iso
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The location of the destination system. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    6
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.3.12.3.7.5. Customizing a live install ISO image for an iSCSI boot device with iBFT

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.
  2. Optional: you have multipathed your iSCSI target.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS ISO image from the RHCOS image mirror page and run the following command to customize the ISO image with the following information:

    $ coreos-installer iso customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/mapper/mpatha \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.firmware=1 \ 5
        --dest-karg-append rd.multipath=default \ 6
        -o custom.iso rhcos-<version>-live.x86_64.iso
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The path to the device. If you are using multipath, the multipath device, /dev/mapper/mpatha, If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI parameter is read from the BIOS firmware.
    6
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.3.12.3.8. Customizing a live RHCOS PXE environment

You can customize a live RHCOS PXE environment directly with the coreos-installer pxe customize subcommand. When you boot the PXE environment, the customizations are applied automatically.

You can use this feature to configure the PXE environment to automatically install RHCOS.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and the Ignition config file, and then run the following command to create a new initramfs file that contains the customizations from your Ignition config:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --dest-ignition bootstrap.ign \ 1
        --dest-device /dev/disk/by-id/scsi-<serial_number> \ 2
        -o rhcos-<version>-custom-initramfs.x86_64.img 3
    1
    The Ignition config file that is generated from openshift-installer.
    2
    When you specify this option, the PXE environment automatically runs an install. Otherwise, the image remains configured for installing, but does not do so automatically unless you specify the coreos.inst.install_dev kernel argument.
    3
    Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

Applying your customizations affects every subsequent boot of RHCOS.

2.3.12.3.8.1. Modifying a live install PXE environment to enable the serial console

On clusters installed with OpenShift Container Platform 4.12 and above, the serial console is disabled by default and all output is written to the graphical console. You can enable the serial console with the following procedure.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and the Ignition config file, and then run the following command to create a new customized initramfs file that enables the serial console to receive output:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
      --dest-ignition <path> \1
      --dest-console tty0 \2
      --dest-console ttyS0,<options> \3
      --dest-device /dev/disk/by-id/scsi-<serial_number> \4
      -o rhcos-<version>-custom-initramfs.x86_64.img 5
    1
    The location of the Ignition config to install.
    2
    The desired secondary console. In this case, the graphical console. Omitting this option will disable the graphical console.
    3
    The desired primary console. In this case, the serial console. The options field defines the baud rate and other settings. A common value for this field is 115200n8. If no options are provided, the default kernel value of 9600n8 is used. For more information on the format of this option, see the Linux kernel serial console documentation.
    4
    The specified disk to install to. If you omit this option, the PXE environment automatically runs the installer which will fail unless you also specify the coreos.inst.install_dev kernel argument.
    5
    Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

    Your customizations are applied and affect every subsequent boot of the PXE environment.

2.3.12.3.8.2. Modifying a live install PXE environment to use a custom certificate authority

You can provide certificate authority (CA) certificates to Ignition with the --ignition-ca flag of the customize subcommand. You can use the CA certificates during both the installation boot and when provisioning the installed system.

Note

Custom CA certificates affect how Ignition fetches remote resources but they do not affect the certificates installed onto the system.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file for use with a custom CA:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --ignition-ca cert.pem \
        -o rhcos-<version>-custom-initramfs.x86_64.img
  3. Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.
Important

The coreos.inst.ignition_url kernel parameter does not work with the --ignition-ca flag. You must use the --dest-ignition flag to create a customized image for each cluster.

Applying your custom CA certificate affects every subsequent boot of RHCOS.

2.3.12.3.8.3. Modifying a live install PXE environment with customized network settings

You can embed a NetworkManager keyfile into the live PXE environment and pass it through to the installed system with the --network-keyfile flag of the customize subcommand.

Warning

When creating a connection profile, you must use a .nmconnection filename extension in the filename of the connection profile. If you do not use a .nmconnection filename extension, the cluster will apply the connection profile to the live environment, but it will not apply the configuration when the cluster first boots up the nodes, resulting in a setup that does not work.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Create a connection profile for a bonded interface. For example, create the bond0.nmconnection file in your local directory with the following content:

    [connection]
    id=bond0
    type=bond
    interface-name=bond0
    multi-connect=1
    
    [bond]
    miimon=100
    mode=active-backup
    
    [ipv4]
    method=auto
    
    [ipv6]
    method=auto
  3. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em1.nmconnection file in your local directory with the following content:

    [connection]
    id=em1
    type=ethernet
    interface-name=em1
    master=bond0
    multi-connect=1
    slave-type=bond
  4. Create a connection profile for a secondary interface to add to the bond. For example, create the bond0-proxy-em2.nmconnection file in your local directory with the following content:

    [connection]
    id=em2
    type=ethernet
    interface-name=em2
    master=bond0
    multi-connect=1
    slave-type=bond
  5. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file that contains your configured networking:

    $ coreos-installer pxe customize rhcos-<version>-live-initramfs.x86_64.img \
        --network-keyfile bond0.nmconnection \
        --network-keyfile bond0-proxy-em1.nmconnection \
        --network-keyfile bond0-proxy-em2.nmconnection \
        -o rhcos-<version>-custom-initramfs.x86_64.img
  6. Use the customized initramfs file in your PXE configuration. Add the ignition.firstboot and ignition.platform.id=metal kernel arguments if they are not already present.

    Network settings are applied to the live system and are carried over to the destination system.

2.3.12.3.8.4. Customizing a live install PXE environment for an iSCSI boot device

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file with the following information:

    $ coreos-installer pxe customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/disk/by-path/<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.initiator=<initiator_iqn> \ 5
        --dest-karg-append netroot=<target_iqn> \ 6
        -o custom.img rhcos-<version>-live-initramfs.x86_64.img
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target and any commands enabling multipathing.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The location of the destination system. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    6
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.3.12.3.8.5. Customizing a live install PXE environment for an iSCSI boot device with iBFT

You can set the iSCSI target and initiator values for automatic mounting, booting and configuration using a customized version of the live RHCOS image.

Prerequisites

  1. You have an iSCSI target you want to install RHCOS on.
  2. Optional: you have multipathed your iSCSI target.

Procedure

  1. Download the coreos-installer binary from the coreos-installer image mirror page.
  2. Retrieve the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page and run the following command to create a new customized initramfs file with the following information:

    $ coreos-installer pxe customize \
        --pre-install mount-iscsi.sh \ 1
        --post-install unmount-iscsi.sh \ 2
        --dest-device /dev/mapper/mpatha \ 3
        --dest-ignition config.ign \ 4
        --dest-karg-append rd.iscsi.firmware=1 \ 5
        --dest-karg-append rd.multipath=default \ 6
        -o custom.img rhcos-<version>-live-initramfs.x86_64.img
    1
    The script that gets run before installation. It should contain the iscsiadm commands for mounting the iSCSI target.
    2
    The script that gets run after installation. It should contain the command iscsiadm --mode node --logout=all.
    3
    The path to the device. If you are using multipath, the multipath device, /dev/mapper/mpatha, If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    4
    The Ignition configuration for the destination system.
    5
    The iSCSI parameter is read from the BIOS firmware.
    6
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

2.3.12.3.9. Advanced RHCOS installation reference

This section illustrates the networking configuration and other advanced options that allow you to modify the Red Hat Enterprise Linux CoreOS (RHCOS) manual installation process. The following tables describe the kernel arguments and command-line options you can use with the RHCOS live installer and the coreos-installer command.

2.3.12.3.9.1. Networking and bonding options for ISO installations

If you install RHCOS from an ISO image, you can add kernel arguments manually when you boot the image to configure networking for a node. If no networking arguments are specified, DHCP is activated in the initramfs when RHCOS detects that networking is required to fetch the Ignition config file.

Important

When adding networking arguments manually, you must also add the rd.neednet=1 kernel argument to bring the network up in the initramfs.

The following information provides examples for configuring networking and bonding on your RHCOS nodes for ISO installations. The examples describe how to use the ip=, nameserver=, and bond= kernel arguments.

Note

Ordering is important when adding the kernel arguments: ip=, nameserver=, and then bond=.

The networking options are passed to the dracut tool during system boot. For more information about the networking options supported by dracut, see the dracut.cmdline manual page.

The following examples are the networking options for ISO installation.

Configuring DHCP or static IP addresses

To configure an IP address, either use DHCP (ip=dhcp) or set an individual static IP address (ip=<host_ip>). If setting a static IP, you must then identify the DNS server IP address (nameserver=<dns_ip>) on each node. The following example sets:

  • The node’s IP address to 10.10.10.2
  • The gateway address to 10.10.10.254
  • The netmask to 255.255.255.0
  • The hostname to core0.example.com
  • The DNS server address to 4.4.4.41
  • The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
nameserver=4.4.4.41
Note

When you use DHCP to configure IP addressing for the RHCOS machines, the machines also obtain the DNS server information through DHCP. For DHCP-based deployments, you can define the DNS server address that is used by the RHCOS nodes through your DHCP server configuration.

Configuring an IP address without a static hostname

You can configure an IP address without assigning a static hostname. If a static hostname is not set by the user, it will be picked up and automatically set by a reverse DNS lookup. To configure an IP address without a static hostname refer to the following example:

  • The node’s IP address to 10.10.10.2
  • The gateway address to 10.10.10.254
  • The netmask to 255.255.255.0
  • The DNS server address to 4.4.4.41
  • The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0::enp1s0:none
nameserver=4.4.4.41
Specifying multiple network interfaces

You can specify multiple network interfaces by setting multiple ip= entries.

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
Configuring default gateway and route

Optional: You can configure routes to additional networks by setting an rd.route= value.

Note

When you configure one or multiple networks, one default gateway is required. If the additional network gateway is different from the primary network gateway, the default gateway must be the primary network gateway.

  • Run the following command to configure the default gateway:

    ip=::10.10.10.254::::
  • Enter the following command to configure the route for the additional network:

    rd.route=20.20.20.0/24:20.20.20.254:enp2s0
Disabling DHCP on a single interface

You can disable DHCP on a single interface, such as when there are two or more network interfaces and only one interface is being used. In the example, the enp1s0 interface has a static networking configuration and DHCP is disabled for enp2s0, which is not used:

ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=::::core0.example.com:enp2s0:none
Combining DHCP and static IP configurations

You can combine DHCP and static IP configurations on systems with multiple network interfaces, for example:

ip=enp1s0:dhcp
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
Configuring VLANs on individual interfaces

Optional: You can configure VLANs on individual interfaces by using the vlan= parameter.

  • To configure a VLAN on a network interface and use a static IP address, run the following command:

    ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0.100:none
    vlan=enp2s0.100:enp2s0
  • To configure a VLAN on a network interface and to use DHCP, run the following command:

    ip=enp2s0.100:dhcp
    vlan=enp2s0.100:enp2s0
Providing multiple DNS servers

You can provide multiple DNS servers by adding a nameserver= entry for each server, for example:

nameserver=1.1.1.1
nameserver=8.8.8.8
Bonding multiple network interfaces to a single interface

Optional: You can bond multiple network interfaces to a single interface by using the bond= option. Refer to the following examples:

  • The syntax for configuring a bonded interface is: bond=<name>[:<network_interfaces>][:options]

    <name> is the bonding device name (bond0), <network_interfaces> represents a comma-separated list of physical (ethernet) interfaces (em1,em2), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.

  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

    • To configure the bonded interface to use DHCP, set the bond’s IP address to dhcp. For example:

      bond=bond0:em1,em2:mode=active-backup
      ip=bond0:dhcp
    • To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:

      bond=bond0:em1,em2:mode=active-backup
      ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Bonding multiple SR-IOV network interfaces to a dual port NIC interface

Optional: You can bond multiple SR-IOV network interfaces to a dual port NIC interface by using the bond= option.

On each node, you must perform the following tasks:

  1. Create the SR-IOV virtual functions (VFs) following the guidance in Managing SR-IOV devices. Follow the procedure in the "Attaching SR-IOV networking devices to virtual machines" section.
  2. Create the bond, attach the desired VFs to the bond and set the bond link state up following the guidance in Configuring network bonding. Follow any of the described procedures to create the bond.

The following examples illustrate the syntax you must use:

  • The syntax for configuring a bonded interface is bond=<name>[:<network_interfaces>][:options].

    <name> is the bonding device name (bond0), <network_interfaces> represents the virtual functions (VFs) by their known name in the kernel and shown in the output of the ip link command(eno1f0, eno2f0), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.

  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

    • To configure the bonded interface to use DHCP, set the bond’s IP address to dhcp. For example:

      bond=bond0:eno1f0,eno2f0:mode=active-backup
      ip=bond0:dhcp
    • To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:

      bond=bond0:eno1f0,eno2f0:mode=active-backup
      ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Using network teaming

Optional: You can use a network teaming as an alternative to bonding by using the team= parameter:

  • The syntax for configuring a team interface is: team=name[:network_interfaces]

    name is the team device name (team0) and network_interfaces represents a comma-separated list of physical (ethernet) interfaces (em1, em2).

Note

Teaming is planned to be deprecated when RHCOS switches to an upcoming version of RHEL. For more information, see this Red Hat Knowledgebase Article.

Use the following example to configure a network team:

team=team0:em1,em2
ip=team0:dhcp
2.3.12.3.9.2. coreos-installer options for ISO and PXE installations

You can install RHCOS by running coreos-installer install <options> <device> at the command prompt, after booting into the RHCOS live environment from an ISO image.

The following table shows the subcommands, options, and arguments you can pass to the coreos-installer command.

Table 2.39. coreos-installer subcommands, command-line options, and arguments

coreos-installer install subcommand

Subcommand

Description

$ coreos-installer install <options> <device>

Embed an Ignition config in an ISO image.

coreos-installer install subcommand options

Option

Description

-u, --image-url <url>

Specify the image URL manually.

-f, --image-file <path>

Specify a local image file manually. Used for debugging.

-i, --ignition-file <path>

Embed an Ignition config from a file.

-I, --ignition-url <URL>

Embed an Ignition config from a URL.

--ignition-hash <digest>

Digest type-value of the Ignition config.

-p, --platform <name>

Override the Ignition platform ID for the installed system.

--console <spec>

Set the kernel and bootloader console for the installed system. For more information about the format of <spec>, see the Linux kernel serial console documentation.

--append-karg <arg>…​

Append a default kernel argument to the installed system.

--delete-karg <arg>…​

Delete a default kernel argument from the installed system.

-n, --copy-network

Copy the network configuration from the install environment.

Important

The --copy-network option only copies networking configuration found under /etc/NetworkManager/system-connections. In particular, it does not copy the system hostname.

--network-dir <path>

For use with -n. Default is /etc/NetworkManager/system-connections/.

--save-partlabel <lx>..

Save partitions with this label glob.

--save-partindex <id>…​

Save partitions with this number or range.

--insecure

Skip RHCOS image signature verification.

--insecure-ignition

Allow Ignition URL without HTTPS or hash.

--architecture <name>

Target CPU architecture. Valid values are x86_64 and aarch64.

--preserve-on-error

Do not clear partition table on error.

-h, --help

Print help information.

coreos-installer install subcommand argument

Argument

Description

<device>

The destination device.

coreos-installer ISO subcommands

Subcommand

Description

$ coreos-installer iso customize <options> <ISO_image>

Customize a RHCOS live ISO image.

coreos-installer iso reset <options> <ISO_image>

Restore a RHCOS live ISO image to default settings.

coreos-installer iso ignition remove <options> <ISO_image>

Remove the embedded Ignition config from an ISO image.

coreos-installer ISO customize subcommand options

Option

Description

--dest-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the destination system.

--dest-console <spec>

Specify the kernel and bootloader console for the destination system.

--dest-device <path>

Install and overwrite the specified destination device.

--dest-karg-append <arg>

Add a kernel argument to each boot of the destination system.

--dest-karg-delete <arg>

Delete a kernel argument from each boot of the destination system.

--network-keyfile <path>

Configure networking by using the specified NetworkManager keyfile for live and destination systems.

--ignition-ca <path>

Specify an additional TLS certificate authority to be trusted by Ignition.

--pre-install <path>

Run the specified script before installation.

--post-install <path>

Run the specified script after installation.

--installer-config <path>

Apply the specified installer configuration file.

--live-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the live environment.

--live-karg-append <arg>

Add a kernel argument to each boot of the live environment.

--live-karg-delete <arg>

Delete a kernel argument from each boot of the live environment.

--live-karg-replace <k=o=n>

Replace a kernel argument in each boot of the live environment, in the form key=old=new.

-f, --force

Overwrite an existing Ignition config.

-o, --output <path>

Write the ISO to a new output file.

-h, --help

Print help information.

coreos-installer PXE subcommands

Subcommand

Description

Note that not all of these options are accepted by all subcommands.

coreos-installer pxe customize <options> <path>

Customize a RHCOS live PXE boot config.

coreos-installer pxe ignition wrap <options>

Wrap an Ignition config in an image.

coreos-installer pxe ignition unwrap <options> <image_name>

Show the wrapped Ignition config in an image.

coreos-installer PXE customize subcommand options

Option

Description

Note that not all of these options are accepted by all subcommands.

--dest-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the destination system.

--dest-console <spec>

Specify the kernel and bootloader console for the destination system.

--dest-device <path>

Install and overwrite the specified destination device.

--network-keyfile <path>

Configure networking by using the specified NetworkManager keyfile for live and destination systems.

--ignition-ca <path>

Specify an additional TLS certificate authority to be trusted by Ignition.

--pre-install <path>

Run the specified script before installation.

post-install <path>

Run the specified script after installation.

--installer-config <path>

Apply the specified installer configuration file.

--live-ignition <path>

Merge the specified Ignition config file into a new configuration fragment for the live environment.

-o, --output <path>

Write the initramfs to a new output file.

Note

This option is required for PXE environments.

-h, --help

Print help information.

2.3.12.3.9.3. coreos.inst boot options for ISO or PXE installations

You can automatically invoke coreos-installer options at boot time by passing coreos.inst boot arguments to the RHCOS live installer. These are provided in addition to the standard boot arguments.

  • For ISO installations, the coreos.inst options can be added by interrupting the automatic boot at the bootloader menu. You can interrupt the automatic boot by pressing TAB while the RHEL CoreOS (Live) menu option is highlighted.
  • For PXE or iPXE installations, the coreos.inst options must be added to the APPEND line before the RHCOS live installer is booted.

The following table shows the RHCOS live installer coreos.inst boot options for ISO and PXE installations.

Table 2.40. coreos.inst boot options
ArgumentDescription

coreos.inst.install_dev

Required. The block device on the system to install to. It is recommended to use the full path, such as /dev/sda, although sda is allowed.

coreos.inst.ignition_url

Optional: The URL of the Ignition config to embed into the installed system. If no URL is specified, no Ignition config is embedded. Only HTTP and HTTPS protocols are supported.

coreos.inst.save_partlabel

Optional: Comma-separated labels of partitions to preserve during the install. Glob-style wildcards are permitted. The specified partitions do not need to exist.

coreos.inst.save_partindex

Optional: Comma-separated indexes of partitions to preserve during the install. Ranges m-n are permitted, and either m or n can be omitted. The specified partitions do not need to exist.

coreos.inst.insecure

Optional: Permits the OS image that is specified by coreos.inst.image_url to be unsigned.

coreos.inst.image_url

Optional: Download and install the specified RHCOS image.

  • This argument should not be used in production environments and is intended for debugging purposes only.
  • While this argument can be used to install a version of RHCOS that does not match the live media, it is recommended that you instead use the media that matches the version you want to install.
  • If you are using coreos.inst.image_url, you must also use coreos.inst.insecure. This is because the bare-metal media are not GPG-signed for OpenShift Container Platform.
  • Only HTTP and HTTPS protocols are supported.

coreos.inst.skip_reboot

Optional: The system will not reboot after installing. After the install finishes, you will receive a prompt that allows you to inspect what is happening during installation. This argument should not be used in production environments and is intended for debugging purposes only.

coreos.inst.platform_id

Optional: The Ignition platform ID of the platform the RHCOS image is being installed on. Default is metal. This option determines whether or not to request an Ignition config from the cloud provider, such as VMware. For example: coreos.inst.platform_id=vmware.

ignition.config.url

Optional: The URL of the Ignition config for the live boot. For example, this can be used to customize how coreos-installer is invoked, or to run code before or after the installation. This is different from coreos.inst.ignition_url, which is the Ignition config for the installed system.

2.3.12.4. Enabling multipathing with kernel arguments on RHCOS

RHCOS supports multipathing on the primary disk, allowing stronger resilience to hardware failure to achieve higher host availability.

You can enable multipathing at installation time for nodes that were provisioned in OpenShift Container Platform 4.8 or later. While postinstallation support is available by activating multipathing via the machine config, enabling multipathing during installation is recommended.

In setups where any I/O to non-optimized paths results in I/O system errors, you must enable multipathing at installation time.

Important

On IBM Z® and IBM® LinuxONE, you can enable multipathing only if you configured your cluster for it during installation. For more information, see "Installing RHCOS and starting the OpenShift Container Platform bootstrap process" in Installing a cluster with z/VM on IBM Z® and IBM® LinuxONE.

The following procedure enables multipath at installation time and appends kernel arguments to the coreos-installer install command so that the installed system itself will use multipath beginning from the first boot.

Note

OpenShift Container Platform does not support enabling multipathing as a day-2 activity on nodes that have been upgraded from 4.6 or earlier.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have reviewed Installing RHCOS and starting the OpenShift Container Platform bootstrap process.

Procedure

  1. To enable multipath and start the multipathd daemon, run the following command on the installation host:

    $ mpathconf --enable && systemctl start multipathd.service
    • Optional: If booting the PXE or ISO, you can instead enable multipath by adding rd.multipath=default from the kernel command line.
  2. Append the kernel arguments by invoking the coreos-installer program:

    • If there is only one multipath device connected to the machine, it should be available at path /dev/mapper/mpatha. For example:

      $ coreos-installer install /dev/mapper/mpatha \1
      --ignition-url=http://host/worker.ign \
      --append-karg rd.multipath=default \
      --append-karg root=/dev/disk/by-label/dm-mpath-root \
      --append-karg rw
      1
      Indicates the path of the single multipathed device.
    • If there are multiple multipath devices connected to the machine, or to be more explicit, instead of using /dev/mapper/mpatha, it is recommended to use the World Wide Name (WWN) symlink available in /dev/disk/by-id. For example:

      $ coreos-installer install /dev/disk/by-id/wwn-<wwn_ID> \1
      --ignition-url=http://host/worker.ign \
      --append-karg rd.multipath=default \
      --append-karg root=/dev/disk/by-label/dm-mpath-root \
      --append-karg rw
      1
      Indicates the WWN ID of the target multipathed device. For example, 0xx194e957fcedb4841.

      This symlink can also be used as the coreos.inst.install_dev kernel argument when using special coreos.inst.* arguments to direct the live installer. For more information, see "Installing RHCOS and starting the OpenShift Container Platform bootstrap process".

  3. Reboot into the installed system.
  4. Check that the kernel arguments worked by going to one of the worker nodes and listing the kernel command line arguments (in /proc/cmdline on the host):

    $ oc debug node/ip-10-0-141-105.ec2.internal

    Example output

    Starting pod/ip-10-0-141-105ec2internal-debug ...
    To use host binaries, run `chroot /host`
    
    sh-4.2# cat /host/proc/cmdline
    ...
    rd.multipath=default root=/dev/disk/by-label/dm-mpath-root
    ...
    
    sh-4.2# exit

    You should see the added kernel arguments.

2.3.12.4.1. Enabling multipathing on secondary disks

RHCOS also supports multipathing on a secondary disk. Instead of kernel arguments, you use Ignition to enable multipathing for the secondary disk at installation time.

Prerequisites

  • You have read the section Disk partitioning.
  • You have read Enabling multipathing with kernel arguments on RHCOS.
  • You have installed the Butane utility.

Procedure

  1. Create a Butane config with information similar to the following:

    Example multipath-config.bu

    variant: openshift
    version: 4.18.0
    systemd:
      units:
        - name: mpath-configure.service
          enabled: true
          contents: |
            [Unit]
            Description=Configure Multipath on Secondary Disk
            ConditionFirstBoot=true
            ConditionPathExists=!/etc/multipath.conf
            Before=multipathd.service 1
            DefaultDependencies=no
    
            [Service]
            Type=oneshot
            ExecStart=/usr/sbin/mpathconf --enable 2
    
            [Install]
            WantedBy=multi-user.target
        - name: mpath-var-lib-container.service
          enabled: true
          contents: |
            [Unit]
            Description=Set Up Multipath On /var/lib/containers
            ConditionFirstBoot=true 3
            Requires=dev-mapper-mpatha.device
            After=dev-mapper-mpatha.device
            After=ostree-remount.service
            Before=kubelet.service
            DefaultDependencies=no
    
            [Service] 4
            Type=oneshot
            ExecStart=/usr/sbin/mkfs.xfs -L containers -m reflink=1 /dev/mapper/mpatha
            ExecStart=/usr/bin/mkdir -p /var/lib/containers
    
            [Install]
            WantedBy=multi-user.target
        - name: var-lib-containers.mount
          enabled: true
          contents: |
            [Unit]
            Description=Mount /var/lib/containers
            After=mpath-var-lib-containers.service
            Before=kubelet.service 5
    
            [Mount] 6
            What=/dev/disk/by-label/dm-mpath-containers
            Where=/var/lib/containers
            Type=xfs
    
            [Install]
            WantedBy=multi-user.target

    1
    The configuration must be set before launching the multipath daemon.
    2
    Starts the mpathconf utility.
    3
    This field must be set to the value true.
    4
    Creates the filesystem and directory /var/lib/containers.
    5
    The device must be mounted before starting any nodes.
    6
    Mounts the device to the /var/lib/containers mount point. This location cannot be a symlink.
  2. Create the Ignition configuration by running the following command:

    $ butane --pretty --strict multipath-config.bu > multipath-config.ign
  3. Continue with the rest of the first boot RHCOS installation process.

    Important

    Do not add the rd.multipath or root kernel arguments on the command-line during installation unless the primary disk is also multipathed.

2.3.12.5. Installing RHCOS manually on an iSCSI boot device

You can manually install RHCOS on an iSCSI target.

Prerequisites

  1. You are in the RHCOS live environment.
  2. You have an iSCSI target that you want to install RHCOS on.

Procedure

  1. Mount the iSCSI target from the live environment by running the following command:

    $ iscsiadm \
        --mode discovery \
        --type sendtargets
        --portal <IP_address> \ 1
        --login
    1
    The IP address of the target portal.
  2. Install RHCOS onto the iSCSI target by running the following command and using the necessary kernel arguments, for example:

    $ coreos-installer install \
        /dev/disk/by-path/ip-<IP_address>:<port>-iscsi-<target_iqn>-lun-<lun> \ 1
        --append-karg rd.iscsi.initiator=<initiator_iqn> \ 2
        --append.karg netroot=<target_iqn> \ 3
        --console ttyS0,115200n8
        --ignition-file <path_to_file>
    1
    The location you are installing to. You must provide the IP address of the target portal, the associated port number, the target iSCSI node in IQN format, and the iSCSI logical unit number (LUN).
    2
    The iSCSI initiator, or client, name in IQN format. The initiator forms a session to connect to the iSCSI target.
    3
    The the iSCSI target, or server, name in IQN format.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

  3. Unmount the iSCSI disk with the following command:

    $ iscsiadm --mode node --logoutall=all

This procedure can also be performed using the coreos-installer iso customize or coreos-installer pxe customize subcommands.

2.3.12.6. Installing RHCOS on an iSCSI boot device using iBFT

On a completely diskless machine, the iSCSI target and initiator values can be passed through iBFT. iSCSI multipathing is also supported.

Prerequisites

  1. You are in the RHCOS live environment.
  2. You have an iSCSI target you want to install RHCOS on.
  3. Optional: you have multipathed your iSCSI target.

Procedure

  1. Mount the iSCSI target from the live environment by running the following command:

    $ iscsiadm \
        --mode discovery \
        --type sendtargets
        --portal <IP_address> \ 1
        --login
    1
    The IP address of the target portal.
  2. Optional: enable multipathing and start the daemon with the following command:

    $ mpathconf --enable && systemctl start multipathd.service
  3. Install RHCOS onto the iSCSI target by running the following command and using the necessary kernel arguments, for example:

    $ coreos-installer install \
        /dev/mapper/mpatha \ 1
        --append-karg rd.iscsi.firmware=1 \ 2
        --append-karg rd.multipath=default \ 3
        --console ttyS0 \
        --ignition-file <path_to_file>
    1
    The path of a single multipathed device. If there are multiple multipath devices connected, or to be explicit, you can use the World Wide Name (WWN) symlink available in /dev/disk/by-path.
    2
    The iSCSI parameter is read from the BIOS firmware.
    3
    Optional: include this parameter if you are enabling multipathing.

    For more information about the iSCSI options supported by dracut, see the dracut.cmdline manual page.

  4. Unmount the iSCSI disk:

    $ iscsiadm --mode node --logout=all

This procedure can also be performed using the coreos-installer iso customize or coreos-installer pxe customize subcommands.

2.3.13. Waiting for the bootstrap process to complete

The OpenShift Container Platform bootstrap process begins after the cluster nodes first boot into the persistent RHCOS environment that has been installed to disk. The configuration information provided through the Ignition config files is used to initialize the bootstrap process and install OpenShift Container Platform on the machines. You must wait for the bootstrap process to complete.

Prerequisites

  • You have created the Ignition config files for your cluster.
  • You have configured suitable network, DNS and load balancing infrastructure.
  • You have obtained the installation program and generated the Ignition config files for your cluster.
  • You installed RHCOS on your cluster machines and provided the Ignition config files that the OpenShift Container Platform installation program generated.

Procedure

  1. Monitor the bootstrap process:

    $ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ 1
        --log-level=info 2
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.
    2
    To view different installation details, specify warn, debug, or error instead of info.

    Example output

    INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
    INFO API v1.31.3 up
    INFO Waiting up to 30m0s for bootstrapping to complete...
    INFO It is now safe to remove the bootstrap resources

    The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.

  2. After the bootstrap process is complete, remove the bootstrap machine from the load balancer.

    Important

    You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the bootstrap machine itself.

Additional resources

2.3.14. Logging in to the cluster by using the CLI

You can log in to your cluster as a default system user by exporting the cluster kubeconfig file. The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server. The file is specific to a cluster and is created during OpenShift Container Platform installation.

Prerequisites

  • You deployed an OpenShift Container Platform cluster.
  • You installed the oc CLI.

Procedure

  1. Export the kubeadmin credentials:

    $ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.
  2. Verify you can run oc commands successfully using the exported configuration:

    $ oc whoami

    Example output

    system:admin

2.3.15. Approving the certificate signing requests for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.

Prerequisites

  • You added machines to your cluster.

Procedure

  1. Confirm that the cluster recognizes the machines:

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
    master-0  Ready     master  63m  v1.31.3
    master-1  Ready     master  63m  v1.31.3
    master-2  Ready     master  64m  v1.31.3

    The output lists all of the machines that you created.

    Note

    The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.

  2. Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

    $ oc get csr

    Example output

    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    ...

    In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

  3. If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:

    Note

    Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. After the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.

    Note

    For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the oc exec, oc rsh, and oc logs commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the node-bootstrapper service account in the system:node or system:admin groups, and confirm the identity of the node.

    • To approve them individually, run the following command for each valid CSR:

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
      Note

      Some Operators might not become available until some CSRs are approved.

  4. Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

    $ oc get csr

    Example output

    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
    csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
    ...

  5. If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:

    • To approve them individually, run the following command for each valid CSR:

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
  6. After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
    master-0  Ready     master  73m  v1.31.3
    master-1  Ready     master  73m  v1.31.3
    master-2  Ready     master  74m  v1.31.3
    worker-0  Ready     worker  11m  v1.31.3
    worker-1  Ready     worker  11m  v1.31.3

    Note

    It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

2.3.16. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

  • Your control plane has initialized.

Procedure

  1. Watch the cluster components come online:

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.18.0    True        False         False      19m
    baremetal                                  4.18.0    True        False         False      37m
    cloud-credential                           4.18.0    True        False         False      40m
    cluster-autoscaler                         4.18.0    True        False         False      37m
    config-operator                            4.18.0    True        False         False      38m
    console                                    4.18.0    True        False         False      26m
    csi-snapshot-controller                    4.18.0    True        False         False      37m
    dns                                        4.18.0    True        False         False      37m
    etcd                                       4.18.0    True        False         False      36m
    image-registry                             4.18.0    True        False         False      31m
    ingress                                    4.18.0    True        False         False      30m
    insights                                   4.18.0    True        False         False      31m
    kube-apiserver                             4.18.0    True        False         False      26m
    kube-controller-manager                    4.18.0    True        False         False      36m
    kube-scheduler                             4.18.0    True        False         False      36m
    kube-storage-version-migrator              4.18.0    True        False         False      37m
    machine-api                                4.18.0    True        False         False      29m
    machine-approver                           4.18.0    True        False         False      37m
    machine-config                             4.18.0    True        False         False      36m
    marketplace                                4.18.0    True        False         False      37m
    monitoring                                 4.18.0    True        False         False      29m
    network                                    4.18.0    True        False         False      38m
    node-tuning                                4.18.0    True        False         False      37m
    openshift-apiserver                        4.18.0    True        False         False      32m
    openshift-controller-manager               4.18.0    True        False         False      30m
    openshift-samples                          4.18.0    True        False         False      32m
    operator-lifecycle-manager                 4.18.0    True        False         False      37m
    operator-lifecycle-manager-catalog         4.18.0    True        False         False      37m
    operator-lifecycle-manager-packageserver   4.18.0    True        False         False      32m
    service-ca                                 4.18.0    True        False         False      38m
    storage                                    4.18.0    True        False         False      37m

  2. Configure the Operators that are not available.

Additional resources

2.3.16.1. Disabling the default OperatorHub catalog sources

Operator catalogs that source content provided by Red Hat and community projects are configured for OperatorHub by default during an OpenShift Container Platform installation. In a restricted network environment, you must disable the default catalogs as a cluster administrator.

Procedure

  • Disable the sources for the default catalogs by adding disableAllDefaultSources: true to the OperatorHub object:

    $ oc patch OperatorHub cluster --type json \
        -p '[{"op": "add", "path": "/spec/disableAllDefaultSources", "value": true}]'
Tip

Alternatively, you can use the web console to manage catalog sources. From the AdministrationCluster SettingsConfigurationOperatorHub page, click the Sources tab, where you can create, update, delete, disable, and enable individual sources.

2.3.16.2. Image registry storage configuration

The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.

Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

2.3.16.2.1. Changing the image registry’s management state

To start the image registry, you must change the Image Registry Operator configuration’s managementState from Removed to Managed.

Procedure

  • Change managementState Image Registry Operator configuration from Removed to Managed. For example:

    $ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"managementState":"Managed"}}'
2.3.16.2.2. Configuring registry storage for bare metal and other manual installations

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites

  • You have access to the cluster as a user with the cluster-admin role.
  • You have a cluster that uses manually-provisioned Red Hat Enterprise Linux CoreOS (RHCOS) nodes, such as bare metal.
  • You have provisioned persistent storage for your cluster, such as Red Hat OpenShift Data Foundation.

    Important

    OpenShift Container Platform supports ReadWriteOnce access for image registry storage when you have only one replica. ReadWriteOnce access also requires that the registry uses the Recreate rollout strategy. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.

  • Must have 100Gi capacity.

Procedure

  1. To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.

    Note

    When you use shared storage, review your security settings to prevent outside access.

  2. Verify that you do not have a registry pod:

    $ oc get pod -n openshift-image-registry -l docker-registry=default

    Example output

    No resources found in openshift-image-registry namespace

    Note

    If you do have a registry pod in your output, you do not need to continue with this procedure.

  3. Check the registry configuration:

    $ oc edit configs.imageregistry.operator.openshift.io

    Example output

    storage:
      pvc:
        claim:

    Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.

  4. Check the clusteroperator status:

    $ oc get clusteroperator image-registry

    Example output

    NAME             VERSION              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
    image-registry   4.18                 True        False         False      6h50m

  5. Ensure that your registry is set to managed to enable building and pushing of images.

    • Run:

      $ oc edit configs.imageregistry/cluster

      Then, change the line

      managementState: Removed

      to

      managementState: Managed
2.3.16.2.3. Configuring storage for the image registry in non-production clusters

You must configure storage for the Image Registry Operator. For non-production clusters, you can set the image registry to an empty directory. If you do so, all images are lost if you restart the registry.

Procedure

  • To set the image registry storage to an empty directory:

    $ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'
    Warning

    Configure this option for only non-production clusters.

    If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:

    Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found

    Wait a few minutes and run the command again.

2.3.16.2.4. Configuring block registry storage for bare metal

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Important

Block storage volumes, or block persistent volumes, are supported but not recommended for use with the image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica.

If you choose to use a block storage volume with the image registry, you must use a filesystem persistent volume claim (PVC).

Procedure

  1. Enter the following command to set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy, and runs with only one (1) replica:

    $ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
  2. Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.

    1. Create a pvc.yaml file with the following contents to define a VMware vSphere PersistentVolumeClaim object:

      kind: PersistentVolumeClaim
      apiVersion: v1
      metadata:
        name: image-registry-storage 1
        namespace: openshift-image-registry 2
      spec:
        accessModes:
        - ReadWriteOnce 3
        resources:
          requests:
            storage: 100Gi 4
      1
      A unique name that represents the PersistentVolumeClaim object.
      2
      The namespace for the PersistentVolumeClaim object, which is openshift-image-registry.
      3
      The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node.
      4
      The size of the persistent volume claim.
    2. Enter the following command to create the PersistentVolumeClaim object from the file:

      $ oc create -f pvc.yaml -n openshift-image-registry
  3. Enter the following command to edit the registry configuration so that it references the correct PVC:

    $ oc edit config.imageregistry.operator.openshift.io -o yaml

    Example output

    storage:
      pvc:
        claim: 1

    1
    By creating a custom PVC, you can leave the claim field blank for the default automatic creation of an image-registry-storage PVC.

2.3.17. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

  • Your control plane has initialized.
  • You have completed the initial Operator configuration.

Procedure

  1. Confirm that all the cluster components are online with the following command:

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
    authentication                             4.18.0    True        False         False      19m
    baremetal                                  4.18.0    True        False         False      37m
    cloud-credential                           4.18.0    True        False         False      40m
    cluster-autoscaler                         4.18.0    True        False         False      37m
    config-operator                            4.18.0    True        False         False      38m
    console                                    4.18.0    True        False         False      26m
    csi-snapshot-controller                    4.18.0    True        False         False      37m
    dns                                        4.18.0    True        False         False      37m
    etcd                                       4.18.0    True        False         False      36m
    image-registry                             4.18.0    True        False         False      31m
    ingress                                    4.18.0    True        False         False      30m
    insights                                   4.18.0    True        False         False      31m
    kube-apiserver                             4.18.0    True        False         False      26m
    kube-controller-manager                    4.18.0    True        False         False      36m
    kube-scheduler                             4.18.0    True        False         False      36m
    kube-storage-version-migrator              4.18.0    True        False         False      37m
    machine-api                                4.18.0    True        False         False      29m
    machine-approver                           4.18.0    True        False         False      37m
    machine-config                             4.18.0    True        False         False      36m
    marketplace                                4.18.0    True        False         False      37m
    monitoring                                 4.18.0    True        False         False      29m
    network                                    4.18.0    True        False         False      38m
    node-tuning                                4.18.0    True        False         False      37m
    openshift-apiserver                        4.18.0    True        False         False      32m
    openshift-controller-manager               4.18.0    True        False         False      30m
    openshift-samples                          4.18.0    True        False         False      32m
    operator-lifecycle-manager                 4.18.0    True        False         False      37m
    operator-lifecycle-manager-catalog         4.18.0    True        False         False      37m
    operator-lifecycle-manager-packageserver   4.18.0    True        False         False      32m
    service-ca                                 4.18.0    True        False         False      38m
    storage                                    4.18.0    True        False         False      37m

    Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

    $ ./openshift-install --dir <installation_directory> wait-for install-complete 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.

    Example output

    INFO Waiting up to 30m0s for the cluster to initialize...

    The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

    Important
    • The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
    • It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.
  2. Confirm that the Kubernetes API server is communicating with the pods.

    1. To view a list of all pods, use the following command:

      $ oc get pods --all-namespaces

      Example output

      NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
      openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
      openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
      openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
      openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
      openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
      ...

    2. View the logs for a pod that is listed in the output of the previous command by using the following command:

      $ oc logs <pod_name> -n <namespace> 1
      1
      Specify the pod name and namespace, as shown in the output of the previous command.

      If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

  3. For an installation with Fibre Channel Protocol (FCP), additional steps are required to enable multipathing. Do not enable multipathing during installation.

    See "Enabling multipathing with kernel arguments on RHCOS" in the Postinstallation machine configuration tasks documentation for more information.

  4. Register your cluster on the Cluster registration page.

2.3.18. Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.18, the Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to OpenShift Cluster Manager.

After you confirm that your OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually by using OpenShift Cluster Manager, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.

Additional resources

2.3.19. Next steps

2.4. Scaling a user-provisioned cluster with the Bare Metal Operator

After deploying a user-provisioned infrastructure cluster, you can use the Bare Metal Operator (BMO) and other metal3 components to scale bare-metal hosts in the cluster. This approach helps you to scale a user-provisioned cluster in a more automated way.

2.4.1. About scaling a user-provisioned cluster with the Bare Metal Operator

You can scale user-provisioned infrastructure clusters by using the Bare Metal Operator (BMO) and other metal3 components. User-provisioned infrastructure installations do not feature the Machine API Operator. The Machine API Operator typically manages the lifecycle of bare-metal nodes in a cluster. However, it is possible to use the BMO and other metal3 components to scale nodes in user-provisioned clusters without requiring the Machine API Operator.

