Installing on bare metal

OpenShift Container Platform 4.14

Installing OpenShift Container Platform on bare metal

Red Hat OpenShift Documentation Team

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Abstract

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

Chapter 1. Preparing for bare metal cluster installation

1.1. Prerequisites

You reviewed details about the OpenShift Container Platform installation and update processes.
You have read the documentation on selecting a cluster installation method and preparing it for users.

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.

Additional resources

1.3. NIC partitioning for SR-IOV devices (Technology Preview)

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

Important

Support for Day 1 operations associated with enabling NIC partitioning for SR-IOV devices 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.

Additional resources

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:

Installing an installer-provisioned cluster on bare metal: You can install OpenShift Container Platform on bare metal by using installer provisioning.

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. Installing a user-provisioned cluster on bare metal

In OpenShift Container Platform 4.14, 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. Prerequisites

You reviewed details about the OpenShift Container Platform installation and update processes.
You read the documentation on selecting a cluster installation method and preparing it for users.
If you use a firewall, you configured it to allow the sites that your cluster requires access to.
Note
Be sure to also review this site list if you are configuring a proxy.

2.2. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.14, 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

See Installing a user-provisioned bare metal cluster on a restricted network for more information about performing a restricted network installation on bare metal infrastructure that you provision.

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.

2.3.1. Required machines for cluster installation

The smallest OpenShift Container Platform clusters require the following hosts:

Table 2.1. Minimum required hosts
Hosts	Description
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.

2.3.2. Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 2.2. Minimum resource requirements
Machine	Operating System	CPU ^[1]	RAM	Storage	Input/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

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.
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.
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

As of OpenShift Container Platform version 4.13, RHCOS is based on RHEL version 9.2, 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 RHEL Architectures.

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

Optimizing storage

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

See Configuring a three-node cluster for details about deploying three-node clusters in bare metal environments.
See Approving the certificate signing requests for your machines for more information about approving cluster certificate signing requests after installation.

2.3.4. Requirements for baremetal clusters on vSphere

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

Additional resources

See Installing RHCOS and starting the OpenShift Container Platform bootstrap process for details on setting the disk.EnableUUID parameter’s value to TRUE on VMware vSphere for user-provisioned infrastructure.

2.3.5. 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.

2.3.5.1. 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.

2.3.5.2. 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
Protocol	Port	Description
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
	`10256`	openshift-sdn
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
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 2.5. Ports used for control plane machine to control plane machine communications
Protocol	Port	Description
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

Configuring chrony time service

2.3.6. 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
Component	Record	Description
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.
Kubernetes API	`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.

2.3.6.1. 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.

Additional resources

Validating DNS resolution for user-provisioned infrastructure

2.3.7. 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:

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
Port	Back-end machines (pool members)	Internal	External	Description
`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.

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
Port	Back-end machines (pool members)	Internal	External	Description
`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.

2.3.7.1. 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 worker0 worker0.ocp4.example.com:443 check inter 1s
  server worker1 worker1.ocp4.example.com:443 check inter 1s
listen ingress-router-80 6
  bind *:80
  mode tcp
  balance source
  server worker0 worker0.ocp4.example.com:80 check inter 1s
  server worker1 worker1.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.

2.4. 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

You have reviewed the OpenShift Container Platform 4.x Tested Integrations page.
You have reviewed the infrastructure requirements detailed in the Requirements for a cluster with user-provisioned infrastructure section.

Procedure

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.
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.
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.
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.
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.
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.

Additional resources

Requirements for a cluster with user-provisioned infrastructure
Installing RHCOS and starting the OpenShift Container Platform bootstrap process
Setting the cluster node hostnames through DHCP
Advanced RHCOS installation configuration
Networking requirements for user-provisioned infrastructure
User-provisioned DNS requirements
Validating DNS resolution for user-provisioned infrastructure
Load balancing requirements for user-provisioned infrastructure

2.5. 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

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.
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.

Additional resources

User-provisioned DNS requirements
Load balancing requirements for user-provisioned infrastructure

2.6. 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 such as AWS key pairs.

Procedure

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.
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
```
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.
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

Verifying node health

2.7. 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 at least 1.2 GB of local disk space.

Procedure

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.
Select your infrastructure provider from the Run it yourself section of the page.
Select your host operating system and architecture from the dropdown menus under OpenShift Installer and click Download Installer.
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.
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
```
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.