2.4.1.1. Prerequisites for scaling a user-provisioned cluster
  • You installed a user-provisioned infrastructure cluster on bare metal.
  • You have baseboard management controller (BMC) access to the hosts.
2.4.1.2. Limitations for scaling a user-provisioned cluster
  • You cannot use a provisioning network to scale user-provisioned infrastructure clusters by using the Bare Metal Operator (BMO).

    • Consequentially, you can only use bare-metal host drivers that support virtual media networking booting, for example redfish-virtualmedia and idrac-virtualmedia.
  • You cannot scale MachineSet objects in user-provisioned infrastructure clusters by using the BMO.

2.4.2. Configuring a provisioning resource to scale user-provisioned clusters

Create a Provisioning custom resource (CR) to enable Metal platform components on a user-provisioned infrastructure cluster.

Prerequisites

  • You installed a user-provisioned infrastructure cluster on bare metal.

Procedure

  1. Create a Provisioning CR.

    1. Save the following YAML in the provisioning.yaml file:

      apiVersion: metal3.io/v1alpha1
      kind: Provisioning
      metadata:
        name: provisioning-configuration
      spec:
        provisioningNetwork: "Disabled"
        watchAllNamespaces: false
      Note

      OpenShift Container Platform 4.18 does not support enabling a provisioning network when you scale a user-provisioned cluster by using the Bare Metal Operator.

  2. Create the Provisioning CR by running the following command:

    $ oc create -f provisioning.yaml

    Example output

    provisioning.metal3.io/provisioning-configuration created

Verification

  • Verify that the provisioning service is running by running the following command:

    $ oc get pods -n openshift-machine-api

    Example output

    NAME                                                  READY   STATUS    RESTARTS        AGE
    cluster-autoscaler-operator-678c476f4c-jjdn5          2/2     Running   0               5d21h
    cluster-baremetal-operator-6866f7b976-gmvgh           2/2     Running   0               5d21h
    control-plane-machine-set-operator-7d8566696c-bh4jz   1/1     Running   0               5d21h
    ironic-proxy-64bdw                                    1/1     Running   0               5d21h
    ironic-proxy-rbggf                                    1/1     Running   0               5d21h
    ironic-proxy-vj54c                                    1/1     Running   0               5d21h
    machine-api-controllers-544d6849d5-tgj9l              7/7     Running   1 (5d21h ago)   5d21h
    machine-api-operator-5c4ff4b86d-6fjmq                 2/2     Running   0               5d21h
    metal3-6d98f84cc8-zn2mx                               5/5     Running   0               5d21h
    metal3-image-customization-59d745768d-bhrp7           1/1     Running   0               5d21h

2.4.3. Provisioning new hosts in a user-provisioned cluster by using the BMO

You can use the Bare Metal Operator (BMO) to provision bare-metal hosts in a user-provisioned cluster by creating a BareMetalHost custom resource (CR).

Note

Provisioning bare-metal hosts to the cluster by using the BMO sets the spec.externallyProvisioned specification in the BareMetalHost custom resource to false by default. Do not set the spec.externallyProvisioned specification to true, because this setting results in unexpected behavior.

Prerequisites

  • You created a user-provisioned bare-metal cluster.
  • You have baseboard management controller (BMC) access to the hosts.
  • You deployed a provisioning service in the cluster by creating a Provisioning CR.

Procedure

  1. Create a configuration file for the bare-metal node. Depending if you use either a static configuration or a DHCP server, choose one of the following example bmh.yaml files and configure it to your needs by replacing values in the YAML to match your environment:

    • To deploy with a static configuration, create the following bmh.yaml file:

      ---
      apiVersion: v1
      kind: Secret
      metadata:
        name: openshift-worker-<num>-network-config-secret 1
        namespace: openshift-machine-api
      type: Opaque
      stringData:
        nmstate: | 2
          interfaces: 3
          - name: <nic1_name> 4
            type: ethernet
            state: up
            ipv4:
              address:
              - ip: <ip_address> 5
                prefix-length: 24
              enabled: true
          dns-resolver:
            config:
              server:
              - <dns_ip_address> 6
          routes:
            config:
            - destination: 0.0.0.0/0
              next-hop-address: <next_hop_ip_address> 7
              next-hop-interface: <next_hop_nic1_name> 8
      ---
      apiVersion: v1
      kind: Secret
      metadata:
        name: openshift-worker-<num>-bmc-secret
        namespace: openshift-machine-api
      type: Opaque
      data:
        username: <base64_of_uid> 9
        password: <base64_of_pwd>
      ---
      apiVersion: metal3.io/v1alpha1
      kind: BareMetalHost
      metadata:
        name: openshift-worker-<num>
        namespace: openshift-machine-api
      spec:
        online: true
        bootMACAddress: <nic1_mac_address> 10
        bmc:
          address: <protocol>://<bmc_url> 11
          credentialsName: openshift-worker-<num>-bmc-secret
          disableCertificateVerification: false
        customDeploy:
          method: install_coreos
        userData:
          name: worker-user-data-managed
          namespace: openshift-machine-api
        rootDeviceHints:
          deviceName: <root_device_hint> 12
        preprovisioningNetworkDataName: openshift-worker-<num>-network-config-secret
      1
      Replace all instances of <num> with a unique compute node number for the bare-metal nodes in the name, credentialsName, and preprovisioningNetworkDataName fields.
      2
      Add the NMState YAML syntax to configure the host interfaces. To configure the network interface for a newly created node, specify the name of the secret that has the network configuration. Follow the nmstate syntax to define the network configuration for your node. See "Preparing the bare-metal node" for details on configuring NMState syntax.
      3
      Optional: If you have configured the network interface with nmstate, and you want to disable an interface, set state: up with the IP addresses set to enabled: false.
      4
      Replace <nic1_name> with the name of the bare-metal node’s first network interface controller (NIC).
      5
      Replace <ip_address> with the IP address of the bare-metal node’s NIC.
      6
      Replace <dns_ip_address> with the IP address of the bare-metal node’s DNS resolver.
      7
      Replace <next_hop_ip_address> with the IP address of the bare-metal node’s external gateway.
      8
      Replace <next_hop_nic1_name> with the name of the bare-metal node’s external gateway.
      9
      Replace <base64_of_uid> and <base64_of_pwd> with the base64 string of the user name and password.
      10
      Replace <nic1_mac_address> with the MAC address of the bare-metal node’s first NIC. See the "BMC addressing" section for additional BMC configuration options.
      11
      Replace <protocol> with the BMC protocol, such as IPMI, Redfish, or others. Replace <bmc_url> with the URL of the bare-metal node’s baseboard management controller.
      12
      Optional: Replace <root_device_hint> with a device path when specifying a root device hint. See "Root device hints" for additional details.
    • When configuring the network interface with a static configuration by using nmstate, set state: up with the IP addresses set to enabled: false:

      ---
      apiVersion: v1
      kind: Secret
      metadata:
        name: openshift-worker-<num>-network-config-secret
        namespace: openshift-machine-api
       # ...
      interfaces:
        - name: <nic_name>
          type: ethernet
          state: up
          ipv4:
            enabled: false
          ipv6:
            enabled: false
      # ...
    • To deploy with a DHCP configuration, create the following bmh.yaml file:

      ---
      apiVersion: v1
      kind: Secret
      metadata:
        name: openshift-worker-<num>-bmc-secret 1
        namespace: openshift-machine-api
      type: Opaque
      data:
        username: <base64_of_uid> 2
        password: <base64_of_pwd>
      ---
      apiVersion: metal3.io/v1alpha1
      kind: BareMetalHost
      metadata:
        name: openshift-worker-<num>
        namespace: openshift-machine-api
      spec:
        online: true
        bootMACAddress: <nic1_mac_address> 3
        bmc:
          address: <protocol>://<bmc_url> 4
          credentialsName: openshift-worker-<num>-bmc
          disableCertificateVerification: false
        customDeploy:
          method: install_coreos
        userData:
          name: worker-user-data-managed
          namespace: openshift-machine-api
        rootDeviceHints:
          deviceName: <root_device_hint> 5
      1
      Replace <num> with a unique compute node number for the bare-metal nodes in the name and credentialsName fields.
      2
      Replace <base64_of_uid> and <base64_of_pwd> with the base64 string of the user name and password.
      3
      Replace <nic1_mac_address> with the MAC address of the bare-metal node’s first NIC. See the "BMC addressing" section for additional BMC configuration options.
      4
      Replace <protocol> with the BMC protocol, such as IPMI, Redfish, or others. Replace <bmc_url> with the URL of the bare-metal node’s baseboard management controller.
      5
      Optional: Replace <root_device_hint> with a device path when specifying a root device hint. See "Root device hints" for additional details.
      Important

      If the MAC address of an existing bare-metal node matches the MAC address of the bare-metal host that you are attempting to provision, then the installation will fail. If the host enrollment, inspection, cleaning, or other steps fail, the Bare Metal Operator retries the installation continuously. See "Diagnosing a duplicate MAC address when provisioning a new host in the cluster" for additional details.

  2. Create the bare-metal node by running the following command:

    $ oc create -f bmh.yaml

    Example output

    secret/openshift-worker-<num>-network-config-secret created
    secret/openshift-worker-<num>-bmc-secret created
    baremetalhost.metal3.io/openshift-worker-<num> created

  3. Inspect the bare-metal node by running the following command:

    $ oc -n openshift-machine-api get bmh openshift-worker-<num>

    where:

    <num>

    Specifies the compute node number.

    Example output

    NAME                    STATE       CONSUMER   ONLINE   ERROR
    openshift-worker-<num>  provisioned true

  4. Approve all certificate signing requests (CSRs).

    1. Get the list of pending CSRs by running the following command:

      $ oc get csr

      Example output

      NAME        AGE   SIGNERNAME                                    REQUESTOR                                         REQUESTEDDURATION CONDITION
      csr-gfm9f   33s   kubernetes.io/kube-apiserver-client-kubelet   system:serviceaccount:openshift-machine-config-o
      perator:node-bootstrapper   <none>              Pending

    2. Approve the CSR by running the following command:

      $ oc adm certificate approve <csr_name>

      Example output

      certificatesigningrequest.certificates.k8s.io/<csr_name> approved

Verification

  • Verify that the node is ready by running the following command:

    $ oc get nodes

    Example output

    NAME        STATUS   ROLES           AGE     VERSION
    app1        Ready    worker          47s     v1.24.0+dc5a2fd
    controller1 Ready    master,worker   2d22h   v1.24.0+dc5a2fd

2.4.4. Optional: Managing existing hosts in a user-provisioned cluster by using the BMO

Optionally, you can use the Bare Metal Operator (BMO) to manage existing bare-metal controller hosts in a user-provisioned cluster by creating a BareMetalHost object for the existing host. It is not a requirement to manage existing user-provisioned hosts; however, you can enroll them as externally-provisioned hosts for inventory purposes.

Important

To manage existing hosts by using the BMO, you must set the spec.externallyProvisioned specification in the BareMetalHost custom resource to true to prevent the BMO from re-provisioning the host.

Prerequisites

  • You created a user-provisioned bare-metal cluster.
  • You have baseboard management controller (BMC) access to the hosts.
  • You deployed a provisioning service in the cluster by creating a Provisioning CR.

Procedure

  1. Create the Secret CR and the BareMetalHost CR.

    1. Save the following YAML in the controller.yaml file:

      ---
      apiVersion: v1
      kind: Secret
      metadata:
        name: controller1-bmc
        namespace: openshift-machine-api
      type: Opaque
      data:
        username: <base64_of_uid>
        password: <base64_of_pwd>
      ---
      apiVersion: metal3.io/v1alpha1
      kind: BareMetalHost
      metadata:
        name: controller1
        namespace: openshift-machine-api
      spec:
        bmc:
          address: <protocol>://<bmc_url> 1
          credentialsName: "controller1-bmc"
        bootMACAddress: <nic1_mac_address>
        customDeploy:
          method: install_coreos
        externallyProvisioned: true 2
        online: true
        userData:
          name: controller-user-data-managed
          namespace: openshift-machine-api
      1
      You can only use bare-metal host drivers that support virtual media networking booting, for example redfish-virtualmedia and idrac-virtualmedia.
      2
      You must set the value to true to prevent the BMO from re-provisioning the bare-metal controller host.
  2. Create the bare-metal host object by running the following command:

    $ oc create -f controller.yaml

    Example output

    secret/controller1-bmc created
    baremetalhost.metal3.io/controller1 created

Verification

  • Verify that the BMO created the bare-metal host object by running the following command:

    $ oc get bmh -A

    Example output

    NAMESPACE               NAME          STATE                    CONSUMER   ONLINE   ERROR   AGE
    openshift-machine-api   controller1   externally provisioned              true             13s

2.4.5. Removing hosts from a user-provisioned cluster by using the BMO

You can use the Bare Metal Operator (BMO) to remove bare-metal hosts from a user-provisioned cluster.

Prerequisites

  • You created a user-provisioned bare-metal cluster.
  • You have baseboard management controller (BMC) access to the hosts.
  • You deployed a provisioning service in the cluster by creating a Provisioning CR.

Procedure

  1. Cordon and drain the node by running the following command:

    $ oc adm drain app1 --force --ignore-daemonsets=true

    Example output

    node/app1 cordoned
    WARNING: ignoring DaemonSet-managed Pods: openshift-cluster-node-tuning-operator/tuned-tvthg, openshift-dns/dns-
    default-9q6rz, openshift-dns/node-resolver-zvt42, openshift-image-registry/node-ca-mzxth, openshift-ingress-cana
    ry/ingress-canary-qq5lf, openshift-machine-config-operator/machine-config-daemon-v79dm, openshift-monitoring/nod
    e-exporter-2vn59, openshift-multus/multus-additional-cni-plugins-wssvj, openshift-multus/multus-fn8tg, openshift
    -multus/network-metrics-daemon-5qv55, openshift-network-diagnostics/network-check-target-jqxn2, openshift-ovn-ku
    bernetes/ovnkube-node-rsvqg
    evicting pod openshift-operator-lifecycle-manager/collect-profiles-27766965-258vp
    evicting pod openshift-operator-lifecycle-manager/collect-profiles-27766950-kg5mk
    evicting pod openshift-operator-lifecycle-manager/collect-profiles-27766935-stf4s
    pod/collect-profiles-27766965-258vp evicted
    pod/collect-profiles-27766950-kg5mk evicted
    pod/collect-profiles-27766935-stf4s evicted
    node/app1 drained

  2. Delete the customDeploy specification from the BareMetalHost CR.

    1. Edit the BareMetalHost CR for the host by running the following command:

      $ oc edit bmh -n openshift-machine-api <host_name>
    2. Delete the lines spec.customDeploy and spec.customDeploy.method:

      ...
        customDeploy:
          method: install_coreos
    3. Verify that the provisioning state of the host changes to deprovisioning by running the following command:

      $ oc get bmh -A

      Example output

      NAMESPACE               NAME          STATE                    CONSUMER   ONLINE   ERROR   AGE
      openshift-machine-api   controller1   externally provisioned              true             58m
      openshift-machine-api   worker1       deprovisioning                      true             57m

  3. Delete the host by running the following command when the BareMetalHost state changes to available:

    $ oc delete bmh -n openshift-machine-api <bmh_name>
    Note

    You can run this step without having to edit the BareMetalHost CR. It might take some time for the BareMetalHost state to change from deprovisioning to available.

  4. Delete the node by running the following command:

    $ oc delete node <node_name>

Verification

  • Verify that you deleted the node by running the following command:

    $ oc get nodes

    Example output

    NAME          STATUS   ROLES           AGE     VERSION
    controller1   Ready    master,worker   2d23h   v1.24.0+dc5a2fd

2.5. Installation configuration parameters for bare metal

Before you deploy an OpenShift Container Platform cluster, you provide a customized install-config.yaml installation configuration file that describes the details for your environment.

2.5.1. Available installation configuration parameters for bare metal

The following tables specify the required, optional, and bare metal-specific installation configuration parameters that you can set as part of the installation process.

Note

After installation, you cannot modify these parameters in the install-config.yaml file.

2.5.1.1. Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 2.41. Required parameters
ParameterDescriptionValues
apiVersion:

The API version for the install-config.yaml content. The current version is v1. The installation program may also support older API versions.

String

baseDomain:

The base domain of your cloud provider. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the baseDomain and metadata.name parameter values that uses the <metadata.name>.<baseDomain> format.

A fully-qualified domain or subdomain name, such as example.com.

metadata:

Kubernetes resource ObjectMeta, from which only the name parameter is consumed.

Object

metadata:
  name:

The name of the cluster. DNS records for the cluster are all subdomains of {{.metadata.name}}.{{.baseDomain}}.

String of lowercase letters and hyphens (-), such as dev.

platform:

The configuration for the specific platform upon which to perform the installation: aws, baremetal, azure, gcp, ibmcloud, nutanix, openstack, powervs, vsphere, or {}. For additional information about platform.<platform> parameters, consult the table for your specific platform that follows.

Object

pullSecret:

Get a pull secret from Red Hat OpenShift Cluster Manager to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io.

{
   "auths":{
      "cloud.openshift.com":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      },
      "quay.io":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      }
   }
}
2.5.1.2. Network configuration parameters

You can customize your installation configuration based on the requirements of your existing network infrastructure. For example, you can expand the IP address block for the cluster network or provide different IP address blocks than the defaults.

Consider the following information before you configure network parameters for your cluster:

  • If you use the Red Hat OpenShift Networking OVN-Kubernetes network plugin, both IPv4 and IPv6 address families are supported.
  • If you deployed nodes in an OpenShift Container Platform cluster with a network that supports both IPv4 and non-link-local IPv6 addresses, configure your cluster to use a dual-stack network.

    • For clusters configured for dual-stack networking, both IPv4 and IPv6 traffic must use the same network interface as the default gateway. This ensures that in a multiple network interface controller (NIC) environment, a cluster can detect what NIC to use based on the available network interface. For more information, see "OVN-Kubernetes IPv6 and dual-stack limitations" in About the OVN-Kubernetes network plugin.
    • To prevent network connectivity issues, do not install a single-stack IPv4 cluster on a host that supports dual-stack networking.

If you configure your cluster to use both IP address families, review the following requirements:

  • Both IP families must use the same network interface for the default gateway.
  • Both IP families must have the default gateway.
  • You must specify IPv4 and IPv6 addresses in the same order for all network configuration parameters. For example, in the following configuration IPv4 addresses are listed before IPv6 addresses.

    networking:
      clusterNetwork:
      - cidr: 10.128.0.0/14
        hostPrefix: 23
      - cidr: fd00:10:128::/56
        hostPrefix: 64
      serviceNetwork:
      - 172.30.0.0/16
      - fd00:172:16::/112
Table 2.42. Network parameters
ParameterDescriptionValues
networking:

The configuration for the cluster network.

Object

Note

You cannot modify parameters specified by the networking object after installation.

networking:
  networkType:

The Red Hat OpenShift Networking network plugin to install.

OVNKubernetes. OVNKubernetes is a CNI plugin for Linux networks and hybrid networks that contain both Linux and Windows servers. The default value is OVNKubernetes.

networking:
  clusterNetwork:

The IP address blocks for pods.

The default value is 10.128.0.0/14 with a host prefix of /23.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  - cidr: fd01::/48
    hostPrefix: 64
networking:
  clusterNetwork:
    cidr:

Required if you use networking.clusterNetwork. An IP address block.

If you use the OVN-Kubernetes network plugin, you can specify IPv4 and IPv6 networks.

An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between 0 and 32. The prefix length for an IPv6 block is between 0 and 128. For example, 10.128.0.0/14 or fd01::/48.

networking:
  clusterNetwork:
    hostPrefix:

The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23 then each node is assigned a /23 subnet out of the given cidr. A hostPrefix value of 23 provides 510 (2^(32 - 23) - 2) pod IP addresses.

A subnet prefix.

For an IPv4 network the default value is 23. For an IPv6 network the default value is 64. The default value is also the minimum value for IPv6.

networking:
  serviceNetwork:

The IP address block for services. The default value is 172.30.0.0/16.

The OVN-Kubernetes network plugins supports only a single IP address block for the service network.

If you use the OVN-Kubernetes network plugin, you can specify an IP address block for both of the IPv4 and IPv6 address families.

An array with an IP address block in CIDR format. For example:

networking:
  serviceNetwork:
   - 172.30.0.0/16
   - fd02::/112
networking:
  machineNetwork:

The IP address blocks for machines.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  machineNetwork:
  - cidr: 10.0.0.0/16
networking:
  machineNetwork:
    cidr:

Required if you use networking.machineNetwork. An IP address block. The default value is 10.0.0.0/16 for all platforms other than libvirt and IBM Power® Virtual Server. For libvirt, the default value is 192.168.126.0/24. For IBM Power® Virtual Server, the default value is 192.168.0.0/24.

An IP network block in CIDR notation.

For example, 10.0.0.0/16 or fd00::/48.

Note

Set the networking.machineNetwork to match the CIDR that the preferred NIC resides in.

networking:
  ovnKubernetesConfig:
    ipv4:
      internalJoinSubnet:

Configures the IPv4 join subnet that is used internally by ovn-kubernetes. This subnet must not overlap with any other subnet that OpenShift Container Platform is using, including the node network. The size of the subnet must be larger than the number of nodes. You cannot change the value after installation.

An IP network block in CIDR notation. The default value is 100.64.0.0/16.

2.5.1.3. Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Table 2.43. Optional parameters
ParameterDescriptionValues
additionalTrustBundle:

A PEM-encoded X.509 certificate bundle that is added to the nodes' trusted certificate store. This trust bundle may also be used when a proxy has been configured.

String

capabilities:

Controls the installation of optional core cluster components. You can reduce the footprint of your OpenShift Container Platform cluster by disabling optional components. For more information, see the "Cluster capabilities" page in Installing.

String array

capabilities:
  baselineCapabilitySet:

Selects an initial set of optional capabilities to enable. Valid values are None, v4.11, v4.12 and vCurrent. The default value is vCurrent.

String

capabilities:
  additionalEnabledCapabilities:

Extends the set of optional capabilities beyond what you specify in baselineCapabilitySet. You may specify multiple capabilities in this parameter.

String array

cpuPartitioningMode:

Enables workload partitioning, which isolates OpenShift Container Platform services, cluster management workloads, and infrastructure pods to run on a reserved set of CPUs. Workload partitioning can only be enabled during installation and cannot be disabled after installation. While this field enables workload partitioning, it does not configure workloads to use specific CPUs. For more information, see the Workload partitioning page in the Scalability and Performance section.

None or AllNodes. None is the default value.

compute:

The configuration for the machines that comprise the compute nodes.

Array of MachinePool objects.

compute:
  architecture:

Determines the instruction set architecture of the machines in the pool. Currently, clusters with varied architectures are not supported. All pools must specify the same architecture. Valid values are amd64 and arm64.

String

compute:
  hyperthreading:

Whether to enable or disable simultaneous multithreading, or hyperthreading, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

Important

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

compute:
  name:

Required if you use compute. The name of the machine pool.

worker

compute:
  platform:

Required if you use compute. Use this parameter to specify the cloud provider to host the worker machines. This parameter value must match the controlPlane.platform parameter value.

aws, azure, gcp, ibmcloud, nutanix, openstack, powervs, vsphere, or {}

compute:
  replicas:

The number of compute machines, which are also known as worker machines, to provision.

A positive integer greater than or equal to 2. The default value is 3.

featureSet:

Enables the cluster for a feature set. A feature set is a collection of OpenShift Container Platform features that are not enabled by default. For more information about enabling a feature set during installation, see "Enabling features using feature gates".

String. The name of the feature set to enable, such as TechPreviewNoUpgrade.

controlPlane:

The configuration for the machines that comprise the control plane.

Array of MachinePool objects.

controlPlane:
  architecture:

Determines the instruction set architecture of the machines in the pool. Currently, clusters with varied architectures are not supported. All pools must specify the same architecture. Valid values are amd64 and arm64.

String

controlPlane:
  hyperthreading:

Whether to enable or disable simultaneous multithreading, or hyperthreading, on control plane machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

Important

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

controlPlane:
  name:

Required if you use controlPlane. The name of the machine pool.

master

controlPlane:
  platform:

Required if you use controlPlane. Use this parameter to specify the cloud provider that hosts the control plane machines. This parameter value must match the compute.platform parameter value.

aws, azure, gcp, ibmcloud, nutanix, openstack, powervs, vsphere, or {}

controlPlane:
  replicas:

The number of control plane machines to provision.

Supported values are 3, or 1 when deploying single-node OpenShift.

credentialsMode:

The Cloud Credential Operator (CCO) mode. If no mode is specified, the CCO dynamically tries to determine the capabilities of the provided credentials, with a preference for mint mode on the platforms where multiple modes are supported.

Note

Not all CCO modes are supported for all cloud providers. For more information about CCO modes, see the "Managing cloud provider credentials" entry in the Authentication and authorization content.

Mint, Passthrough, Manual or an empty string ("").

fips:

Enable or disable FIPS mode. The default is false (disabled). If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.

Important

To enable FIPS mode for your cluster, you must run the installation program from a Red Hat Enterprise Linux (RHEL) computer configured to operate in FIPS mode. For more information about configuring FIPS mode on RHEL, see Switching RHEL to FIPS mode.

When running Red Hat Enterprise Linux (RHEL) or Red Hat Enterprise Linux CoreOS (RHCOS) booted in FIPS mode, OpenShift Container Platform core components use the RHEL cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures.

Note

If you are using Azure File storage, you cannot enable FIPS mode.

false or true

imageContentSources:

Sources and repositories for the release-image content.

Array of objects. Includes a source and, optionally, mirrors, as described in the following rows of this table.

imageContentSources:
  source:

Required if you use imageContentSources. Specify the repository that users refer to, for example, in image pull specifications.

String

imageContentSources:
  mirrors:

Specify one or more repositories that may also contain the same images.

Array of strings

publish:

How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes.

Internal or External. The default value is External.

Setting this field to Internal is not supported on non-cloud platforms.

Important

If the value of the field is set to Internal, the cluster will become non-functional. For more information, refer to BZ#1953035.

sshKey:

The SSH key to authenticate access to your cluster machines.

Note

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

For example, sshKey: ssh-ed25519 AAAA...

Chapter 3. Installer-provisioned infrastructure

3.1. Overview

Installer-provisioned installation on bare metal nodes deploys and configures the infrastructure that an OpenShift Container Platform cluster runs on. This guide provides a methodology to achieving a successful installer-provisioned bare-metal installation. The following diagram illustrates the installation environment in phase 1 of deployment:

Deployment phase one

For the installation, the key elements in the previous diagram are:

  • Provisioner: A physical machine that runs the installation program and hosts the bootstrap VM that deploys the control plane of a new OpenShift Container Platform cluster.
  • Bootstrap VM: A virtual machine used in the process of deploying an OpenShift Container Platform cluster.
  • Network bridges: The bootstrap VM connects to the bare metal network and to the provisioning network, if present, via network bridges, eno1 and eno2.
  • API VIP: An API virtual IP address (VIP) is used to provide failover of the API server across the control plane nodes. The API VIP first resides on the bootstrap VM. A script generates the keepalived.conf configuration file before launching the service. The VIP moves to one of the control plane nodes after the bootstrap process has completed and the bootstrap VM stops.

In phase 2 of the deployment, the provisioner destroys the bootstrap VM automatically and moves the virtual IP addresses (VIPs) to the appropriate nodes.

The keepalived.conf file sets the control plane machines with a lower Virtual Router Redundancy Protocol (VRRP) priority than the bootstrap VM, which ensures that the API on the control plane machines is fully functional before the API VIP moves from the bootstrap VM to the control plane. Once the API VIP moves to one of the control plane nodes, traffic sent from external clients to the API VIP routes to an haproxy load balancer running on that control plane node. This instance of haproxy load balances the API VIP traffic across the control plane nodes.

The Ingress VIP moves to the compute nodes. The keepalived instance also manages the Ingress VIP.

The following diagram illustrates phase 2 of deployment:

Deployment phase two

After this point, the node used by the provisioner can be removed or repurposed. From here, all additional provisioning tasks are carried out by the control plane.

Note

For installer-provisioned infrastructure installations, CoreDNS exposes port 53 at the node level, making it accessible from other routable networks.

Additional resources

Important

The provisioning network is optional, but it is required for PXE booting. If you deploy without a provisioning network, you must use a virtual media baseboard management controller (BMC) addressing option such as redfish-virtualmedia or idrac-virtualmedia.

3.2. Prerequisites

Installer-provisioned installation of OpenShift Container Platform requires:

  1. One provisioner node with Red Hat Enterprise Linux (RHEL) 9.x installed. The provisioner can be removed after installation.
  2. Three control plane nodes
  3. Baseboard management controller (BMC) access to each node
  4. At least one network:

    1. One required routable network
    2. One optional provisioning network
    3. One optional management network

Before starting an installer-provisioned installation of OpenShift Container Platform, ensure the hardware environment meets the following requirements.

3.2.1. Node requirements

Installer-provisioned installation involves a number of hardware node requirements:

  • CPU architecture: All nodes must use x86_64 or aarch64 CPU architecture.
  • Similar nodes: Red Hat recommends nodes have an identical configuration per role. That is, Red Hat recommends nodes be the same brand and model with the same CPU, memory, and storage configuration.
  • Baseboard Management Controller: The provisioner node must be able to access the baseboard management controller (BMC) of each OpenShift Container Platform cluster node. You may use IPMI, Redfish, or a proprietary protocol.
  • Latest generation: Nodes must be of the most recent generation. Installer-provisioned installation relies on BMC protocols, which must be compatible across nodes. Additionally, RHEL 9.x ships with the most recent drivers for RAID controllers. Ensure that the nodes are recent enough to support RHEL 9.x for the provisioner node and RHCOS 9.x for the control plane and worker nodes.
  • Registry node: (Optional) If setting up a disconnected mirrored registry, it is recommended the registry reside in its own node.
  • Provisioner node: Installer-provisioned installation requires one provisioner node.
  • Control plane: Installer-provisioned installation requires three control plane nodes for high availability. You can deploy an OpenShift Container Platform cluster with only three control plane nodes, making the control plane nodes schedulable as worker nodes. Smaller clusters are more resource efficient for administrators and developers during development, production, and testing.
  • Worker nodes: While not required, a typical production cluster has two or more worker nodes.

    Important

    Do not deploy a cluster with only one worker node, because the cluster will deploy with routers and ingress traffic in a degraded state.

  • Network interfaces: Each node must have at least one network interface for the routable baremetal network. Each node must have one network interface for a provisioning network when using the provisioning network for deployment. Using the provisioning network is the default configuration.

    Note

    Only one network card (NIC) on the same subnet can route traffic through the gateway. By default, Address Resolution Protocol (ARP) uses the lowest numbered NIC. Use a single NIC for each node in the same subnet to ensure that network load balancing works as expected. When using multiple NICs for a node in the same subnet, use a single bond or team interface. Then add the other IP addresses to that interface in the form of an alias IP address. If you require fault tolerance or load balancing at the network interface level, use an alias IP address on the bond or team interface. Alternatively, you can disable a secondary NIC on the same subnet or ensure that it has no IP address.

  • Unified Extensible Firmware Interface (UEFI): Installer-provisioned installation requires UEFI boot on all OpenShift Container Platform nodes when using IPv6 addressing on the provisioning network. In addition, UEFI Device PXE Settings must be set to use the IPv6 protocol on the provisioning network NIC, but omitting the provisioning network removes this requirement.

    Important

    When starting the installation from virtual media such as an ISO image, delete all old UEFI boot table entries. If the boot table includes entries that are not generic entries provided by the firmware, the installation might fail.

  • Secure Boot: Many production scenarios require nodes with Secure Boot enabled to verify the node only boots with trusted software, such as UEFI firmware drivers, EFI applications, and the operating system. You may deploy with Secure Boot manually or managed.

    1. Manually: To deploy an OpenShift Container Platform cluster with Secure Boot manually, you must enable UEFI boot mode and Secure Boot on each control plane node and each worker node. Red Hat supports Secure Boot with manually enabled UEFI and Secure Boot only when installer-provisioned installations use Redfish virtual media. See "Configuring nodes for Secure Boot manually" in the "Configuring nodes" section for additional details.
    2. Managed: To deploy an OpenShift Container Platform cluster with managed Secure Boot, you must set the bootMode value to UEFISecureBoot in the install-config.yaml file. Red Hat only supports installer-provisioned installation with managed Secure Boot on 10th generation HPE hardware and 13th generation Dell hardware running firmware version 2.75.75.75 or greater. Deploying with managed Secure Boot does not require Redfish virtual media. See "Configuring managed Secure Boot" in the "Setting up the environment for an OpenShift installation" section for details.

      Note

      Red Hat does not support managing self-generated keys, or other keys, for Secure Boot.

3.2.2. Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 3.1. Minimum resource requirements
MachineOperating SystemCPU [1]RAMStorageInput/Output Per Second (IOPS)[2]

Bootstrap

RHEL

4

16 GB

100 GB

300

Control plane

RHCOS

4

16 GB

100 GB

300

Compute

RHCOS

2

8 GB

100 GB

300

  1. One CPU is equivalent to one physical core when simultaneous multithreading (SMT), or Hyper-Threading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = CPUs.
  2. OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
Note

For OpenShift Container Platform version 4.18, RHCOS is based on RHEL version 9.4, which updates the micro-architecture requirements. The following list contains the minimum instruction set architectures (ISA) that each architecture requires:

  • x86-64 architecture requires x86-64-v2 ISA
  • ARM64 architecture requires ARMv8.0-A ISA
  • IBM Power architecture requires Power 9 ISA
  • s390x architecture requires z14 ISA

For more information, see Architectures (RHEL documentation).

If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.

3.2.3. Planning a bare metal cluster for OpenShift Virtualization

If you will use OpenShift Virtualization, it is important to be aware of several requirements before you install your bare metal cluster.

  • If you want to use live migration features, you must have multiple worker nodes at the time of cluster installation. This is because live migration requires the cluster-level high availability (HA) flag to be set to true. The HA flag is set when a cluster is installed and cannot be changed afterwards. If there are fewer than two worker nodes defined when you install your cluster, the HA flag is set to false for the life of the cluster.

    Note

    You can install OpenShift Virtualization on a single-node cluster, but single-node OpenShift does not support high availability.

  • Live migration requires shared storage. Storage for OpenShift Virtualization must support and use the ReadWriteMany (RWX) access mode.
  • If you plan to use Single Root I/O Virtualization (SR-IOV), ensure that your network interface controllers (NICs) are supported by OpenShift Container Platform.

3.2.4. Firmware requirements for installing with virtual media

The installation program for installer-provisioned OpenShift Container Platform clusters validates the hardware and firmware compatibility with Redfish virtual media. The installation program does not begin installation on a node if the node firmware is not compatible. The following tables list the minimum firmware versions tested and verified to work for installer-provisioned OpenShift Container Platform clusters deployed by using Redfish virtual media.

Note

Red Hat does not test every combination of firmware, hardware, or other third-party components. For further information about third-party support, see Red Hat third-party support policy. For information about updating the firmware, see the hardware documentation for the nodes or contact the hardware vendor.

Table 3.2. Firmware compatibility for HP hardware with Redfish virtual media
ModelManagementFirmware versions

11th Generation

iLO6

1.57 or later

10th Generation

iLO5

2.63 or later

Table 3.3. Firmware compatibility for Dell hardware with Redfish virtual media
ModelManagementFirmware versions

16th Generation

iDRAC 9

v7.10.70.00

15th Generation

iDRAC 9

v6.10.30.00 and v7.10.70.00

14th Generation

iDRAC 9

v6.10.30.00

Table 3.4. Firmware compatibility for Cisco UCS hardware with Redfish virtual media
ModelManagementFirmware versions

UCS X-Series servers [a]

CIMC

5.2(2) or later

UCS C-Series servers in UCS managed domain

CIMC

4.3 or later

[a] Installer-provisioned installation is supported for UCS M6 Platform and later.

3.2.5. Network requirements

Installer-provisioned installation of OpenShift Container Platform involves multiple network requirements. First, installer-provisioned installation involves an optional non-routable provisioning network for provisioning the operating system on each bare-metal node. Second, installer-provisioned installation involves a routable baremetal network.

Installer-provisioned networking
3.2.5.1. Ensuring required ports are open

Certain ports must be open between cluster nodes for installer-provisioned installations to complete successfully. In certain situations, such as using separate subnets for far edge worker nodes, you must ensure that the nodes in these subnets can communicate with nodes in the other subnets on the following required ports.

Table 3.5. Required ports
PortDescription

67,68

When using a provisioning network, cluster nodes access the dnsmasq DHCP server over their provisioning network interfaces using ports 67 and 68.

69

When using a provisioning network, cluster nodes communicate with the TFTP server on port 69 using their provisioning network interfaces. The TFTP server runs on the bootstrap VM. The bootstrap VM runs on the provisioner node.

80

When not using the image caching option or when using virtual media, the provisioner node must have port 80 open on the baremetal machine network interface to stream the Red Hat Enterprise Linux CoreOS (RHCOS) image from the provisioner node to the cluster nodes.

123

The cluster nodes must access the NTP server on port 123 using the baremetal machine network.

5050

The Ironic Inspector API runs on the control plane nodes and listens on port 5050. The Inspector API is responsible for hardware introspection, which collects information about the hardware characteristics of the bare-metal nodes.

5051

Port 5050 uses port 5051 as a proxy.

6180

When deploying with virtual media and not using TLS, the provisioner node and the control plane nodes must have port 6180 open on the baremetal machine network interface so that the baseboard management controller (BMC) of the worker nodes can access the RHCOS image. Starting with OpenShift Container Platform 4.13, the default HTTP port is 6180.

6183

When deploying with virtual media and using TLS, the provisioner node and the control plane nodes must have port 6183 open on the baremetal machine network interface so that the BMC of the worker nodes can access the RHCOS image.

6385

The Ironic API server runs initially on the bootstrap VM and later on the control plane nodes and listens on port 6385. The Ironic API allows clients to interact with Ironic for bare-metal node provisioning and management, including operations such as enrolling new nodes, managing their power state, deploying images, and cleaning the hardware.

6388

Port 6385 uses port 6388 as a proxy.

8080

When using image caching without TLS, port 8080 must be open on the provisioner node and accessible by the BMC interfaces of the cluster nodes.

8083

When using the image caching option with TLS, port 8083 must be open on the provisioner node and accessible by the BMC interfaces of the cluster nodes.

9999

By default, the Ironic Python Agent (IPA) listens on TCP port 9999 for API calls from the Ironic conductor service. Communication between the bare-metal node where IPA is running and the Ironic conductor service uses this port.

3.2.5.2. Increase the network MTU

Before deploying OpenShift Container Platform, increase the network maximum transmission unit (MTU) to 1500 or more. If the MTU is lower than 1500, the Ironic image that is used to boot the node might fail to communicate with the Ironic inspector pod, and inspection will fail. If this occurs, installation stops because the nodes are not available for installation.

3.2.5.3. Configuring NICs

OpenShift Container Platform deploys with two networks:

  • provisioning: The provisioning network is an optional non-routable network used for provisioning the underlying operating system on each node that is a part of the OpenShift Container Platform cluster. The network interface for the provisioning network on each cluster node must have the BIOS or UEFI configured to PXE boot.

    The provisioningNetworkInterface configuration setting specifies the provisioning network NIC name on the control plane nodes, which must be identical on the control plane nodes. The bootMACAddress configuration setting provides a means to specify a particular NIC on each node for the provisioning network.

    The provisioning network is optional, but it is required for PXE booting. If you deploy without a provisioning network, you must use a virtual media BMC addressing option such as redfish-virtualmedia or idrac-virtualmedia.

  • baremetal: The baremetal network is a routable network. You can use any NIC to interface with the baremetal network provided the NIC is not configured to use the provisioning network.
Important

When using a VLAN, each NIC must be on a separate VLAN corresponding to the appropriate network.

3.2.5.4. DNS requirements

Clients access the OpenShift Container Platform cluster nodes over the baremetal network. A network administrator must configure a subdomain or subzone where the canonical name extension is the cluster name.

<cluster_name>.<base_domain>

For example:

test-cluster.example.com

OpenShift Container Platform includes functionality that uses cluster membership information to generate A/AAAA records. This resolves the node names to their IP addresses. After the nodes are registered with the API, the cluster can disperse node information without using CoreDNS-mDNS. This eliminates the network traffic associated with multicast DNS.

CoreDNS requires both TCP and UDP connections to the upstream DNS server to function correctly. Ensure the upstream DNS server can receive both TCP and UDP connections from OpenShift Container Platform cluster nodes.

In OpenShift Container Platform deployments, DNS name resolution is required for the following components:

  • The Kubernetes API
  • The OpenShift Container Platform application wildcard ingress API

A/AAAA records are used for name resolution and PTR records are used for reverse name resolution. Red Hat Enterprise Linux CoreOS (RHCOS) uses the reverse records or DHCP to set the hostnames for all the nodes.

Installer-provisioned installation includes functionality that uses cluster membership information to generate A/AAAA records. This resolves the node names to their IP addresses. In each record, <cluster_name> is the cluster name and <base_domain> is the base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 3.6. Required DNS records
ComponentRecordDescription

Kubernetes API

api.<cluster_name>.<base_domain>.

An A/AAAA record and a PTR record identify the API load balancer. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

Routes

*.apps.<cluster_name>.<base_domain>.

The wildcard A/AAAA record refers to the application ingress load balancer. The application ingress load balancer targets the nodes that run the Ingress Controller pods. The Ingress Controller pods run on the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

For example, console-openshift-console.apps.<cluster_name>.<base_domain> is used as a wildcard route to the OpenShift Container Platform console.

Tip

You can use the dig command to verify DNS resolution.

3.2.5.5. Dynamic Host Configuration Protocol (DHCP) requirements

By default, installer-provisioned installation deploys ironic-dnsmasq with DHCP enabled for the provisioning network. No other DHCP servers should be running on the provisioning network when the provisioningNetwork configuration setting is set to managed, which is the default value. If you have a DHCP server running on the provisioning network, you must set the provisioningNetwork configuration setting to unmanaged in the install-config.yaml file.