2.8. Installing the OpenShift CLI by downloading the binary

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 4.14. 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

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the architecture from the Product Variant drop-down list.
Select the appropriate version from the Version drop-down list.
Click Download Now next to the OpenShift v4.14 Linux Client entry and save the file.
Unpack the archive:
```
$ tar xvf <file>
```
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

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the appropriate version from the Version drop-down list.
Click Download Now next to the OpenShift v4.14 Windows Client entry and save the file.
Unzip the archive with a ZIP program.
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

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the appropriate version from the Version drop-down list.
Click Download Now next to the OpenShift v4.14 macOS Client entry and save the file.
Note
For macOS arm64, choose the OpenShift v4.14 macOS arm64 Client entry.
Unpack and unzip the archive.
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>
```

2.9. Manually creating 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

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.
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.
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.

Additional resources

Installation configuration parameters for bare metal

2.9.1. 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": ...}' 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 supported values are OVNKubernetes and OpenShiftSDN. The default value is OVNKubernetes.
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 Installing the system in 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

See Load balancing requirements for user-provisioned infrastructure for more information on the API and application ingress load balancing requirements.
See Enabling cluster capabilities for more information on enabling cluster capabilities that were disabled prior to installation.
See Optional cluster capabilities in OpenShift Container Platform 4.14 for more information about the features provided by each capability.

2.9.2. 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

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
```
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.

2.9.3. 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.

2.10. 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.
You created the install-config.yaml installation configuration file.

Procedure

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.
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.
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

See Recovering from expired control plane certificates for more information about recovering kubelet certificates.

2.11. 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.

Note

As of OpenShift Container Platform 4.6, the RHCOS ISO and other installation artifacts provide support for installation on disks with 4K sectors.

2.11.1. 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

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.
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.

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.

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-4.14-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso",
"location": "<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso",
"location": "<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso",
"location": "<url>/art/storage/releases/rhcos-4.14/<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
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.
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.
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
```
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.
After RHCOS installs, you must reboot the system. During the system reboot, it applies the Ignition config file that you specified.

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

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.

2.11.2. 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

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.

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.

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-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-kernel-aarch64"
"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-initramfs.aarch64.img"
"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-rootfs.aarch64.img"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/49.84.202110081256-0/ppc64le/rhcos-<release>-live-kernel-ppc64le"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live-initramfs.ppc64le.img"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live-rootfs.ppc64le.img"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-kernel-s390x"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-initramfs.s390x.img"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-rootfs.s390x.img"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-kernel-x86_64"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-initramfs.x86_64.img"
"<url>/art/storage/releases/rhcos-4.14/<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

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.
Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
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.
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.
After RHCOS installs, the system reboots. During reboot, the system applies the Ignition config file that you specified.

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

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.

2.11.3. 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.

2.11.3.1. 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

Boot the ISO installer.
From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.
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.
Reboot into the installed system.

Additional resources

See Getting started with nmcli and Getting started with nmtui in the RHEL 8 documentation for more information about the nmcli and nmtui tools.

2.11.3.2. 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.

2.11.3.2.1. 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

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>
```
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: 4.14.0
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.
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
```
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.

2.11.3.2.2. 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

2.11.3.3. 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.

2.11.3.4. Default console configuration

Red Hat Enterprise Linux CoreOS (RHCOS) nodes installed from an OpenShift Container Platform 4.14 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.

2.11.3.5. 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

Boot the ISO installer.
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.
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.

2.11.3.6. 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.

2.11.3.7. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.
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.

2.11.3.7.1. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.
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.

2.11.3.7.2. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

2.11.3.7.3. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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
```
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
```
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.

2.11.3.8. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

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

Note

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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.

2.11.3.8.3. 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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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
```
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
```

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

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.

2.11.3.9. 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.

2.11.3.9.1. 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

Important

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

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:

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.
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

2.11.3.9.2. `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.

2.11.3.9.3. `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
Argument	Description
`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.

2.11.4. 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

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.
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".
Reboot into the installed system.

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.

2.11.4.1. 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

Create a Butane config with information similar to the following:

Example multipath-config.bu

variant: openshift
version: 4.14.0
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.

Create the Ignition configuration by running the following command:

$ butane --pretty --strict multipath-config.bu > multipath-config.ign

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.

Additional resources

See Installing RHCOS and starting the OpenShift Container Platform bootstrap process for more information on using special coreos.inst.* arguments to direct the live installer.

2.12. 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

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 v1.27.3 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.
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

See Monitoring installation progress for more information about monitoring the installation logs and retrieving diagnostic data if installation issues arise.

2.13. 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

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.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

2.14. 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

Confirm that the cluster recognizes the machines:
```
$ oc get nodes
```
Example output
```
NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.27.3
master-1  Ready     master  63m  v1.27.3
master-2  Ready     master  64m  v1.27.3
```
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.

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.

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.

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
...

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
```

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  v1.27.3
master-1  Ready     master  73m  v1.27.3
master-2  Ready     master  74m  v1.27.3
worker-0  Ready     worker  11m  v1.27.3
worker-1  Ready     worker  11m  v1.27.3

Note

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

Additional information

For more information on CSRs, see Certificate Signing Requests.

2.15. 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

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.14.0    True        False         False      19m
baremetal                                  4.14.0    True        False         False      37m
cloud-credential                           4.14.0    True        False         False      40m
cluster-autoscaler                         4.14.0    True        False         False      37m
config-operator                            4.14.0    True        False         False      38m
console                                    4.14.0    True        False         False      26m
csi-snapshot-controller                    4.14.0    True        False         False      37m
dns                                        4.14.0    True        False         False      37m
etcd                                       4.14.0    True        False         False      36m
image-registry                             4.14.0    True        False         False      31m
ingress                                    4.14.0    True        False         False      30m
insights                                   4.14.0    True        False         False      31m
kube-apiserver                             4.14.0    True        False         False      26m
kube-controller-manager                    4.14.0    True        False         False      36m
kube-scheduler                             4.14.0    True        False         False      36m
kube-storage-version-migrator              4.14.0    True        False         False      37m
machine-api                                4.14.0    True        False         False      29m
machine-approver                           4.14.0    True        False         False      37m
machine-config                             4.14.0    True        False         False      36m
marketplace                                4.14.0    True        False         False      37m
monitoring                                 4.14.0    True        False         False      29m
network                                    4.14.0    True        False         False      38m
node-tuning                                4.14.0    True        False         False      37m
openshift-apiserver                        4.14.0    True        False         False      32m
openshift-controller-manager               4.14.0    True        False         False      30m
openshift-samples                          4.14.0    True        False         False      32m
operator-lifecycle-manager                 4.14.0    True        False         False      37m
operator-lifecycle-manager-catalog         4.14.0    True        False         False      37m
operator-lifecycle-manager-packageserver   4.14.0    True        False         False      32m
service-ca                                 4.14.0    True        False         False      38m
storage                                    4.14.0    True        False         False      37m

Configure the Operators that are not available.

Additional resources

See Gathering logs from a failed installation for details about gathering data in the event of a failed OpenShift Container Platform installation.
See Troubleshooting Operator issues for steps to check Operator pod health across the cluster and gather Operator logs for diagnosis.

2.15.1. 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.

2.15.2. 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.

2.15.2.1. 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

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.
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.
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.

Check the clusteroperator status:

$ oc get clusteroperator image-registry

Example output

NAME             VERSION              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
image-registry   4.14                 True        False         False      6h50m