Network administrators must reserve IP addresses for each node in the OpenShift Container Platform cluster for the baremetal network on an external DHCP server.

3.2.5.6. Reserving IP addresses for nodes with the DHCP server

For the baremetal network, a network administrator must reserve several IP addresses, including:

  1. Two unique virtual IP addresses.

    • One virtual IP address for the API endpoint.
    • One virtual IP address for the wildcard ingress endpoint.
  2. One IP address for the provisioner node.
  3. One IP address for each control plane node.
  4. One IP address for each worker node, if applicable.
Reserving IP addresses so they become static IP addresses

Some administrators prefer to use static IP addresses so that each node’s IP address remains constant in the absence of a DHCP server. To configure static IP addresses with NMState, see "(Optional) Configuring node network interfaces" in the "Setting up the environment for an OpenShift installation" section.

Networking between external load balancers and control plane nodes

External load balancing services and the control plane nodes must run on the same L2 network, and on the same VLAN when using VLANs to route traffic between the load balancing services and the control plane nodes.

Important

The storage interface requires a DHCP reservation or a static IP.

The following table provides an exemplary embodiment of fully qualified domain names. The API and name server addresses begin with canonical name extensions. The hostnames of the control plane and worker nodes are exemplary, so you can use any host naming convention you prefer.

UsageHost NameIP

API

api.<cluster_name>.<base_domain>

<ip>

Ingress LB (apps)

*.apps.<cluster_name>.<base_domain>

<ip>

Provisioner node

provisioner.<cluster_name>.<base_domain>

<ip>

Control-plane-0

openshift-control-plane-0.<cluster_name>.<base_domain>

<ip>

Control-plane-1

openshift-control-plane-1.<cluster_name>-.<base_domain>

<ip>

Control-plane-2

openshift-control-plane-2.<cluster_name>.<base_domain>

<ip>

Worker-0

openshift-worker-0.<cluster_name>.<base_domain>

<ip>

Worker-1

openshift-worker-1.<cluster_name>.<base_domain>

<ip>

Worker-n

openshift-worker-n.<cluster_name>.<base_domain>

<ip>

Note

If you do not create DHCP reservations, the installation program requires reverse DNS resolution to set the hostnames for the Kubernetes API node, the provisioner node, the control plane nodes, and the worker nodes.

3.2.5.7. Provisioner node requirements

You must specify the MAC address for the provisioner node in your installation configuration. The bootMacAddress specification is typically associated with PXE network booting. However, the Ironic provisioning service also requires the bootMacAddress specification to identify nodes during the inspection of the cluster, or during node redeployment in the cluster.

The provisioner node requires layer 2 connectivity for network booting, DHCP and DNS resolution, and local network communication. The provisioner node requires layer 3 connectivity for virtual media booting.

3.2.5.8. Network Time Protocol (NTP)

Each OpenShift Container Platform node in the cluster must have access to an NTP server. OpenShift Container Platform nodes use NTP to synchronize their clocks. For example, cluster nodes use SSL/TLS certificates that require validation, which might fail if the date and time between the nodes are not in sync.

Important

Define a consistent clock date and time format in each cluster node’s BIOS settings, or installation might fail.

You can reconfigure the control plane nodes to act as NTP servers on disconnected clusters, and reconfigure worker nodes to retrieve time from the control plane nodes.

3.2.5.9. Port access for the out-of-band management IP address

The out-of-band management IP address is on a separate network from the node. To ensure that the out-of-band management can communicate with the provisioner node during installation, the out-of-band management IP address must be granted access to port 6180 on the provisioner node and on the OpenShift Container Platform control plane nodes. TLS port 6183 is required for virtual media installation, for example, by using Redfish.

Additional resources

3.2.6. Configuring nodes

Configuring nodes when using the provisioning network

Each node in the cluster requires the following configuration for proper installation.

Warning

A mismatch between nodes will cause an installation failure.

While the cluster nodes can contain more than two NICs, the installation process only focuses on the first two NICs. In the following table, NIC1 is a non-routable network (provisioning) that is only used for the installation of the OpenShift Container Platform cluster.

NICNetworkVLAN

NIC1

provisioning

<provisioning_vlan>

NIC2

baremetal

<baremetal_vlan>

The Red Hat Enterprise Linux (RHEL) 9.x installation process on the provisioner node might vary. To install Red Hat Enterprise Linux (RHEL) 9.x using a local Satellite server or a PXE server, PXE-enable NIC2.

PXEBoot order

NIC1 PXE-enabled provisioning network

1

NIC2 baremetal network. PXE-enabled is optional.

2

Note

Ensure PXE is disabled on all other NICs.

Configure the control plane and worker nodes as follows:

PXEBoot order

NIC1 PXE-enabled (provisioning network)

1

Configuring nodes without the provisioning network

The installation process requires one NIC:

NICNetworkVLAN

NICx

baremetal

<baremetal_vlan>

NICx is a routable network (baremetal) that is used for the installation of the OpenShift Container Platform cluster, and routable to the internet.

Important

The provisioning network is optional, but it is required for PXE booting. If you deploy without a provisioning network, you must use a virtual media BMC addressing option such as redfish-virtualmedia or idrac-virtualmedia.

Configuring nodes for Secure Boot manually

Secure Boot prevents a node from booting unless it verifies the node is using only trusted software, such as UEFI firmware drivers, EFI applications, and the operating system.

Note

Red Hat only supports manually configured Secure Boot when deploying with Redfish virtual media.

To enable Secure Boot manually, refer to the hardware guide for the node and execute the following:

Procedure

  1. Boot the node and enter the BIOS menu.
  2. Set the node’s boot mode to UEFI Enabled.
  3. Enable Secure Boot.
Important

Red Hat does not support Secure Boot with self-generated keys.

3.2.7. Out-of-band management

Nodes typically have an additional NIC used by the baseboard management controllers (BMCs). These BMCs must be accessible from the provisioner node.

Each node must be accessible via out-of-band management. When using an out-of-band management network, the provisioner node requires access to the out-of-band management network for a successful OpenShift Container Platform installation.

The out-of-band management setup is out of scope for this document. Using a separate management network for out-of-band management can enhance performance and improve security. However, using the provisioning network or the bare metal network are valid options.

Note

The bootstrap VM features a maximum of two network interfaces. If you configure a separate management network for out-of-band management, and you are using a provisioning network, the bootstrap VM requires routing access to the management network through one of the network interfaces. In this scenario, the bootstrap VM can then access three networks:

  • the bare metal network
  • the provisioning network
  • the management network routed through one of the network interfaces

3.2.8. Required data for installation

Prior to the installation of the OpenShift Container Platform cluster, gather the following information from all cluster nodes:

  • Out-of-band management IP

    • Examples

      • Dell (iDRAC) IP
      • HP (iLO) IP
      • Fujitsu (iRMC) IP

When using the provisioning network

  • NIC (provisioning) MAC address
  • NIC (baremetal) MAC address

When omitting the provisioning network

  • NIC (baremetal) MAC address

3.2.9. Validation checklist for nodes

When using the provisioning network

  • ❏ NIC1 VLAN is configured for the provisioning network.
  • ❏ NIC1 for the provisioning network is PXE-enabled on the provisioner, control plane, and worker nodes.
  • ❏ NIC2 VLAN is configured for the baremetal network.
  • ❏ PXE has been disabled on all other NICs.
  • ❏ DNS is configured with API and Ingress endpoints.
  • ❏ Control plane and worker nodes are configured.
  • ❏ All nodes accessible via out-of-band management.
  • ❏ (Optional) A separate management network has been created.
  • ❏ Required data for installation.

When omitting the provisioning network

  • ❏ NIC1 VLAN is configured for the baremetal network.
  • ❏ DNS is configured with API and Ingress endpoints.
  • ❏ Control plane and worker nodes are configured.
  • ❏ All nodes accessible via out-of-band management.
  • ❏ (Optional) A separate management network has been created.
  • ❏ Required data for installation.

3.3. Setting up the environment for an OpenShift installation

3.3.1. Installing RHEL on the provisioner node

With the configuration of the prerequisites complete, the next step is to install RHEL 9.x on the provisioner node. The installer uses the provisioner node as the orchestrator while installing the OpenShift Container Platform cluster. For the purposes of this document, installing RHEL on the provisioner node is out of scope. However, options include but are not limited to using a RHEL Satellite server, PXE, or installation media.

3.3.2. Preparing the provisioner node for OpenShift Container Platform installation

Perform the following steps to prepare the environment.

Procedure

  1. Log in to the provisioner node via ssh.
  2. Create a non-root user (kni) and provide that user with sudo privileges:

    # useradd kni
    # passwd kni
    # echo "kni ALL=(root) NOPASSWD:ALL" | tee -a /etc/sudoers.d/kni
    # chmod 0440 /etc/sudoers.d/kni
  3. Create an ssh key for the new user:

    # su - kni -c "ssh-keygen -t ed25519 -f /home/kni/.ssh/id_rsa -N ''"
  4. Log in as the new user on the provisioner node:

    # su - kni
  5. Use Red Hat Subscription Manager to register the provisioner node:

    $ sudo subscription-manager register --username=<user> --password=<pass> --auto-attach
    $ sudo subscription-manager repos --enable=rhel-9-for-<architecture>-appstream-rpms --enable=rhel-9-for-<architecture>-baseos-rpms
    Note

    For more information about Red Hat Subscription Manager, see Registering a RHEL system with command-line tools.

  6. Install the following packages:

    $ sudo dnf install -y libvirt qemu-kvm mkisofs python3-devel jq ipmitool
  7. Modify the user to add the libvirt group to the newly created user:

    $ sudo usermod --append --groups libvirt <user>
  8. Restart firewalld and enable the http service:

    $ sudo systemctl start firewalld
    $ sudo firewall-cmd --zone=public --add-service=http --permanent
    $ sudo firewall-cmd --reload
  9. Start and enable the libvirtd service:

    $ sudo systemctl enable libvirtd --now
  10. Create the default storage pool and start it:

    $ sudo virsh pool-define-as --name default --type dir --target /var/lib/libvirt/images
    $ sudo virsh pool-start default
    $ sudo virsh pool-autostart default
  11. Create a pull-secret.txt file:

    $ vim pull-secret.txt

    In a web browser, navigate to Install OpenShift on Bare Metal with installer-provisioned infrastructure. Click Copy pull secret. Paste the contents into the pull-secret.txt file and save the contents in the kni user’s home directory.

3.3.3. Checking NTP server synchronization

The OpenShift Container Platform installation program installs the chrony Network Time Protocol (NTP) service on the cluster nodes. To complete installation, each node must have access to an NTP time server. You can verify NTP server synchronization by using the chrony service.

For disconnected clusters, you must configure the NTP servers on the control plane nodes. For more information see the Additional resources section.

Prerequisites

  • You installed the chrony package on the target node.

Procedure

  1. Log in to the node by using the ssh command.
  2. View the NTP servers available to the node by running the following command:

    $ chronyc sources

    Example output

    MS Name/IP address         Stratum Poll Reach LastRx Last sample
    ===============================================================================
    ^+ time.cloudflare.com           3  10   377   187   -209us[ -209us] +/-   32ms
    ^+ t1.time.ir2.yahoo.com         2  10   377   185  -4382us[-4382us] +/-   23ms
    ^+ time.cloudflare.com           3  10   377   198   -996us[-1220us] +/-   33ms
    ^* brenbox.westnet.ie            1  10   377   193  -9538us[-9761us] +/-   24ms

  3. Use the ping command to ensure that the node can access an NTP server, for example:

    $ ping time.cloudflare.com

    Example output

    PING time.cloudflare.com (162.159.200.123) 56(84) bytes of data.
    64 bytes from time.cloudflare.com (162.159.200.123): icmp_seq=1 ttl=54 time=32.3 ms
    64 bytes from time.cloudflare.com (162.159.200.123): icmp_seq=2 ttl=54 time=30.9 ms
    64 bytes from time.cloudflare.com (162.159.200.123): icmp_seq=3 ttl=54 time=36.7 ms
    ...

3.3.4. Configuring networking

Before installation, you must configure the networking on the provisioner node. Installer-provisioned clusters deploy with a bare-metal bridge and network, and an optional provisioning bridge and network.

Configure networking
Note

You can also configure networking from the web console.

Procedure

  1. Export the bare-metal network NIC name by running the following command:

    $ export PUB_CONN=<baremetal_nic_name>
  2. Configure the bare-metal network:

    Note

    The SSH connection might disconnect after executing these steps.

    1. For a network using DHCP, run the following command:

      $ sudo nohup bash -c "
          nmcli con down \"$PUB_CONN\"
          nmcli con delete \"$PUB_CONN\"
          # RHEL 8.1 appends the word \"System\" in front of the connection, delete in case it exists
          nmcli con down \"System $PUB_CONN\"
          nmcli con delete \"System $PUB_CONN\"
          nmcli connection add ifname baremetal type bridge <con_name> baremetal bridge.stp no 1
          nmcli con add type bridge-slave ifname \"$PUB_CONN\" master baremetal
          pkill dhclient;dhclient baremetal
      "
      1
      Replace <con_name> with the connection name.
    2. For a network using static IP addressing and no DHCP network, run the following command:

      $ sudo nohup bash -c "
          nmcli con down \"$PUB_CONN\"
          nmcli con delete \"$PUB_CONN\"
          # RHEL 8.1 appends the word \"System\" in front of the connection, delete in case it exists
          nmcli con down \"System $PUB_CONN\"
          nmcli con delete \"System $PUB_CONN\"
          nmcli connection add ifname baremetal type bridge con-name baremetal bridge.stp no ipv4.method manual ipv4.addr "x.x.x.x/yy" ipv4.gateway "a.a.a.a" ipv4.dns "b.b.b.b" 1
          nmcli con add type bridge-slave ifname \"$PUB_CONN\" master baremetal
          nmcli con up baremetal
      "
      1
      Replace <con_name> with the connection name. Replace x.x.x.x/yy with the IP address and CIDR for the network. Replace a.a.a.a with the network gateway. Replace b.b.b.b with the IP address of the DNS server.
  3. Optional: If you are deploying with a provisioning network, export the provisioning network NIC name by running the following command:

    $ export PROV_CONN=<prov_nic_name>
  4. Optional: If you are deploying with a provisioning network, configure the provisioning network by running the following command:

    $ sudo nohup bash -c "
        nmcli con down \"$PROV_CONN\"
        nmcli con delete \"$PROV_CONN\"
        nmcli connection add ifname provisioning type bridge con-name provisioning
        nmcli con add type bridge-slave ifname \"$PROV_CONN\" master provisioning
        nmcli connection modify provisioning ipv6.addresses fd00:1101::1/64 ipv6.method manual
        nmcli con down provisioning
        nmcli con up provisioning
    "
    Note

    The SSH connection might disconnect after executing these steps.

    The IPv6 address can be any address that is not routable through the bare-metal network.

    Ensure that UEFI is enabled and UEFI PXE settings are set to the IPv6 protocol when using IPv6 addressing.

  5. Optional: If you are deploying with a provisioning network, configure the IPv4 address on the provisioning network connection by running the following command:

    $ nmcli connection modify provisioning ipv4.addresses 172.22.0.254/24 ipv4.method manual
  6. SSH back into the provisioner node (if required) by running the following command:

    # ssh kni@provisioner.<cluster-name>.<domain>
  7. Verify that the connection bridges have been properly created by running the following command:

    $ sudo nmcli con show

    Example output

    NAME               UUID                                  TYPE      DEVICE
    baremetal          4d5133a5-8351-4bb9-bfd4-3af264801530  bridge    baremetal
    provisioning       43942805-017f-4d7d-a2c2-7cb3324482ed  bridge    provisioning
    virbr0             d9bca40f-eee1-410b-8879-a2d4bb0465e7  bridge    virbr0
    bridge-slave-eno1  76a8ed50-c7e5-4999-b4f6-6d9014dd0812  ethernet  eno1
    bridge-slave-eno2  f31c3353-54b7-48de-893a-02d2b34c4736  ethernet  eno2

3.3.5. Creating a manifest object that includes a customized br-ex bridge

As an alternative to using the configure-ovs.sh shell script to set a br-ex bridge on a bare-metal platform, you can create a MachineConfig object that includes an NMState configuration file. The NMState configuration file creates a customized br-ex bridge network configuration on each node in your cluster.

Consider the following use cases for creating a manifest object that includes a customized br-ex bridge:

  • You want to make postinstallation changes to the bridge, such as changing the Open vSwitch (OVS) or OVN-Kubernetes br-ex bridge network. The configure-ovs.sh shell script does not support making postinstallation changes to the bridge.
  • You want to deploy the bridge on a different interface than the interface available on a host or server IP address.
  • You want to make advanced configurations to the bridge that are not possible with the configure-ovs.sh shell script. Using the script for these configurations might result in the bridge failing to connect multiple network interfaces and facilitating data forwarding between the interfaces.
Note

If you require an environment with a single network interface controller (NIC) and default network settings, use the configure-ovs.sh shell script.

After you install Red Hat Enterprise Linux CoreOS (RHCOS) and the system reboots, the Machine Config Operator injects Ignition configuration files into each node in your cluster, so that each node received the br-ex bridge network configuration. To prevent configuration conflicts, the configure-ovs.sh shell script receives a signal to not configure the br-ex bridge.

Prerequisites

  • Optional: You have installed the nmstate API so that you can validate the NMState configuration.

Procedure

  1. Create a NMState configuration file that has decoded base64 information for your customized br-ex bridge network:

    Example of an NMState configuration for a customized br-ex bridge network

    interfaces:
    - name: enp2s0 1
      type: ethernet 2
      state: up 3
      ipv4:
        enabled: false 4
      ipv6:
        enabled: false
    - name: br-ex
      type: ovs-bridge
      state: up
      ipv4:
        enabled: false
        dhcp: false
      ipv6:
        enabled: false
        dhcp: false
      bridge:
        port:
        - name: enp2s0 5
        - name: br-ex
    - name: br-ex
      type: ovs-interface
      state: up
      copy-mac-from: enp2s0
      ipv4:
        enabled: true
        dhcp: true
      ipv6:
        enabled: false
        dhcp: false
    # ...

    1
    Name of the interface.
    2
    The type of ethernet.
    3
    The requested state for the interface after creation.
    4
    Disables IPv4 and IPv6 in this example.
    5
    The node NIC to which the bridge attaches.
  2. Use the cat command to base64-encode the contents of the NMState configuration:

    $ cat <nmstate_configuration>.yaml | base64 1
    1
    Replace <nmstate_configuration> with the name of your NMState resource YAML file.
  3. Create a MachineConfig manifest file and define a customized br-ex bridge network configuration analogous to the following example:

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    metadata:
      labels:
        machineconfiguration.openshift.io/role: worker 1
      name: 10-br-ex-worker 2
    spec:
      config:
        ignition:
          version: 3.2.0
        storage:
          files:
          - contents:
              source: data:text/plain;charset=utf-8;base64,<base64_encoded_nmstate_configuration> 3
            mode: 0644
            overwrite: true
            path: /etc/nmstate/openshift/cluster.yml
    # ...
    1
    For each node in your cluster, specify the hostname path to your node and the base-64 encoded Ignition configuration file data for the machine type. If you have a single global configuration specified in an /etc/nmstate/openshift/cluster.yml configuration file that you want to apply to all nodes in your cluster, you do not need to specify the hostname path for each node. The worker role is the default role for nodes in your cluster. The .yaml extension does not work when specifying the hostname path for each node or all nodes in the MachineConfig manifest file.
    2
    The name of the policy.
    3
    Writes the encoded base64 information to the specified path.
3.3.5.1. Scaling each machine set to compute nodes

To apply a customized br-ex bridge configuration to all compute nodes in your OpenShift Container Platform cluster, you must edit your MachineConfig custom resource (CR) and modify its roles. Additionally, you must create a BareMetalHost CR that defines information for your bare-metal machine, such as hostname, credentials, and so on.

After you configure these resources, you must scale machine sets, so that the machine sets can apply the resource configuration to each compute node and reboot the nodes.

Prerequisites

  • You created a MachineConfig manifest object that includes a customized br-ex bridge configuration.

Procedure

  1. Edit the MachineConfig CR by entering the following command:

    $ oc edit mc <machineconfig_custom_resource_name>
  2. Add each compute node configuration to the CR, so that the CR can manage roles for each defined compute node in your cluster.
  3. Create a Secret object named extraworker-secret that has a minimal static IP configuration.
  4. Apply the extraworker-secret secret to each node in your cluster by entering the following command. This step provides each compute node access to the Ignition config file.

    $ oc apply -f ./extraworker-secret.yaml
  5. Create a BareMetalHost resource and specify the network secret in the preprovisioningNetworkDataName parameter:

    Example BareMetalHost resource with an attached network secret

    apiVersion: metal3.io/v1alpha1
    kind: BareMetalHost
    spec:
    # ...
      preprovisioningNetworkDataName: ostest-extraworker-0-network-config-secret
    # ...

  6. To manage the BareMetalHost object within the openshift-machine-api namespace of your cluster, change to the namespace by entering the following command:

    $ oc project openshift-machine-api
  7. Get the machine sets:

    $ oc get machinesets
  8. Scale each machine set by entering the following command. You must run this command for each machine set.

    $ oc scale machineset <machineset_name> --replicas=<n> 1
    1
    Where <machineset_name> is the name of the machine set and <n> is the number of compute nodes.

3.3.6. Establishing communication between subnets

In a typical OpenShift Container Platform cluster setup, all nodes, including the control plane and compute nodes, reside in the same network. However, for edge computing scenarios, it can be beneficial to locate compute nodes closer to the edge. This often involves using different network segments or subnets for the remote nodes than the subnet used by the control plane and local compute nodes. Such a setup can reduce latency for the edge and allow for enhanced scalability.

Before installing OpenShift Container Platform, you must configure the network properly to ensure that the edge subnets containing the remote nodes can reach the subnet containing the control plane nodes and receive traffic from the control plane too.

You can run control plane nodes in the same subnet or multiple subnets by configuring a user-managed load balancer in place of the default load balancer. With a multiple subnet environment, you can reduce the risk of your OpenShift Container Platform cluster from failing because of a hardware failure or a network outage. For more information, see "Services for a user-managed load balancer" and "Configuring a user-managed load balancer".

Running control plane nodes in a multiple subnet environment requires completion of the following key tasks:

  • Configuring a user-managed load balancer instead of the default load balancer by specifying UserManaged in the loadBalancer.type parameter of the install-config.yaml file.
  • Configuring a user-managed load balancer address in the ingressVIPs and apiVIPs parameters of the install-config.yaml file.
  • Adding the multiple subnet Classless Inter-Domain Routing (CIDR) and the user-managed load balancer IP addresses to the networking.machineNetworks parameter in the install-config.yaml file.
Note

Deploying a cluster with multiple subnets requires using virtual media, such as redfish-virtualmedia and idrac-virtualmedia.

This procedure details the network configuration required to allow the remote compute nodes in the second subnet to communicate effectively with the control plane nodes in the first subnet and to allow the control plane nodes in the first subnet to communicate effectively with the remote compute nodes in the second subnet.

In this procedure, the cluster spans two subnets:

  • The first subnet (10.0.0.0) contains the control plane and local compute nodes.
  • The second subnet (192.168.0.0) contains the edge compute nodes.

Procedure

  1. Configure the first subnet to communicate with the second subnet:

    1. Log in as root to a control plane node by running the following command:

      $ sudo su -
    2. Get the name of the network interface by running the following command:

      # nmcli dev status
    3. Add a route to the second subnet (192.168.0.0) via the gateway by running the following command:

      # nmcli connection modify <interface_name> +ipv4.routes "192.168.0.0/24 via <gateway>"

      Replace <interface_name> with the interface name. Replace <gateway> with the IP address of the actual gateway.

      Example

      # nmcli connection modify eth0 +ipv4.routes "192.168.0.0/24 via 192.168.0.1"

    4. Apply the changes by running the following command:

      # nmcli connection up <interface_name>

      Replace <interface_name> with the interface name.

    5. Verify the routing table to ensure the route has been added successfully:

      # ip route
    6. Repeat the previous steps for each control plane node in the first subnet.

      Note

      Adjust the commands to match your actual interface names and gateway.

  2. Configure the second subnet to communicate with the first subnet:

    1. Log in as root to a remote compute node by running the following command:

      $ sudo su -
    2. Get the name of the network interface by running the following command:

      # nmcli dev status
    3. Add a route to the first subnet (10.0.0.0) via the gateway by running the following command:

      # nmcli connection modify <interface_name> +ipv4.routes "10.0.0.0/24 via <gateway>"

      Replace <interface_name> with the interface name. Replace <gateway> with the IP address of the actual gateway.

      Example

      # nmcli connection modify eth0 +ipv4.routes "10.0.0.0/24 via 10.0.0.1"

    4. Apply the changes by running the following command:

      # nmcli connection up <interface_name>

      Replace <interface_name> with the interface name.

    5. Verify the routing table to ensure the route has been added successfully by running the following command:

      # ip route
    6. Repeat the previous steps for each compute node in the second subnet.

      Note

      Adjust the commands to match your actual interface names and gateway.

  3. After you have configured the networks, test the connectivity to ensure the remote nodes can reach the control plane nodes and the control plane nodes can reach the remote nodes.

    1. From the control plane nodes in the first subnet, ping a remote node in the second subnet by running the following command:

      $ ping <remote_node_ip_address>

      If the ping is successful, it means the control plane nodes in the first subnet can reach the remote nodes in the second subnet. If you do not receive a response, review the network configurations and repeat the procedure for the node.

    2. From the remote nodes in the second subnet, ping a control plane node in the first subnet by running the following command:

      $ ping <control_plane_node_ip_address>

      If the ping is successful, it means the remote compute nodes in the second subnet can reach the control plane in the first subnet. If you do not receive a response, review the network configurations and repeat the procedure for the node.

3.3.7. Retrieving the OpenShift Container Platform installer

Use the stable-4.x version of the installation program and your selected architecture to deploy the generally available stable version of OpenShift Container Platform:

$ export VERSION=stable-4.18
$ export RELEASE_ARCH=<architecture>
$ export RELEASE_IMAGE=$(curl -s https://mirror.openshift.com/pub/openshift-v4/$RELEASE_ARCH/clients/ocp/$VERSION/release.txt | grep 'Pull From: quay.io' | awk -F ' ' '{print $3}')

3.3.8. Extracting the OpenShift Container Platform installer

After retrieving the installer, the next step is to extract it.

Procedure

  1. Set the environment variables:

    $ export cmd=openshift-baremetal-install
    $ export pullsecret_file=~/pull-secret.txt
    $ export extract_dir=$(pwd)
  2. Get the oc binary:

    $ curl -s https://mirror.openshift.com/pub/openshift-v4/clients/ocp/$VERSION/openshift-client-linux.tar.gz | tar zxvf - oc
  3. Extract the installer:

    $ sudo cp oc /usr/local/bin
    $ oc adm release extract --registry-config "${pullsecret_file}" --command=$cmd --to "${extract_dir}" ${RELEASE_IMAGE}
    $ sudo cp openshift-baremetal-install /usr/local/bin

3.3.9. Creating an RHCOS images cache

To employ image caching, you must download the Red Hat Enterprise Linux CoreOS (RHCOS) image used by the bootstrap VM to provision the cluster nodes. Image caching is optional, but it is especially useful when running the installation program on a network with limited bandwidth.

Note

The installation program no longer needs the clusterOSImage RHCOS image because the correct image is in the release payload.

If you are running the installation program on a network with limited bandwidth and the RHCOS images download takes more than 15 to 20 minutes, the installation program will timeout. Caching images on a web server will help in such scenarios.

Warning

If you enable TLS for the HTTPD server, you must confirm the root certificate is signed by an authority trusted by the client and verify the trusted certificate chain between your OpenShift Container Platform hub and spoke clusters and the HTTPD server. Using a server configured with an untrusted certificate prevents the images from being downloaded to the image creation service. Using untrusted HTTPS servers is not supported.

Install a container that contains the images.

Procedure

  1. Install podman:

    $ sudo dnf install -y podman
  2. Open firewall port 8080 to be used for RHCOS image caching:

    $ sudo firewall-cmd --add-port=8080/tcp --zone=public --permanent
    $ sudo firewall-cmd --reload
  3. Create a directory to store the bootstraposimage:

    $ mkdir /home/kni/rhcos_image_cache
  4. Set the appropriate SELinux context for the newly created directory:

    $ sudo semanage fcontext -a -t httpd_sys_content_t "/home/kni/rhcos_image_cache(/.*)?"
    $ sudo restorecon -Rv /home/kni/rhcos_image_cache/
  5. Get the URI for the RHCOS image that the installation program will deploy on the bootstrap VM:

    $ export RHCOS_QEMU_URI=$(/usr/local/bin/openshift-baremetal-install coreos print-stream-json | jq -r --arg ARCH "$(arch)" '.architectures[$ARCH].artifacts.qemu.formats["qcow2.gz"].disk.location')
  6. Get the name of the image that the installation program will deploy on the bootstrap VM:

    $ export RHCOS_QEMU_NAME=${RHCOS_QEMU_URI##*/}
  7. Get the SHA hash for the RHCOS image that will be deployed on the bootstrap VM:

    $ export RHCOS_QEMU_UNCOMPRESSED_SHA256=$(/usr/local/bin/openshift-baremetal-install coreos print-stream-json | jq -r --arg ARCH "$(arch)" '.architectures[$ARCH].artifacts.qemu.formats["qcow2.gz"].disk["uncompressed-sha256"]')
  8. Download the image and place it in the /home/kni/rhcos_image_cache directory:

    $ curl -L ${RHCOS_QEMU_URI} -o /home/kni/rhcos_image_cache/${RHCOS_QEMU_NAME}
  9. Confirm SELinux type is of httpd_sys_content_t for the new file:

    $ ls -Z /home/kni/rhcos_image_cache
  10. Create the pod:

    $ podman run -d --name rhcos_image_cache \1
    -v /home/kni/rhcos_image_cache:/var/www/html \
    -p 8080:8080/tcp \
    registry.access.redhat.com/ubi9/httpd-24
    1
    Creates a caching webserver with the name rhcos_image_cache. This pod serves the bootstrapOSImage image in the install-config.yaml file for deployment.
  11. Generate the bootstrapOSImage configuration:

    $ export BAREMETAL_IP=$(ip addr show dev baremetal | awk '/inet /{print $2}' | cut -d"/" -f1)
    $ export BOOTSTRAP_OS_IMAGE="http://${BAREMETAL_IP}:8080/${RHCOS_QEMU_NAME}?sha256=${RHCOS_QEMU_UNCOMPRESSED_SHA256}"
    $ echo "    bootstrapOSImage=${BOOTSTRAP_OS_IMAGE}"
  12. Add the required configuration to the install-config.yaml file under platform.baremetal:

    platform:
      baremetal:
        bootstrapOSImage: <bootstrap_os_image>  1
    1
    Replace <bootstrap_os_image> with the value of $BOOTSTRAP_OS_IMAGE.

    See the "Configuring the install-config.yaml file" section for additional details.

3.3.10. Services for a user-managed load balancer

You can configure an OpenShift Container Platform cluster to use a user-managed load balancer in place of the default load balancer.

Important

Configuring a user-managed load balancer depends on your vendor’s load balancer.

The information and examples in this section are for guideline purposes only. Consult the vendor documentation for more specific information about the vendor’s load balancer.

Red Hat supports the following services for a user-managed load balancer:

  • Ingress Controller
  • OpenShift API
  • OpenShift MachineConfig API

You can choose whether you want to configure one or all of these services for a user-managed load balancer. Configuring only the Ingress Controller service is a common configuration option. To better understand each service, view the following diagrams:

Figure 3.1. Example network workflow that shows an Ingress Controller operating in an OpenShift Container Platform environment

An image that shows an example network workflow of an Ingress Controller operating in an OpenShift Container Platform environment.

Figure 3.2. Example network workflow that shows an OpenShift API operating in an OpenShift Container Platform environment

An image that shows an example network workflow of an OpenShift API operating in an OpenShift Container Platform environment.

Figure 3.3. Example network workflow that shows an OpenShift MachineConfig API operating in an OpenShift Container Platform environment

An image that shows an example network workflow of an OpenShift MachineConfig API operating in an OpenShift Container Platform environment.

The following configuration options are supported for user-managed load balancers:

  • Use a node selector to map the Ingress Controller to a specific set of nodes. You must assign a static IP address to each node in this set, or configure each node to receive the same IP address from the Dynamic Host Configuration Protocol (DHCP). Infrastructure nodes commonly receive this type of configuration.
  • Target all IP addresses on a subnet. This configuration can reduce maintenance overhead, because you can create and destroy nodes within those networks without reconfiguring the load balancer targets. If you deploy your ingress pods by using a machine set on a smaller network, such as a /27 or /28, you can simplify your load balancer targets.

    Tip

    You can list all IP addresses that exist in a network by checking the machine config pool’s resources.

Before you configure a user-managed load balancer for your OpenShift Container Platform cluster, consider the following information:

  • For a front-end IP address, you can use the same IP address for the front-end IP address, the Ingress Controller’s load balancer, and API load balancer. Check the vendor’s documentation for this capability.
  • For a back-end IP address, ensure that an IP address for an OpenShift Container Platform control plane node does not change during the lifetime of the user-managed load balancer. You can achieve this by completing one of the following actions:

    • Assign a static IP address to each control plane node.
    • Configure each node to receive the same IP address from the DHCP every time the node requests a DHCP lease. Depending on the vendor, the DHCP lease might be in the form of an IP reservation or a static DHCP assignment.
  • Manually define each node that runs the Ingress Controller in the user-managed load balancer for the Ingress Controller back-end service. For example, if the Ingress Controller moves to an undefined node, a connection outage can occur.
3.3.10.1. Configuring a user-managed load balancer

You can configure an OpenShift Container Platform cluster to use a user-managed load balancer in place of the default load balancer.

Important

Before you configure a user-managed load balancer, ensure that you read the "Services for a user-managed load balancer" section.

Read the following prerequisites that apply to the service that you want to configure for your user-managed load balancer.

Note

MetalLB, which runs on a cluster, functions as a user-managed load balancer.

OpenShift API prerequisites

  • You defined a front-end IP address.
  • TCP ports 6443 and 22623 are exposed on the front-end IP address of your load balancer. Check the following items:

    • Port 6443 provides access to the OpenShift API service.
    • Port 22623 can provide ignition startup configurations to nodes.
  • The front-end IP address and port 6443 are reachable by all users of your system with a location external to your OpenShift Container Platform cluster.
  • The front-end IP address and port 22623 are reachable only by OpenShift Container Platform nodes.
  • The load balancer backend can communicate with OpenShift Container Platform control plane nodes on port 6443 and 22623.

Ingress Controller prerequisites

  • You defined a front-end IP address.
  • TCP ports 443 and 80 are exposed on the front-end IP address of your load balancer.
  • The front-end IP address, port 80 and port 443 are be reachable by all users of your system with a location external to your OpenShift Container Platform cluster.
  • The front-end IP address, port 80 and port 443 are reachable to all nodes that operate in your OpenShift Container Platform cluster.
  • The load balancer backend can communicate with OpenShift Container Platform nodes that run the Ingress Controller on ports 80, 443, and 1936.

Prerequisite for health check URL specifications

You can configure most load balancers by setting health check URLs that determine if a service is available or unavailable. OpenShift Container Platform provides these health checks for the OpenShift API, Machine Configuration API, and Ingress Controller backend services.

The following examples show health check specifications for the previously listed backend services:

Example of a Kubernetes API health check specification

Path: HTTPS:6443/readyz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10

Example of a Machine Config API health check specification

Path: HTTPS:22623/healthz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10

Example of an Ingress Controller health check specification

Path: HTTP:1936/healthz/ready
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 5
Interval: 10

Procedure

  1. Configure the HAProxy Ingress Controller, so that you can enable access to the cluster from your load balancer on ports 6443, 22623, 443, and 80. Depending on your needs, you can specify the IP address of a single subnet or IP addresses from multiple subnets in your HAProxy configuration.

    Example HAProxy configuration with one listed subnet

    # ...
    listen my-cluster-api-6443
        bind 192.168.1.100:6443
        mode tcp
        balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /readyz
      http-check expect status 200
        server my-cluster-master-2 192.168.1.101:6443 check inter 10s rise 2 fall 2
        server my-cluster-master-0 192.168.1.102:6443 check inter 10s rise 2 fall 2
        server my-cluster-master-1 192.168.1.103:6443 check inter 10s rise 2 fall 2
    
    listen my-cluster-machine-config-api-22623
        bind 192.168.1.100:22623
        mode tcp
        balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /healthz
      http-check expect status 200
        server my-cluster-master-2 192.168.1.101:22623 check inter 10s rise 2 fall 2
        server my-cluster-master-0 192.168.1.102:22623 check inter 10s rise 2 fall 2
        server my-cluster-master-1 192.168.1.103:22623 check inter 10s rise 2 fall 2
    
    listen my-cluster-apps-443
        bind 192.168.1.100:443
        mode tcp
        balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /healthz/ready
      http-check expect status 200
        server my-cluster-worker-0 192.168.1.111:443 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-1 192.168.1.112:443 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-2 192.168.1.113:443 check port 1936 inter 10s rise 2 fall 2
    
    listen my-cluster-apps-80
       bind 192.168.1.100:80
       mode tcp
       balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /healthz/ready
      http-check expect status 200
        server my-cluster-worker-0 192.168.1.111:80 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-1 192.168.1.112:80 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-2 192.168.1.113:80 check port 1936 inter 10s rise 2 fall 2
    # ...

    Example HAProxy configuration with multiple listed subnets

    # ...
    listen api-server-6443
        bind *:6443
        mode tcp
          server master-00 192.168.83.89:6443 check inter 1s
          server master-01 192.168.84.90:6443 check inter 1s
          server master-02 192.168.85.99:6443 check inter 1s
          server bootstrap 192.168.80.89:6443 check inter 1s
    
    listen machine-config-server-22623
        bind *:22623
        mode tcp
          server master-00 192.168.83.89:22623 check inter 1s
          server master-01 192.168.84.90:22623 check inter 1s
          server master-02 192.168.85.99:22623 check inter 1s
          server bootstrap 192.168.80.89:22623 check inter 1s
    
    listen ingress-router-80
        bind *:80
        mode tcp
        balance source
          server worker-00 192.168.83.100:80 check inter 1s
          server worker-01 192.168.83.101:80 check inter 1s
    
    listen ingress-router-443
        bind *:443
        mode tcp
        balance source
          server worker-00 192.168.83.100:443 check inter 1s
          server worker-01 192.168.83.101:443 check inter 1s
    
    listen ironic-api-6385
        bind *:6385
        mode tcp
        balance source
          server master-00 192.168.83.89:6385 check inter 1s
          server master-01 192.168.84.90:6385 check inter 1s
          server master-02 192.168.85.99:6385 check inter 1s
          server bootstrap 192.168.80.89:6385 check inter 1s
    
    listen inspector-api-5050
        bind *:5050
        mode tcp
        balance source
          server master-00 192.168.83.89:5050 check inter 1s
          server master-01 192.168.84.90:5050 check inter 1s
          server master-02 192.168.85.99:5050 check inter 1s
          server bootstrap 192.168.80.89:5050 check inter 1s
    # ...

  2. Use the curl CLI command to verify that the user-managed load balancer and its resources are operational:

    1. Verify that the cluster machine configuration API is accessible to the Kubernetes API server resource, by running the following command and observing the response:

      $ curl https://<loadbalancer_ip_address>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
        "major": "1",
        "minor": "11+",
        "gitVersion": "v1.11.0+ad103ed",
        "gitCommit": "ad103ed",
        "gitTreeState": "clean",
        "buildDate": "2019-01-09T06:44:10Z",
        "goVersion": "go1.10.3",
        "compiler": "gc",
        "platform": "linux/amd64"
      }
    2. Verify that the cluster machine configuration API is accessible to the Machine config server resource, by running the following command and observing the output:

      $ curl -v https://<loadbalancer_ip_address>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      Content-Length: 0
    3. Verify that the controller is accessible to the Ingress Controller resource on port 80, by running the following command and observing the output:

      $ curl -I -L -H "Host: console-openshift-console.apps.<cluster_name>.<base_domain>" http://<load_balancer_front_end_IP_address>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
      content-length: 0
      location: https://console-openshift-console.apps.ocp4.private.opequon.net/
      cache-control: no-cache
    4. Verify that the controller is accessible to the Ingress Controller resource on port 443, by running the following command and observing the output:

      $ curl -I -L --insecure --resolve console-openshift-console.apps.<cluster_name>.<base_domain>:443:<Load Balancer Front End IP Address> https://console-openshift-console.apps.<cluster_name>.<base_domain>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Wed, 04 Oct 2023 16:29:38 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private
  3. Configure the DNS records for your cluster to target the front-end IP addresses of the user-managed load balancer. You must update records to your DNS server for the cluster API and applications over the load balancer.

    Examples of modified DNS records

    <load_balancer_ip_address>  A  api.<cluster_name>.<base_domain>
    A record pointing to Load Balancer Front End

    <load_balancer_ip_address>   A apps.<cluster_name>.<base_domain>
    A record pointing to Load Balancer Front End
    Important

    DNS propagation might take some time for each DNS record to become available. Ensure that each DNS record propagates before validating each record.

  4. For your OpenShift Container Platform cluster to use the user-managed load balancer, you must specify the following configuration in your cluster’s install-config.yaml file:

    # ...
    platform:
      baremetal:
        loadBalancer:
          type: UserManaged 1
        apiVIPs:
        - <api_ip> 2
        ingressVIPs:
        - <ingress_ip> 3
    # ...
    1
    Set UserManaged for the type parameter to specify a user-managed load balancer for your cluster. The parameter defaults to OpenShiftManagedDefault, which denotes the default internal load balancer. For services defined in an openshift-kni-infra namespace, a user-managed load balancer can deploy the coredns service to pods in your cluster but ignores keepalived and haproxy services.
    2
    Required parameter when you specify a user-managed load balancer. Specify the user-managed load balancer’s public IP address, so that the Kubernetes API can communicate with the user-managed load balancer.
    3
    Required parameter when you specify a user-managed load balancer. Specify the user-managed load balancer’s public IP address, so that the user-managed load balancer can manage ingress traffic for your cluster.