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
```

2.15.2.2. 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.

2.15.2.3. 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

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}}'
```
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
```
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.

2.16. 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

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                             4.14.0    True        False         False      19m
baremetal                                  4.14.0    True        False         False      37m
cloud-credential                           4.14.0    True        False         False      40m
cluster-autoscaler                         4.14.0    True        False         False      37m
config-operator                            4.14.0    True        False         False      38m
console                                    4.14.0    True        False         False      26m
csi-snapshot-controller                    4.14.0    True        False         False      37m
dns                                        4.14.0    True        False         False      37m
etcd                                       4.14.0    True        False         False      36m
image-registry                             4.14.0    True        False         False      31m
ingress                                    4.14.0    True        False         False      30m
insights                                   4.14.0    True        False         False      31m
kube-apiserver                             4.14.0    True        False         False      26m
kube-controller-manager                    4.14.0    True        False         False      36m
kube-scheduler                             4.14.0    True        False         False      36m
kube-storage-version-migrator              4.14.0    True        False         False      37m
machine-api                                4.14.0    True        False         False      29m
machine-approver                           4.14.0    True        False         False      37m
machine-config                             4.14.0    True        False         False      36m
marketplace                                4.14.0    True        False         False      37m
monitoring                                 4.14.0    True        False         False      29m
network                                    4.14.0    True        False         False      38m
node-tuning                                4.14.0    True        False         False      37m
openshift-apiserver                        4.14.0    True        False         False      32m
openshift-controller-manager               4.14.0    True        False         False      30m
openshift-samples                          4.14.0    True        False         False      32m
operator-lifecycle-manager                 4.14.0    True        False         False      37m
operator-lifecycle-manager-catalog         4.14.0    True        False         False      37m
operator-lifecycle-manager-packageserver   4.14.0    True        False         False      32m
service-ca                                 4.14.0    True        False         False      38m
storage                                    4.14.0    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.

Confirm that the Kubernetes API server is communicating with the pods.

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
...

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.

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.

2.17. Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.14, 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

See About remote health monitoring for more information about the Telemetry service

2.18. Next steps

Validating an installation.
Customize your cluster.
If necessary, you can opt out of remote health reporting.
Set up your registry and configure registry storage.

Chapter 3. Installing a user-provisioned bare metal cluster with network customizations

In OpenShift Container Platform 4.14, 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.

3.1. Prerequisites

You reviewed details about the OpenShift Container Platform installation and update processes.
You read the documentation on selecting a cluster installation method and preparing it for users.
If you use a firewall and plan to use the Telemetry service, you configured the firewall to allow the sites that your cluster requires access to.

3.2. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.14, 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

Additional resources

See Installing a user-provisioned bare metal cluster on a restricted network for more information about performing a restricted network installation on bare metal infrastructure that you provision.

3.3. 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.

3.3.1. Required machines for cluster installation

The smallest OpenShift Container Platform clusters require the following hosts:

Table 3.1. Minimum required hosts
Hosts	Description
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

Important

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

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.

3.3.2. Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 3.2. Minimum resource requirements
Machine	Operating System	CPU ^[1]	RAM	Storage	Input/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

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.
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.
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

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 RHEL Architectures.

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

Optimizing storage

3.3.3. Certificate signing requests management

Additional resources

See Configuring a three-node cluster for details about deploying three-node clusters in bare metal environments.
See Approving the certificate signing requests for your machines for more information about approving cluster certificate signing requests after installation.

3.3.4. 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.

Note

3.3.4.1. Setting the cluster node hostnames through DHCP

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

3.3.4.2. Network connectivity requirements

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 3.3. Ports used for all-machine to all-machine communications
Protocol	Port	Description
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
	`10256`	openshift-sdn
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 3.4. Ports used for all-machine to control plane communications
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 3.5. Ports used for control plane machine to control plane machine communications
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server and peer ports

NTP configuration for user-provisioned infrastructure

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

Configuring chrony time service

3.3.5. 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.

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.

Table 3.6. Required DNS records
Component	Record	Description
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.
Kubernetes API	`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.

3.3.5.1. Example DNS configuration for user-provisioned clusters

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 3.1. 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 3.2. 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.

Validating DNS resolution for user-provisioned infrastructure

3.3.6. Load balancing requirements for user-provisioned infrastructure

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:

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

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

Table 3.7. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`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

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

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

Table 3.8. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`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

3.3.6.1. Example load balancer configuration for user-provisioned clusters

Note

Example 3.3. 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 worker0 worker0.ocp4.example.com:443 check inter 1s
  server worker1 worker1.ocp4.example.com:443 check inter 1s
listen ingress-router-80 6
  bind *:80
  mode tcp
  balance source
  server worker0 worker0.ocp4.example.com:80 check inter 1s
  server worker1 worker1.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.

3.4. Preparing the user-provisioned infrastructure

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

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

Prerequisites

You have reviewed the OpenShift Container Platform 4.x Tested Integrations page.
You have reviewed the infrastructure requirements detailed in the Requirements for a cluster with user-provisioned infrastructure section.

Procedure

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.
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.
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.
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.
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.
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.

Additional resources

Requirements for a cluster with user-provisioned infrastructure
Installing RHCOS and starting the OpenShift Container Platform bootstrap process
Setting the cluster node hostnames through DHCP
Advanced RHCOS installation configuration
Networking requirements for user-provisioned infrastructure
User-provisioned DNS requirements
Validating DNS resolution for user-provisioned infrastructure
Load balancing requirements for user-provisioned infrastructure

3.5. 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

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.
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.

Additional resources

User-provisioned DNS requirements
Load balancing requirements for user-provisioned infrastructure

3.6. Generating a key pair for cluster node SSH access

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 such as AWS key pairs.

Procedure

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.
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
```
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.
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

Verifying node health

3.7. 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 at least 1.2 GB of local disk space.

Procedure

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.
Select your infrastructure provider from the Run it yourself section of the page.
Select your host operating system and architecture from the dropdown menus under OpenShift Installer and click Download Installer.
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.
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
```
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

3.8. Installing the OpenShift CLI by downloading the binary

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 4.14. 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

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the architecture from the Product Variant drop-down list.
Select the appropriate version from the Version drop-down list.
Click Download Now next to the OpenShift v4.14 Linux Client entry and save the file.
Unpack the archive:
```
$ tar xvf <file>
```
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

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the appropriate version from the Version drop-down list.
Click Download Now next to the OpenShift v4.14 Windows Client entry and save the file.
Unzip the archive with a ZIP program.
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

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the appropriate version from the Version drop-down list.
Click Download Now next to the OpenShift v4.14 macOS Client entry and save the file.
Note
For macOS arm64, choose the OpenShift v4.14 macOS arm64 Client entry.
Unpack and unzip the archive.
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>
```

3.9. Manually creating 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

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.
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.
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.

Additional resources

Installation configuration parameters for bare metal

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": ...}' 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 supported values are OVNKubernetes and OpenShiftSDN. The default value is OVNKubernetes.
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 Installing the system in 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

See Load balancing requirements for user-provisioned infrastructure for more information on the API and application ingress load balancing requirements.

3.10. 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
For more information on these fields, refer to Installation configuration parameters.
Note
Set the networking.machineNetwork to match the CIDR that the preferred NIC resides in.
Important
The CIDR range 172.17.0.0/16 is reserved by libVirt. You cannot use this range or any range that overlaps with this range for any 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 advanced network configuration.

You cannot override the values specified in phase 1 in the install-config.yaml file during phase 2. However, you can further customize the network plugin during phase 2.