Verification

  1. Use the curl CLI command to verify that the user-managed load balancer and DNS record configuration are operational:

    1. Verify that you can access the cluster API, by running the following command and observing the output:

      $ curl https://api.<cluster_name>.<base_domain>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
        "major": "1",
        "minor": "11+",
        "gitVersion": "v1.11.0+ad103ed",
        "gitCommit": "ad103ed",
        "gitTreeState": "clean",
        "buildDate": "2019-01-09T06:44:10Z",
        "goVersion": "go1.10.3",
        "compiler": "gc",
        "platform": "linux/amd64"
        }
    2. Verify that you can access the cluster machine configuration, by running the following command and observing the output:

      $ curl -v https://api.<cluster_name>.<base_domain>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      Content-Length: 0
    3. Verify that you can access each cluster application on port, by running the following command and observing the output:

      $ curl http://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
      content-length: 0
      location: https://console-openshift-console.apps.<cluster-name>.<base domain>/
      cache-control: no-cacheHTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=39HoZgztDnzjJkq/JuLJMeoKNXlfiVv2YgZc09c3TBOBU4NI6kDXaJH1LdicNhN1UsQWzon4Dor9GWGfopaTEQ==; Path=/; Secure
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Tue, 17 Nov 2020 08:42:10 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=9b714eb87e93cf34853e87a92d6894be; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private
    4. Verify that you can access each cluster application on port 443, by running the following command and observing the output:

      $ curl https://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Wed, 04 Oct 2023 16:29:38 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private

3.3.11. Setting the cluster node hostnames through DHCP

On Red Hat Enterprise Linux CoreOS (RHCOS) machines, NetworkManager sets the hostnames. By default, DHCP provides the hostnames to NetworkManager, which is the recommended method. NetworkManager gets the hostnames through a reverse DNS lookup in the following cases:

  • If DHCP does not provide the hostnames
  • If you use kernel arguments to set the hostnames
  • If you use another method to set the hostnames

Reverse DNS lookup occurs after the network has been initialized on a node, and can increase the time it takes NetworkManager to set the hostname. Other system services can start prior to NetworkManager setting the hostname, which can cause those services to use a default hostname such as localhost.

Tip

You can avoid the delay in setting hostnames by using DHCP to provide the hostname for each cluster node. Additionally, setting the hostnames through DHCP can bypass manual DNS record name configuration errors in environments that have a DNS split-horizon implementation.

3.3.12. Configuring the install-config.yaml file

3.3.12.1. Configuring the install-config.yaml file

The install-config.yaml file requires some additional details. Most of the information teaches the installation program and the resulting cluster enough about the available hardware that it is able to fully manage it.

Note

The installation program no longer needs the clusterOSImage RHCOS image because the correct image is in the release payload.

  1. Configure install-config.yaml. Change the appropriate variables to match the environment, including pullSecret and sshKey:

    apiVersion: v1
    baseDomain: <domain>
    metadata:
      name: <cluster_name>
    networking:
      machineNetwork:
      - cidr: <public_cidr>
      networkType: OVNKubernetes
    compute:
    - name: worker
      replicas: 2 1
    controlPlane:
      name: master
      replicas: 3
      platform:
        baremetal: {}
    platform:
      baremetal:
        additionalNTPServers: 2
          - <ntp_domain_or_ip>
        apiVIPs:
          - <api_ip>
        ingressVIPs:
          - <wildcard_ip>
        provisioningNetworkCIDR: <CIDR>
        bootstrapExternalStaticIP: <bootstrap_static_ip_address> 3
        bootstrapExternalStaticGateway: <bootstrap_static_gateway> 4
        bootstrapExternalStaticDNS: <bootstrap_static_dns> 5
        hosts:
          - name: openshift-master-0
            role: master
            bmc:
              address: ipmi://<out_of_band_ip> 6
              username: <user>
              password: <password>
            bootMACAddress: <NIC1_mac_address>
            rootDeviceHints:
             deviceName: "<installation_disk_drive_path>" 7
          - name: <openshift_master_1>
            role: master
            bmc:
              address: ipmi://<out_of_band_ip>
              username: <user>
              password: <password>
            bootMACAddress: <NIC1_mac_address>
            rootDeviceHints:
             deviceName: "<installation_disk_drive_path>"
          - name: <openshift_master_2>
            role: master
            bmc:
              address: ipmi://<out_of_band_ip>
              username: <user>
              password: <password>
            bootMACAddress: <NIC1_mac_address>
            rootDeviceHints:
             deviceName: "<installation_disk_drive_path>"
          - name: <openshift_worker_0>
            role: worker
            bmc:
              address: ipmi://<out_of_band_ip>
              username: <user>
              password: <password>
            bootMACAddress: <NIC1_mac_address>
          - name: <openshift_worker_1>
            role: worker
            bmc:
              address: ipmi://<out_of_band_ip>
              username: <user>
              password: <password>
            bootMACAddress: <NIC1_mac_address>
            rootDeviceHints:
             deviceName: "<installation_disk_drive_path>"
    pullSecret: '<pull_secret>'
    sshKey: '<ssh_pub_key>'
    1
    Scale the compute machines based on the number of compute nodes that are part of the OpenShift Container Platform cluster. Valid options for the replicas value are 0 and integers greater than or equal to 2. Set the number of replicas to 0 to deploy a three-node cluster, which contains only three control plane machines. A three-node cluster is a smaller, more resource-efficient cluster that can be used for testing, development, and production. You cannot install the cluster with only one compute node.
    2
    An optional list of additional NTP server domain names or IP addresses to add to each host configuration when the cluster host clocks are out of synchronization.
    3
    When deploying a cluster with static IP addresses, you must set the bootstrapExternalStaticIP configuration setting to specify the static IP address of the bootstrap VM when there is no DHCP server on the bare metal network.
    4
    When deploying a cluster with static IP addresses, you must set the bootstrapExternalStaticGateway configuration setting to specify the gateway IP address for the bootstrap VM when there is no DHCP server on the bare metal network.
    5
    When deploying a cluster with static IP addresses, you must set the bootstrapExternalStaticDNS configuration setting to specify the DNS address for the bootstrap VM when there is no DHCP server on the bare metal network.
    6
    See the BMC addressing sections for more options.
    7
    To set the path to the installation disk drive, enter the kernel name of the disk. For example, /dev/sda.
    Important

    Because the disk discovery order is not guaranteed, the kernel name of the disk can change across booting options for machines with multiple disks. For example, /dev/sda becomes /dev/sdb and vice versa. To avoid this issue, you must use persistent disk attributes, such as the disk World Wide Name (WWN) or /dev/disk/by-path/. It is recommended to use the /dev/disk/by-path/<device_path> link to the storage location. To use the disk WWN, replace the deviceName parameter with the wwnWithExtension parameter. Depending on the parameter that you use, enter either of the following values:

    • The disk name. For example, /dev/sda, or /dev/disk/by-path/.
    • The disk WWN. For example, "0x64cd98f04fde100024684cf3034da5c2". Ensure that you enter the disk WWN value within quotes so that it is used as a string value and not a hexadecimal value.

    Failure to meet these requirements for the rootDeviceHints parameter might result in the following error:

    ironic-inspector inspection failed: No disks satisfied root device hints
    Note

    Before OpenShift Container Platform 4.12, the cluster installation program only accepted an IPv4 address or an IPv6 address for the apiVIP and ingressVIP configuration settings. In OpenShift Container Platform 4.12 and later, these configuration settings are deprecated. Instead, use a list format in the apiVIPs and ingressVIPs configuration settings to specify IPv4 addresses, IPv6 addresses, or both IP address formats.

  2. Create a directory to store the cluster configuration:

    $ mkdir ~/clusterconfigs
  3. Copy the install-config.yaml file to the new directory:

    $ cp install-config.yaml ~/clusterconfigs
  4. Ensure all bare metal nodes are powered off prior to installing the OpenShift Container Platform cluster:

    $ ipmitool -I lanplus -U <user> -P <password> -H <management-server-ip> power off
  5. Remove old bootstrap resources if any are left over from a previous deployment attempt:

    for i in $(sudo virsh list | tail -n +3 | grep bootstrap | awk {'print $2'});
    do
      sudo virsh destroy $i;
      sudo virsh undefine $i;
      sudo virsh vol-delete $i --pool $i;
      sudo virsh vol-delete $i.ign --pool $i;
      sudo virsh pool-destroy $i;
      sudo virsh pool-undefine $i;
    done
3.3.12.2. Additional install-config parameters

See the following tables for the required parameters, the hosts parameter, and the bmc parameter for the install-config.yaml file.

Table 3.7. Required parameters
ParametersDefaultDescription

baseDomain

 

The domain name for the cluster. For example, example.com.

bootMode

UEFI

The boot mode for a node. Options are legacy, UEFI, and UEFISecureBoot. If bootMode is not set, Ironic sets it while inspecting the node.

platform:
  baremetal:
    bootstrapExternalStaticDNS
 

The static network DNS of the bootstrap node. You must set this value when deploying a cluster with static IP addresses when there is no Dynamic Host Configuration Protocol (DHCP) server on the bare-metal network. If you do not set this value, the installation program will use the value from bootstrapExternalStaticGateway, which causes problems when the IP address values of the gateway and DNS are different.

platform:
  baremetal:
    bootstrapExternalStaticIP
 

The static IP address for the bootstrap VM. You must set this value when deploying a cluster with static IP addresses when there is no DHCP server on the bare-metal network.

platform:
  baremetal:
    bootstrapExternalStaticGateway
 

The static IP address of the gateway for the bootstrap VM. You must set this value when deploying a cluster with static IP addresses when there is no DHCP server on the bare-metal network.

sshKey

 

The sshKey configuration setting has the key in the ~/.ssh/id_rsa.pub file required to access the control plane nodes and compute nodes. Typically, this key is from the provisioner node.

pullSecret

 

The pullSecret configuration setting has a copy of the pull secret downloaded from the Install OpenShift on Bare Metal page when preparing the provisioner node.

metadata:
    name:
 

The name of the OpenShift Container Platform cluster. For example, openshift.

networking:
    machineNetwork:
    - cidr:
 

The public CIDR (Classless Inter-Domain Routing) of the external network. For example, 10.0.0.0/24.

compute:
  - name: worker
 

The OpenShift Container Platform cluster requires you to provide a name for compute nodes even if there are zero nodes.

compute:
    replicas: 2
 

Replicas sets the number of compute nodes in the OpenShift Container Platform cluster.

controlPlane:
    name: master
 

The OpenShift Container Platform cluster requires a name for control plane nodes.

controlPlane:
    replicas: 3
 

Replicas sets the number of control plane nodes included as part of the OpenShift Container Platform cluster.

provisioningNetworkInterface

 

The name of the network interface on nodes connected to the provisioning network. For OpenShift Container Platform 4.9 and later releases, use the bootMACAddress configuration setting to enable Ironic to identify the IP address of the NIC instead of using the provisioningNetworkInterface configuration setting to identify the name of the NIC.

defaultMachinePlatform

 

The default configuration used for machine pools without a platform configuration.

apiVIPs

 

(Optional) The virtual IP address for Kubernetes API communication.

You must either provide this setting in the install-config.yaml file as a reserved IP from the MachineNetwork parameter or preconfigured in the DNS so that the default name resolves correctly. Use the virtual IP address and not the FQDN when adding a value to the apiVIPs configuration setting in the install-config.yaml file. The primary IP address must be from the IPv4 network when using dual stack networking. If not set, the installation program uses api.<cluster_name>.<base_domain> to derive the IP address from the DNS.

Note

Before OpenShift Container Platform 4.12, the cluster installation program only accepted an IPv4 address or an IPv6 address for the apiVIP configuration setting. From OpenShift Container Platform 4.12 or later, the apiVIP configuration setting is deprecated. Instead, use a list format for the apiVIPs configuration setting to specify an IPv4 address, an IPv6 address or both IP address formats.

disableCertificateVerification

False

redfish and redfish-virtualmedia need this parameter to manage BMC addresses. The value should be True when using a self-signed certificate for BMC addresses.

ingressVIPs

 

(Optional) The virtual IP address for ingress traffic.

You must either provide this setting in the install-config.yaml file as a reserved IP from the MachineNetwork parameter or preconfigured in the DNS so that the default name resolves correctly. Use the virtual IP address and not the FQDN when adding a value to the ingressVIPs configuration setting in the install-config.yaml file. The primary IP address must be from the IPv4 network when using dual stack networking. If not set, the installation program uses test.apps.<cluster_name>.<base_domain> to derive the IP address from the DNS.

Note

Before OpenShift Container Platform 4.12, the cluster installation program only accepted an IPv4 address or an IPv6 address for the ingressVIP configuration setting. In OpenShift Container Platform 4.12 and later, the ingressVIP configuration setting is deprecated. Instead, use a list format for the ingressVIPs configuration setting to specify an IPv4 addresses, an IPv6 addresses or both IP address formats.

Table 3.8. Optional Parameters
ParametersDefaultDescription
platform:
  baremetal:
    additionalNTPServers:
    - <ip_address_or_domain_name>
 

An optional list of additional NTP servers to add to each host. You can use an IP address or a domain name to specify each NTP server. Additional NTP servers are user-defined NTP servers that enable preinstallation clock synchronization when the cluster host clocks are out of synchronization.

provisioningDHCPRange

172.22.0.10,172.22.0.100

Defines the IP range for nodes on the provisioning network.

provisioningNetworkCIDR

172.22.0.0/24

The CIDR for the network to use for provisioning. The installation program requires this option when not using the default address range on the provisioning network.

clusterProvisioningIP

The third IP address of the provisioningNetworkCIDR.

The IP address within the cluster where the provisioning services run. Defaults to the third IP address of the provisioning subnet. For example, 172.22.0.3.

bootstrapProvisioningIP

The second IP address of the provisioningNetworkCIDR.

The IP address on the bootstrap VM where the provisioning services run while the installation program is deploying the control plane (master) nodes. Defaults to the second IP address of the provisioning subnet. For example, 172.22.0.2 or 2620:52:0:1307::2.

externalBridge

baremetal

The name of the bare-metal bridge of the hypervisor attached to the bare-metal network.

provisioningBridge

provisioning

The name of the provisioning bridge on the provisioner host attached to the provisioning network.

architecture

 

Defines the host architecture for your cluster. Valid values are amd64 or arm64.

defaultMachinePlatform

 

The default configuration used for machine pools without a platform configuration.

bootstrapOSImage

 

A URL to override the default operating system image for the bootstrap node. The URL must contain a SHA-256 hash of the image. For example: https://mirror.openshift.com/rhcos-<version>-qemu.qcow2.gz?sha256=<uncompressed_sha256>.

provisioningNetwork

 

The provisioningNetwork configuration setting determines whether the cluster uses the provisioning network. If it does, the configuration setting also determines if the cluster manages the network.

Disabled: Set this parameter to Disabled to disable the requirement for a provisioning network. When set to Disabled, you must only use virtual media based provisioning, or start the cluster by using the Assisted Installer. If set to Disabled and using power management, BMCs must be accessible from the bare-metal network. If set to Disabled, you must provide two IP addresses on the bare-metal network that the installation program uses for the provisioning services.

Managed: Set this parameter to Managed, which is the default, to fully manage the provisioning network, including DHCP, TFTP, and so on.

Unmanaged: Set this parameter to Unmanaged to enable the provisioning network but take care of manual configuration of DHCP. Virtual media provisioning is recommended but PXE is still available if required.

httpProxy

 

Set this parameter to the appropriate HTTP proxy used within your environment.

httpsProxy

 

Set this parameter to the appropriate HTTPS proxy used within your environment.

noProxy

 

Set this parameter to the appropriate list of exclusions for proxy usage within your environment.

Hosts

The hosts parameter is a list of separate bare metal assets used to build the cluster.

Table 3.9. Hosts
NameDefaultDescription

name

 

The name of the BareMetalHost resource to associate with the details. For example, openshift-master-0.

role

 

The role of the bare-metal node. Either master (control plane node) or worker (compute node).

bmc

 

Connection details for the baseboard management controller. See the BMC addressing section for additional details.

bootMACAddress

 

The MAC address of the NIC that the host uses for the provisioning network. Ironic retrieves the IP address using the bootMACAddress configuration setting. Then, it binds to the host.

Note

You must provide a valid MAC address from the host if you disabled the provisioning network.

networkConfig

 

Set this optional parameter to configure the network interface of a host. See "(Optional) Configuring host network interfaces" for additional details.

3.3.12.3. BMC addressing

Most vendors support Baseboard Management Controller (BMC) addressing with the Intelligent Platform Management Interface (IPMI). IPMI does not encrypt communications. It is suitable for use within a data center over a secured or dedicated management network. Check with your vendor to see if they support Redfish network boot. Redfish delivers simple and secure management for converged, hybrid IT and the Software Defined Data Center (SDDC). Redfish is human readable and machine capable, and leverages common internet and web services standards to expose information directly to the modern tool chain. If your hardware does not support Redfish network boot, use IPMI.

You can modify the BMC address during installation while the node is in the Registering state. If you need to modify the BMC address after the node leaves the Registering state, you must disconnect the node from Ironic, edit the BareMetalHost resource, and reconnect the node to Ironic. See the Editing a BareMetalHost resource section for details.

IPMI

Hosts using IPMI use the ipmi://<out-of-band-ip>:<port> address format, which defaults to port 623 if not specified. The following example demonstrates an IPMI configuration within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: ipmi://<out-of-band-ip>
          username: <user>
          password: <password>
Important

The provisioning network is required when PXE booting using IPMI for BMC addressing. It is not possible to PXE boot hosts without a provisioning network. If you deploy without a provisioning network, you must use a virtual media BMC addressing option such as redfish-virtualmedia or idrac-virtualmedia. See "Redfish virtual media for HPE iLO" in the "BMC addressing for HPE iLO" section or "Redfish virtual media for Dell iDRAC" in the "BMC addressing for Dell iDRAC" section for additional details.

Redfish network boot

To enable Redfish, use redfish:// or redfish+http:// to disable TLS. The installer requires both the hostname or the IP address and the path to the system ID. The following example demonstrates a Redfish configuration within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish://<out-of-band-ip>/redfish/v1/Systems/1
          username: <user>
          password: <password>

While it is recommended to have a certificate of authority for the out-of-band management addresses, you must include disableCertificateVerification: True in the bmc configuration if using self-signed certificates. The following example demonstrates a Redfish configuration using the disableCertificateVerification: True configuration parameter within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish://<out-of-band-ip>/redfish/v1/Systems/1
          username: <user>
          password: <password>
          disableCertificateVerification: True

Additional resources

3.3.12.4. Verifying support for Redfish APIs

When installing using the Redfish API, the installation program calls several Redfish endpoints on the baseboard management controller (BMC) when using installer-provisioned infrastructure on bare metal. If you use Redfish, ensure that your BMC supports all of the Redfish APIs before installation.

Procedure

  1. Set the IP address or hostname of the BMC by running the following command:

    $ export SERVER=<ip_address> 1
    1
    Replace <ip_address> with the IP address or hostname of the BMC.
  2. Set the ID of the system by running the following command:

    $ export SystemID=<system_id> 1
    1
    Replace <system_id> with the system ID. For example, System.Embedded.1 or 1. See the following vendor-specific BMC sections for details.

List of Redfish APIs

  1. Check power on support by running the following command:

    $ curl -u $USER:$PASS -X POST -H'Content-Type: application/json' -H'Accept: application/json' -d '{"ResetType": "On"}' https://$SERVER/redfish/v1/Systems/$SystemID/Actions/ComputerSystem.Reset
  2. Check power off support by running the following command:

    $ curl -u $USER:$PASS -X POST -H'Content-Type: application/json' -H'Accept: application/json' -d '{"ResetType": "ForceOff"}' https://$SERVER/redfish/v1/Systems/$SystemID/Actions/ComputerSystem.Reset
  3. Check the temporary boot implementation that uses pxe by running the following command:

    $ curl -u $USER:$PASS -X PATCH -H "Content-Type: application/json" -H "If-Match: <ETAG>"  https://$Server/redfish/v1/Systems/$SystemID/ -d '{"Boot": {"BootSourceOverrideTarget": "pxe", "BootSourceOverrideEnabled": "Once"}}
  4. Check the status of setting the firmware boot mode that uses Legacy or UEFI by running the following command:

    $ curl -u $USER:$PASS -X PATCH -H "Content-Type: application/json" -H "If-Match: <ETAG>"  https://$Server/redfish/v1/Systems/$SystemID/ -d '{"Boot": {"BootSourceOverrideMode":"UEFI"}}

List of Redfish virtual media APIs

  1. Check the ability to set the temporary boot device that uses cd or dvd by running the following command:

    $ curl -u $USER:$PASS -X PATCH -H "Content-Type: application/json" -H "If-Match: <ETAG>" https://$Server/redfish/v1/Systems/$SystemID/ -d '{"Boot": {"BootSourceOverrideTarget": "cd", "BootSourceOverrideEnabled": "Once"}}'
  2. Virtual media might use POST or PATCH, depending on your hardware. Check the ability to mount virtual media by running one of the following commands:

    $ curl -u $USER:$PASS -X POST -H "Content-Type: application/json" https://$Server/redfish/v1/Managers/$ManagerID/VirtualMedia/$VmediaId -d '{"Image": "https://example.com/test.iso", "TransferProtocolType": "HTTPS", "UserName": "", "Password":""}'
    $ curl -u $USER:$PASS -X PATCH -H "Content-Type: application/json" -H "If-Match: <ETAG>" https://$Server/redfish/v1/Managers/$ManagerID/VirtualMedia/$VmediaId -d '{"Image": "https://example.com/test.iso", "TransferProtocolType": "HTTPS", "UserName": "", "Password":""}'
Note

The PowerOn and PowerOff commands for Redfish APIs are the same for the Redfish virtual media APIs. In some hardware, you might only find the VirtualMedia resource under Systems/$SystemID instead of Managers/$ManagerID. For the VirtualMedia resource, the UserName and Password fields are optional.

Important

HTTPS and HTTP are the only supported parameter types for TransferProtocolTypes.

3.3.12.5. BMC addressing for Dell iDRAC

The address field for each bmc entry is a URL for connecting to the OpenShift Container Platform cluster nodes, including the type of controller in the URL scheme and its location on the network.

platform:
  baremetal:
    hosts:
      - name: <hostname>
        role: <master | worker>
        bmc:
          address: <address> 1
          username: <user>
          password: <password>
1
The address configuration setting specifies the protocol.

For Dell hardware, Red Hat supports integrated Dell Remote Access Controller (iDRAC) virtual media, Redfish network boot, and IPMI.

BMC address formats for Dell iDRAC
ProtocolAddress Format

iDRAC virtual media

idrac-virtualmedia://<out-of-band-ip>/redfish/v1/Systems/System.Embedded.1

Redfish network boot

redfish://<out-of-band-ip>/redfish/v1/Systems/System.Embedded.1

IPMI

ipmi://<out-of-band-ip>

Important

Use idrac-virtualmedia as the protocol for Redfish virtual media. redfish-virtualmedia will not work on Dell hardware. Dell’s idrac-virtualmedia uses the Redfish standard with Dell’s OEM extensions.

See the following sections for additional details.

Redfish virtual media for Dell iDRAC

For Redfish virtual media on Dell servers, use idrac-virtualmedia:// in the address setting. Using redfish-virtualmedia:// will not work.

Note

Use idrac-virtualmedia:// as the protocol for Redfish virtual media. Using redfish-virtualmedia:// will not work on Dell hardware, because the idrac-virtualmedia:// protocol corresponds to the idrac hardware type and the Redfish protocol in Ironic. Dell’s idrac-virtualmedia:// protocol uses the Redfish standard with Dell’s OEM extensions. Ironic also supports the idrac type with the WSMAN protocol. Therefore, you must specify idrac-virtualmedia:// to avoid unexpected behavior when electing to use Redfish with virtual media on Dell hardware.

The following example demonstrates using iDRAC virtual media within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: idrac-virtualmedia://<out-of-band-ip>/redfish/v1/Systems/System.Embedded.1
          username: <user>
          password: <password>

While it is recommended to have a certificate of authority for the out-of-band management addresses, you must include disableCertificateVerification: True in the bmc configuration if using self-signed certificates.

Note

Ensure the OpenShift Container Platform cluster nodes have AutoAttach enabled through the iDRAC console. The menu path is: ConfigurationVirtual MediaAttach ModeAutoAttach.

The following example demonstrates a Redfish configuration using the disableCertificateVerification: True configuration parameter within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: idrac-virtualmedia://<out-of-band-ip>/redfish/v1/Systems/System.Embedded.1
          username: <user>
          password: <password>
          disableCertificateVerification: True
Redfish network boot for iDRAC

To enable Redfish, use redfish:// or redfish+http:// to disable transport layer security (TLS). The installer requires both the hostname or the IP address and the path to the system ID. The following example demonstrates a Redfish configuration within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish://<out-of-band-ip>/redfish/v1/Systems/System.Embedded.1
          username: <user>
          password: <password>

While it is recommended to have a certificate of authority for the out-of-band management addresses, you must include disableCertificateVerification: True in the bmc configuration if using self-signed certificates. The following example demonstrates a Redfish configuration using the disableCertificateVerification: True configuration parameter within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish://<out-of-band-ip>/redfish/v1/Systems/System.Embedded.1
          username: <user>
          password: <password>
          disableCertificateVerification: True
Note

There is a known issue on Dell iDRAC 9 with firmware version 04.40.00.00 and all releases up to including the 5.xx series for installer-provisioned installations on bare metal deployments. The virtual console plugin defaults to eHTML5, an enhanced version of HTML5, which causes problems with the InsertVirtualMedia workflow. Set the plugin to use HTML5 to avoid this issue. The menu path is ConfigurationVirtual consolePlug-in TypeHTML5 .

Ensure the OpenShift Container Platform cluster nodes have AutoAttach enabled through the iDRAC console. The menu path is: ConfigurationVirtual MediaAttach ModeAutoAttach .

3.3.12.6. BMC addressing for HPE iLO

The address field for each bmc entry is a URL for connecting to the OpenShift Container Platform cluster nodes, including the type of controller in the URL scheme and its location on the network.

platform:
  baremetal:
    hosts:
      - name: <hostname>
        role: <master | worker>
        bmc:
          address: <address> 1
          username: <user>
          password: <password>
1
The address configuration setting specifies the protocol.

For HPE integrated Lights Out (iLO), Red Hat supports Redfish virtual media, Redfish network boot, and IPMI.

Table 3.10. BMC address formats for HPE iLO
ProtocolAddress Format

Redfish virtual media

redfish-virtualmedia://<out-of-band-ip>/redfish/v1/Systems/1

Redfish network boot

redfish://<out-of-band-ip>/redfish/v1/Systems/1

IPMI

ipmi://<out-of-band-ip>

See the following sections for additional details.

Redfish virtual media for HPE iLO

To enable Redfish virtual media for HPE servers, use redfish-virtualmedia:// in the address setting. The following example demonstrates using Redfish virtual media within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish-virtualmedia://<out-of-band-ip>/redfish/v1/Systems/1
          username: <user>
          password: <password>

While it is recommended to have a certificate of authority for the out-of-band management addresses, you must include disableCertificateVerification: True in the bmc configuration if using self-signed certificates. The following example demonstrates a Redfish configuration using the disableCertificateVerification: True configuration parameter within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish-virtualmedia://<out-of-band-ip>/redfish/v1/Systems/1
          username: <user>
          password: <password>
          disableCertificateVerification: True
Note

Redfish virtual media is not supported on 9th generation systems running iLO4, because Ironic does not support iLO4 with virtual media.

Redfish network boot for HPE iLO

To enable Redfish, use redfish:// or redfish+http:// to disable TLS. The installer requires both the hostname or the IP address and the path to the system ID. The following example demonstrates a Redfish configuration within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish://<out-of-band-ip>/redfish/v1/Systems/1
          username: <user>
          password: <password>

While it is recommended to have a certificate of authority for the out-of-band management addresses, you must include disableCertificateVerification: True in the bmc configuration if using self-signed certificates. The following example demonstrates a Redfish configuration using the disableCertificateVerification: True configuration parameter within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish://<out-of-band-ip>/redfish/v1/Systems/1
          username: <user>
          password: <password>
          disableCertificateVerification: True
3.3.12.7. BMC addressing for Fujitsu iRMC

The address field for each bmc entry is a URL for connecting to the OpenShift Container Platform cluster nodes, including the type of controller in the URL scheme and its location on the network.

platform:
  baremetal:
    hosts:
      - name: <hostname>
        role: <master | worker>
        bmc:
          address: <address> 1
          username: <user>
          password: <password>
1
The address configuration setting specifies the protocol.

For Fujitsu hardware, Red Hat supports integrated Remote Management Controller (iRMC) and IPMI.

Table 3.11. BMC address formats for Fujitsu iRMC
ProtocolAddress Format

iRMC

irmc://<out-of-band-ip>

IPMI

ipmi://<out-of-band-ip>

iRMC

Fujitsu nodes can use irmc://<out-of-band-ip> and defaults to port 443. The following example demonstrates an iRMC configuration within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: irmc://<out-of-band-ip>
          username: <user>
          password: <password>
Note

Currently Fujitsu supports iRMC S5 firmware version 3.05P and above for installer-provisioned installation on bare metal.

3.3.12.8. BMC addressing for Cisco CIMC

The address field for each bmc entry is a URL for connecting to the OpenShift Container Platform cluster nodes, including the type of controller in the URL scheme and its location on the network.

platform:
  baremetal:
    hosts:
      - name: <hostname>
        role: <master | worker>
        bmc:
          address: <address> 1
          username: <user>
          password: <password>
1
The address configuration setting specifies the protocol.

For Cisco UCS C-Series and X-Series servers, Red Hat supports Cisco Integrated Management Controller (CIMC).

Table 3.12. BMC address format for Cisco CIMC
ProtocolAddress Format

Redfish virtual media

redfish-virtualmedia://<server_kvm_ip>/redfish/v1/Systems/<serial_number>

To enable Redfish virtual media for Cisco UCS C-Series and X-Series servers, use redfish-virtualmedia:// in the address setting. The following example demonstrates using Redfish virtual media within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish-virtualmedia://<server_kvm_ip>/redfish/v1/Systems/<serial_number>
          username: <user>
          password: <password>

While it is recommended to have a certificate of authority for the out-of-band management addresses, you must include disableCertificateVerification: True in the bmc configuration if using self-signed certificates. The following example demonstrates a Redfish configuration by using the disableCertificateVerification: True configuration parameter within the install-config.yaml file.

platform:
  baremetal:
    hosts:
      - name: openshift-master-0
        role: master
        bmc:
          address: redfish-virtualmedia://<server_kvm_ip>/redfish/v1/Systems/<serial_number>
          username: <user>
          password: <password>
          disableCertificateVerification: True
3.3.12.9. Root device hints

The rootDeviceHints parameter enables the installer to provision the Red Hat Enterprise Linux CoreOS (RHCOS) image to a particular device. The installer examines the devices in the order it discovers them, and compares the discovered values with the hint values. The installer uses the first discovered device that matches the hint value. The configuration can combine multiple hints, but a device must match all hints for the installer to select it.

Table 3.13. Subfields
SubfieldDescription

deviceName

A string containing a Linux device name such as /dev/vda or /dev/disk/by-path/. It is recommended to use the /dev/disk/by-path/<device_path> link to the storage location. The hint must match the actual value exactly.

hctl

A string containing a SCSI bus address like 0:0:0:0. The hint must match the actual value exactly.

model

A string containing a vendor-specific device identifier. The hint can be a substring of the actual value.

vendor

A string containing the name of the vendor or manufacturer of the device. The hint can be a sub-string of the actual value.

serialNumber

A string containing the device serial number. The hint must match the actual value exactly.

minSizeGigabytes

An integer representing the minimum size of the device in gigabytes.

wwn

A string containing the unique storage identifier. The hint must match the actual value exactly.

wwnWithExtension

A string containing the unique storage identifier with the vendor extension appended. The hint must match the actual value exactly.

wwnVendorExtension

A string containing the unique vendor storage identifier. The hint must match the actual value exactly.

rotational

A boolean indicating whether the device should be a rotating disk (true) or not (false).

Example usage

     - name: master-0
       role: master
       bmc:
         address: ipmi://10.10.0.3:6203
         username: admin
         password: redhat
       bootMACAddress: de:ad:be:ef:00:40
       rootDeviceHints:
         deviceName: "/dev/sda"

3.3.12.10. Setting proxy settings

To deploy an OpenShift Container Platform cluster while using a proxy, make the following changes to the install-config.yaml file.

Procedure

  1. Add proxy values under the proxy key mapping:

    apiVersion: v1
    baseDomain: <domain>
    proxy:
      httpProxy: http://USERNAME:PASSWORD@proxy.example.com:PORT
      httpsProxy: https://USERNAME:PASSWORD@proxy.example.com:PORT
      noProxy: <WILDCARD_OF_DOMAIN>,<PROVISIONING_NETWORK/CIDR>,<BMC_ADDRESS_RANGE/CIDR>

    The following is an example of noProxy with values.

    noProxy: .example.com,172.22.0.0/24,10.10.0.0/24
  2. With a proxy enabled, set the appropriate values of the proxy in the corresponding key/value pair.

    Key considerations:

    • If the proxy does not have an HTTPS proxy, change the value of httpsProxy from https:// to http://.
    • If the cluster uses a provisioning network, include it in the noProxy setting, otherwise the installation program fails.
    • Set all of the proxy settings as environment variables within the provisioner node. For example, HTTP_PROXY, HTTPS_PROXY, and NO_PROXY.
3.3.12.11. Deploying with no provisioning network

To deploy an OpenShift Container Platform cluster without a provisioning network, make the following changes to the install-config.yaml file.

platform:
  baremetal:
    apiVIPs:
      - <api_VIP>
    ingressVIPs:
      - <ingress_VIP>
    provisioningNetwork: "Disabled" 1
1
Add the provisioningNetwork configuration setting, if needed, and set it to Disabled.
Important

The provisioning network is required for PXE booting. If you deploy without a provisioning network, you must use a virtual media BMC addressing option such as redfish-virtualmedia or idrac-virtualmedia. See "Redfish virtual media for HPE iLO" in the "BMC addressing for HPE iLO" section or "Redfish virtual media for Dell iDRAC" in the "BMC addressing for Dell iDRAC" section for additional details.

3.3.12.12. Deploying with dual-stack networking

For dual-stack networking in OpenShift Container Platform clusters, you can configure IPv4 and IPv6 address endpoints for cluster nodes. To configure IPv4 and IPv6 address endpoints for cluster nodes, edit the machineNetwork, clusterNetwork, and serviceNetwork configuration settings in the install-config.yaml file. Each setting must have two CIDR entries each. For a cluster with the IPv4 family as the primary address family, specify the IPv4 setting first. For a cluster with the IPv6 family as the primary address family, specify the IPv6 setting first.

machineNetwork:
- cidr: {{ extcidrnet }}
- cidr: {{ extcidrnet6 }}
clusterNetwork:
- cidr: 10.128.0.0/14
  hostPrefix: 23
- cidr: fd02::/48
  hostPrefix: 64
serviceNetwork:
- 172.30.0.0/16
- fd03::/112
Important

On a bare-metal platform, if you specified an NMState configuration in the networkConfig section of your install-config.yaml file, add interfaces.wait-ip: ipv4+ipv6 to the NMState YAML file to resolve an issue that prevents your cluster from deploying on a dual-stack network.

Example NMState YAML configuration file that includes the wait-ip parameter

networkConfig:
  nmstate:
    interfaces:
    - name: <interface_name>
# ...
      wait-ip: ipv4+ipv6
# ...

To provide an interface to the cluster for applications that use IPv4 and IPv6 addresses, configure IPv4 and IPv6 virtual IP (VIP) address endpoints for the Ingress VIP and API VIP services. To configure IPv4 and IPv6 address endpoints, edit the apiVIPs and ingressVIPs configuration settings in the install-config.yaml file . The apiVIPs and ingressVIPs configuration settings use a list format. The order of the list indicates the primary and secondary VIP address for each service.

platform:
  baremetal:
    apiVIPs:
      - <api_ipv4>
      - <api_ipv6>
    ingressVIPs:
      - <wildcard_ipv4>
      - <wildcard_ipv6>
Note

For a cluster with dual-stack networking configuration, you must assign both IPv4 and IPv6 addresses to the same interface.

3.3.12.13. Configuring host network interfaces

Before installation, you can set the networkConfig configuration setting in the install-config.yaml file to configure host network interfaces using NMState.

The most common use case for this functionality is to specify a static IP address on the bare-metal network, but you can also configure other networks such as a storage network. This functionality supports other NMState features such as VLAN, VXLAN, bridges, bonds, routes, MTU, and DNS resolver settings.

Prerequisites

  • Configure a PTR DNS record with a valid hostname for each node with a static IP address.
  • Install the NMState CLI (nmstate).

Procedure

  1. Optional: Consider testing the NMState syntax with nmstatectl gc before including it in the install-config.yaml file, because the installer will not check the NMState YAML syntax.

    Note

    Errors in the YAML syntax might result in a failure to apply the network configuration. Additionally, maintaining the validated YAML syntax is useful when applying changes using Kubernetes NMState after deployment or when expanding the cluster.

    1. Create an NMState YAML file:

      interfaces:
      - name: <nic1_name> 1
        type: ethernet
        state: up
        ipv4:
          address:
          - ip: <ip_address> 2
            prefix-length: 24
          enabled: true
      dns-resolver:
        config:
          server:
          - <dns_ip_address> 3
      routes:
        config:
        - destination: 0.0.0.0/0
          next-hop-address: <next_hop_ip_address> 4
          next-hop-interface: <next_hop_nic1_name> 5
      1 2 3 4 5
      Replace <nic1_name>, <ip_address>, <dns_ip_address>, <next_hop_ip_address> and <next_hop_nic1_name> with appropriate values.
    2. Test the configuration file by running the following command:

      $ nmstatectl gc <nmstate_yaml_file>

      Replace <nmstate_yaml_file> with the configuration file name.

  2. Use the networkConfig configuration setting by adding the NMState configuration to hosts within the install-config.yaml file:

        hosts:
          - name: openshift-master-0
            role: master
            bmc:
              address: redfish+http://<out_of_band_ip>/redfish/v1/Systems/
              username: <user>
              password: <password>
              disableCertificateVerification: null
            bootMACAddress: <NIC1_mac_address>
            bootMode: UEFI
            rootDeviceHints:
              deviceName: "/dev/sda"
            networkConfig: 1
              interfaces:
              - name: <nic1_name> 2
                type: ethernet
                state: up
                ipv4:
                  address:
                  - ip: <ip_address> 3
                    prefix-length: 24
                  enabled: true
              dns-resolver:
                config:
                  server:
                  - <dns_ip_address> 4
              routes:
                config:
                - destination: 0.0.0.0/0
                  next-hop-address: <next_hop_ip_address> 5
                  next-hop-interface: <next_hop_nic1_name> 6
    1
    Add the NMState YAML syntax to configure the host interfaces.
    2 3 4 5 6
    Replace <nic1_name>, <ip_address>, <dns_ip_address>, <next_hop_ip_address> and <next_hop_nic1_name> with appropriate values.
    Important

    After deploying the cluster, you cannot modify the networkConfig configuration setting of install-config.yaml file to make changes to the host network interface. Use the Kubernetes NMState Operator to make changes to the host network interface after deployment.

3.3.12.14. Configuring host network interfaces for subnets

For edge computing scenarios, it can be beneficial to locate compute nodes closer to the edge. To locate remote nodes in subnets, you might use different network segments or subnets for the remote nodes than you used for the control plane subnet and local compute nodes. You can reduce latency for the edge and allow for enhanced scalability by setting up subnets for edge computing scenarios.

Important

When using the default load balancer, OpenShiftManagedDefault and adding remote nodes to your OpenShift Container Platform cluster, all control plane nodes must run in the same subnet. When using more than one subnet, you can also configure the Ingress VIP to run on the control plane nodes by using a manifest. See "Configuring network components to run on the control plane" for details.

If you have established different network segments or subnets for remote nodes as described in the section on "Establishing communication between subnets", you must specify the subnets in the machineNetwork configuration setting if the workers are using static IP addresses, bonds or other advanced networking. When setting the node IP address in the networkConfig parameter for each remote node, you must also specify the gateway and the DNS server for the subnet containing the control plane nodes when using static IP addresses. This ensures that the remote nodes can reach the subnet containing the control plane and that they can receive network traffic from the control plane.

Note

Deploying a cluster with multiple subnets requires using virtual media, such as redfish-virtualmedia or idrac-virtualmedia, because remote nodes cannot access the local provisioning network.

Procedure

  1. Add the subnets to the machineNetwork in the install-config.yaml file when using static IP addresses:

    networking:
      machineNetwork:
      - cidr: 10.0.0.0/24
      - cidr: 192.168.0.0/24
      networkType: OVNKubernetes
  2. Add the gateway and DNS configuration to the networkConfig parameter of each edge compute node using NMState syntax when using a static IP address or advanced networking such as bonds:

    networkConfig:
      interfaces:
      - name: <interface_name> 1
        type: ethernet
        state: up
        ipv4:
          enabled: true
          dhcp: false
          address:
          - ip: <node_ip> 2
            prefix-length: 24
          gateway: <gateway_ip> 3
      dns-resolver:
        config:
          server:
          - <dns_ip> 4
    1
    Replace <interface_name> with the interface name.
    2
    Replace <node_ip> with the IP address of the node.
    3
    Replace <gateway_ip> with the IP address of the gateway.
    4
    Replace <dns_ip> with the IP address of the DNS server.
3.3.12.15. Configuring address generation modes for SLAAC in dual-stack networks

For dual-stack clusters that use Stateless Address AutoConfiguration (SLAAC), you must specify a global value for the ipv6.addr-gen-mode network setting. You can set this value using NMState to configure the RAM disk and the cluster configuration files. If you do not configure a consistent ipv6.addr-gen-mode in these locations, IPv6 address mismatches can occur between CSR resources and BareMetalHost resources in the cluster.