3.11. 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

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.
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:
```

Specify the advanced network configuration for your cluster in the cluster-network-03-config.yml file, such as in the following examples:

Specify a different VXLAN port for the OpenShift SDN network provider

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    openshiftSDNConfig:
      vxlanPort: 4800

Enable IPsec for the OVN-Kubernetes network provider

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    ovnKubernetesConfig:
      ipsecConfig: {}

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.

3.12. 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, such as OpenShift SDN or OVN-Kubernetes.

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.

3.12.1. Cluster Network Operator configuration object

The fields for the Cluster Network Operator (CNO) are described in the following table:

Table 3.9. Cluster Network Operator configuration object
Field	Type	Description
`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 OpenShift SDN and OVN-Kubernetes network plugins support 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.

defaultNetwork object configuration

The values for the defaultNetwork object are defined in the following table:

Table 3.10. defaultNetwork object
Field	Type	Description
`type`	`string`	Either `OpenShiftSDN` or `OVNKubernetes`. The Red Hat OpenShift Networking network plugin is selected during installation. You can change this value by migrating from OpenShift SDN to OVN-Kubernetes. Note OpenShift Container Platform uses the OVN-Kubernetes network plugin by default.
`openshiftSDNConfig`	`object`	This object is only valid for the OpenShift SDN network plugin.
`ovnKubernetesConfig`	`object`	This object is only valid for the OVN-Kubernetes network plugin.

Configuration for the OpenShift SDN network plugin

The following table describes the configuration fields for the OpenShift SDN network plugin:

Table 3.11. openshiftSDNConfig object
Field	Type	Description
`mode`	`string`	Configures the network isolation mode for OpenShift SDN. The default value is `NetworkPolicy`. The values `Multitenant` and `Subnet` are available for backwards compatibility with OpenShift Container Platform 3.x but are not recommended. This value cannot be changed after cluster installation.
`mtu`	`integer`	The maximum transmission unit (MTU) for the VXLAN 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 `50` 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 `1450`. This value cannot be changed after cluster installation.
`vxlanPort`	`integer`	The port to use for all VXLAN packets. The default value is `4789`. This value cannot be changed after cluster installation. If you are running in a virtualized environment with existing nodes that are part of another VXLAN network, then you might be required to change this. For example, when running an OpenShift SDN overlay on top of VMware NSX-T, you must select an alternate port for the VXLAN, because both SDNs use the same default VXLAN port number. On Amazon Web Services (AWS), you can select an alternate port for the VXLAN between port `9000` and port `9999`.

Example OpenShift SDN configuration

defaultNetwork:
  type: OpenShiftSDN
  openshiftSDNConfig:
    mode: NetworkPolicy
    mtu: 1450
    vxlanPort: 4789

Configuration for the OVN-Kubernetes network plugin

The following table describes the configuration fields for the OVN-Kubernetes network plugin:

Table 3.12. ovnKubernetesConfig object
Field	Type	Description
`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 an empty object to enable IPsec encryption.
`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.
`v4InternalSubnet`	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`. This field cannot be changed after installation.	The default value is `100.64.0.0/16`.
`v6InternalSubnet`	If your existing network infrastructure overlaps with the `fd98::/48` 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. This field cannot be changed after installation.	The default value is `fd98::/48`.

Table 3.13. policyAuditConfig object
Field	Type	Description
`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 3.14. gatewayConfig object
Field	Type	Description
`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, the default is `Global`.

Example OVN-Kubernetes configuration with IPSec enabled

defaultNetwork:
  type: OVNKubernetes
  ovnKubernetesConfig:
    mtu: 1400
    genevePort: 6081
    ipsecConfig: {}

kubeProxyConfig object configuration (OpenShiftSDN container network interface only)

The values for the kubeProxyConfig object are defined in the following table:

Table 3.15. kubeProxyConfig object
Field	Type	Description
`iptablesSyncPeriod`	`string`	The refresh period for `iptables` rules. The default value is `30s`. Valid suffixes include `s`, `m`, and `h` and are described in the Go `time` package documentation. Note Because of performance improvements introduced in OpenShift Container Platform 4.3 and greater, adjusting the `iptablesSyncPeriod` parameter is no longer necessary.
`proxyArguments.iptables-min-sync-period`	`array`	The minimum duration before refreshing `iptables` rules. This field ensures that the refresh does not happen too frequently. Valid suffixes include `s`, `m`, and `h` and are described in the Go `time` package. The default value is: kubeProxyConfig: proxyArguments: iptables-min-sync-period: - 0s

3.13. 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
```

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

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

Note

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.

Note

As of OpenShift Container Platform 4.6, the RHCOS ISO and other installation artifacts provide support for installation on disks with 4K sectors.

3.14.1. 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

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.
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.

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.

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-4.14-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso",
"location": "<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso",
"location": "<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso",
"location": "<url>/art/storage/releases/rhcos-4.14/<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
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.
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.
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
```
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.
After RHCOS installs, you must reboot the system. During the system reboot, it applies the Ignition config file that you specified.

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

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.

3.14.2. 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

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.

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.

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

Example output

"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-kernel-aarch64"
"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-initramfs.aarch64.img"
"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-rootfs.aarch64.img"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/49.84.202110081256-0/ppc64le/rhcos-<release>-live-kernel-ppc64le"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live-initramfs.ppc64le.img"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live-rootfs.ppc64le.img"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-kernel-s390x"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-initramfs.s390x.img"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-rootfs.s390x.img"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-kernel-x86_64"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-initramfs.x86_64.img"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-rootfs.x86_64.img"

Important

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

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.
Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
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.
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.
After RHCOS installs, the system reboots. During reboot, the system applies the Ignition config file that you specified.

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

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.

3.14.3. Advanced RHCOS installation configuration

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

3.14.3.1. Using advanced networking options for PXE and ISO installations

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

Boot the ISO installer.
From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.
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.
Reboot into the installed system.

Additional resources

See Getting started with nmcli and Getting started with nmtui in the RHEL 8 documentation for more information about the nmcli and nmtui tools.

3.14.3.2. Disk partitioning

Important

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, /.

Important

3.14.3.2.1. Creating a separate `/var` partition

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.

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.

Procedure

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>
```
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: 4.14.0
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.
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
```
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.

3.14.3.2.2. Retaining existing 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

3.14.3.3. 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.

3.14.3.4. Default console configuration

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.

3.14.3.5. Enabling the serial console for PXE and ISO installations

Procedure

Boot the ISO installer.
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.
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.

3.14.3.6. Customizing a live RHCOS ISO or PXE install

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.

3.14.3.7. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.
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.

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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.
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.

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

Note

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

3.14.3.7.3. 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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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
```
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
```
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.

3.14.3.8. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

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

Note

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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.

3.14.3.8.3. 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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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
```
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
```

$ 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

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.

3.14.3.9. Advanced RHCOS installation reference

3.14.3.9.1. Networking and bonding options for ISO installations

Important

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

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

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

Configuring an IP address without a static hostname

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

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

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

Important

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

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:

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.
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

3.14.3.9.2. `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 3.16. 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.

3.14.3.9.3. `coreos.inst` boot options for ISO or PXE installations

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 3.17. coreos.inst boot options
Argument	Description
`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.

3.14.4. 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.

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

Important

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

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.
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".
Reboot into the installed system.

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.

3.14.4.1. 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

Create a Butane config with information similar to the following:

Example multipath-config.bu

variant: openshift
version: 4.14.0
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.

Create the Ignition configuration by running the following command:

$ butane --pretty --strict multipath-config.bu > multipath-config.ign

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.

3.15. Waiting 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

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 v1.27.3 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.
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

See Monitoring installation progress for more information about monitoring the installation logs and retrieving diagnostic data if installation issues arise.

3.16. Logging in to the cluster by using the CLI

Prerequisites

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

Procedure

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.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

3.17. Approving the certificate signing requests for your machines

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:
```
$ oc get nodes
```
Example output
```
NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.27.3
master-1  Ready     master  63m  v1.27.3
master-2  Ready     master  64m  v1.27.3
```
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.

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.

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.

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
...

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
```