Prerequisites

  • Install the NMState CLI (nmstate).

Procedure

  1. Optional: Consider testing the NMState YAML syntax with the nmstatectl gc command before including it in the install-config.yaml file because the installation program will not check the NMState YAML syntax.

    1. Create an NMState YAML file:

      interfaces:
      - name: eth0
        ipv6:
          addr-gen-mode: <address_mode> 1
      1
      Replace <address_mode> with the type of address generation mode required for IPv6 addresses in the cluster. Valid values are eui64, stable-privacy, or random.
    2. Test the configuration file by running the following command:

      $ nmstatectl gc <nmstate_yaml_file> 1
      1
      Replace <nmstate_yaml_file> with the name of the test configuration file.
  2. Add the NMState configuration to the hosts.networkConfig section within the install-config.yaml file:

        hosts:
          - name: openshift-master-0
            role: master
            bmc:
              address: redfish+http://<out_of_band_ip>/redfish/v1/Systems/
              username: <user>
              password: <password>
              disableCertificateVerification: null
            bootMACAddress: <NIC1_mac_address>
            bootMode: UEFI
            rootDeviceHints:
              deviceName: "/dev/sda"
            networkConfig:
              interfaces:
              - name: eth0
                ipv6:
                  addr-gen-mode: <address_mode> 1
    ...
    1
    Replace <address_mode> with the type of address generation mode required for IPv6 addresses in the cluster. Valid values are eui64, stable-privacy, or random.
3.3.12.16. Configuring host network interfaces for dual port NIC

Before installation, you can set the networkConfig configuration setting in the install-config.yaml file to configure host network interfaces by using NMState to support dual port NIC.

OpenShift Virtualization only supports the following bond modes:

  • mode=1 active-backup
  • mode=2 balance-xor
  • mode=4 802.3ad

Prerequisites

  • Configure a PTR DNS record with a valid hostname for each node with a static IP address.
  • Install the NMState CLI (nmstate).
Note

Errors in the YAML syntax might result in a failure to apply the network configuration. Additionally, maintaining the validated YAML syntax is useful when applying changes by using Kubernetes NMState after deployment or when expanding the cluster.

Procedure

  1. Add the NMState configuration to the networkConfig field to hosts within the install-config.yaml file:

        hosts:
          - name: worker-0
            role: worker
            bmc:
              address: redfish+http://<out_of_band_ip>/redfish/v1/Systems/
              username: <user>
              password: <password>
              disableCertificateVerification: false
            bootMACAddress: <NIC1_mac_address>
            bootMode: UEFI
            networkConfig: 1
              interfaces: 2
               - name: eno1 3
                 type: ethernet 4
                 state: up
                 mac-address: 0c:42:a1:55:f3:06
                 ipv4:
                   enabled: true
                   dhcp: false 5
                 ethernet:
                   sr-iov:
                     total-vfs: 2 6
                 ipv6:
                   enabled: false
                   dhcp: false
               - name: sriov:eno1:0
                 type: ethernet
                 state: up 7
                 ipv4:
                   enabled: false 8
                 ipv6:
                   enabled: false
               - name: sriov:eno1:1
                 type: ethernet
                 state: down
               - name: eno2
                 type: ethernet
                 state: up
                 mac-address: 0c:42:a1:55:f3:07
                 ipv4:
                   enabled: true
                 ethernet:
                   sr-iov:
                     total-vfs: 2
                 ipv6:
                   enabled: false
               - name: sriov:eno2:0
                 type: ethernet
                 state: up
                 ipv4:
                   enabled: false
                 ipv6:
                   enabled: false
               - name: sriov:eno2:1
                 type: ethernet
                 state: down
               - name: bond0
                 type: bond
                 state: up
                 min-tx-rate: 100 9
                 max-tx-rate: 200 10
                 link-aggregation:
                   mode: active-backup 11
                   options:
                     primary: sriov:eno1:0 12
                   port:
                     - sriov:eno1:0
                     - sriov:eno2:0
                 ipv4:
                   address:
                     - ip: 10.19.16.57 13
                       prefix-length: 23
                   dhcp: false
                   enabled: true
                 ipv6:
                   enabled: false
              dns-resolver:
                config:
                  server:
                    - 10.11.5.160
                    - 10.2.70.215
              routes:
                config:
                  - destination: 0.0.0.0/0
                    next-hop-address: 10.19.17.254
                    next-hop-interface: bond0 14
                    table-id: 254
    1
    The networkConfig field has information about the network configuration of the host, with subfields including interfaces, dns-resolver, and routes.
    2
    The interfaces field is an array of network interfaces defined for the host.
    3
    The name of the interface.
    4
    The type of interface. This example creates a ethernet interface.
    5
    Set this to `false to disable DHCP for the physical function (PF) if it is not strictly required.
    6
    Set to the number of SR-IOV virtual functions (VFs) to instantiate.
    7
    Set this to up.
    8
    Set this to false to disable IPv4 addressing for the VF attached to the bond.
    9
    Sets a minimum transmission rate, in Mbps, for the VF. This sample value sets a rate of 100 Mbps.
    • This value must be less than or equal to the maximum transmission rate.
    • Intel NICs do not support the min-tx-rate parameter. For more information, see BZ#1772847.
    10
    Sets a maximum transmission rate, in Mbps, for the VF. This sample value sets a rate of 200 Mbps.
    11
    Sets the desired bond mode.
    12
    Sets the preferred port of the bonding interface. The bond uses the primary device as the first device of the bonding interfaces. The bond does not abandon the primary device interface unless it fails. This setting is particularly useful when one NIC in the bonding interface is faster and, therefore, able to handle a bigger load. This setting is only valid when the bonding interface is in active-backup mode (mode 1) and balance-tlb (mode 5).
    13
    Sets a static IP address for the bond interface. This is the node IP address.
    14
    Sets bond0 as the gateway for the default route.
    Important

    After deploying the cluster, you cannot change the networkConfig configuration setting of the install-config.yaml file to make changes to the host network interface. Use the Kubernetes NMState Operator to make changes to the host network interface after deployment.

Additional resources

3.3.12.17. Configuring multiple cluster nodes

You can simultaneously configure OpenShift Container Platform cluster nodes with identical settings. Configuring multiple cluster nodes avoids adding redundant information for each node to the install-config.yaml file. This file contains specific parameters to apply an identical configuration to multiple nodes in the cluster.

Compute nodes are configured separately from the controller node. However, configurations for both node types use the highlighted parameters in the install-config.yaml file to enable multi-node configuration. Set the networkConfig parameters to BOND, as shown in the following example:

hosts:
- name: ostest-master-0
 [...]
 networkConfig: &BOND
   interfaces:
   - name: bond0
     type: bond
     state: up
     ipv4:
       dhcp: true
       enabled: true
     link-aggregation:
       mode: active-backup
       port:
       - enp2s0
       - enp3s0
- name: ostest-master-1
 [...]
 networkConfig: *BOND
- name: ostest-master-2
 [...]
 networkConfig: *BOND
Note

Configuration of multiple cluster nodes is only available for initial deployments on installer-provisioned infrastructure.

3.3.12.18. Configuring managed Secure Boot

You can enable managed Secure Boot when deploying an installer-provisioned cluster using Redfish BMC addressing, such as redfish, redfish-virtualmedia, or idrac-virtualmedia. To enable managed Secure Boot, add the bootMode configuration setting to each node:

Example

hosts:
  - name: openshift-master-0
    role: master
    bmc:
      address: redfish://<out_of_band_ip> 1
      username: <username>
      password: <password>
    bootMACAddress: <NIC1_mac_address>
    rootDeviceHints:
     deviceName: "/dev/sda"
    bootMode: UEFISecureBoot 2

1
Ensure the bmc.address setting uses redfish, redfish-virtualmedia, or idrac-virtualmedia as the protocol. See "BMC addressing for HPE iLO" or "BMC addressing for Dell iDRAC" for additional details.
2
The bootMode setting is UEFI by default. Change it to UEFISecureBoot to enable managed Secure Boot.
Note

See "Configuring nodes" in the "Prerequisites" to ensure the nodes can support managed Secure Boot. If the nodes do not support managed Secure Boot, see "Configuring nodes for Secure Boot manually" in the "Configuring nodes" section. Configuring Secure Boot manually requires Redfish virtual media.

Note

Red Hat does not support Secure Boot with IPMI, because IPMI does not provide Secure Boot management facilities.

3.3.13. Manifest configuration files

3.3.13.1. Creating the OpenShift Container Platform manifests
  1. Create the OpenShift Container Platform manifests.

    $ ./openshift-baremetal-install --dir ~/clusterconfigs create manifests
    INFO Consuming Install Config from target directory
    WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings
    WARNING Discarding the OpenShift Manifest that was provided in the target directory because its dependencies are dirty and it needs to be regenerated
3.3.13.2. Configuring NTP for disconnected clusters

OpenShift Container Platform installs the chrony Network Time Protocol (NTP) service on the cluster nodes.

Configuring NTP for disconnected clusters

OpenShift Container Platform nodes must agree on a date and time to run properly. When compute nodes retrieve the date and time from the NTP servers on the control plane nodes, it enables the installation and operation of clusters that are not connected to a routable network and thereby do not have access to a higher stratum NTP server.

Procedure

  1. Install Butane on your installation host by using the following command:

    $ sudo dnf -y install butane
  2. Create a Butane config, 99-master-chrony-conf-override.bu, including the contents of the chrony.conf file for the control plane nodes.

    Note

    See "Creating machine configs with Butane" for information about Butane.

    Butane config example

    variant: openshift
    version: 4.18.0
    metadata:
      name: 99-master-chrony-conf-override
      labels:
        machineconfiguration.openshift.io/role: master
    storage:
      files:
        - path: /etc/chrony.conf
          mode: 0644
          overwrite: true
          contents:
            inline: |
              # Use public servers from the pool.ntp.org project.
              # Please consider joining the pool (https://www.pool.ntp.org/join.html).
    
              # The Machine Config Operator manages this file
              server openshift-master-0.<cluster-name>.<domain> iburst 1
              server openshift-master-1.<cluster-name>.<domain> iburst
              server openshift-master-2.<cluster-name>.<domain> iburst
    
              stratumweight 0
              driftfile /var/lib/chrony/drift
              rtcsync
              makestep 10 3
              bindcmdaddress 127.0.0.1
              bindcmdaddress ::1
              keyfile /etc/chrony.keys
              commandkey 1
              generatecommandkey
              noclientlog
              logchange 0.5
              logdir /var/log/chrony
    
              # Configure the control plane nodes to serve as local NTP servers
              # for all compute nodes, even if they are not in sync with an
              # upstream NTP server.
    
              # Allow NTP client access from the local network.
              allow all
              # Serve time even if not synchronized to a time source.
              local stratum 3 orphan

    1
    You must replace <cluster-name> with the name of the cluster and replace <domain> with the fully qualified domain name.
  3. Use Butane to generate a MachineConfig object file, 99-master-chrony-conf-override.yaml, containing the configuration to be delivered to the control plane nodes:

    $ butane 99-master-chrony-conf-override.bu -o 99-master-chrony-conf-override.yaml
  4. Create a Butane config, 99-worker-chrony-conf-override.bu, including the contents of the chrony.conf file for the compute nodes that references the NTP servers on the control plane nodes.

    Butane config example

    variant: openshift
    version: 4.18.0
    metadata:
      name: 99-worker-chrony-conf-override
      labels:
        machineconfiguration.openshift.io/role: worker
    storage:
      files:
        - path: /etc/chrony.conf
          mode: 0644
          overwrite: true
          contents:
            inline: |
              # The Machine Config Operator manages this file.
              server openshift-master-0.<cluster-name>.<domain> iburst 1
              server openshift-master-1.<cluster-name>.<domain> iburst
              server openshift-master-2.<cluster-name>.<domain> iburst
    
              stratumweight 0
              driftfile /var/lib/chrony/drift
              rtcsync
              makestep 10 3
              bindcmdaddress 127.0.0.1
              bindcmdaddress ::1
              keyfile /etc/chrony.keys
              commandkey 1
              generatecommandkey
              noclientlog
              logchange 0.5
              logdir /var/log/chrony

    1
    You must replace <cluster-name> with the name of the cluster and replace <domain> with the fully qualified domain name.
  5. Use Butane to generate a MachineConfig object file, 99-worker-chrony-conf-override.yaml, containing the configuration to be delivered to the worker nodes:

    $ butane 99-worker-chrony-conf-override.bu -o 99-worker-chrony-conf-override.yaml
3.3.13.3. Configuring network components to run on the control plane

You can configure networking components to run exclusively on the control plane nodes. By default, OpenShift Container Platform allows any node in the machine config pool to host the ingressVIP virtual IP address. However, some environments deploy compute nodes in separate subnets from the control plane nodes, which requires configuring the ingressVIP virtual IP address to run on the control plane nodes.

Important

When deploying remote nodes in separate subnets, you must place the ingressVIP virtual IP address exclusively with the control plane nodes.

Installer-provisioned networking

Procedure

  1. Change to the directory storing the install-config.yaml file:

    $ cd ~/clusterconfigs
  2. Switch to the manifests subdirectory:

    $ cd manifests
  3. Create a file named cluster-network-avoid-workers-99-config.yaml:

    $ touch cluster-network-avoid-workers-99-config.yaml
  4. Open the cluster-network-avoid-workers-99-config.yaml file in an editor and enter a custom resource (CR) that describes the Operator configuration:

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    metadata:
      name: 50-worker-fix-ipi-rwn
      labels:
        machineconfiguration.openshift.io/role: worker
    spec:
      config:
        ignition:
          version: 3.2.0
        storage:
          files:
            - path: /etc/kubernetes/manifests/keepalived.yaml
              mode: 0644
              contents:
                source: data:,

    This manifest places the ingressVIP virtual IP address on the control plane nodes. Additionally, this manifest deploys the following processes on the control plane nodes only:

    • openshift-ingress-operator
    • keepalived
  5. Save the cluster-network-avoid-workers-99-config.yaml file.
  6. Create a manifests/cluster-ingress-default-ingresscontroller.yaml file:

    apiVersion: operator.openshift.io/v1
    kind: IngressController
    metadata:
      name: default
      namespace: openshift-ingress-operator
    spec:
      nodePlacement:
        nodeSelector:
          matchLabels:
            node-role.kubernetes.io/master: ""
  7. Consider backing up the manifests directory. The installer deletes the manifests/ directory when creating the cluster.
  8. Modify the cluster-scheduler-02-config.yml manifest to make the control plane nodes schedulable by setting the mastersSchedulable field to true. Control plane nodes are not schedulable by default. For example:

    $ sed -i "s;mastersSchedulable: false;mastersSchedulable: true;g" clusterconfigs/manifests/cluster-scheduler-02-config.yml
    Note

    If control plane nodes are not schedulable after completing this procedure, deploying the cluster will fail.

3.3.13.4. Deploying routers on compute nodes

During installation, the installation program deploys router pods on compute nodes. By default, the installation program installs two router pods. If a deployed cluster requires additional routers to handle external traffic loads destined for services within the OpenShift Container Platform cluster, you can create a yaml file to set an appropriate number of router replicas.

Important

Deploying a cluster with only one compute node is not supported. While modifying the router replicas will address issues with the degraded state when deploying with one compute node, the cluster loses high availability for the ingress API, which is not suitable for production environments.

Note

By default, the installation program deploys two routers. If the cluster has no compute nodes, the installation program deploys the two routers on the control plane nodes by default.

Procedure

  1. Create a router-replicas.yaml file:

    apiVersion: operator.openshift.io/v1
    kind: IngressController
    metadata:
      name: default
      namespace: openshift-ingress-operator
    spec:
      replicas: <num-of-router-pods>
      endpointPublishingStrategy:
        type: HostNetwork
      nodePlacement:
        nodeSelector:
          matchLabels:
            node-role.kubernetes.io/worker: ""
    Note

    Replace <num-of-router-pods> with an appropriate value. If working with just one compute node, set replicas: to 1. If working with more than 3 compute nodes, you can increase replicas: from the default value 2 as appropriate.

  2. Save and copy the router-replicas.yaml file to the clusterconfigs/openshift directory:

    $ cp ~/router-replicas.yaml clusterconfigs/openshift/99_router-replicas.yaml
3.3.13.5. Configuring the BIOS

The following procedure configures the BIOS during the installation process.

Procedure

  1. Create the manifests.
  2. Modify the BareMetalHost resource file corresponding to the node:

    $ vim clusterconfigs/openshift/99_openshift-cluster-api_hosts-*.yaml
  3. Add the BIOS configuration to the spec section of the BareMetalHost resource:

    spec:
      firmware:
        simultaneousMultithreadingEnabled: true
        sriovEnabled: true
        virtualizationEnabled: true
    Note

    Red Hat supports three BIOS configurations. Only servers with BMC type irmc are supported. Other types of servers are currently not supported.

  4. Create the cluster.
3.3.13.6. Configuring the RAID

The following procedure configures a redundant array of independent disks (RAID) using baseboard management controllers (BMCs) during the installation process.

Note

If you want to configure a hardware RAID for the node, verify that the node has a supported RAID controller. OpenShift Container Platform 4.18 does not support software RAID.

Table 3.14. Hardware RAID support by vendor
VendorBMC and protocolFirmware versionRAID levels

Fujitsu

iRMC

N/A

0, 1, 5, 6, and 10

Dell

iDRAC with Redfish

Version 6.10.30.20 or later

0, 1, and 5

Procedure

  1. Create the manifests.
  2. Modify the BareMetalHost resource corresponding to the node:

    $ vim clusterconfigs/openshift/99_openshift-cluster-api_hosts-*.yaml
    Note

    The following example uses a hardware RAID configuration because OpenShift Container Platform 4.18 does not support software RAID.

    1. If you added a specific RAID configuration to the spec section, this causes the node to delete the original RAID configuration in the preparing phase and perform a specified configuration on the RAID. For example:

      spec:
        raid:
          hardwareRAIDVolumes:
          - level: "0" 1
            name: "sda"
            numberOfPhysicalDisks: 1
            rotational: true
            sizeGibibytes: 0
      1
      level is a required field, and the others are optional fields.
    2. If you added an empty RAID configuration to the spec section, the empty configuration causes the node to delete the original RAID configuration during the preparing phase, but does not perform a new configuration. For example:

      spec:
        raid:
          hardwareRAIDVolumes: []
    3. If you do not add a raid field in the spec section, the original RAID configuration is not deleted, and no new configuration will be performed.
  3. Create the cluster.
3.3.13.7. Configuring storage on nodes

You can make changes to operating systems on OpenShift Container Platform nodes by creating MachineConfig objects that are managed by the Machine Config Operator (MCO).

The MachineConfig specification includes an ignition config for configuring the machines at first boot. This config object can be used to modify files, systemd services, and other operating system features running on OpenShift Container Platform machines.

Procedure

Use the ignition config to configure storage on nodes. The following MachineSet manifest example demonstrates how to add a partition to a device on a primary node. In this example, apply the manifest before installation to have a partition named recovery with a size of 16 GiB on the primary node.

  1. Create a custom-partitions.yaml file and include a MachineConfig object that contains your partition layout:

    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    metadata:
      labels:
        machineconfiguration.openshift.io/role: primary
      name: 10_primary_storage_config
    spec:
      config:
        ignition:
          version: 3.2.0
        storage:
          disks:
            - device: </dev/xxyN>
              partitions:
                - label: recovery
                  startMiB: 32768
                  sizeMiB: 16384
          filesystems:
            - device: /dev/disk/by-partlabel/recovery
              label: recovery
              format: xfs
  2. Save and copy the custom-partitions.yaml file to the clusterconfigs/openshift directory:

    $ cp ~/<MachineConfig_manifest> ~/clusterconfigs/openshift

3.3.14. Creating a disconnected registry

In some cases, you might want to install an OpenShift Container Platform cluster using a local copy of the installation registry. This could be for enhancing network efficiency because the cluster nodes are on a network that does not have access to the internet.

A local, or mirrored, copy of the registry requires the following:

  • A certificate for the registry node. This can be a self-signed certificate.
  • A web server that a container on a system will serve.
  • An updated pull secret that contains the certificate and local repository information.
Note

Creating a disconnected registry on a registry node is optional. If you need to create a disconnected registry on a registry node, you must complete all of the following sub-sections.

Prerequisites
3.3.14.1. Preparing the registry node to host the mirrored registry

The following steps must be completed prior to hosting a mirrored registry on bare metal.

Procedure

  1. Open the firewall port on the registry node:

    $ sudo firewall-cmd --add-port=5000/tcp --zone=libvirt  --permanent
    $ sudo firewall-cmd --add-port=5000/tcp --zone=public   --permanent
    $ sudo firewall-cmd --reload
  2. Install the required packages for the registry node:

    $ sudo yum -y install python3 podman httpd httpd-tools jq
  3. Create the directory structure where the repository information will be held:

    $ sudo mkdir -p /opt/registry/{auth,certs,data}
3.3.14.2. Mirroring the OpenShift Container Platform image repository for a disconnected registry

Complete the following steps to mirror the OpenShift Container Platform image repository for a disconnected registry.

Prerequisites

  • Your mirror host has access to the internet.
  • You configured a mirror registry to use in your restricted network and can access the certificate and credentials that you configured.
  • You downloaded the pull secret from Red Hat OpenShift Cluster Manager and modified it to include authentication to your mirror repository.

Procedure

  1. Review the OpenShift Container Platform downloads page to determine the version of OpenShift Container Platform that you want to install and determine the corresponding tag on the Repository Tags page.
  2. Set the required environment variables:

    1. Export the release version:

      $ OCP_RELEASE=<release_version>

      For <release_version>, specify the tag that corresponds to the version of OpenShift Container Platform to install, such as 4.5.4.

    2. Export the local registry name and host port:

      $ LOCAL_REGISTRY='<local_registry_host_name>:<local_registry_host_port>'

      For <local_registry_host_name>, specify the registry domain name for your mirror repository, and for <local_registry_host_port>, specify the port that it serves content on.

    3. Export the local repository name:

      $ LOCAL_REPOSITORY='<local_repository_name>'

      For <local_repository_name>, specify the name of the repository to create in your registry, such as ocp4/openshift4.

    4. Export the name of the repository to mirror:

      $ PRODUCT_REPO='openshift-release-dev'

      For a production release, you must specify openshift-release-dev.

    5. Export the path to your registry pull secret:

      $ LOCAL_SECRET_JSON='<path_to_pull_secret>'

      For <path_to_pull_secret>, specify the absolute path to and file name of the pull secret for your mirror registry that you created.

    6. Export the release mirror:

      $ RELEASE_NAME="ocp-release"

      For a production release, you must specify ocp-release.

    7. Export the type of architecture for your cluster:

      $ ARCHITECTURE=<cluster_architecture> 1
      1
      Specify the architecture of the cluster, such as x86_64, aarch64, s390x, or ppc64le.
    8. Export the path to the directory to host the mirrored images:

      $ REMOVABLE_MEDIA_PATH=<path> 1
      1
      Specify the full path, including the initial forward slash (/) character.
  3. Mirror the version images to the mirror registry:

    • If your mirror host does not have internet access, take the following actions:

      1. Connect the removable media to a system that is connected to the internet.
      2. Review the images and configuration manifests to mirror:

        $ oc adm release mirror -a ${LOCAL_SECRET_JSON}  \
             --from=quay.io/${PRODUCT_REPO}/${RELEASE_NAME}:${OCP_RELEASE}-${ARCHITECTURE} \
             --to=${LOCAL_REGISTRY}/${LOCAL_REPOSITORY} \
             --to-release-image=${LOCAL_REGISTRY}/${LOCAL_REPOSITORY}:${OCP_RELEASE}-${ARCHITECTURE} --dry-run
      3. Record the entire imageContentSources section from the output of the previous command. The information about your mirrors is unique to your mirrored repository, and you must add the imageContentSources section to the install-config.yaml file during installation.
      4. Mirror the images to a directory on the removable media:

        $ oc adm release mirror -a ${LOCAL_SECRET_JSON} --to-dir=${REMOVABLE_MEDIA_PATH}/mirror quay.io/${PRODUCT_REPO}/${RELEASE_NAME}:${OCP_RELEASE}-${ARCHITECTURE}
      5. Take the media to the restricted network environment and upload the images to the local container registry.

        $ oc image mirror -a ${LOCAL_SECRET_JSON} --from-dir=${REMOVABLE_MEDIA_PATH}/mirror "file://openshift/release:${OCP_RELEASE}*" ${LOCAL_REGISTRY}/${LOCAL_REPOSITORY} 1
        1
        For REMOVABLE_MEDIA_PATH, you must use the same path that you specified when you mirrored the images.
    • If the local container registry is connected to the mirror host, take the following actions:

      1. Directly push the release images to the local registry by using following command:

        $ oc adm release mirror -a ${LOCAL_SECRET_JSON}  \
             --from=quay.io/${PRODUCT_REPO}/${RELEASE_NAME}:${OCP_RELEASE}-${ARCHITECTURE} \
             --to=${LOCAL_REGISTRY}/${LOCAL_REPOSITORY} \
             --to-release-image=${LOCAL_REGISTRY}/${LOCAL_REPOSITORY}:${OCP_RELEASE}-${ARCHITECTURE}

        This command pulls the release information as a digest, and its output includes the imageContentSources data that you require when you install your cluster.

      2. Record the entire imageContentSources section from the output of the previous command. The information about your mirrors is unique to your mirrored repository, and you must add the imageContentSources section to the install-config.yaml file during installation.

        Note

        The image name gets patched to Quay.io during the mirroring process, and the podman images will show Quay.io in the registry on the bootstrap virtual machine.

  4. To create the installation program that is based on the content that you mirrored, extract it and pin it to the release:

    • If your mirror host does not have internet access, run the following command:

      $ oc adm release extract -a ${LOCAL_SECRET_JSON} --command=openshift-baremetal-install "${LOCAL_REGISTRY}/${LOCAL_REPOSITORY}:${OCP_RELEASE}"
    • If the local container registry is connected to the mirror host, run the following command:

      $ oc adm release extract -a ${LOCAL_SECRET_JSON} --command=openshift-baremetal-install "${LOCAL_REGISTRY}/${LOCAL_REPOSITORY}:${OCP_RELEASE}-${ARCHITECTURE}"
      Important

      To ensure that you use the correct images for the version of OpenShift Container Platform that you selected, you must extract the installation program from the mirrored content.

      You must perform this step on a machine with an active internet connection.

      If you are in a disconnected environment, use the --image flag as part of must-gather and point to the payload image.

  5. For clusters using installer-provisioned infrastructure, run the following command:

    $ openshift-baremetal-install
3.3.14.3. Modify the install-config.yaml file to use the disconnected registry

On the provisioner node, the install-config.yaml file should use the newly created pull-secret from the pull-secret-update.txt file. The install-config.yaml file must also contain the disconnected registry node’s certificate and registry information.

Procedure

  1. Add the disconnected registry node’s certificate to the install-config.yaml file:

    $ echo "additionalTrustBundle: |" >> install-config.yaml

    The certificate should follow the "additionalTrustBundle: |" line and be properly indented, usually by two spaces.

    $ sed -e 's/^/  /' /opt/registry/certs/domain.crt >> install-config.yaml
  2. Add the mirror information for the registry to the install-config.yaml file:

    $ echo "imageContentSources:" >> install-config.yaml
    $ echo "- mirrors:" >> install-config.yaml
    $ echo "  - registry.example.com:5000/ocp4/openshift4" >> install-config.yaml

    Replace registry.example.com with the registry’s fully qualified domain name.

    $ echo "  source: quay.io/openshift-release-dev/ocp-release" >> install-config.yaml
    $ echo "- mirrors:" >> install-config.yaml
    $ echo "  - registry.example.com:5000/ocp4/openshift4" >> install-config.yaml

    Replace registry.example.com with the registry’s fully qualified domain name.

    $ echo "  source: quay.io/openshift-release-dev/ocp-v4.0-art-dev" >> install-config.yaml

3.3.15. Validation checklist for installation

  • ❏ OpenShift Container Platform installer has been retrieved.
  • ❏ OpenShift Container Platform installer has been extracted.
  • ❏ Required parameters for the install-config.yaml have been configured.
  • ❏ The hosts parameter for the install-config.yaml has been configured.
  • ❏ The bmc parameter for the install-config.yaml has been configured.
  • ❏ Conventions for the values configured in the bmc address field have been applied.
  • ❏ Created the OpenShift Container Platform manifests.
  • ❏ (Optional) Deployed routers on compute nodes.
  • ❏ (Optional) Created a disconnected registry.
  • ❏ (Optional) Validate disconnected registry settings if in use.

3.4. Installing a cluster

3.4.1. Cleaning up previous installations

In case of an earlier failed deployment, remove the artifacts from the failed attempt before trying to deploy OpenShift Container Platform again.

Procedure

  1. Power off all bare-metal nodes before installing the OpenShift Container Platform cluster by using the following command:

    $ ipmitool -I lanplus -U <user> -P <password> -H <management_server_ip> power off
  2. Remove all old bootstrap resources if any remain from an earlier deployment attempt by using the following script:

    for i in $(sudo virsh list | tail -n +3 | grep bootstrap | awk {'print $2'});
    do
      sudo virsh destroy $i;
      sudo virsh undefine $i;
      sudo virsh vol-delete $i --pool $i;
      sudo virsh vol-delete $i.ign --pool $i;
      sudo virsh pool-destroy $i;
      sudo virsh pool-undefine $i;
    done
  3. Delete the artifacts that the earlier installation generated by using the following command:

    $ cd ; /bin/rm -rf auth/ bootstrap.ign master.ign worker.ign metadata.json \
    .openshift_install.log .openshift_install_state.json
  4. Re-create the OpenShift Container Platform manifests by using the following command:

    $ ./openshift-baremetal-install --dir ~/clusterconfigs create manifests

3.4.2. Deploying the cluster via the OpenShift Container Platform installer

Run the OpenShift Container Platform installer:

$ ./openshift-baremetal-install --dir ~/clusterconfigs --log-level debug create cluster

3.4.3. Following the progress of the installation

During the deployment process, you can check the installation’s overall status by issuing the tail command to the .openshift_install.log log file in the install directory folder:

$ tail -f /path/to/install-dir/.openshift_install.log

3.4.4. Verifying static IP address configuration

If the DHCP reservation for a cluster node specifies an infinite lease, after the installer successfully provisions the node, the dispatcher script checks the node’s network configuration. If the script determines that the network configuration contains an infinite DHCP lease, it creates a new connection using the IP address of the DHCP lease as a static IP address.

Note

The dispatcher script might run on successfully provisioned nodes while the provisioning of other nodes in the cluster is ongoing.

Verify the network configuration is working properly.

Procedure

  1. Check the network interface configuration on the node.
  2. Turn off the DHCP server and reboot the OpenShift Container Platform node and ensure that the network configuration works properly.

3.4.5. Additional resources

3.5. Troubleshooting the installation

3.5.1. Troubleshooting the installation program workflow

Before troubleshooting the installation environment, it is critical to understand the overall flow of the installer-provisioned installation on bare metal. The following diagrams illustrate a troubleshooting flow with a step-by-step breakdown for the environment.

Flow-Diagram-1

Workflow 1 of 4 illustrates a troubleshooting workflow when the install-config.yaml file has errors or the Red Hat Enterprise Linux CoreOS (RHCOS) images are inaccessible. See Troubleshooting install-config.yaml for troubleshooting suggestions.

Flow-Diagram-2

Workflow 2 of 4 illustrates a troubleshooting workflow for bootstrap VM issues, bootstrap VMs that cannot boot up the cluster nodes, and inspecting logs. When installing an OpenShift Container Platform cluster without the provisioning network, this workflow does not apply.

Flow-Diagram-3

Workflow 3 of 4 illustrates a troubleshooting workflow for cluster nodes that will not PXE boot. If installing using Redfish virtual media, each node must meet minimum firmware requirements for the installation program to deploy the node. See Firmware requirements for installing with virtual media in the Prerequisites section for additional details.

Flow-Diagram-4

Workflow 4 of 4 illustrates a troubleshooting workflow from a non-accessible API to a validated installation.

3.5.2. Troubleshooting install-config.yaml

The install-config.yaml configuration file represents all of the nodes that are part of the OpenShift Container Platform cluster. The file contains the necessary options consisting of but not limited to apiVersion, baseDomain, imageContentSources and virtual IP addresses. If errors occur early in the deployment of the OpenShift Container Platform cluster, the errors are likely in the install-config.yaml configuration file.

Procedure

  1. Use the guidelines in YAML-tips.
  2. Verify the YAML syntax is correct using syntax-check.
  3. Verify the Red Hat Enterprise Linux CoreOS (RHCOS) QEMU images are properly defined and accessible via the URL provided in the install-config.yaml. For example:

    $ curl -s -o /dev/null -I -w "%{http_code}\n" http://webserver.example.com:8080/rhcos-44.81.202004250133-0-qemu.<architecture>.qcow2.gz?sha256=7d884b46ee54fe87bbc3893bf2aa99af3b2d31f2e19ab5529c60636fbd0f1ce7

    If the output is 200, there is a valid response from the webserver storing the bootstrap VM image.

3.5.3. Troubleshooting bootstrap VM issues

The OpenShift Container Platform installation program spawns a bootstrap node virtual machine, which handles provisioning the OpenShift Container Platform cluster nodes.

Procedure

  1. About 10 to 15 minutes after triggering the installation program, check to ensure the bootstrap VM is operational using the virsh command:

    $ sudo virsh list
     Id    Name                           State
     --------------------------------------------
     12    openshift-xf6fq-bootstrap      running
    Note

    The name of the bootstrap VM is always the cluster name followed by a random set of characters and ending in the word "bootstrap."

  2. If the bootstrap VM is not running after 10-15 minutes, verify libvirtd is running on the system by executing the following command:

    $ systemctl status libvirtd
    ● libvirtd.service - Virtualization daemon
       Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
       Active: active (running) since Tue 2020-03-03 21:21:07 UTC; 3 weeks 5 days ago
         Docs: man:libvirtd(8)
               https://libvirt.org
     Main PID: 9850 (libvirtd)
        Tasks: 20 (limit: 32768)
       Memory: 74.8M
       CGroup: /system.slice/libvirtd.service
               ├─ 9850 /usr/sbin/libvirtd

    If the bootstrap VM is operational, log in to it.

  3. Use the virsh console command to find the IP address of the bootstrap VM:

    $ sudo virsh console example.com
    Connected to domain example.com
    Escape character is ^]
    Red Hat Enterprise Linux CoreOS 43.81.202001142154.0 (Ootpa) 4.3
    SSH host key: SHA256:BRWJktXZgQQRY5zjuAV0IKZ4WM7i4TiUyMVanqu9Pqg (ED25519)
    SSH host key: SHA256:7+iKGA7VtG5szmk2jB5gl/5EZ+SNcJ3a2g23o0lnIio (ECDSA)
    SSH host key: SHA256:DH5VWhvhvagOTaLsYiVNse9ca+ZSW/30OOMed8rIGOc (RSA)
    ens3:  fd35:919d:4042:2:c7ed:9a9f:a9ec:7
    ens4: 172.22.0.2 fe80::1d05:e52e:be5d:263f
    localhost login:
    Important

    When deploying an OpenShift Container Platform cluster without the provisioning network, you must use a public IP address and not a private IP address like 172.22.0.2.

  4. After you obtain the IP address, log in to the bootstrap VM using the ssh command:

    Note

    In the console output of the previous step, you can use the IPv6 IP address provided by ens3 or the IPv4 IP provided by ens4.

    $ ssh core@172.22.0.2

If you are not successful logging in to the bootstrap VM, you have likely encountered one of the following scenarios:

  • You cannot reach the 172.22.0.0/24 network. Verify the network connectivity between the provisioner and the provisioning network bridge. This issue might occur if you are using a provisioning network.
  • You cannot reach the bootstrap VM through the public network. When attempting to SSH via baremetal network, verify connectivity on the provisioner host specifically around the baremetal network bridge.
  • You encountered Permission denied (publickey,password,keyboard-interactive). When attempting to access the bootstrap VM, a Permission denied error might occur. Verify that the SSH key for the user attempting to log in to the VM is set within the install-config.yaml file.
3.5.3.1. Bootstrap VM cannot boot up the cluster nodes

During the deployment, it is possible for the bootstrap VM to fail to boot the cluster nodes, which prevents the VM from provisioning the nodes with the RHCOS image. This scenario can arise due to:

  • A problem with the install-config.yaml file.
  • Issues with out-of-band network access when using the baremetal network.

To verify the issue, there are three containers related to ironic:

  • ironic
  • ironic-inspector

Procedure

  1. Log in to the bootstrap VM:

    $ ssh core@172.22.0.2
  2. To check the container logs, execute the following:

    [core@localhost ~]$ sudo podman logs -f <container_name>

    Replace <container_name> with one of ironic or ironic-inspector. If you encounter an issue where the control plane nodes are not booting up from PXE, check the ironic pod. The ironic pod contains information about the attempt to boot the cluster nodes, because it attempts to log in to the node over IPMI.

Potential reason

The cluster nodes might be in the ON state when deployment started.

Solution

Power off the OpenShift Container Platform cluster nodes before you begin the installation over IPMI:

$ ipmitool -I lanplus -U root -P <password> -H <out_of_band_ip> power off
3.5.3.2. Inspecting logs

When experiencing issues downloading or accessing the RHCOS images, first verify that the URL is correct in the install-config.yaml configuration file.

Example of internal webserver hosting RHCOS images

bootstrapOSImage: http://<ip:port>/rhcos-43.81.202001142154.0-qemu.<architecture>.qcow2.gz?sha256=9d999f55ff1d44f7ed7c106508e5deecd04dc3c06095d34d36bf1cd127837e0c
clusterOSImage: http://<ip:port>/rhcos-43.81.202001142154.0-openstack.<architecture>.qcow2.gz?sha256=a1bda656fa0892f7b936fdc6b6a6086bddaed5dafacedcd7a1e811abb78fe3b0

The coreos-downloader container downloads resources from a webserver or from the external quay.io registry, whichever the install-config.yaml configuration file specifies. Verify that the coreos-downloader container is up and running and inspect its logs as needed.

Procedure

  1. Log in to the bootstrap VM:

    $ ssh core@172.22.0.2
  2. Check the status of the coreos-downloader container within the bootstrap VM by running the following command:

    [core@localhost ~]$ sudo podman logs -f coreos-downloader

    If the bootstrap VM cannot access the URL to the images, use the curl command to verify that the VM can access the images.

  3. To inspect the bootkube logs that indicate if all the containers launched during the deployment phase, execute the following:

    [core@localhost ~]$ journalctl -xe
    [core@localhost ~]$ journalctl -b -f -u bootkube.service
  4. Verify all the pods, including dnsmasq, mariadb, httpd, and ironic, are running:

    [core@localhost ~]$ sudo podman ps
  5. If there are issues with the pods, check the logs of the containers with issues. To check the logs of the ironic service, run the following command:

    [core@localhost ~]$ sudo podman logs ironic

3.5.4. Investigating an unavailable Kubernetes API

When the Kubernetes API is unavailable, check the control plane nodes to ensure that they are running the correct components. Also, check the hostname resolution.

Procedure

  1. Ensure that etcd is running on each of the control plane nodes by running the following command:

    $ sudo crictl logs $(sudo crictl ps --pod=$(sudo crictl pods --name=etcd-member --quiet) --quiet)
  2. If the previous command fails, ensure that Kubelet created the etcd pods by running the following command:

    $ sudo crictl pods --name=etcd-member

    If there are no pods, investigate etcd.

  3. Check the cluster nodes to ensure they have a fully qualified domain name, and not just localhost.localdomain, by using the following command:

    $ hostname

    If a hostname is not set, set the correct hostname. For example:

    $ sudo hostnamectl set-hostname <hostname>
  4. Ensure that each node has the correct name resolution in the DNS server using the dig command:

    $ dig api.<cluster_name>.example.com
    ; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el8 <<>> api.<cluster_name>.example.com
    ;; global options: +cmd
    ;; Got answer:
    ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37551
    ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2
    
    ;; OPT PSEUDOSECTION:
    ; EDNS: version: 0, flags:; udp: 4096
    ; COOKIE: 866929d2f8e8563582af23f05ec44203d313e50948d43f60 (good)
    ;; QUESTION SECTION:
    ;api.<cluster_name>.example.com. IN A
    
    ;; ANSWER SECTION:
    api.<cluster_name>.example.com. 10800 IN	A 10.19.13.86
    
    ;; AUTHORITY SECTION:
    <cluster_name>.example.com. 10800 IN NS	<cluster_name>.example.com.
    
    ;; ADDITIONAL SECTION:
    <cluster_name>.example.com. 10800 IN A	10.19.14.247
    
    ;; Query time: 0 msec
    ;; SERVER: 10.19.14.247#53(10.19.14.247)
    ;; WHEN: Tue May 19 20:30:59 UTC 2020
    ;; MSG SIZE  rcvd: 140

    The output in the foregoing example indicates that the appropriate IP address for the api.<cluster_name>.example.com VIP is 10.19.13.86. This IP address should reside on the baremetal network.

3.5.5. Troubleshooting a failure to initialize the cluster

The installation program uses the Cluster Version Operator to create all the components of an OpenShift Container Platform cluster. When the installation program fails to initialize the cluster, you can retrieve the most important information from the ClusterVersion and ClusterOperator objects.

Procedure

  1. Inspect the ClusterVersion object by running the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get clusterversion -o yaml

    Example output

    apiVersion: config.openshift.io/v1
    kind: ClusterVersion
    metadata:
      creationTimestamp: 2019-02-27T22:24:21Z
      generation: 1
      name: version
      resourceVersion: "19927"
      selfLink: /apis/config.openshift.io/v1/clusterversions/version
      uid: 6e0f4cf8-3ade-11e9-9034-0a923b47ded4
    spec:
      channel: stable-4.1
      clusterID: 5ec312f9-f729-429d-a454-61d4906896ca
    status:
      availableUpdates: null
      conditions:
      - lastTransitionTime: 2019-02-27T22:50:30Z
        message: Done applying 4.1.1
        status: "True"
        type: Available
      - lastTransitionTime: 2019-02-27T22:50:30Z
        status: "False"
        type: Failing
      - lastTransitionTime: 2019-02-27T22:50:30Z
        message: Cluster version is 4.1.1
        status: "False"
        type: Progressing
      - lastTransitionTime: 2019-02-27T22:24:31Z
        message: 'Unable to retrieve available updates: unknown version 4.1.1
        reason: RemoteFailed
        status: "False"
        type: RetrievedUpdates
      desired:
        image: registry.svc.ci.openshift.org/openshift/origin-release@sha256:91e6f754975963e7db1a9958075eb609ad226968623939d262d1cf45e9dbc39a
        version: 4.1.1
      history:
      - completionTime: 2019-02-27T22:50:30Z
        image: registry.svc.ci.openshift.org/openshift/origin-release@sha256:91e6f754975963e7db1a9958075eb609ad226968623939d262d1cf45e9dbc39a
        startedTime: 2019-02-27T22:24:31Z
        state: Completed
        version: 4.1.1
      observedGeneration: 1
      versionHash: Wa7as_ik1qE=

  2. View the conditions by running the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get clusterversion version \
         -o=jsonpath='{range .status.conditions[*]}{.type}{" "}{.status}{" "}{.message}{"\n"}{end}'

    Some of most important conditions include Failing, Available and Progressing.

    Example output

    Available True Done applying 4.1.1
    Failing False
    Progressing False Cluster version is 4.0.0-0.alpha-2019-02-26-194020
    RetrievedUpdates False Unable to retrieve available updates: unknown version 4.1.1

  3. Inspect the ClusterOperator object by running the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get clusteroperator

    The command returns the status of the cluster Operators.

    Example output

    NAME                                  VERSION   AVAILABLE   PROGRESSING   FAILING   SINCE
    cluster-baremetal-operator                      True        False         False     17m
    cluster-autoscaler                              True        False         False     17m
    cluster-storage-operator                        True        False         False     10m
    console                                         True        False         False     7m21s
    dns                                             True        False         False     31m
    image-registry                                  True        False         False     9m58s
    ingress                                         True        False         False     10m
    kube-apiserver                                  True        False         False     28m
    kube-controller-manager                         True        False         False     21m
    kube-scheduler                                  True        False         False     25m
    machine-api                                     True        False         False     17m
    machine-config                                  True        False         False     17m
    marketplace-operator                            True        False         False     10m
    monitoring                                      True        False         False     8m23s
    network                                         True        False         False     13m
    node-tuning                                     True        False         False     11m
    openshift-apiserver                             True        False         False     15m
    openshift-authentication                        True        False         False     20m
    openshift-cloud-credential-operator             True        False         False     18m
    openshift-controller-manager                    True        False         False     10m
    openshift-samples                               True        False         False     8m42s
    operator-lifecycle-manager                      True        False         False     17m
    service-ca                                      True        False         False     30m

  4. Inspect individual cluster Operators by running the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get clusteroperator <operator> -oyaml 1
    1
    Replace <operator> with the name of a cluster Operator. This command is useful for identifying why an cluster Operator has not achieved the Available state or is in the Failed state.

    Example output

    apiVersion: config.openshift.io/v1
    kind: ClusterOperator
    metadata:
      creationTimestamp: 2019-02-27T22:47:04Z
      generation: 1
      name: monitoring
      resourceVersion: "24677"
      selfLink: /apis/config.openshift.io/v1/clusteroperators/monitoring
      uid: 9a6a5ef9-3ae1-11e9-bad4-0a97b6ba9358
    spec: {}
    status:
      conditions:
      - lastTransitionTime: 2019-02-27T22:49:10Z
        message: Successfully rolled out the stack.
        status: "True"
        type: Available
      - lastTransitionTime: 2019-02-27T22:49:10Z
        status: "False"
        type: Progressing
      - lastTransitionTime: 2019-02-27T22:49:10Z
        status: "False"
        type: Failing
      extension: null
      relatedObjects: null
      version: ""

  5. To get the cluster Operator’s status condition, run the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get clusteroperator <operator> \
         -o=jsonpath='{range .status.conditions[*]}{.type}{" "}{.status}{" "}{.message}{"\n"}{end}'

    Replace <operator> with the name of one of the operators above.

    Example output

    Available True Successfully rolled out the stack
    Progressing False
    Failing False

  6. To retrieve the list of objects owned by the cluster Operator, execute the following command:

    oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get clusteroperator kube-apiserver \
       -o=jsonpath='{.status.relatedObjects}'

    Example output

    [map[resource:kubeapiservers group:operator.openshift.io name:cluster] map[group: name:openshift-config resource:namespaces] map[group: name:openshift-config-managed resource:namespaces] map[group: name:openshift-kube-apiserver-operator resource:namespaces] map[group: name:openshift-kube-apiserver resource:namespaces]]

3.5.6. Troubleshooting a failure to fetch the console URL

The installation program retrieves the URL for the OpenShift Container Platform console by using [route][route-object] within the openshift-console namespace. If the installation program fails the retrieve the URL for the console, use the following procedure.

Procedure

  1. Check if the console router is in the Available or Failing state by running the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get clusteroperator console -oyaml
    apiVersion: config.openshift.io/v1
    kind: ClusterOperator
    metadata:
      creationTimestamp: 2019-02-27T22:46:57Z
      generation: 1
      name: console
      resourceVersion: "19682"
      selfLink: /apis/config.openshift.io/v1/clusteroperators/console
      uid: 960364aa-3ae1-11e9-bad4-0a97b6ba9358
    spec: {}
    status:
      conditions:
      - lastTransitionTime: 2019-02-27T22:46:58Z
        status: "False"
        type: Failing
      - lastTransitionTime: 2019-02-27T22:50:12Z
        status: "False"
        type: Progressing
      - lastTransitionTime: 2019-02-27T22:50:12Z
        status: "True"
        type: Available
      - lastTransitionTime: 2019-02-27T22:46:57Z
        status: "True"
        type: Upgradeable
      extension: null
      relatedObjects:
      - group: operator.openshift.io
        name: cluster
        resource: consoles
      - group: config.openshift.io
        name: cluster
        resource: consoles
      - group: oauth.openshift.io
        name: console
        resource: oauthclients
      - group: ""
        name: openshift-console-operator
        resource: namespaces
      - group: ""
        name: openshift-console
        resource: namespaces
      versions: null
  2. Manually retrieve the console URL by executing the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get route console -n openshift-console \
         -o=jsonpath='{.spec.host}' console-openshift-console.apps.adahiya-1.devcluster.openshift.com

3.5.7. Troubleshooting a failure to add the ingress certificate to kubeconfig

The installation program adds the default ingress certificate to the list of trusted client certificate authorities in ${INSTALL_DIR}/auth/kubeconfig. If the installation program fails to add the ingress certificate to the kubeconfig file, you can retrieve the certificate from the cluster and add it.

Procedure

  1. Retrieve the certificate from the cluster using the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig get configmaps default-ingress-cert \
         -n openshift-config-managed -o=jsonpath='{.data.ca-bundle\.crt}'
    -----BEGIN CERTIFICATE-----
    MIIC/TCCAeWgAwIBAgIBATANBgkqhkiG9w0BAQsFADAuMSwwKgYDVQQDDCNjbHVz
    dGVyLWluZ3Jlc3Mtb3BlcmF0b3JAMTU1MTMwNzU4OTAeFw0xOTAyMjcyMjQ2Mjha
    Fw0yMTAyMjYyMjQ2MjlaMC4xLDAqBgNVBAMMI2NsdXN0ZXItaW5ncmVzcy1vcGVy
    YXRvckAxNTUxMzA3NTg5MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA
    uCA4fQ+2YXoXSUL4h/mcvJfrgpBfKBW5hfB8NcgXeCYiQPnCKblH1sEQnI3VC5Pk
    2OfNCF3PUlfm4i8CHC95a7nCkRjmJNg1gVrWCvS/ohLgnO0BvszSiRLxIpuo3C4S
    EVqqvxValHcbdAXWgZLQoYZXV7RMz8yZjl5CfhDaaItyBFj3GtIJkXgUwp/5sUfI
    LDXW8MM6AXfuG+kweLdLCMm3g8WLLfLBLvVBKB+4IhIH7ll0buOz04RKhnYN+Ebw
    tcvFi55vwuUCWMnGhWHGEQ8sWm/wLnNlOwsUz7S1/sW8nj87GFHzgkaVM9EOnoNI
    gKhMBK9ItNzjrP6dgiKBCQIDAQABoyYwJDAOBgNVHQ8BAf8EBAMCAqQwEgYDVR0T
    AQH/BAgwBgEB/wIBADANBgkqhkiG9w0BAQsFAAOCAQEAq+vi0sFKudaZ9aUQMMha
    CeWx9CZvZBblnAWT/61UdpZKpFi4eJ2d33lGcfKwHOi2NP/iSKQBebfG0iNLVVPz
    vwLbSG1i9R9GLdAbnHpPT9UG6fLaDIoKpnKiBfGENfxeiq5vTln2bAgivxrVlyiq
    +MdDXFAWb6V4u2xh6RChI7akNsS3oU9PZ9YOs5e8vJp2YAEphht05X0swA+X8V8T
    C278FFifpo0h3Q0Dbv8Rfn4UpBEtN4KkLeS+JeT+0o2XOsFZp7Uhr9yFIodRsnNo
    H/Uwmab28ocNrGNiEVaVH6eTTQeeZuOdoQzUbClElpVmkrNGY0M42K0PvOQ/e7+y
    AQ==
    -----END CERTIFICATE-----
  2. Add the certificate to the client-certificate-authority-data field in the ${INSTALL_DIR}/auth/kubeconfig file.

3.5.8. Troubleshooting SSH access to cluster nodes

For added security, you cannot SSH into the cluster from outside the cluster by default. However, you can access control plane and worker nodes from the provisioner node. If you cannot SSH into the cluster nodes from the provisioner node, the nodes might be waiting on the bootstrap VM. The control plane nodes retrieve their boot configuration from the bootstrap VM, and they cannot boot successfully if they do not retrieve the boot configuration.

Procedure

  1. If you have physical access to the nodes, check their console output to determine if they have successfully booted. If the nodes are still retrieving their boot configuration, there might be problems with the bootstrap VM .
  2. Ensure you have configured the sshKey: '<ssh_pub_key>' setting in the install-config.yaml file, where <ssh_pub_key> is the public key of the kni user on the provisioner node.

3.5.9. Cluster nodes will not PXE boot

When OpenShift Container Platform cluster nodes will not PXE boot, execute the following checks on the cluster nodes that will not PXE boot. This procedure does not apply when installing an OpenShift Container Platform cluster without the provisioning network.

Procedure

  1. Check the network connectivity to the provisioning network.
  2. Ensure PXE is enabled on the NIC for the provisioning network and PXE is disabled for all other NICs.
  3. Verify that the install-config.yaml configuration file includes the rootDeviceHints parameter and boot MAC address for the NIC connected to the provisioning network. For example:

    control plane node settings

    bootMACAddress: 24:6E:96:1B:96:90 # MAC of bootable provisioning NIC

    Worker node settings

    bootMACAddress: 24:6E:96:1B:96:90 # MAC of bootable provisioning NIC

3.5.10. Installing creates no worker nodes

The installation program does not provision worker nodes directly. Instead, the Machine API Operator scales nodes up and down on supported platforms. If worker nodes are not created after 15 to 20 minutes, depending on the speed of the cluster’s internet connection, investigate the Machine API Operator.

Procedure

  1. Check the Machine API Operator by running the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig \
       --namespace=openshift-machine-api get deployments

    If ${INSTALL_DIR} is not set in your environment, replace the value with the name of the installation directory.

    Example output

    NAME                          READY   UP-TO-DATE   AVAILABLE   AGE
    cluster-autoscaler-operator   1/1     1            1           86m
    cluster-baremetal-operator    1/1     1            1           86m
    machine-api-controllers       1/1     1            1           85m
    machine-api-operator          1/1     1            1           86m

  2. Check the machine controller logs by running the following command:

    $ oc --kubeconfig=${INSTALL_DIR}/auth/kubeconfig \
         --namespace=openshift-machine-api logs deployments/machine-api-controllers \
         --container=machine-controller

3.5.11. Troubleshooting the Cluster Network Operator

The Cluster Network Operator is responsible for deploying the networking components. It runs early in the installation process, after the control plane nodes have come up but before the installation program removes the bootstrap control plane. Issues with this Operator might indicate installation program issues.

Procedure

  1. Ensure the network configuration exists by running the following command:

    $ oc get network -o yaml cluster

    If it does not exist, the installation program did not create it. To find out why, run the following command:

    $ openshift-install create manifests

    Review the manifests to determine why the installation program did not create the network configuration.

  2. Ensure the network is running by entering the following command:

    $ oc get po -n openshift-network-operator

3.5.12. Unable to discover new bare metal hosts using the BMC

In some cases, the installation program will not be able to discover the new bare metal hosts and issue an error, because it cannot mount the remote virtual media share.

For example:

ProvisioningError 51s metal3-baremetal-controller Image provisioning failed: Deploy step deploy.deploy failed with BadRequestError: HTTP POST
https://<bmc_address>/redfish/v1/Managers/iDRAC.Embedded.1/VirtualMedia/CD/Actions/VirtualMedia.InsertMedia
returned code 400.
Base.1.8.GeneralError: A general error has occurred. See ExtendedInfo for more information
Extended information: [
  {
    "Message": "Unable to mount remote share https://<ironic_address>/redfish/boot-<uuid>.iso.",
    "MessageArgs": [
      "https://<ironic_address>/redfish/boot-<uuid>.iso"
    ],
    "MessageArgs@odata.count": 1,
    "MessageId": "IDRAC.2.5.RAC0720",
    "RelatedProperties": [
      "#/Image"
    ],
    "RelatedProperties@odata.count": 1,
    "Resolution": "Retry the operation.",
    "Severity": "Informational"
  }
].

In this situation, if you are using virtual media with an unknown certificate authority, you can configure your baseboard management controller (BMC) remote file share settings to trust an unknown certificate authority to avoid this error.

Note

This resolution was tested on OpenShift Container Platform 4.11 with Dell iDRAC 9 and firmware version 5.10.50.

3.5.13. Troubleshooting worker nodes that cannot join the cluster

Installer-provisioned clusters deploy with a DNS server that includes a DNS entry for the api-int.<cluster_name>.<base_domain> URL. If the nodes within the cluster use an external or upstream DNS server to resolve the api-int.<cluster_name>.<base_domain> URL and there is no such entry, worker nodes might fail to join the cluster. Ensure that all nodes in the cluster can resolve the domain name.

Procedure

  1. Add a DNS A/AAAA or CNAME record to internally identify the API load balancer. For example, when using dnsmasq, modify the dnsmasq.conf configuration file:

    $ sudo nano /etc/dnsmasq.conf
    address=/api-int.<cluster_name>.<base_domain>/<IP_address>
    address=/api-int.mycluster.example.com/192.168.1.10
    address=/api-int.mycluster.example.com/2001:0db8:85a3:0000:0000:8a2e:0370:7334
  2. Add a DNS PTR record to internally identify the API load balancer. For example, when using dnsmasq, modify the dnsmasq.conf configuration file:

    $ sudo nano /etc/dnsmasq.conf
    ptr-record=<IP_address>.in-addr.arpa,api-int.<cluster_name>.<base_domain>
    ptr-record=10.1.168.192.in-addr.arpa,api-int.mycluster.example.com
  3. Restart the DNS server. For example, when using dnsmasq, execute the following command:

    $ sudo systemctl restart dnsmasq

These records must be resolvable from all the nodes within the cluster.

3.5.14. Cleaning up previous installations

In case of an earlier failed deployment, remove the artifacts from the failed attempt before trying to deploy OpenShift Container Platform again.

Procedure

  1. Power off all bare-metal nodes before installing the OpenShift Container Platform cluster by using the following command:

    $ ipmitool -I lanplus -U <user> -P <password> -H <management_server_ip> power off
  2. Remove all old bootstrap resources if any remain from an earlier deployment attempt by using the following script:

    for i in $(sudo virsh list | tail -n +3 | grep bootstrap | awk {'print $2'});
    do
      sudo virsh destroy $i;
      sudo virsh undefine $i;
      sudo virsh vol-delete $i --pool $i;
      sudo virsh vol-delete $i.ign --pool $i;
      sudo virsh pool-destroy $i;
      sudo virsh pool-undefine $i;
    done
  3. Delete the artifacts that the earlier installation generated by using the following command:

    $ cd ; /bin/rm -rf auth/ bootstrap.ign master.ign worker.ign metadata.json \
    .openshift_install.log .openshift_install_state.json
  4. Re-create the OpenShift Container Platform manifests by using the following command:

    $ ./openshift-baremetal-install --dir ~/clusterconfigs create manifests

3.5.15. Issues with creating the registry

When creating a disconnected registry, you might encounter a "User Not Authorized" error when attempting to mirror the registry. This error might occur if you fail to append the new authentication to the existing pull-secret.txt file.

Procedure

  1. Check to ensure authentication is successful:

    $ /usr/local/bin/oc adm release mirror \
      -a pull-secret-update.json
      --from=$UPSTREAM_REPO \
      --to-release-image=$LOCAL_REG/$LOCAL_REPO:${VERSION} \
      --to=$LOCAL_REG/$LOCAL_REPO
    Note

    Example output of the variables used to mirror the install images:

    UPSTREAM_REPO=${RELEASE_IMAGE}
    LOCAL_REG=<registry_FQDN>:<registry_port>
    LOCAL_REPO='ocp4/openshift4'

    The values of RELEASE_IMAGE and VERSION were set during the Retrieving OpenShift Installer step of the Setting up the environment for an OpenShift installation section.

  2. After mirroring the registry, confirm that you can access it in your disconnected environment:

    $ curl -k -u <user>:<password> https://registry.example.com:<registry_port>/v2/_catalog
    {"repositories":["<Repo_Name>"]}

3.5.16. Miscellaneous issues

3.5.16.1. Addressing the runtime network not ready error

After the deployment of a cluster you might receive the following error:

`runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:Network plugin returns error: Missing CNI default network`

The Cluster Network Operator is responsible for deploying the networking components in response to a special object created by the installation program. It runs very early in the installation process, after the control plane (master) nodes have come up, but before the bootstrap control plane has been torn down. It can be indicative of more subtle installation program issues, such as long delays in bringing up control plane (master) nodes or issues with apiserver communication.

Procedure

  1. Inspect the pods in the openshift-network-operator namespace:

    $ oc get all -n openshift-network-operator
    NAME                                    READY STATUS            RESTARTS   AGE
    pod/network-operator-69dfd7b577-bg89v   0/1   ContainerCreating 0          149m
  2. On the provisioner node, determine that the network configuration exists:

    $ kubectl get network.config.openshift.io cluster -oyaml
    apiVersion: config.openshift.io/v1
    kind: Network
    metadata:
      name: cluster
    spec:
      serviceNetwork:
      - 172.30.0.0/16
      clusterNetwork:
      - cidr: 10.128.0.0/14
        hostPrefix: 23
      networkType: OVNKubernetes

    If it does not exist, the installation program did not create it. To determine why the installation program did not create it, execute the following:

    $ openshift-install create manifests
  3. Check that the network-operator is running:

    $ kubectl -n openshift-network-operator get pods
  4. Retrieve the logs:

    $ kubectl -n openshift-network-operator logs -l "name=network-operator"

    On high availability clusters with three or more control plane nodes, the Operator will perform leader election and all other Operators will sleep. For additional details, see Troubleshooting.

3.5.16.2. Addressing the "No disk found with matching rootDeviceHints" error message

After you deploy a cluster, you might receive the following error message:

No disk found with matching rootDeviceHints

To address the No disk found with matching rootDeviceHints error message, a temporary workaround is to change the rootDeviceHints to minSizeGigabytes: 300.

After you change the rootDeviceHints settings, boot the CoreOS and then verify the disk information by using the following command:

$ udevadm info /dev/sda

If you are using DL360 Gen 10 servers, be aware that they have an SD-card slot that might be assigned the /dev/sda device name. If no SD card is present in the server, it can cause conflicts. Ensure that the SD card slot is disabled in the server’s BIOS settings.

If the minSizeGigabytes workaround is not fulfilling the requirements, you might need to revert rootDeviceHints back to /dev/sda. This change allows ironic images to boot successfully.

An alternative approach to fixing this problem is by using the serial ID of the disk. However, be aware that finding the serial ID can be challenging and might make the configuration file less readable. If you choose this path, ensure that you gather the serial ID using the previously documented command and incorporate it into your configuration.

3.5.16.3. Cluster nodes not getting the correct IPv6 address over DHCP

If the cluster nodes are not getting the correct IPv6 address over DHCP, check the following:

  1. Ensure the reserved IPv6 addresses reside outside the DHCP range.
  2. In the IP address reservation on the DHCP server, ensure the reservation specifies the correct DHCP Unique Identifier (DUID). For example:

    # This is a dnsmasq dhcp reservation, 'id:00:03:00:01' is the client id and '18:db:f2:8c:d5:9f' is the MAC Address for the NIC
    id:00:03:00:01:18:db:f2:8c:d5:9f,openshift-master-1,[2620:52:0:1302::6]
  3. Ensure that route announcements are working.
  4. Ensure that the DHCP server is listening on the required interfaces serving the IP address ranges.
3.5.16.4. Cluster nodes not getting the correct hostname over DHCP

During IPv6 deployment, cluster nodes must get their hostname over DHCP. Sometimes the NetworkManager does not assign the hostname immediately. A control plane (master) node might report an error such as:

Failed Units: 2
  NetworkManager-wait-online.service
  nodeip-configuration.service

This error indicates that the cluster node likely booted without first receiving a hostname from the DHCP server, which causes kubelet to boot with a localhost.localdomain hostname. To address the error, force the node to renew the hostname.

Procedure

  1. Retrieve the hostname:

    [core@master-X ~]$ hostname

    If the hostname is localhost, proceed with the following steps.

    Note

    Where X is the control plane node number.

  2. Force the cluster node to renew the DHCP lease:

    [core@master-X ~]$ sudo nmcli con up "<bare_metal_nic>"

    Replace <bare_metal_nic> with the wired connection corresponding to the baremetal network.

  3. Check hostname again:

    [core@master-X ~]$ hostname
  4. If the hostname is still localhost.localdomain, restart NetworkManager:

    [core@master-X ~]$ sudo systemctl restart NetworkManager
  5. If the hostname is still localhost.localdomain, wait a few minutes and check again. If the hostname remains localhost.localdomain, repeat the previous steps.
  6. Restart the nodeip-configuration service:

    [core@master-X ~]$ sudo systemctl restart nodeip-configuration.service

    This service will reconfigure the kubelet service with the correct hostname references.

  7. Reload the unit files definition since the kubelet changed in the previous step:

    [core@master-X ~]$ sudo systemctl daemon-reload
  8. Restart the kubelet service:

    [core@master-X ~]$ sudo systemctl restart kubelet.service
  9. Ensure kubelet booted with the correct hostname:

    [core@master-X ~]$ sudo journalctl -fu kubelet.service

If the cluster node is not getting the correct hostname over DHCP after the cluster is up and running, such as during a reboot, the cluster will have a pending csr. Do not approve a csr, or other issues might arise.

Addressing a csr

  1. Get CSRs on the cluster:

    $ oc get csr
  2. Verify if a pending csr contains Subject Name: localhost.localdomain:

    $ oc get csr <pending_csr> -o jsonpath='{.spec.request}' | base64 --decode | openssl req -noout -text
  3. Remove any csr that contains Subject Name: localhost.localdomain:

    $ oc delete csr <wrong_csr>
3.5.16.5. Routes do not reach endpoints

During the installation process, it is possible to encounter a Virtual Router Redundancy Protocol (VRRP) conflict. This conflict might occur if a previously used OpenShift Container Platform node that was once part of a cluster deployment using a specific cluster name is still running but not part of the current OpenShift Container Platform cluster deployment using that same cluster name. For example, a cluster was deployed using the cluster name openshift, deploying three control plane (master) nodes and three worker nodes. Later, a separate install uses the same cluster name openshift, but this redeployment only installed three control plane (master) nodes, leaving the three worker nodes from a previous deployment in an ON state. This might cause a Virtual Router Identifier (VRID) conflict and a VRRP conflict.

  1. Get the route:

    $ oc get route oauth-openshift
  2. Check the service endpoint:

    $ oc get svc oauth-openshift
    NAME              TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
    oauth-openshift   ClusterIP   172.30.19.162   <none>        443/TCP   59m
  3. Attempt to reach the service from a control plane (master) node:

    [core@master0 ~]$ curl -k https://172.30.19.162
    {
      "kind": "Status",
      "apiVersion": "v1",
      "metadata": {
      },
      "status": "Failure",
      "message": "forbidden: User \"system:anonymous\" cannot get path \"/\"",
      "reason": "Forbidden",
      "details": {
      },
      "code": 403
  4. Identify the authentication-operator errors from the provisioner node:

    $ oc logs deployment/authentication-operator -n openshift-authentication-operator
    Event(v1.ObjectReference{Kind:"Deployment", Namespace:"openshift-authentication-operator", Name:"authentication-operator", UID:"225c5bd5-b368-439b-9155-5fd3c0459d98", APIVersion:"apps/v1", ResourceVersion:"", FieldPath:""}): type: 'Normal' reason: 'OperatorStatusChanged' Status for clusteroperator/authentication changed: Degraded message changed from "IngressStateEndpointsDegraded: All 2 endpoints for oauth-server are reporting"

Solution

  1. Ensure that the cluster name for every deployment is unique, ensuring no conflict.
  2. Turn off all the rogue nodes which are not part of the cluster deployment that are using the same cluster name. Otherwise, the authentication pod of the OpenShift Container Platform cluster might never start successfully.
3.5.16.6. Failed Ignition during Firstboot

During the Firstboot, the Ignition configuration may fail.

Procedure

  1. Connect to the node where the Ignition configuration failed:

    Failed Units: 1
      machine-config-daemon-firstboot.service
  2. Restart the machine-config-daemon-firstboot service:

    [core@worker-X ~]$ sudo systemctl restart machine-config-daemon-firstboot.service
3.5.16.7. NTP out of sync

The deployment of OpenShift Container Platform clusters depends on NTP synchronized clocks among the cluster nodes. Without synchronized clocks, the deployment may fail due to clock drift if the time difference is greater than two seconds.

Procedure

  1. Check for differences in the AGE of the cluster nodes. For example:

    $ oc get nodes
    NAME                         STATUS   ROLES    AGE   VERSION
    master-0.cloud.example.com   Ready    master   145m   v1.31.3
    master-1.cloud.example.com   Ready    master   135m   v1.31.3
    master-2.cloud.example.com   Ready    master   145m   v1.31.3
    worker-2.cloud.example.com   Ready    worker   100m   v1.31.3
  2. Check for inconsistent timing delays due to clock drift. For example:

    $ oc get bmh -n openshift-machine-api
    master-1   error registering master-1  ipmi://<out_of_band_ip>
    $ sudo timedatectl
                   Local time: Tue 2020-03-10 18:20:02 UTC
               Universal time: Tue 2020-03-10 18:20:02 UTC
                     RTC time: Tue 2020-03-10 18:36:53
                    Time zone: UTC (UTC, +0000)
    System clock synchronized: no
                  NTP service: active
              RTC in local TZ: no

Addressing clock drift in existing clusters

  1. Create a Butane config file including the contents of the chrony.conf file to be delivered to the nodes. In the following example, create 99-master-chrony.bu to add the file to the control plane nodes. You can modify the file for worker nodes or repeat this procedure for the worker role.

    Note

    See "Creating machine configs with Butane" for information about Butane.

    variant: openshift
    version: 4.18.0
    metadata:
      name: 99-master-chrony
      labels:
        machineconfiguration.openshift.io/role: master
    storage:
      files:
      - path: /etc/chrony.conf
        mode: 0644
        overwrite: true
        contents:
          inline: |
            server <NTP_server> iburst 1
            stratumweight 0
            driftfile /var/lib/chrony/drift
            rtcsync
            makestep 10 3
            bindcmdaddress 127.0.0.1
            bindcmdaddress ::1
            keyfile /etc/chrony.keys
            commandkey 1
            generatecommandkey
            noclientlog
            logchange 0.5
            logdir /var/log/chrony
    1
    Replace <NTP_server> with the IP address of the NTP server.
  2. Use Butane to generate a MachineConfig object file, 99-master-chrony.yaml, containing the configuration to be delivered to the nodes:

    $ butane 99-master-chrony.bu -o 99-master-chrony.yaml
  3. Apply the MachineConfig object file:

    $ oc apply -f 99-master-chrony.yaml
  4. Ensure the System clock synchronized value is yes:

    $ sudo timedatectl
                   Local time: Tue 2020-03-10 19:10:02 UTC
               Universal time: Tue 2020-03-10 19:10:02 UTC
                     RTC time: Tue 2020-03-10 19:36:53
                    Time zone: UTC (UTC, +0000)
    System clock synchronized: yes
                  NTP service: active
              RTC in local TZ: no

    To setup clock synchronization prior to deployment, generate the manifest files and add this file to the openshift directory. For example:

    $ cp chrony-masters.yaml ~/clusterconfigs/openshift/99_masters-chrony-configuration.yaml

    Then, continue to create the cluster.

3.5.17. Reviewing the installation

After installation, ensure the installation program deployed the nodes and pods successfully.

Procedure

  1. When the OpenShift Container Platform cluster nodes are installed appropriately, the following Ready state is seen within the STATUS column:

    $ oc get nodes
    NAME                   STATUS   ROLES           AGE  VERSION
    master-0.example.com   Ready    master,worker   4h   v1.31.3
    master-1.example.com   Ready    master,worker   4h   v1.31.3
    master-2.example.com   Ready    master,worker   4h   v1.31.3
  2. Confirm the installation program deployed all pods successfully. The following command removes any pods that are still running or have completed as part of the output.

    $ oc get pods --all-namespaces | grep -iv running | grep -iv complete

3.6. Installer-provisioned postinstallation configuration

After successfully deploying an installer-provisioned cluster, consider the following postinstallation procedures.

3.6.1. Configuring NTP for disconnected clusters

OpenShift Container Platform installs the chrony Network Time Protocol (NTP) service on the cluster nodes. Use the following procedure to configure NTP servers on the control plane nodes and configure compute nodes as NTP clients of the control plane nodes after a successful deployment.

Configuring NTP for disconnected clusters

OpenShift Container Platform nodes must agree on a date and time to run properly. When compute nodes retrieve the date and time from the NTP servers on the control plane nodes, it enables the installation and operation of clusters that are not connected to a routable network and thereby do not have access to a higher stratum NTP server.

Procedure

  1. Install Butane on your installation host by using the following command:

    $ sudo dnf -y install butane
  2. Create a Butane config, 99-master-chrony-conf-override.bu, including the contents of the chrony.conf file for the control plane nodes.

    Note

    See "Creating machine configs with Butane" for information about Butane.

    Butane config example

    variant: openshift
    version: 4.18.0
    metadata:
      name: 99-master-chrony-conf-override
      labels:
        machineconfiguration.openshift.io/role: master
    storage:
      files:
        - path: /etc/chrony.conf
          mode: 0644
          overwrite: true
          contents:
            inline: |
              # Use public servers from the pool.ntp.org project.
              # Please consider joining the pool (https://www.pool.ntp.org/join.html).
    
              # The Machine Config Operator manages this file
              server openshift-master-0.<cluster-name>.<domain> iburst 1
              server openshift-master-1.<cluster-name>.<domain> iburst
              server openshift-master-2.<cluster-name>.<domain> iburst
    
              stratumweight 0
              driftfile /var/lib/chrony/drift
              rtcsync
              makestep 10 3
              bindcmdaddress 127.0.0.1
              bindcmdaddress ::1
              keyfile /etc/chrony.keys
              commandkey 1
              generatecommandkey
              noclientlog
              logchange 0.5
              logdir /var/log/chrony
    
              # Configure the control plane nodes to serve as local NTP servers
              # for all compute nodes, even if they are not in sync with an
              # upstream NTP server.
    
              # Allow NTP client access from the local network.
              allow all
              # Serve time even if not synchronized to a time source.
              local stratum 3 orphan

    1
    You must replace <cluster-name> with the name of the cluster and replace <domain> with the fully qualified domain name.
  3. Use Butane to generate a MachineConfig object file, 99-master-chrony-conf-override.yaml, containing the configuration to be delivered to the control plane nodes:

    $ butane 99-master-chrony-conf-override.bu -o 99-master-chrony-conf-override.yaml
  4. Create a Butane config, 99-worker-chrony-conf-override.bu, including the contents of the chrony.conf file for the compute nodes that references the NTP servers on the control plane nodes.

    Butane config example

    variant: openshift
    version: 4.18.0
    metadata:
      name: 99-worker-chrony-conf-override
      labels:
        machineconfiguration.openshift.io/role: worker
    storage:
      files:
        - path: /etc/chrony.conf
          mode: 0644
          overwrite: true
          contents:
            inline: |
              # The Machine Config Operator manages this file.
              server openshift-master-0.<cluster-name>.<domain> iburst 1
              server openshift-master-1.<cluster-name>.<domain> iburst
              server openshift-master-2.<cluster-name>.<domain> iburst
    
              stratumweight 0
              driftfile /var/lib/chrony/drift
              rtcsync
              makestep 10 3
              bindcmdaddress 127.0.0.1
              bindcmdaddress ::1
              keyfile /etc/chrony.keys
              commandkey 1
              generatecommandkey
              noclientlog
              logchange 0.5
              logdir /var/log/chrony

    1
    You must replace <cluster-name> with the name of the cluster and replace <domain> with the fully qualified domain name.
  5. Use Butane to generate a MachineConfig object file, 99-worker-chrony-conf-override.yaml, containing the configuration to be delivered to the worker nodes:

    $ butane 99-worker-chrony-conf-override.bu -o 99-worker-chrony-conf-override.yaml
  6. Apply the 99-master-chrony-conf-override.yaml policy to the control plane nodes.

    $ oc apply -f 99-master-chrony-conf-override.yaml

    Example output

    machineconfig.machineconfiguration.openshift.io/99-master-chrony-conf-override created

  7. Apply the 99-worker-chrony-conf-override.yaml policy to the compute nodes.

    $ oc apply -f 99-worker-chrony-conf-override.yaml

    Example output

    machineconfig.machineconfiguration.openshift.io/99-worker-chrony-conf-override created

  8. Check the status of the applied NTP settings.

    $ oc describe machineconfigpool

3.6.2. Enabling a provisioning network after installation

The assisted installer and installer-provisioned installation for bare metal clusters provide the ability to deploy a cluster without a provisioning network. This capability is for scenarios such as proof-of-concept clusters or deploying exclusively with Redfish virtual media when each node’s baseboard management controller is routable via the baremetal network.

You can enable a provisioning network after installation using the Cluster Baremetal Operator (CBO).

Prerequisites

  • A dedicated physical network must exist, connected to all worker and control plane nodes.
  • You must isolate the native, untagged physical network.
  • The network cannot have a DHCP server when the provisioningNetwork configuration setting is set to Managed.
  • You can omit the provisioningInterface setting in OpenShift Container Platform 4.10 to use the bootMACAddress configuration setting.

Procedure

  1. When setting the provisioningInterface setting, first identify the provisioning interface name for the cluster nodes. For example, eth0 or eno1.
  2. Enable the Preboot eXecution Environment (PXE) on the provisioning network interface of the cluster nodes.
  3. Retrieve the current state of the provisioning network and save it to a provisioning custom resource (CR) file:

    $ oc get provisioning -o yaml > enable-provisioning-nw.yaml
  4. Modify the provisioning CR file:

    $ vim ~/enable-provisioning-nw.yaml

    Scroll down to the provisioningNetwork configuration setting and change it from Disabled to Managed. Then, add the provisioningIP, provisioningNetworkCIDR, provisioningDHCPRange, provisioningInterface, and watchAllNameSpaces configuration settings after the provisioningNetwork setting. Provide appropriate values for each setting.

    apiVersion: v1
    items:
    - apiVersion: metal3.io/v1alpha1
      kind: Provisioning
      metadata:
        name: provisioning-configuration
      spec:
        provisioningNetwork: 1
        provisioningIP: 2
        provisioningNetworkCIDR: 3
        provisioningDHCPRange: 4
        provisioningInterface: 5
        watchAllNameSpaces: 6
    1
    The provisioningNetwork is one of Managed, Unmanaged, or Disabled. When set to Managed, Metal3 manages the provisioning network and the CBO deploys the Metal3 pod with a configured DHCP server. When set to Unmanaged, the system administrator configures the DHCP server manually.
    2
    The provisioningIP is the static IP address that the DHCP server and ironic use to provision the network. This static IP address must be within the provisioning subnet, and outside of the DHCP range. If you configure this setting, it must have a valid IP address even if the provisioning network is Disabled. The static IP address is bound to the metal3 pod. If the metal3 pod fails and moves to another server, the static IP address also moves to the new server.
    3
    The Classless Inter-Domain Routing (CIDR) address. If you configure this setting, it must have a valid CIDR address even if the provisioning network is Disabled. For example: 192.168.0.1/24.
    4
    The DHCP range. This setting is only applicable to a Managed provisioning network. Omit this configuration setting if the provisioning network is Disabled. For example: 192.168.0.64, 192.168.0.253.
    5
    The NIC name for the provisioning interface on cluster nodes. The provisioningInterface setting is only applicable to Managed and Unmanaged provisioning networks. Omit the provisioningInterface configuration setting if the provisioning network is Disabled. Omit the provisioningInterface configuration setting to use the bootMACAddress configuration setting instead.
    6
    Set this setting to true if you want metal3 to watch namespaces other than the default openshift-machine-api namespace. The default value is false.
  5. Save the changes to the provisioning CR file.
  6. Apply the provisioning CR file to the cluster:

    $ oc apply -f enable-provisioning-nw.yaml

3.6.3. Creating a manifest object that includes a customized br-ex bridge

As an alternative to using the configure-ovs.sh shell script to set a br-ex bridge on a bare-metal platform, you can create a NodeNetworkConfigurationPolicy custom resource (CR) that includes an NMState configuration file. The NMState configuration file creates a customized br-ex bridge network configuration on each node in your cluster.

This feature supports the following tasks:

  • Modifying the maximum transmission unit (MTU) for your cluster.
  • Modifying attributes of a different bond interface, such as MIImon (Media Independent Interface Monitor), bonding mode, or Quality of Service (QoS).
  • Updating DNS values.

Consider the following use cases for creating a manifest object that includes a customized br-ex bridge:

  • You want to make postinstallation changes to the bridge, such as changing the Open vSwitch (OVS) or OVN-Kubernetes br-ex bridge network. The configure-ovs.sh shell script does not support making postinstallation changes to the bridge.
  • You want to deploy the bridge on a different interface than the interface available on a host or server IP address.
  • You want to make advanced configurations to the bridge that are not possible with the configure-ovs.sh shell script. Using the script for these configurations might result in the bridge failing to connect multiple network interfaces and facilitating data forwarding between the interfaces.

Prerequisites

  • You set a customized br-ex by using the alternative method to configure-ovs.
  • You installed the Kubernetes NMState Operator.

Procedure

  • Create a NodeNetworkConfigurationPolicy (NNCP) CR and define a customized br-ex bridge network configuration. Depending on your needs, ensure that you set a masquerade IP for either the ipv4.address.ip, ipv6.address.ip, or both parameters. A masquerade IP address must match an in-use IP address block.

    Important

    As a post-installation task, you can configure most parameters for a customized br-ex bridge that you defined in an existing NNCP CR, except for the IP address.

    Example of an NNCP CR that sets IPv6 and IPv4 masquerade IP addresses

    apiVersion: nmstate.io/v1
    kind: NodeNetworkConfigurationPolicy
    metadata:
      name: worker-0-br-ex 1
    spec:
      nodeSelector:
        kubernetes.io/hostname: worker-0
        desiredState:
        interfaces:
        - name: enp2s0 2
          type: ethernet 3
          state: up 4
          ipv4:
            enabled: false 5
          ipv6:
            enabled: false
        - name: br-ex
          type: ovs-bridge
          state: up
          ipv4:
            enabled: false
            dhcp: false
          ipv6:
            enabled: false
            dhcp: false
          bridge:
            port:
            - name: enp2s0 6
            - name: br-ex
        - name: br-ex
          type: ovs-interface
          state: up
          copy-mac-from: enp2s0
          ipv4:
            enabled: true
            dhcp: true
            address:
            - ip: "169.254.169.2"
              prefix-length: 29
          ipv6:
            enabled: false
            dhcp: false
            address:
            - ip: "fd69::2"
            prefix-length: 125

    1
    Name of the policy.
    2
    Name of the interface.
    3
    The type of ethernet.
    4
    The requested state for the interface after creation.
    5
    Disables IPv4 and IPv6 in this example.
    6
    The node NIC to which the bridge is attached.

3.6.4. Creating an IP over InfiniBand interface on nodes

On the OpenShift Container Platform web console, you can install a Red Hat certified third-party Operator, such as the NVIDIA Network Operator, that supports InfiniBand (IPoIB) mode. Typically, you would use the third-party Operator with other vendor infrastructure to manage resources in an OpenShift Container Platform cluster. To create an IPoIB interface on nodes in your cluster, you must define an InfiniBand (IPoIB) interface in a NodeNetworkConfigurationPolicy (NNCP) manifest file.

Important

The OpenShift Container Platform documentation describes defining only the IPoIB interface configuration in a NodeNetworkConfigurationPolicy (NNCP) manifest file. You must refer to the NVIDIA and other third-party vendor documentation for the majority of the configuring steps. Red Hat support does not extend to anything external to the NNCP configuration.

For more information about the NVIDIA Operator, see Getting Started with Red Hat OpenShift (NVIDIA Docs Hub).

Prerequisites

  • You installed a Red Hat certified third-party Operator that supports an IPoIB interface.

Procedure

  1. Create or edit a NodeNetworkConfigurationPolicy (NNCP) manifest file, and then specify an IPoIB interface in the file.

    apiVersion: nmstate.io/v1
    kind: NodeNetworkConfigurationPolicy
    metadata:
      name: worker-0-ipoib
    spec:
    # ...
        interfaces:
        - description: ""
          infiniband:
            mode: datagram 1
            pkey: "0xffff" 2
          ipv4:
            address:
            - ip: 100.125.3.4
              prefix-length: 16
            dhcp: false
            enabled: true
          ipv6:
            enabled: false
          name: ibp27s0
          state: up
          type: infiniband 3
    # ...
    1
    datagram is the default mode for an IPoIB interface, and this mode improves optimizes performance and latency. connected mode is a supported mode but consider only using this mode when you need to adjust the maximum transmission unit (MTU) value to improve node connectivity with surrounding network devices.
    2
    Supports a string or an integer value. The parameter defines the protection key, or P-key, for the interface for the purposes of authentication and encrypted communications with a third-party vendor, such as NVIDIA. Values None and 0xffff indicate the protection key for the base interface in an InfiniBand system.
    3
    Sets the type of interface to `infiniband `.
  2. Apply the NNCP configuration to each node in your cluster by running the following command. The Kubernetes NMState Operator can then create an IPoIB interface on each node.

    $ oc apply -f <nncp_file_name> 1
    1
    Replace <nncp_file_name> with the name of your NNCP file.

3.6.5. Services for a user-managed load balancer

You can configure an OpenShift Container Platform cluster to use a user-managed load balancer in place of the default load balancer.

Important

Configuring a user-managed load balancer depends on your vendor’s load balancer.

The information and examples in this section are for guideline purposes only. Consult the vendor documentation for more specific information about the vendor’s load balancer.

Red Hat supports the following services for a user-managed load balancer:

  • Ingress Controller
  • OpenShift API
  • OpenShift MachineConfig API

You can choose whether you want to configure one or all of these services for a user-managed load balancer. Configuring only the Ingress Controller service is a common configuration option. To better understand each service, view the following diagrams:

Figure 3.4. Example network workflow that shows an Ingress Controller operating in an OpenShift Container Platform environment

An image that shows an example network workflow of an Ingress Controller operating in an OpenShift Container Platform environment.

Figure 3.5. Example network workflow that shows an OpenShift API operating in an OpenShift Container Platform environment

An image that shows an example network workflow of an OpenShift API operating in an OpenShift Container Platform environment.

Figure 3.6. Example network workflow that shows an OpenShift MachineConfig API operating in an OpenShift Container Platform environment

An image that shows an example network workflow of an OpenShift MachineConfig API operating in an OpenShift Container Platform environment.

The following configuration options are supported for user-managed load balancers:

  • Use a node selector to map the Ingress Controller to a specific set of nodes. You must assign a static IP address to each node in this set, or configure each node to receive the same IP address from the Dynamic Host Configuration Protocol (DHCP). Infrastructure nodes commonly receive this type of configuration.
  • Target all IP addresses on a subnet. This configuration can reduce maintenance overhead, because you can create and destroy nodes within those networks without reconfiguring the load balancer targets. If you deploy your ingress pods by using a machine set on a smaller network, such as a /27 or /28, you can simplify your load balancer targets.

    Tip

    You can list all IP addresses that exist in a network by checking the machine config pool’s resources.

Before you configure a user-managed load balancer for your OpenShift Container Platform cluster, consider the following information:

  • For a front-end IP address, you can use the same IP address for the front-end IP address, the Ingress Controller’s load balancer, and API load balancer. Check the vendor’s documentation for this capability.
  • For a back-end IP address, ensure that an IP address for an OpenShift Container Platform control plane node does not change during the lifetime of the user-managed load balancer. You can achieve this by completing one of the following actions:

    • Assign a static IP address to each control plane node.
    • Configure each node to receive the same IP address from the DHCP every time the node requests a DHCP lease. Depending on the vendor, the DHCP lease might be in the form of an IP reservation or a static DHCP assignment.
  • Manually define each node that runs the Ingress Controller in the user-managed load balancer for the Ingress Controller back-end service. For example, if the Ingress Controller moves to an undefined node, a connection outage can occur.
3.6.5.1. Configuring a user-managed load balancer

You can configure an OpenShift Container Platform cluster to use a user-managed load balancer in place of the default load balancer.

Important

Before you configure a user-managed load balancer, ensure that you read the "Services for a user-managed load balancer" section.

Read the following prerequisites that apply to the service that you want to configure for your user-managed load balancer.

Note

MetalLB, which runs on a cluster, functions as a user-managed load balancer.

OpenShift API prerequisites

  • You defined a front-end IP address.
  • TCP ports 6443 and 22623 are exposed on the front-end IP address of your load balancer. Check the following items:

    • Port 6443 provides access to the OpenShift API service.
    • Port 22623 can provide ignition startup configurations to nodes.
  • The front-end IP address and port 6443 are reachable by all users of your system with a location external to your OpenShift Container Platform cluster.
  • The front-end IP address and port 22623 are reachable only by OpenShift Container Platform nodes.
  • The load balancer backend can communicate with OpenShift Container Platform control plane nodes on port 6443 and 22623.

Ingress Controller prerequisites

  • You defined a front-end IP address.
  • TCP ports 443 and 80 are exposed on the front-end IP address of your load balancer.
  • The front-end IP address, port 80 and port 443 are be reachable by all users of your system with a location external to your OpenShift Container Platform cluster.
  • The front-end IP address, port 80 and port 443 are reachable to all nodes that operate in your OpenShift Container Platform cluster.
  • The load balancer backend can communicate with OpenShift Container Platform nodes that run the Ingress Controller on ports 80, 443, and 1936.

Prerequisite for health check URL specifications

You can configure most load balancers by setting health check URLs that determine if a service is available or unavailable. OpenShift Container Platform provides these health checks for the OpenShift API, Machine Configuration API, and Ingress Controller backend services.

The following examples show health check specifications for the previously listed backend services:

Example of a Kubernetes API health check specification

Path: HTTPS:6443/readyz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10

Example of a Machine Config API health check specification

Path: HTTPS:22623/healthz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10

Example of an Ingress Controller health check specification

Path: HTTP:1936/healthz/ready
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 5
Interval: 10

Procedure

  1. Configure the HAProxy Ingress Controller, so that you can enable access to the cluster from your load balancer on ports 6443, 22623, 443, and 80. Depending on your needs, you can specify the IP address of a single subnet or IP addresses from multiple subnets in your HAProxy configuration.

    Example HAProxy configuration with one listed subnet

    # ...
    listen my-cluster-api-6443
        bind 192.168.1.100:6443
        mode tcp
        balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /readyz
      http-check expect status 200
        server my-cluster-master-2 192.168.1.101:6443 check inter 10s rise 2 fall 2
        server my-cluster-master-0 192.168.1.102:6443 check inter 10s rise 2 fall 2
        server my-cluster-master-1 192.168.1.103:6443 check inter 10s rise 2 fall 2
    
    listen my-cluster-machine-config-api-22623
        bind 192.168.1.100:22623
        mode tcp
        balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /healthz
      http-check expect status 200
        server my-cluster-master-2 192.168.1.101:22623 check inter 10s rise 2 fall 2
        server my-cluster-master-0 192.168.1.102:22623 check inter 10s rise 2 fall 2
        server my-cluster-master-1 192.168.1.103:22623 check inter 10s rise 2 fall 2
    
    listen my-cluster-apps-443
        bind 192.168.1.100:443
        mode tcp
        balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /healthz/ready
      http-check expect status 200
        server my-cluster-worker-0 192.168.1.111:443 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-1 192.168.1.112:443 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-2 192.168.1.113:443 check port 1936 inter 10s rise 2 fall 2
    
    listen my-cluster-apps-80
       bind 192.168.1.100:80
       mode tcp
       balance roundrobin
      option httpchk
      http-check connect
      http-check send meth GET uri /healthz/ready
      http-check expect status 200
        server my-cluster-worker-0 192.168.1.111:80 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-1 192.168.1.112:80 check port 1936 inter 10s rise 2 fall 2
        server my-cluster-worker-2 192.168.1.113:80 check port 1936 inter 10s rise 2 fall 2
    # ...

    Example HAProxy configuration with multiple listed subnets

    # ...
    listen api-server-6443
        bind *:6443
        mode tcp
          server master-00 192.168.83.89:6443 check inter 1s
          server master-01 192.168.84.90:6443 check inter 1s
          server master-02 192.168.85.99:6443 check inter 1s
          server bootstrap 192.168.80.89:6443 check inter 1s
    
    listen machine-config-server-22623
        bind *:22623
        mode tcp
          server master-00 192.168.83.89:22623 check inter 1s
          server master-01 192.168.84.90:22623 check inter 1s
          server master-02 192.168.85.99:22623 check inter 1s
          server bootstrap 192.168.80.89:22623 check inter 1s
    
    listen ingress-router-80
        bind *:80
        mode tcp
        balance source
          server worker-00 192.168.83.100:80 check inter 1s
          server worker-01 192.168.83.101:80 check inter 1s
    
    listen ingress-router-443
        bind *:443
        mode tcp
        balance source
          server worker-00 192.168.83.100:443 check inter 1s
          server worker-01 192.168.83.101:443 check inter 1s
    
    listen ironic-api-6385
        bind *:6385
        mode tcp
        balance source
          server master-00 192.168.83.89:6385 check inter 1s
          server master-01 192.168.84.90:6385 check inter 1s
          server master-02 192.168.85.99:6385 check inter 1s
          server bootstrap 192.168.80.89:6385 check inter 1s
    
    listen inspector-api-5050
        bind *:5050
        mode tcp
        balance source
          server master-00 192.168.83.89:5050 check inter 1s
          server master-01 192.168.84.90:5050 check inter 1s
          server master-02 192.168.85.99:5050 check inter 1s
          server bootstrap 192.168.80.89:5050 check inter 1s
    # ...

  2. Use the curl CLI command to verify that the user-managed load balancer and its resources are operational:

    1. Verify that the cluster machine configuration API is accessible to the Kubernetes API server resource, by running the following command and observing the response:

      $ curl https://<loadbalancer_ip_address>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
        "major": "1",
        "minor": "11+",
        "gitVersion": "v1.11.0+ad103ed",
        "gitCommit": "ad103ed",
        "gitTreeState": "clean",
        "buildDate": "2019-01-09T06:44:10Z",
        "goVersion": "go1.10.3",
        "compiler": "gc",
        "platform": "linux/amd64"
      }
    2. Verify that the cluster machine configuration API is accessible to the Machine config server resource, by running the following command and observing the output:

      $ curl -v https://<loadbalancer_ip_address>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      Content-Length: 0
    3. Verify that the controller is accessible to the Ingress Controller resource on port 80, by running the following command and observing the output:

      $ curl -I -L -H "Host: console-openshift-console.apps.<cluster_name>.<base_domain>" http://<load_balancer_front_end_IP_address>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
      content-length: 0
      location: https://console-openshift-console.apps.ocp4.private.opequon.net/
      cache-control: no-cache
    4. Verify that the controller is accessible to the Ingress Controller resource on port 443, by running the following command and observing the output:

      $ curl -I -L --insecure --resolve console-openshift-console.apps.<cluster_name>.<base_domain>:443:<Load Balancer Front End IP Address> https://console-openshift-console.apps.<cluster_name>.<base_domain>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Wed, 04 Oct 2023 16:29:38 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private
  3. Configure the DNS records for your cluster to target the front-end IP addresses of the user-managed load balancer. You must update records to your DNS server for the cluster API and applications over the load balancer.

    Examples of modified DNS records

    <load_balancer_ip_address>  A  api.<cluster_name>.<base_domain>
    A record pointing to Load Balancer Front End

    <load_balancer_ip_address>   A apps.<cluster_name>.<base_domain>
    A record pointing to Load Balancer Front End
    Important

    DNS propagation might take some time for each DNS record to become available. Ensure that each DNS record propagates before validating each record.

  4. For your OpenShift Container Platform cluster to use the user-managed load balancer, you must specify the following configuration in your cluster’s install-config.yaml file:

    # ...
    platform:
        loadBalancer:
          type: UserManaged 1
        apiVIPs:
        - <api_ip> 2
        ingressVIPs:
        - <ingress_ip> 3
    # ...
    1
    Set UserManaged for the type parameter to specify a user-managed load balancer for your cluster. The parameter defaults to OpenShiftManagedDefault, which denotes the default internal load balancer. For services defined in an openshift-kni-infra namespace, a user-managed load balancer can deploy the coredns service to pods in your cluster but ignores keepalived and haproxy services.
    2
    Required parameter when you specify a user-managed load balancer. Specify the user-managed load balancer’s public IP address, so that the Kubernetes API can communicate with the user-managed load balancer.
    3
    Required parameter when you specify a user-managed load balancer. Specify the user-managed load balancer’s public IP address, so that the user-managed load balancer can manage ingress traffic for your cluster.

Verification

  1. Use the curl CLI command to verify that the user-managed load balancer and DNS record configuration are operational:

    1. Verify that you can access the cluster API, by running the following command and observing the output:

      $ curl https://api.<cluster_name>.<base_domain>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
        "major": "1",
        "minor": "11+",
        "gitVersion": "v1.11.0+ad103ed",
        "gitCommit": "ad103ed",
        "gitTreeState": "clean",
        "buildDate": "2019-01-09T06:44:10Z",
        "goVersion": "go1.10.3",
        "compiler": "gc",
        "platform": "linux/amd64"
        }
    2. Verify that you can access the cluster machine configuration, by running the following command and observing the output:

      $ curl -v https://api.<cluster_name>.<base_domain>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      Content-Length: 0
    3. Verify that you can access each cluster application on port, by running the following command and observing the output:

      $ curl http://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
      content-length: 0
      location: https://console-openshift-console.apps.<cluster-name>.<base domain>/
      cache-control: no-cacheHTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=39HoZgztDnzjJkq/JuLJMeoKNXlfiVv2YgZc09c3TBOBU4NI6kDXaJH1LdicNhN1UsQWzon4Dor9GWGfopaTEQ==; Path=/; Secure
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Tue, 17 Nov 2020 08:42:10 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=9b714eb87e93cf34853e87a92d6894be; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private
    4. Verify that you can access each cluster application on port 443, by running the following command and observing the output:

      $ curl https://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Wed, 04 Oct 2023 16:29:38 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private

3.6.6. Configuration using the Bare Metal Operator

When deploying OpenShift Container Platform on bare-metal hosts, there are times when you need to make changes to the host either before or after provisioning. This can include inspecting the host’s hardware, firmware, and firmware details. It can also include formatting disks or changing modifiable firmware settings.

You can use the Bare Metal Operator (BMO) to provision, manage, and inspect bare-metal hosts in your cluster. The BMO can complete the following operations:

  • Provision bare-metal hosts to the cluster with a specific image.
  • Turn a host on or off.
  • Inspect hardware details of the host and report them to the bare-metal host.
  • Upgrade or downgrade a host’s firmware to a specific version.
  • Inspect firmware and configure BIOS settings.
  • Clean disk contents for the host before or after provisioning the host.

The BMO uses the following resources to complete these tasks:

  • BareMetalHost
  • HostFirmwareSettings
  • FirmwareSchema
  • HostFirmwareComponents
  • HostUpdatePolicy

The BMO maintains an inventory of the physical hosts in the cluster by mapping each bare-metal host to an instance of the BareMetalHost custom resource definition. Each BareMetalHost resource features hardware, software, and firmware details. The BMO continually inspects the bare-metal hosts in the cluster to ensure each BareMetalHost resource accurately details the components of the corresponding host.

The BMO also uses the HostFirmwareSettings resource, the FirmwareSchema resource, and the HostFirmwareComponents resource to detail firmware specifications and upgrade or downgrade firmware for the bare-metal host.

The BMO interfaces with bare-metal hosts in the cluster by using the Ironic API service. The Ironic service uses the Baseboard Management Controller (BMC) on the host to interface with the machine.

The BMO HostUpdatePolicy can enable or disable live updates to the firmware settings, BMC settings, or BIOS settings of a bare-metal host after provisioning the host. By default, the BMO disables live updates.

3.6.6.1. Bare Metal Operator architecture

The Bare Metal Operator (BMO) uses the following resources to provision, manage, and inspect bare-metal hosts in your cluster. The following diagram illustrates the architecture of these resources:

BMO architecture overview

BareMetalHost

The BareMetalHost resource defines a physical host and its properties. When you provision a bare-metal host to the cluster, you must define a BareMetalHost resource for that host. For ongoing management of the host, you can inspect the information in the BareMetalHost resource or update this information.

The BareMetalHost resource features provisioning information such as the following:

  • Deployment specifications such as the operating system boot image or the custom RAM disk
  • Provisioning state
  • Baseboard Management Controller (BMC) address
  • Desired power state

The BareMetalHost resource features hardware information such as the following:

  • Number of CPUs
  • MAC address of a NIC
  • Size of the host’s storage device
  • Current power state

HostFirmwareSettings

You can use the HostFirmwareSettings resource to retrieve and manage the firmware settings for a host. When a host moves to the Available state, the Ironic service reads the host’s firmware settings and creates the HostFirmwareSettings resource. There is a one-to-one mapping between the BareMetalHost resource and the HostFirmwareSettings resource.

You can use the HostFirmwareSettings resource to inspect the firmware specifications for a host or to update a host’s firmware specifications.

Note

You must adhere to the schema specific to the vendor firmware when you edit the spec field of the HostFirmwareSettings resource. This schema is defined in the read-only FirmwareSchema resource.

FirmwareSchema

Firmware settings vary among hardware vendors and host models. A FirmwareSchema resource is a read-only resource that contains the types and limits for each firmware setting on each host model. The data comes directly from the BMC by using the Ironic service. You can use the FirmwareSchema resource to identify valid values that you can specify in the spec field of the HostFirmwareSettings resource.

A FirmwareSchema resource can apply to many BareMetalHost resources if the schema is the same.

HostFirmwareComponents

Metal3 provides the HostFirmwareComponents resource, which describes BIOS and baseboard management controller (BMC) firmware versions. You can upgrade or downgrade the host’s firmware to a specific version by editing the spec field of the HostFirmwareComponents resource. This is useful when deploying with validated patterns that have been tested against specific firmware versions.

HostUpdatePolicy

The HostUpdatePolicy resource can enable or disable live updates to the firmware settings, BMC settings, or BIOS settings of bare-metal hosts. By default, the HostUpdatePolicy resource for each bare-metal host restricts updates to hosts during provisioning. You must modify the HostUpdatePolicy resource for a host when you want to update the firmware settings, BMC settings, or BIOS settings after provisioning the host.

3.6.6.2. About the BareMetalHost resource

Metal3 introduces the concept of the BareMetalHost resource, which defines a physical host and its properties. The BareMetalHost resource contains two sections:

  1. The BareMetalHost spec
  2. The BareMetalHost status
3.6.6.2.1. The BareMetalHost spec

The spec section of the BareMetalHost resource defines the desired state of the host.

Table 3.15. BareMetalHost spec
ParametersDescription

automatedCleaningMode

An interface to enable or disable automated cleaning during provisioning and de-provisioning. When set to disabled, it skips automated cleaning. When set to metadata, automated cleaning is enabled. The default setting is metadata.

bmc:
  address:
  credentialsName:
  disableCertificateVerification:

The bmc configuration setting contains the connection information for the baseboard management controller (BMC) on the host. The fields are:

  • address: The URL for communicating with the host’s BMC controller.
  • credentialsName: A reference to a secret containing the username and password for the BMC.
  • disableCertificateVerification: A boolean to skip certificate validation when set to true.

bootMACAddress

The MAC address of the NIC used for provisioning the host.

bootMode

The boot mode of the host. It defaults to UEFI, but it can also be set to legacy for BIOS boot, or UEFISecureBoot.

consumerRef

A reference to another resource that is using the host. It could be empty if another resource is not currently using the host. For example, a Machine resource might use the host when the machine-api is using the host.

description

A human-provided string to help identify the host.

externallyProvisioned

A boolean indicating whether the host provisioning and deprovisioning are managed externally. When set:

  • Power status can still be managed using the online field.
  • Hardware inventory will be monitored, but no provisioning or deprovisioning operations are performed on the host.

firmware

Contains information about the BIOS configuration of bare metal hosts. Currently, firmware is only supported by iRMC, iDRAC, iLO4 and iLO5 BMCs. The sub fields are:

  • simultaneousMultithreadingEnabled: Allows a single physical processor core to appear as several logical processors. Valid settings are true or false.
  • sriovEnabled: SR-IOV support enables a hypervisor to create virtual instances of a PCI-express device, potentially increasing performance. Valid settings are true or false.
  • virtualizationEnabled: Supports the virtualization of platform hardware. Valid settings are true or false.
image:
  url:
  checksum:
  checksumType:
  format:

The image configuration setting holds the details for the image to be deployed on the host. Ironic requires the image fields. However, when the externallyProvisioned configuration setting is set to true and the external management does not require power control, the fields can be empty. The setting supports the following fields:

  • url: The URL of an image to deploy to the host.
  • checksum: The actual checksum or a URL to a file containing the checksum for the image at image.url.
  • checksumType: You can specify checksum algorithms. Currently image.checksumType only supports md5, sha256, and sha512. The default checksum type is md5.
  • format: This is the disk format of the image. It can be one of raw, qcow2, vdi, vmdk, live-iso or be left unset. Setting it to raw enables raw image streaming in the Ironic agent for that image. Setting it to live-iso enables iso images to live boot without deploying to disk, and it ignores the checksum fields.

networkData

A reference to the secret containing the network configuration data and its namespace, so that it can be attached to the host before the host boots to set up the network.

online

A boolean indicating whether the host should be powered on (true) or off (false). Changing this value will trigger a change in the power state of the physical host.

raid:
  hardwareRAIDVolumes:
  softwareRAIDVolumes:

(Optional) Contains the information about the RAID configuration for bare metal hosts. If not specified, it retains the current configuration.

Note

OpenShift Container Platform 4.18 supports hardware RAID on the installation drive for BMCs, including:

  • Fujitsu iRMC with support for RAID levels 0, 1, 5, 6, and 10
  • Dell iDRAC using the Redfish API with firmware version 6.10.30.20 or later and RAID levels 0, 1, and 5

OpenShift Container Platform 4.18 does not support software RAID on the installation drive.

See the following configuration settings:

  • hardwareRAIDVolumes: Contains the list of logical drives for hardware RAID, and defines the desired volume configuration in the hardware RAID. If you do not specify rootDeviceHints, the first volume is the root volume. The sub-fields are:

    • level: The RAID level for the logical drive. The following levels are supported: 0,1,2,5,6,1+0,5+0,6+0.
    • name: The name of the volume as a string. It should be unique within the server. If not specified, the volume name will be auto-generated.
    • numberOfPhysicalDisks: The number of physical drives as an integer to use for the logical drove. Defaults to the minimum number of disk drives required for the particular RAID level.
    • physicalDisks: The list of names of physical disk drives as a string. This is an optional field. If specified, the controller field must be specified too.
    • controller: (Optional) The name of the RAID controller as a string to use in the hardware RAID volume.
    • rotational: If set to true, it will only select rotational disk drives. If set to false, it will only select solid-state and NVMe drives. If not set, it selects any drive types, which is the default behavior.
    • sizeGibibytes: The size of the logical drive as an integer to create in GiB. If unspecified or set to 0, it will use the maximum capacity of physical drive for the logical drive.
  • softwareRAIDVolumes: OpenShift Container Platform 4.18 does not support software RAID on the installation drive. This configuration contains the list of logical disks for software RAID. If you do not specify rootDeviceHints, the first volume is the root volume. If you set HardwareRAIDVolumes, this item will be invalid. Software RAIDs will always be deleted. The number of created software RAID devices must be 1 or 2. If there is only one software RAID device, it must be RAID-1. If there are two RAID devices, the first device must be RAID-1, while the RAID level for the second device can be 0, 1, or 1+0. The first RAID device will be the deployment device, which cannot be a software RAID volume. Enforcing RAID-1 reduces the risk of a non-booting node in case of a device failure. The softwareRAIDVolume field defines the desired configuration of the volume in the software RAID. The sub-fields are:

    • level: The RAID level for the logical drive. The following levels are supported: 0,1,1+0.
    • physicalDisks: A list of device hints. The number of items should be greater than or equal to 2.
    • sizeGibibytes: The size of the logical disk drive as an integer to be created in GiB. If unspecified or set to 0, it will use the maximum capacity of physical drive for logical drive.

You can set the hardwareRAIDVolume as an empty slice to clear the hardware RAID configuration. For example:

spec:
   raid:
     hardwareRAIDVolume: []

If you receive an error message indicating that the driver does not support RAID, set the raid, hardwareRAIDVolumes or softwareRAIDVolumes to nil. You might need to ensure the host has a RAID controller.

rootDeviceHints:
  deviceName:
  hctl:
  model:
  vendor:
  serialNumber:
  minSizeGigabytes:
  wwn:
  wwnWithExtension:
  wwnVendorExtension:
  rotational:

The rootDeviceHints parameter enables provisioning of the RHCOS image to a particular device. It examines the devices in the order it discovers them, and compares the discovered values with the hint values. It uses the first discovered device that matches the hint value. The configuration can combine multiple hints, but a device must match all hints to get selected. The fields are:

  • deviceName: A string containing a Linux device name like /dev/vda. The hint must match the actual value exactly.
  • hctl: A string containing a SCSI bus address like 0:0:0:0. The hint must match the actual value exactly.
  • model: A string containing a vendor-specific device identifier. The hint can be a substring of the actual value.
  • vendor: A string containing the name of the vendor or manufacturer of the device. The hint can be a sub-string of the actual value.
  • serialNumber: A string containing the device serial number. The hint must match the actual value exactly.
  • minSizeGigabytes: An integer representing the minimum size of the device in gigabytes.
  • wwn: A string containing the unique storage identifier. The hint must match the actual value exactly.
  • wwnWithExtension: A string containing the unique storage identifier with the vendor extension appended. The hint must match the actual value exactly.
  • wwnVendorExtension: A string containing the unique vendor storage identifier. The hint must match the actual value exactly.
  • rotational: A boolean indicating whether the device should be a rotating disk (true) or not (false).
3.6.6.2.2. The BareMetalHost status

The BareMetalHost status represents the host’s current state, and includes tested credentials, current hardware details, and other information.

Table 3.16. BareMetalHost status
ParametersDescription

goodCredentials

A reference to the secret and its namespace holding the last set of baseboard management controller (BMC) credentials the system was able to validate as working.

errorMessage

Details of the last error reported by the provisioning backend, if any.

errorType

Indicates the class of problem that has caused the host to enter an error state. The error types are:

  • provisioned registration error: Occurs when the controller is unable to re-register an already provisioned host.
  • registration error: Occurs when the controller is unable to connect to the host’s baseboard management controller.
  • inspection error: Occurs when an attempt to obtain hardware details from the host fails.
  • preparation error: Occurs when cleaning fails.
  • provisioning error: Occurs when the controller fails to provision or deprovision the host.
  • power management error: Occurs when the controller is unable to modify the power state of the host.
  • detach error: Occurs when the controller is unable to detatch the host from the provisioner.
hardware:
  cpu
    arch:
    model:
    clockMegahertz:
    flags:
    count:

The hardware.cpu field details of the CPU(s) in the system. The fields include:

  • arch: The architecture of the CPU.
  • model: The CPU model as a string.
  • clockMegahertz: The speed in MHz of the CPU.
  • flags: The list of CPU flags. For example, 'mmx','sse','sse2','vmx' etc.
  • count: The number of CPUs available in the system.
hardware:
  firmware:

Contains BIOS firmware information. For example, the hardware vendor and version.

hardware:
  nics:
  - ip:
    name:
    mac:
    speedGbps:
    vlans:
    vlanId:
    pxe:

The hardware.nics field contains a list of network interfaces for the host. The fields include:

  • ip: The IP address of the NIC, if one was assigned when the discovery agent ran.
  • name: A string identifying the network device. For example, nic-1.
  • mac: The MAC address of the NIC.
  • speedGbps: The speed of the device in Gbps.
  • vlans: A list holding all the VLANs available for this NIC.
  • vlanId: The untagged VLAN ID.
  • pxe: Whether the NIC is able to boot using PXE.
hardware:
  ramMebibytes:

The host’s amount of memory in Mebibytes (MiB).

hardware:
  storage:
  - name:
    rotational:
    sizeBytes:
    serialNumber:

The hardware.storage field contains a list of storage devices available to the host. The fields include:

  • name: A string identifying the storage device. For example, disk 1 (boot).
  • rotational: Indicates whether the disk is rotational, and returns either true or false.
  • sizeBytes: The size of the storage device.
  • serialNumber: The device’s serial number.
hardware:
  systemVendor:
    manufacturer:
    productName:
    serialNumber:

Contains information about the host’s manufacturer, the productName, and the serialNumber.

lastUpdated

The timestamp of the last time the status of the host was updated.

operationalStatus

The status of the server. The status is one of the following:

  • OK: Indicates all the details for the host are known, correctly configured, working, and manageable.
  • discovered: Implies some of the host’s details are either not working correctly or missing. For example, the BMC address is known but the login credentials are not.
  • error: Indicates the system found some sort of irrecoverable error. Refer to the errorMessage field in the status section for more details.
  • delayed: Indicates that provisioning is delayed to limit simultaneous provisioning of multiple hosts.
  • detached: Indicates the host is marked unmanaged.

poweredOn

Boolean indicating whether the host is powered on.

provisioning:
  state:
  id:
  image:
  raid:
  firmware:
  rootDeviceHints:

The provisioning field contains values related to deploying an image to the host. The sub-fields include:

  • state: The current state of any ongoing provisioning operation. The states include:

    • <empty string>: There is no provisioning happening at the moment.
    • unmanaged: There is insufficient information available to register the host.
    • registering: The agent is checking the host’s BMC details.
    • match profile: The agent is comparing the discovered hardware details on the host against known profiles.
    • available: The host is available for provisioning. This state was previously known as ready.
    • preparing: The existing configuration will be removed, and the new configuration will be set on the host.
    • provisioning: The provisioner is writing an image to the host’s storage.
    • provisioned: The provisioner wrote an image to the host’s storage.
    • externally provisioned: Metal3 does not manage the image on the host.
    • deprovisioning: The provisioner is wiping the image from the host’s storage.
    • inspecting: The agent is collecting hardware details for the host.
    • deleting: The agent is deleting the from the cluster.
  • id: The unique identifier for the service in the underlying provisioning tool.
  • image: The image most recently provisioned to the host.
  • raid: The list of hardware or software RAID volumes recently set.
  • firmware: The BIOS configuration for the bare metal server.
  • rootDeviceHints: The root device selection instructions used for the most recent provisioning operation.

triedCredentials

A reference to the secret and its namespace holding the last set of BMC credentials that were sent to the provisioning backend.

3.6.6.3. Getting the BareMetalHost resource

The BareMetalHost resource contains the properties of a physical host. You must get the BareMetalHost resource for a physical host to review its properties.

Procedure

  1. Get the list of BareMetalHost resources:

    $ oc get bmh -n openshift-machine-api -o yaml
    Note

    You can use baremetalhost as the long form of bmh with oc get command.

  2. Get the list of hosts:

    $ oc get bmh -n openshift-machine-api
  3. Get the BareMetalHost resource for a specific host:

    $ oc get bmh <host_name> -n openshift-machine-api -o yaml

    Where <host_name> is the name of the host.

    Example output

    apiVersion: metal3.io/v1alpha1
    kind: BareMetalHost
    metadata:
      creationTimestamp: "2022-06-16T10:48:33Z"
      finalizers:
      - baremetalhost.metal3.io
      generation: 2
      name: openshift-worker-0
      namespace: openshift-machine-api
      resourceVersion: "30099"
      uid: 1513ae9b-e092-409d-be1b-ad08edeb1271
    spec:
      automatedCleaningMode: metadata
      bmc:
        address: redfish://10.46.61.19:443/redfish/v1/Systems/1
        credentialsName: openshift-worker-0-bmc-secret
        disableCertificateVerification: true
      bootMACAddress: 48:df:37:c7:f7:b0
      bootMode: UEFI
      consumerRef:
        apiVersion: machine.openshift.io/v1beta1
        kind: Machine
        name: ocp-edge-958fk-worker-0-nrfcg
        namespace: openshift-machine-api
      customDeploy:
        method: install_coreos
      online: true
      rootDeviceHints:
        deviceName: /dev/disk/by-id/scsi-<serial_number>
      userData:
        name: worker-user-data-managed
        namespace: openshift-machine-api
    status:
      errorCount: 0
      errorMessage: ""
      goodCredentials:
        credentials:
          name: openshift-worker-0-bmc-secret
          namespace: openshift-machine-api
        credentialsVersion: "16120"
      hardware:
        cpu:
          arch: x86_64
          clockMegahertz: 2300
          count: 64
          flags:
          - 3dnowprefetch
          - abm
          - acpi
          - adx
          - aes
          model: Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz
        firmware:
          bios:
            date: 10/26/2020
            vendor: HPE
            version: U30
        hostname: openshift-worker-0
        nics:
        - mac: 48:df:37:c7:f7:b3
          model: 0x8086 0x1572
          name: ens1f3
        ramMebibytes: 262144
        storage:
        - hctl: "0:0:0:0"
          model: VK000960GWTTB
          name: /dev/disk/by-id/scsi-<serial_number>
          sizeBytes: 960197124096
          type: SSD
          vendor: ATA
        systemVendor:
          manufacturer: HPE
          productName: ProLiant DL380 Gen10 (868703-B21)
          serialNumber: CZ200606M3
      lastUpdated: "2022-06-16T11:41:42Z"
      operationalStatus: OK
      poweredOn: true
      provisioning:
        ID: 217baa14-cfcf-4196-b764-744e184a3413
        bootMode: UEFI
        customDeploy:
          method: install_coreos
        image:
          url: ""
        raid:
          hardwareRAIDVolumes: null
          softwareRAIDVolumes: []
        rootDeviceHints:
          deviceName: /dev/disk/by-id/scsi-<serial_number>
        state: provisioned
      triedCredentials:
        credentials:
          name: openshift-worker-0-bmc-secret
          namespace: openshift-machine-api
        credentialsVersion: "16120"

3.6.6.4. Editing a BareMetalHost resource

After you deploy an OpenShift Container Platform cluster on bare metal, you might need to edit a node’s BareMetalHost resource. Consider the following examples:

  • You deploy a cluster with the Assisted Installer and need to add or edit the baseboard management controller (BMC) host name or IP address.
  • You want to move a node from one cluster to another without deprovisioning it.

Prerequisites

  • Ensure the node is in the Provisioned, ExternallyProvisioned, or Available state.

Procedure

  1. Get the list of nodes:

    $ oc get bmh -n openshift-machine-api
  2. Before editing the node’s BareMetalHost resource, detach the node from Ironic by running the following command:

    $ oc annotate baremetalhost <node_name> -n openshift-machine-api 'baremetalhost.metal3.io/detached=true' 1
    1
    Replace <node_name> with the name of the node.
  3. Edit the BareMetalHost resource by running the following command:

    $ oc edit bmh <node_name> -n openshift-machine-api
  4. Reattach the node to Ironic by running the following command:

    $ oc annotate baremetalhost <node_name> -n openshift-machine-api 'baremetalhost.metal3.io/detached'-
3.6.6.5. Troubleshooting latency when deleting a BareMetalHost resource

When the Bare Metal Operator (BMO) deletes a BareMetalHost resource, Ironic deprovisions the bare-metal host with a process called cleaning. When cleaning fails, Ironic retries the cleaning process three times, which is the source of the latency. The cleaning process might not succeed, causing the provisioning status of the bare-metal host to remain in the deleting state indefinitely. When this occurs, use the following procedure to disable the cleaning process.

Warning

Do not remove finalizers from the BareMetalHost resource.

Procedure

  1. If the cleaning process fails and restarts, wait for it to finish. This might take about 5 minutes.
  2. If the provisioning status remains in the deleting state, disable the cleaning process by modifying the BareMetalHost resource and setting the automatedCleaningMode field to disabled.

See "Editing a BareMetalHost resource" for additional details.

3.6.6.6. Attaching a non-bootable ISO to a bare-metal node

You can attach a generic, non-bootable ISO virtual media image to a provisioned node by using the DataImage resource. After you apply the resource, the ISO image becomes accessible to the operating system after it has booted. This is useful for configuring a node after provisioning the operating system and before the node boots for the first time.

Prerequisites

  • The node must use Redfish or drivers derived from it to support this feature.
  • The node must be in the Provisioned or ExternallyProvisioned state.
  • The name must be the same as the name of the node defined in its BareMetalHost resource.
  • You have a valid url to the ISO image.

Procedure

  1. Create a DataImage resource:

    apiVersion: metal3.io/v1alpha1
    kind: DataImage
    metadata:
      name: <node_name> 1
    spec:
      url: "http://dataimage.example.com/non-bootable.iso" 2
    1
    Specify the name of the node as defined in its BareMetalHost resource.
    2
    Specify the URL and path to the ISO image.
  2. Save the DataImage resource to a file by running the following command:

    $ vim <node_name>-dataimage.yaml
  3. Apply the DataImage resource by running the following command:

    $ oc apply -f <node_name>-dataimage.yaml -n <node_namespace> 1
    1
    Replace <node_namespace> so that the namespace matches the namespace for the BareMetalHost resource. For example, openshift-machine-api.
  4. Reboot the node.

    Note

    To reboot the node, attach the reboot.metal3.io annotation, or reset set the online status in the BareMetalHost resource. A forced reboot of the bare-metal node will change the state of the node to NotReady for awhile. For example, 5 minutes or more.

  5. View the DataImage resource by running the following command:

    $ oc get dataimage <node_name> -n openshift-machine-api -o yaml

    Example output

    apiVersion: v1
    items:
    - apiVersion: metal3.io/v1alpha1
      kind: DataImage
      metadata:
        annotations:
          kubectl.kubernetes.io/last-applied-configuration: |
            {"apiVersion":"metal3.io/v1alpha1","kind":"DataImage","metadata":{"annotations":{},"name":"bmh-node-1","namespace":"openshift-machine-api"},"spec":{"url":"http://dataimage.example.com/non-bootable.iso"}}
        creationTimestamp: "2024-06-10T12:00:00Z"
        finalizers:
        - dataimage.metal3.io
        generation: 1
        name: bmh-node-1
        namespace: openshift-machine-api
        ownerReferences:
        - apiVersion: metal3.io/v1alpha1
          blockOwnerDeletion: true
          controller: true
          kind: BareMetalHost
          name: bmh-node-1
          uid: 046cdf8e-0e97-485a-8866-e62d20e0f0b3
        resourceVersion: "21695581"
        uid: c5718f50-44b6-4a22-a6b7-71197e4b7b69
      spec:
        url: http://dataimage.example.com/non-bootable.iso
      status:
        attachedImage:
          url: http://dataimage.example.com/non-bootable.iso
        error:
          count: 0
          message: ""
        lastReconciled: "2024-06-10T12:05:00Z"

3.6.6.7. About the HostFirmwareSettings resource

You can use the HostFirmwareSettings resource to retrieve and manage the BIOS settings for a host. When a host moves to the Available state, Ironic reads the host’s BIOS settings and creates the HostFirmwareSettings resource. The resource contains the complete BIOS configuration returned from the baseboard management controller (BMC). Whereas, the firmware field in the BareMetalHost resource returns three vendor-independent fields, the HostFirmwareSettings resource typically comprises many BIOS settings of vendor-specific fields per host.

The HostFirmwareSettings resource contains two sections:

  1. The HostFirmwareSettings spec.
  2. The HostFirmwareSettings status.
Note

Reading and modifying firmware settings is only supported for drivers based on the vendor-independent Redfish protocol, Fujitsu iRMC or HP iLO.

3.6.6.7.1. The HostFirmwareSettings spec

The spec section of the HostFirmwareSettings resource defines the desired state of the host’s BIOS, and it is empty by default. Ironic uses the settings in the spec.settings section to update the baseboard management controller (BMC) when the host is in the Preparing state. Use the FirmwareSchema resource to ensure that you do not send invalid name/value pairs to hosts. See "About the FirmwareSchema resource" for additional details.

Example

spec:
  settings:
    ProcTurboMode: Disabled1

1
In the foregoing example, the spec.settings section contains a name/value pair that will set the ProcTurboMode BIOS setting to Disabled.
Note

Integer parameters listed in the status section appear as strings. For example, "1". When setting integers in the spec.settings section, the values should be set as integers without quotes. For example, 1.

3.6.6.7.2. The HostFirmwareSettings status

The status represents the current state of the host’s BIOS.

Table 3.17. HostFirmwareSettings
ParametersDescription
status:
  conditions:
  - lastTransitionTime:
    message:
    observedGeneration:
    reason:
    status:
    type:

The conditions field contains a list of state changes. The sub-fields include:

  • lastTransitionTime: The last time the state changed.
  • message: A description of the state change.
  • observedGeneration: The current generation of the status. If metadata.generation and this field are not the same, the status.conditions might be out of date.
  • reason: The reason for the state change.
  • status: The status of the state change. The status can be True, False or Unknown.
  • type: The type of state change. The types are Valid and ChangeDetected.
status:
  schema:
    name:
    namespace:
    lastUpdated:

The FirmwareSchema for the firmware settings. The fields include:

  • name: The name or unique identifier referencing the schema.
  • namespace: The namespace where the schema is stored.
  • lastUpdated: The last time the resource was updated.
status:
  settings:

The settings field contains a list of name/value pairs of a host’s current BIOS settings.

3.6.6.8. Getting the HostFirmwareSettings resource

The HostFirmwareSettings resource contains the vendor-specific BIOS properties of a physical host. You must get the HostFirmwareSettings resource for a physical host to review its BIOS properties.

Procedure

  1. Get the detailed list of HostFirmwareSettings resources by running the following command:

    $ oc get hfs -n openshift-machine-api -o yaml
    Note

    You can use hostfirmwaresettings as the long form of hfs with the oc get command.

  2. Get the list of HostFirmwareSettings resources by running the following command:

    $ oc get hfs -n openshift-machine-api
  3. Get the HostFirmwareSettings resource for a particular host by running the following command:

    $ oc get hfs <host_name> -n openshift-machine-api -o yaml

    Where <host_name> is the name of the host.

3.6.6.9. Editing the HostFirmwareSettings resource of a provisioned host

To make changes to the HostFirmwareSettings spec for a provisioned host, perform the following actions:

  • Edit the host HostFirmwareSettings resource.
  • Delete the host from the machine set.
  • Scale down the machine set.
  • Scale up the machine set to make the changes take effect.
Important

You can only edit hosts when they are in the provisioned state, excluding read-only values. You cannot edit hosts in the externally provisioned state.

Procedure

  1. Get the list of HostFirmwareSettings resources by running the following command:

    $ oc get hfs -n openshift-machine-api
  2. Edit the host HostFirmwareSettings resource by running the following command:

    $ oc edit hfs <hostname> -n openshift-machine-api

    Where <hostname> is the name of a provisioned host. The HostFirmwareSettings resource will open in the default editor for your terminal.

  3. Add name and value pairs to the spec.settings section by running the following command:

    Example

    spec:
      settings:
        name: value 1

    1
    Use the FirmwareSchema resource to identify the available settings for the host. You cannot set values that are read-only.
  4. Save the changes and exit the editor.
  5. Get the host machine name by running the following command:

     $ oc get bmh <hostname> -n openshift-machine name

    Where <hostname> is the name of the host. The terminal displays the machine name under the CONSUMER field.

  6. Annotate the machine to delete it from the machine set by running the following command:

    $ oc annotate machine <machine_name> machine.openshift.io/delete-machine=true -n openshift-machine-api

    Where <machine_name> is the name of the machine to delete.

  7. Get a list of nodes and count the number of worker nodes by running the following command:

    $ oc get nodes
  8. Get the machine set by running the following command:

    $ oc get machinesets -n openshift-machine-api
  9. Scale the machine set by running the following command:

    $ oc scale machineset <machineset_name> -n openshift-machine-api --replicas=<n-1>

    Where <machineset_name> is the name of the machine set and <n-1> is the decremented number of worker nodes.

  10. When the host enters the Available state, scale up the machine set to make the HostFirmwareSettings resource changes take effect by running the following command:

    $ oc scale machineset <machineset_name> -n openshift-machine-api --replicas=<n>

    Where <machineset_name> is the name of the machine set and <n> is the number of worker nodes.

3.6.6.10. Performing a live update to the HostFirmwareSettings resource

You can perform a live update to the HostFirmareSettings resource after it has begun running workloads. Live updates do not trigger deprovisioning and reprovisioning the host.

Important

Live updating a host is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

Prerequisites

  • The HostUpdatePolicy resource must the have firmwareSettings parameter set to onReboot.

Procedure

  1. Update the HostFirmwareSettings resource by running the following command:

    $ oc patch hostfirmwaresettings <hostname> --type merge -p \1
        '{"spec": {"settings": {"<name>": "<value>"}}}' 2
    1
    Replace <hostname> with the name of the host.
    2
    Replace <name> with the name of the setting. Replace <value> with the value of the setting. You can set multiple name-value pairs.
    Note

    Get the FirmwareSchema resource to determine which settings the hardware supports and what settings and values you can update. You cannot update read-only values and you cannot update the FirmwareSchema resource. You can also use the oc edit <hostname> hostfirmwaresettings -n openshift-machine-api command to update the HostFirmwareSettings resource.

  2. Cordon and drain the node by running the following command:

    $ oc drain <node_name> --force 1
    1
    Replace <node_name> with the name of the node.
  3. Power off the host for a period of 5 minutes by running the following command:

    $ oc patch bmh <hostname> --type merge -p '{"spec": {"online": false}}'

    This step ensures that daemonsets or controllers can mark any infrastructure pods that might be running on the host as offline, while the remaining hosts handle incoming requests.

  4. After 5 minutes, power on the host by running the following command:

    $ oc patch bmh <hostname> --type merge -p '{"spec": {"online": true}}'

    The servicing operation commences and the Bare Metal Operator (BMO) sets the operationalStatus parameter of the BareMetalHost to servicing. The BMO updates the operationalStatus parameter to OK after updating the resource. If an error occurs, the BMO updates the operationalStatus parameter to error and retries the operation.

  5. Once Ironic completes the update and the host powers up, uncordon the node by running the following command:

    $ oc uncordon <node_name>
3.6.6.11. Verifying the HostFirmware Settings resource is valid

When the user edits the spec.settings section to make a change to the HostFirmwareSetting(HFS) resource, the Bare Metal Operator (BMO) validates the change against the FimwareSchema resource, which is a read-only resource. If the setting is invalid, the BMO will set the Type value of the status.Condition setting to False and also generate an event and store it in the HFS resource. Use the following procedure to verify that the resource is valid.

Procedure

  1. Get a list of HostFirmwareSetting resources:

    $ oc get hfs -n openshift-machine-api
  2. Verify that the HostFirmwareSettings resource for a particular host is valid:

    $ oc describe hfs <host_name> -n openshift-machine-api

    Where <host_name> is the name of the host.

    Example output

    Events:
      Type    Reason            Age    From                                    Message
      ----    ------            ----   ----                                    -------
      Normal  ValidationFailed  2m49s  metal3-hostfirmwaresettings-controller  Invalid BIOS setting: Setting ProcTurboMode is invalid, unknown enumeration value - Foo

    Important

    If the response returns ValidationFailed, there is an error in the resource configuration and you must update the values to conform to the FirmwareSchema resource.

3.6.6.12. About the FirmwareSchema resource

BIOS settings vary among hardware vendors and host models. A FirmwareSchema resource is a read-only resource that contains the types and limits for each BIOS setting on each host model. The data comes directly from the BMC through Ironic. The FirmwareSchema enables you to identify valid values you can specify in the spec field of the HostFirmwareSettings resource. The FirmwareSchema resource has a unique identifier derived from its settings and limits. Identical host models use the same FirmwareSchema identifier. It is likely that multiple instances of HostFirmwareSettings use the same FirmwareSchema.

Table 3.18. FirmwareSchema specification
ParametersDescription
<BIOS_setting_name>
  attribute_type:
  allowable_values:
  lower_bound:
  upper_bound:
  min_length:
  max_length:
  read_only:
  unique:

The spec is a simple map consisting of the BIOS setting name and the limits of the setting. The fields include:

  • attribute_type: The type of setting. The supported types are:

    • Enumeration
    • Integer
    • String
    • Boolean
  • allowable_values: A list of allowable values when the attribute_type is Enumeration.
  • lower_bound: The lowest allowed value when attribute_type is Integer.
  • upper_bound: The highest allowed value when attribute_type is Integer.
  • min_length: The shortest string length that the value can have when attribute_type is String.
  • max_length: The longest string length that the value can have when attribute_type is String.
  • read_only: The setting is read only and cannot be modified.
  • unique: The setting is specific to this host.
3.6.6.13. Getting the FirmwareSchema resource

Each host model from each vendor has different BIOS settings. When editing the HostFirmwareSettings resource’s spec section, the name/value pairs you set must conform to that host’s firmware schema. To ensure you are setting valid name/value pairs, get the FirmwareSchema for the host and review it.

Procedure

  1. Get the list of FirmwareSchema resource instances by running the following command:

    $ oc get firmwareschema -n openshift-machine-api
  2. Get a particular FirmwareSchema instance by running the following command:

    $ oc get firmwareschema <instance_name> -n openshift-machine-api -o yaml

    Where <instance_name> is the name of the schema instance stated in the HostFirmwareSettings resource (see Table 3).

3.6.6.14. About the HostFirmwareComponents resource

Metal3 provides the HostFirmwareComponents resource, which describes BIOS and baseboard management controller (BMC) firmware versions. The HostFirmwareComponents resource contains two sections:

  1. The HostFirmwareComponents spec
  2. The HostFirmwareComponents status
3.6.6.14.1. HostFirmwareComponents spec

The spec section of the HostFirmwareComponents resource defines the desired state of the host’s BIOS and BMC versions.

Table 3.19. HostFirmwareComponents spec
ParametersDescription
updates:
  component:
  url:

The updates configuration setting contains the components to update. The fields are:

  • component: The name of the component. The valid settings are bios or bmc.
  • url: The URL to the component’s firmware specification and version.
3.6.6.14.2. HostFirmwareComponents status

The status section of the HostFirmwareComponents resource returns the current status of the host’s BIOS and BMC versions.

Table 3.20. HostFirmwareComponents status
ParametersDescription
components:
  component:
  initialVersion:
  currentVersion:
  lastVersionFlashed:
  updatedAt:

The components section contains the status of the components. The fields are:

  • component: The name of the firmware component. It returns bios or bmc.
  • initialVersion: The initial firmware version of the component. Ironic retrieves this information when creating the BareMetalHost resource. You cannot change it.
  • currentVersion: The current firmware version of the component. Initially, the value matches the initialVersion value until Ironic updates the firmware on the bare-metal host.
  • lastVersionFlashed: The last firmware version of the component flashed on the bare-metal host. This field returns null until Ironic updates the firmware.
  • updatedAt: The timestamp when Ironic updated the bare-metal host’s firmware.
updates:
  component:
  url:

The updates configuration setting contains the updated components. The fields are:

  • component: The name of the component.
  • url: The URL to the component’s firmware specification and version.
3.6.6.15. Getting the HostFirmwareComponents resource

The HostFirmwareComponents resource contains the specific firmware version of the BIOS and baseboard management controller (BMC) of a physical host. You must get the HostFirmwareComponents resource for a physical host to review the firmware version and status.

Procedure

  1. Get the detailed list of HostFirmwareComponents resources by running the following command:

    $ oc get hostfirmwarecomponents -n openshift-machine-api -o yaml
  2. Get the list of HostFirmwareComponents resources by running the following command:

    $ oc get hostfirmwarecomponents -n openshift-machine-api
  3. Get the HostFirmwareComponents resource for a particular host by running the following command:

    $ oc get hostfirmwarecomponents <host_name> -n openshift-machine-api -o yaml

    Where <host_name> is the name of the host.

    Example output

    ---
    apiVersion: metal3.io/v1alpha1
    kind: HostFirmwareComponents
    metadata:
      creationTimestamp: 2024-04-25T20:32:06Z"
      generation: 1
      name: ostest-master-2
      namespace: openshift-machine-api
      ownerReferences:
      - apiVersion: metal3.io/v1alpha1
        blockOwnerDeletion: true
        controller: true
        kind: BareMetalHost
        name: ostest-master-2
        uid: 16022566-7850-4dc8-9e7d-f216211d4195
      resourceVersion: "2437"
      uid: 2038d63f-afc0-4413-8ffe-2f8e098d1f6c
    spec:
      updates: []
    status:
      components:
      - component: bios
        currentVersion: 1.0.0
        initialVersion: 1.0.0
      - component: bmc
        currentVersion: "1.00"
        initialVersion: "1.00"
      conditions:
      - lastTransitionTime: "2024-04-25T20:32:06Z"
        message: ""
        observedGeneration: 1
        reason: OK
        status: "True"
        type: Valid
      - lastTransitionTime: "2024-04-25T20:32:06Z"
        message: ""
        observedGeneration: 1
        reason: OK
        status: "False"
        type: ChangeDetected
      lastUpdated: "2024-04-25T20:32:06Z"
      updates: []

3.6.6.16. Editing the HostFirmwareComponents resource of a provisioned host

You can edit the HostFirmwareComponents resource of a provisioned host.

Procedure

  1. Get the detailed list of HostFirmwareComponents resources by running the following command:

    $ oc get hostfirmwarecomponents -n openshift-machine-api -o yaml
  2. Edit the HostFirmwareComponents resource by running the following command:

    $ oc edit <hostname> hostfirmwarecomponents -n openshift-machine-api 1
    1
    Where <hostname> is the name of the host. The HostFirmwareComponents resource will open in the default editor for your terminal.
  3. Make the appropriate edits.

    Example output

    ---
    apiVersion: metal3.io/v1alpha1
    kind: HostFirmwareComponents
    metadata:
      creationTimestamp: 2024-04-25T20:32:06Z"
      generation: 1
      name: ostest-master-2
      namespace: openshift-machine-api
      ownerReferences:
      - apiVersion: metal3.io/v1alpha1
        blockOwnerDeletion: true
        controller: true
        kind: BareMetalHost
        name: ostest-master-2
        uid: 16022566-7850-4dc8-9e7d-f216211d4195
      resourceVersion: "2437"
      uid: 2038d63f-afc0-4413-8ffe-2f8e098d1f6c
    spec:
      updates:
        - name: bios 1
          url: https://myurl.with.firmware.for.bios 2
        - name: bmc 3
          url: https://myurl.with.firmware.for.bmc 4
    status:
      components:
      - component: bios
        currentVersion: 1.0.0
        initialVersion: 1.0.0
      - component: bmc
        currentVersion: "1.00"
        initialVersion: "1.00"
      conditions:
      - lastTransitionTime: "2024-04-25T20:32:06Z"
        message: ""
        observedGeneration: 1
        reason: OK
        status: "True"
        type: Valid
      - lastTransitionTime: "2024-04-25T20:32:06Z"
        message: ""
        observedGeneration: 1
        reason: OK
        status: "False"
        type: ChangeDetected
      lastUpdated: "2024-04-25T20:32:06Z"

    1
    To set a BIOS version, set the name attribute to bios.
    2
    To set a BIOS version, set the url attribute to the URL for the firmware version of the BIOS.
    3
    To set a BMC version, set the name attribute to bmc.
    4
    To set a BMC version, set the url attribute to the URL for the firmware version of the BMC.
  4. Save the changes and exit the editor.
  5. Get the host machine name by running the following command:

    $ oc get bmh <host_name> -n openshift-machine name 1
    1
    Where <host_name> is the name of the host. The terminal displays the machine name under the CONSUMER field.
  6. Annotate the machine to delete it from the machine set by running the following command:

    $ oc annotate machine <machine_name> machine.openshift.io/delete-machine=true -n openshift-machine-api 1
    1
    Where <machine_name> is the name of the machine to delete.
  7. Get a list of nodes and count the number of worker nodes by running the following command:

    $ oc get nodes
  8. Get the machine set by running the following command:

    $ oc get machinesets -n openshift-machine-api
  9. Scale down the machine set by running the following command:

    $ oc scale machineset <machineset_name> -n openshift-machine-api --replicas=<n-1> 1
    1
    Where <machineset_name> is the name of the machine set and <n-1> is the decremented number of worker nodes.
  10. When the host enters the Available state, scale up the machine set to make the HostFirmwareComponents resource changes take effect by running the following command:

    $ oc scale machineset <machineset_name> -n openshift-machine-api --replicas=<n> 1
    1
    Where <machineset_name> is the name of the machine set and <n> is the number of worker nodes.
3.6.6.17. Performing a live update to the HostFirmwareComponents resource

You can perform a live update to the HostFirmwareComponents resource on an already provisioned host. Live updates do not trigger deprovisioning and reprovisioning the host.

Important

Live updating a host is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

Important

Do not perform live updates on production hosts. You can perform live updates to the BIOS for testing purposes. We do not recommend that you perform live updates to the BMC on OpenShift Container Platform 4.18 for test purposes, especially on earlier generation hardware.

Prerequisites

  • The HostUpdatePolicy resource must have the firmwareUpdates parameter set to onReboot.

Procedure

  1. Update the HostFirmwareComponents resource by running the following command:

    $ oc patch hostfirmwarecomponents <hostname> --type merge -p \1
        '{"spec": {"updates": [{"component": "<type>", \2
                            "url": "<url>"}]}}' 3
    1
    Replace <hostname> with the name of the host.
    2
    Replace <type> with the type of component. Specify bios or bmc.
    3
    Replace <url> with the URL for the component.
    Note

    You can also use the oc edit <hostname> hostfirmwarecomponents -n openshift-machine-api command to update the resource.

  2. Cordon and drain the node by running the following command:

    $ oc drain <node_name> --force 1
    1
    Replace <node_name> with the name of the node.
  3. Power off the host for a period of 5 minutes by running the following command:

    $ oc patch bmh <hostname> --type merge -p '{"spec": {"online": false}}'

    This step ensures that daemonsets or controllers mark any infrastructure pods that might be running on the node as offline, while the remaining nodes handle incoming requests.

  4. After 5 minutes, power on the host by running the following command:

    $ oc patch bmh <hostname> --type merge -p '{"spec": {"online": true}}'

    The servicing operation commences and the Bare Metal Operator (BMO) sets the operationalStatus parameter of the BareMetalHost to servicing. The BMO updates the operationalStatus parameter to OK after updating the resource. If an error occurs, the BMO updates the operationalStatus parameter to error and retries the operation.

  5. Uncordon the node by running the following command:

    $ oc uncordon <node_name>
3.6.6.18. About the HostUpdatePolicy resource

You can use the HostUpdatePolicy resource to enable or disable applying live updates to the firmware settings, BMC settings, or firmware settings of each bare-metal host. By default, the Operator disables live updates to already provisioned bare-metal hosts by default.

The HostUpdatePolicy spec

The spec section of the HostUpdatePolicy resource provides two settings:

firmwareSettings
This setting corresponds to the HostFirmwareSettings resource.
firmwareUpdates
This setting corresponds to the HostFirmwareComponents resource.

When you set the value to onPreparing, you can only update the host during provisioning, which is the default setting. When you set the value to onReboot, you can update a provisioned host by applying the resource and rebooting the bare-metal host. Then, follow the procedure for editing the HostFirmwareSettings or HostFirmwareComponents resource.

Example HostUpdatePolicy resource

apiVersion: metal3.io/v1alpha1
kind: HostUpdatePolicy
metadata:
  name: <hostname> 1
  namespace: openshift-machine-api
spec:
  firmwareSettings: <setting> 2
  firmwareUpdates: <setting>

1
The name of the bare-metal host.
2
The update policy setting. Specify onPreparing to disable live updates. Specify onReboot to enable live updates.
3.6.6.19. Setting the HostUpdatePolicy resource

By default, the HostUpdatePolicy disables live updates. To enable live updates, use the following procedure.

Important

Setting the HostUpdatePolicy resource is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

Procedure

  1. Create the HostUpdatePolicy resource by running the following command:

    $ vim hup.yaml

    You can use any text editor you prefer.

    Example HostUpdatePolicy resource

    apiVersion: metal3.io/v1alpha1
    kind: HostUpdatePolicy
    metadata:
      name: <hostname> 1
      namespace: openshift-machine-api
    spec:
      firmwareSettings: onReboot
      firmwareUpdates: onReboot

    1
    Replace <hostname> with the name of the host.
  2. Save the changes to the hup.yaml file.
  3. Apply the policy by running the following command:

    $ oc apply -f hup.yaml

3.7. Expanding the cluster

After deploying an installer-provisioned OpenShift Container Platform cluster, you can use the following procedures to expand the number of worker nodes. Ensure that each prospective worker node meets the prerequisites.

Note

Expanding the cluster using RedFish Virtual Media involves meeting minimum firmware requirements. See Firmware requirements for installing with virtual media in the Prerequisites section for additional details when expanding the cluster using RedFish Virtual Media.

3.7.1. Preparing the bare metal node

To expand your cluster, you must provide the node with the relevant IP address. This can be done with a static configuration, or with a DHCP (Dynamic Host Configuration protocol) server. When expanding the cluster using a DHCP server, each node must have a DHCP reservation.

Reserving IP addresses so they become static IP addresses

Some administrators prefer to use static IP addresses so that each node’s IP address remains constant in the absence of a DHCP server. To configure static IP addresses with NMState, see "Optional: Configuring host network interfaces in the install-config.yaml file" in the "Setting up the environment for an OpenShift installation" section for additional details.

Preparing the bare metal node requires executing the following procedure from the provisioner node.

Procedure

  1. Get the oc binary:

    $ curl -s https://mirror.openshift.com/pub/openshift-v4/clients/ocp/$VERSION/openshift-client-linux-$VERSION.tar.gz | tar zxvf - oc
    $ sudo cp oc /usr/local/bin
  2. Power off the bare metal node by using the baseboard management controller (BMC), and ensure it is off.
  3. Retrieve the user name and password of the bare metal node’s baseboard management controller. Then, create base64 strings from the user name and password:

    $ echo -ne "root" | base64
    $ echo -ne "password" | base64
  4. Create a configuration file for the bare metal node. Depending on whether you are using a static configuration or a DHCP server, use one of the following example bmh.yaml files, replacing values in the YAML to match your environment:

    $ vim bmh.yaml
    • Static configuration bmh.yaml:

      ---
      apiVersion: v1 1
      kind: Secret
      metadata:
       name: openshift-worker-<num>-network-config-secret 2
       namespace: openshift-machine-api
      type: Opaque
      stringData:
       nmstate: | 3
        interfaces: 4
        - name: <nic1_name> 5
          type: ethernet
          state: up
          ipv4:
            address:
            - ip: <ip_address> 6
              prefix-length: 24
            enabled: true
        dns-resolver:
          config:
            server:
            - <dns_ip_address> 7
        routes:
          config:
          - destination: 0.0.0.0/0
            next-hop-address: <next_hop_ip_address> 8
            next-hop-interface: <next_hop_nic1_name> 9
      ---
      apiVersion: v1
      kind: Secret
      metadata:
        name: openshift-worker-<num>-bmc-secret 10
        namespace: openshift-machine-api
      type: Opaque
      data:
        username: <base64_of_uid> 11
        password: <base64_of_pwd> 12
      ---
      apiVersion: metal3.io/v1alpha1
      kind: BareMetalHost
      metadata:
        name: openshift-worker-<num> 13
        namespace: openshift-machine-api
      spec:
        online: True
        bootMACAddress: <nic1_mac_address> 14
        bmc:
          address: <protocol>://<bmc_url> 15
          credentialsName: openshift-worker-<num>-bmc-secret 16
          disableCertificateVerification: True 17
          username: <bmc_username> 18
          password: <bmc_password> 19
        rootDeviceHints:
          deviceName: <root_device_hint> 20
        preprovisioningNetworkDataName: openshift-worker-<num>-network-config-secret 21
      1
      To configure the network interface for a newly created node, specify the name of the secret that contains the network configuration. Follow the nmstate syntax to define the network configuration for your node. See "Optional: Configuring host network interfaces in the install-config.yaml file" for details on configuring NMState syntax.
      2 10 13 16
      Replace <num> for the worker number of the bare metal node in the name fields, the credentialsName field, and the preprovisioningNetworkDataName field.
      3
      Add the NMState YAML syntax to configure the host interfaces.
      4
      Optional: If you have configured the network interface with nmstate, and you want to disable an interface, set state: up with the IP addresses set to enabled: false as shown:
      ---
         interfaces:
         - name: <nic_name>
           type: ethernet
           state: up
           ipv4:
             enabled: false
           ipv6:
             enabled: false
      5 6 7 8 9
      Replace <nic1_name>, <ip_address>, <dns_ip_address>, <next_hop_ip_address> and <next_hop_nic1_name> with appropriate values.
      11 12
      Replace <base64_of_uid> and <base64_of_pwd> with the base64 string of the user name and password.
      14
      Replace <nic1_mac_address> with the MAC address of the bare metal node’s first NIC. See the "BMC addressing" section for additional BMC configuration options.
      15
      Replace <protocol> with the BMC protocol, such as IPMI, RedFish, or others. Replace <bmc_url> with the URL of the bare metal node’s baseboard management controller.
      17
      To skip certificate validation, set disableCertificateVerification to true.
      18 19
      Replace <bmc_username> and <bmc_password> with the string of the BMC user name and password.
      20
      Optional: Replace <root_device_hint> with a device path if you specify a root device hint.
      21
      Optional: If you have configured the network interface for the newly created node, provide the network configuration secret name in the preprovisioningNetworkDataName of the BareMetalHost CR.
    • DHCP configuration bmh.yaml:

      ---
      apiVersion: v1
      kind: Secret
      metadata:
        name: openshift-worker-<num>-bmc-secret 1
        namespace: openshift-machine-api
      type: Opaque
      data:
        username: <base64_of_uid> 2
        password: <base64_of_pwd> 3
      ---
      apiVersion: metal3.io/v1alpha1
      kind: BareMetalHost
      metadata:
        name: openshift-worker-<num> 4
        namespace: openshift-machine-api
      spec:
        online: True
        bootMACAddress: <nic1_mac_address> 5
        bmc:
          address: <protocol>://<bmc_url> 6
          credentialsName: openshift-worker-<num>-bmc-secret 7
          disableCertificateVerification: True 8
          username: <bmc_username> 9
          password: <bmc_password> 10
        rootDeviceHints:
          deviceName: <root_device_hint> 11
        preprovisioningNetworkDataName: openshift-worker-<num>-network-config-secret 12
      1 4 7
      Replace <num> for the worker number of the bare metal node in the name fields, the credentialsName field, and the preprovisioningNetworkDataName field.
      2 3
      Replace <base64_of_uid> and <base64_of_pwd> with the base64 string of the user name and password.
      5
      Replace <nic1_mac_address> with the MAC address of the bare metal node’s first NIC. See the "BMC addressing" section for additional BMC configuration options.
      6
      Replace <protocol> with the BMC protocol, such as IPMI, RedFish, or others. Replace <bmc_url> with the URL of the bare metal node’s baseboard management controller.
      8
      To skip certificate validation, set disableCertificateVerification to true.
      9 10
      Replace <bmc_username> and <bmc_password> with the string of the BMC user name and password.
      11
      Optional: Replace <root_device_hint> with a device path if you specify a root device hint.
      12
      Optional: If you have configured the network interface for the newly created node, provide the network configuration secret name in the preprovisioningNetworkDataName of the BareMetalHost CR.
    Note

    If the MAC address of an existing bare metal node matches the MAC address of a bare metal host that you are attempting to provision, then the Ironic installation will fail. If the host enrollment, inspection, cleaning, or other Ironic steps fail, the Bare Metal Operator retries the installation continuously. See "Diagnosing a host duplicate MAC address" for more information.

  5. Create the bare metal node:

    $ oc -n openshift-machine-api create -f bmh.yaml

    Example output

    secret/openshift-worker-<num>-network-config-secret created
    secret/openshift-worker-<num>-bmc-secret created
    baremetalhost.metal3.io/openshift-worker-<num> created

    Where <num> will be the worker number.

  6. Power up and inspect the bare metal node:

    $ oc -n openshift-machine-api get bmh openshift-worker-<num>

    Where <num> is the worker node number.

    Example output

    NAME                    STATE       CONSUMER   ONLINE   ERROR
    openshift-worker-<num>  available              true

    Note

    To allow the worker node to join the cluster, scale the machineset object to the number of the BareMetalHost objects. You can scale nodes either manually or automatically. To scale nodes automatically, use the metal3.io/autoscale-to-hosts annotation for machineset.

Additional resources

3.7.2. Replacing a bare-metal control plane node

Use the following procedure to replace an installer-provisioned OpenShift Container Platform control plane node.

Important

If you reuse the BareMetalHost object definition from an existing control plane host, do not leave the externallyProvisioned field set to true.

Existing control plane BareMetalHost objects may have the externallyProvisioned flag set to true if they were provisioned by the OpenShift Container Platform installation program.

Prerequisites

  • You have access to the cluster as a user with the cluster-admin role.
  • You have taken an etcd backup.

    Important

    Take an etcd backup before performing this procedure so that you can restore your cluster if you encounter any issues. For more information about taking an etcd backup, see the Additional resources section.

Procedure

  1. Ensure that the Bare Metal Operator is available:

    $ oc get clusteroperator baremetal

    Example output

    NAME        VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
    baremetal   4.18   True        False         False      3d15h

  2. Remove the old BareMetalHost and Machine objects:

    $ oc delete bmh -n openshift-machine-api <host_name>
    $ oc delete machine -n openshift-machine-api <machine_name>

    Replace <host_name> with the name of the host and <machine_name> with the name of the machine. The machine name appears under the CONSUMER field.

    After you remove the BareMetalHost and Machine objects, then the machine controller automatically deletes the Node object.

  3. Create the new BareMetalHost object and the secret to store the BMC credentials:

    $ cat <<EOF | oc apply -f -
    apiVersion: v1
    kind: Secret
    metadata:
      name: control-plane-<num>-bmc-secret 1
      namespace: openshift-machine-api
    data:
      username: <base64_of_uid> 2
      password: <base64_of_pwd> 3
    type: Opaque
    ---
    apiVersion: metal3.io/v1alpha1
    kind: BareMetalHost
    metadata:
      name: control-plane-<num> 4
      namespace: openshift-machine-api
    spec:
      automatedCleaningMode: disabled
      bmc:
        address: <protocol>://<bmc_ip> 5
        credentialsName: control-plane-<num>-bmc-secret 6
      bootMACAddress: <NIC1_mac_address> 7
      bootMode: UEFI
      externallyProvisioned: false
      online: true
    EOF
    1 4 6
    Replace <num> for the control plane number of the bare metal node in the name fields and the credentialsName field.
    2
    Replace <base64_of_uid> with the base64 string of the user name.
    3
    Replace <base64_of_pwd> with the base64 string of the password.
    5
    Replace <protocol> with the BMC protocol, such as redfish, redfish-virtualmedia, idrac-virtualmedia, or others. Replace <bmc_ip> with the IP address of the bare metal node’s baseboard management controller. For additional BMC configuration options, see "BMC addressing" in the Additional resources section.
    7
    Replace <NIC1_mac_address> with the MAC address of the bare metal node’s first NIC.

    After the inspection is complete, the BareMetalHost object is created and available to be provisioned.

  4. View available BareMetalHost objects:

    $ oc get bmh -n openshift-machine-api

    Example output

    NAME                          STATE                    CONSUMER                   ONLINE   ERROR   AGE
    control-plane-1.example.com   available                control-plane-1            true             1h10m
    control-plane-2.example.com   externally provisioned   control-plane-2            true             4h53m
    control-plane-3.example.com   externally provisioned   control-plane-3            true             4h53m
    compute-1.example.com         provisioned              compute-1-ktmmx            true             4h53m
    compute-1.example.com         provisioned              compute-2-l2zmb            true             4h53m

    There are no MachineSet objects for control plane nodes, so you must create a Machine object instead. You can copy the providerSpec from another control plane Machine object.

  5. Create a Machine object:

    $ cat <<EOF | oc apply -f -
    apiVersion: machine.openshift.io/v1beta1
    kind: Machine
    metadata:
      annotations:
        metal3.io/BareMetalHost: openshift-machine-api/control-plane-<num> 1
      labels:
        machine.openshift.io/cluster-api-cluster: control-plane-<num> 2
        machine.openshift.io/cluster-api-machine-role: master
        machine.openshift.io/cluster-api-machine-type: master
      name: control-plane-<num> 3
      namespace: openshift-machine-api
    spec:
      metadata: {}
      providerSpec:
        value:
          apiVersion: baremetal.cluster.k8s.io/v1alpha1
          customDeploy:
            method: install_coreos
          hostSelector: {}
          image:
            checksum: ""
            url: ""
          kind: BareMetalMachineProviderSpec
          metadata:
            creationTimestamp: null
          userData:
            name: master-user-data-managed
    EOF
    1 2 3
    Replace <num> for the control plane number of the bare metal node in the name, labels and annotations fields.
  6. To view the BareMetalHost objects, run the following command:

    $ oc get bmh -A

    Example output

    NAME                          STATE                    CONSUMER                   ONLINE   ERROR   AGE
    control-plane-1.example.com   provisioned              control-plane-1            true             2h53m
    control-plane-2.example.com   externally provisioned   control-plane-2            true             5h53m
    control-plane-3.example.com   externally provisioned   control-plane-3            true             5h53m
    compute-1.example.com         provisioned              compute-1-ktmmx            true             5h53m
    compute-2.example.com         provisioned              compute-2-l2zmb            true             5h53m

  7. After the RHCOS installation, verify that the BareMetalHost is added to the cluster:

    $ oc get nodes

    Example output

    NAME                           STATUS      ROLES     AGE   VERSION
    control-plane-1.example.com    available   master    4m2s  v1.31.3
    control-plane-2.example.com    available   master    141m  v1.31.3
    control-plane-3.example.com    available   master    141m  v1.31.3
    compute-1.example.com          available   worker    87m   v1.31.3
    compute-2.example.com          available   worker    87m   v1.31.3

    Note

    After replacement of the new control plane node, the etcd pod running in the new node is in crashloopback status. See "Replacing an unhealthy etcd member" in the Additional resources section for more information.

3.7.3. Preparing to deploy with Virtual Media on the baremetal network

If the provisioning network is enabled and you want to expand the cluster using Virtual Media on the baremetal network, use the following procedure.

Prerequisites

  • There is an existing cluster with a baremetal network and a provisioning network.

Procedure

  1. Edit the provisioning custom resource (CR) to enable deploying with Virtual Media on the baremetal network:

    oc edit provisioning
      apiVersion: metal3.io/v1alpha1
      kind: Provisioning
      metadata:
        creationTimestamp: "2021-08-05T18:51:50Z"
        finalizers:
        - provisioning.metal3.io
        generation: 8
        name: provisioning-configuration
        resourceVersion: "551591"
        uid: f76e956f-24c6-4361-aa5b-feaf72c5b526
      spec:
        provisioningDHCPRange: 172.22.0.10,172.22.0.254
        provisioningIP: 172.22.0.3
        provisioningInterface: enp1s0
        provisioningNetwork: Managed
        provisioningNetworkCIDR: 172.22.0.0/24
        virtualMediaViaExternalNetwork: true 1
      status:
        generations:
        - group: apps
          hash: ""
          lastGeneration: 7
          name: metal3
          namespace: openshift-machine-api
          resource: deployments
        - group: apps
          hash: ""
          lastGeneration: 1
          name: metal3-image-cache
          namespace: openshift-machine-api
          resource: daemonsets
        observedGeneration: 8
        readyReplicas: 0
    1
    Add virtualMediaViaExternalNetwork: true to the provisioning CR.
  2. If the image URL exists, edit the machineset to use the API VIP address. This step only applies to clusters installed in versions 4.9 or earlier.

    oc edit machineset
      apiVersion: machine.openshift.io/v1beta1
      kind: MachineSet
      metadata:
        creationTimestamp: "2021-08-05T18:51:52Z"
        generation: 11
        labels:
          machine.openshift.io/cluster-api-cluster: ostest-hwmdt
          machine.openshift.io/cluster-api-machine-role: worker
          machine.openshift.io/cluster-api-machine-type: worker
        name: ostest-hwmdt-worker-0
        namespace: openshift-machine-api
        resourceVersion: "551513"
        uid: fad1c6e0-b9da-4d4a-8d73-286f78788931
      spec:
        replicas: 2
        selector:
          matchLabels:
            machine.openshift.io/cluster-api-cluster: ostest-hwmdt
            machine.openshift.io/cluster-api-machineset: ostest-hwmdt-worker-0
        template:
          metadata:
            labels:
              machine.openshift.io/cluster-api-cluster: ostest-hwmdt
              machine.openshift.io/cluster-api-machine-role: worker
              machine.openshift.io/cluster-api-machine-type: worker
              machine.openshift.io/cluster-api-machineset: ostest-hwmdt-worker-0
          spec:
            metadata: {}
            providerSpec:
              value:
                apiVersion: baremetal.cluster.k8s.io/v1alpha1
                hostSelector: {}
                image:
                  checksum: http:/172.22.0.3:6181/images/rhcos-<version>.<architecture>.qcow2.<md5sum> 1
                  url: http://172.22.0.3:6181/images/rhcos-<version>.<architecture>.qcow2 2
                kind: BareMetalMachineProviderSpec
                metadata:
                  creationTimestamp: null
                userData:
                  name: worker-user-data
      status:
        availableReplicas: 2
        fullyLabeledReplicas: 2
        observedGeneration: 11
        readyReplicas: 2
        replicas: 2
    1
    Edit the checksum URL to use the API VIP address.
    2
    Edit the url URL to use the API VIP address.

3.7.4. Diagnosing a duplicate MAC address when provisioning a new host in the cluster

If the MAC address of an existing bare-metal node in the cluster matches the MAC address of a bare-metal host you are attempting to add to the cluster, the Bare Metal Operator associates the host with the existing node. If the host enrollment, inspection, cleaning, or other Ironic steps fail, the Bare Metal Operator retries the installation continuously. A registration error is displayed for the failed bare-metal host.

You can diagnose a duplicate MAC address by examining the bare-metal hosts that are running in the openshift-machine-api namespace.

Prerequisites

  • Install an OpenShift Container Platform cluster on bare metal.
  • Install the OpenShift Container Platform CLI oc.
  • Log in as a user with cluster-admin privileges.

Procedure

To determine whether a bare-metal host that fails provisioning has the same MAC address as an existing node, do the following:

  1. Get the bare-metal hosts running in the openshift-machine-api namespace:

    $ oc get bmh -n openshift-machine-api

    Example output

    NAME                 STATUS   PROVISIONING STATUS      CONSUMER
    openshift-master-0   OK       externally provisioned   openshift-zpwpq-master-0
    openshift-master-1   OK       externally provisioned   openshift-zpwpq-master-1
    openshift-master-2   OK       externally provisioned   openshift-zpwpq-master-2
    openshift-worker-0   OK       provisioned              openshift-zpwpq-worker-0-lv84n
    openshift-worker-1   OK       provisioned              openshift-zpwpq-worker-0-zd8lm
    openshift-worker-2   error    registering

  2. To see more detailed information about the status of the failing host, run the following command replacing <bare_metal_host_name> with the name of the host:

    $ oc get -n openshift-machine-api bmh <bare_metal_host_name> -o yaml

    Example output

    ...
    status:
      errorCount: 12
      errorMessage: MAC address b4:96:91:1d:7c:20 conflicts with existing node openshift-worker-1
      errorType: registration error
    ...

3.7.5. Provisioning the bare metal node

Provisioning the bare metal node requires executing the following procedure from the provisioner node.

Procedure

  1. Ensure the STATE is available before provisioning the bare metal node.

    $  oc -n openshift-machine-api get bmh openshift-worker-<num>

    Where <num> is the worker node number.

    NAME              STATE     ONLINE ERROR  AGE
    openshift-worker  available true          34h
  2. Get a count of the number of worker nodes.

    $ oc get nodes
    NAME                                                STATUS   ROLES           AGE     VERSION
    openshift-master-1.openshift.example.com            Ready    master          30h     v1.31.3
    openshift-master-2.openshift.example.com            Ready    master          30h     v1.31.3
    openshift-master-3.openshift.example.com            Ready    master          30h     v1.31.3
    openshift-worker-0.openshift.example.com            Ready    worker          30h     v1.31.3
    openshift-worker-1.openshift.example.com            Ready    worker          30h     v1.31.3
  3. Get the compute machine set.

    $ oc get machinesets -n openshift-machine-api
    NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
    ...
    openshift-worker-0.example.com      1         1         1       1           55m
    openshift-worker-1.example.com      1         1         1       1           55m
  4. Increase the number of worker nodes by one.

    $ oc scale --replicas=<num> machineset <machineset> -n openshift-machine-api

    Replace <num> with the new number of worker nodes. Replace <machineset> with the name of the compute machine set from the previous step.

  5. Check the status of the bare metal node.

    $ oc -n openshift-machine-api get bmh openshift-worker-<num>

    Where <num> is the worker node number. The STATE changes from ready to provisioning.

    NAME                    STATE             CONSUMER                          ONLINE   ERROR
    openshift-worker-<num>  provisioning      openshift-worker-<num>-65tjz      true

    The provisioning status remains until the OpenShift Container Platform cluster provisions the node. This can take 30 minutes or more. After the node is provisioned, the state will change to provisioned.

    NAME                    STATE             CONSUMER                          ONLINE   ERROR
    openshift-worker-<num>  provisioned       openshift-worker-<num>-65tjz      true
  6. After provisioning completes, ensure the bare metal node is ready.

    $ oc get nodes
    NAME                                          STATUS   ROLES   AGE     VERSION
    openshift-master-1.openshift.example.com      Ready    master  30h     v1.31.3
    openshift-master-2.openshift.example.com      Ready    master  30h     v1.31.3
    openshift-master-3.openshift.example.com      Ready    master  30h     v1.31.3
    openshift-worker-0.openshift.example.com      Ready    worker  30h     v1.31.3
    openshift-worker-1.openshift.example.com      Ready    worker  30h     v1.31.3
    openshift-worker-<num>.openshift.example.com  Ready    worker  3m27s   v1.31.3

    You can also check the kubelet.

    $ ssh openshift-worker-<num>
    [kni@openshift-worker-<num>]$ journalctl -fu kubelet

Legal Notice

Copyright © 2024 Red Hat, Inc.

OpenShift documentation is licensed under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0).

Modified versions must remove all Red Hat trademarks.

Portions adapted from https://github.com/kubernetes-incubator/service-catalog/ with modifications by Red Hat.

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