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  v1.27.3
master-1  Ready     master  73m  v1.27.3
master-2  Ready     master  74m  v1.27.3
worker-0  Ready     worker  11m  v1.27.3
worker-1  Ready     worker  11m  v1.27.3

Note

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

Additional information

For more information on CSRs, see Certificate Signing Requests.

3.18. 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

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.14.0    True        False         False      19m
baremetal                                  4.14.0    True        False         False      37m
cloud-credential                           4.14.0    True        False         False      40m
cluster-autoscaler                         4.14.0    True        False         False      37m
config-operator                            4.14.0    True        False         False      38m
console                                    4.14.0    True        False         False      26m
csi-snapshot-controller                    4.14.0    True        False         False      37m
dns                                        4.14.0    True        False         False      37m
etcd                                       4.14.0    True        False         False      36m
image-registry                             4.14.0    True        False         False      31m
ingress                                    4.14.0    True        False         False      30m
insights                                   4.14.0    True        False         False      31m
kube-apiserver                             4.14.0    True        False         False      26m
kube-controller-manager                    4.14.0    True        False         False      36m
kube-scheduler                             4.14.0    True        False         False      36m
kube-storage-version-migrator              4.14.0    True        False         False      37m
machine-api                                4.14.0    True        False         False      29m
machine-approver                           4.14.0    True        False         False      37m
machine-config                             4.14.0    True        False         False      36m
marketplace                                4.14.0    True        False         False      37m
monitoring                                 4.14.0    True        False         False      29m
network                                    4.14.0    True        False         False      38m
node-tuning                                4.14.0    True        False         False      37m
openshift-apiserver                        4.14.0    True        False         False      32m
openshift-controller-manager               4.14.0    True        False         False      30m
openshift-samples                          4.14.0    True        False         False      32m
operator-lifecycle-manager                 4.14.0    True        False         False      37m
operator-lifecycle-manager-catalog         4.14.0    True        False         False      37m
operator-lifecycle-manager-packageserver   4.14.0    True        False         False      32m
service-ca                                 4.14.0    True        False         False      38m
storage                                    4.14.0    True        False         False      37m

Configure the Operators that are not available.

Additional resources

See Gathering logs from a failed installation for details about gathering data in the event of a failed OpenShift Container Platform installation.
See Troubleshooting Operator issues for steps to check Operator pod health across the cluster and gather Operator logs for diagnosis.

3.18.1. Image registry removed during installation

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.

3.18.2. Image registry storage configuration

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

3.18.3. 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

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

Procedure

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}}'
```
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
```
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.

3.19. 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

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                             4.14.0    True        False         False      19m
baremetal                                  4.14.0    True        False         False      37m
cloud-credential                           4.14.0    True        False         False      40m
cluster-autoscaler                         4.14.0    True        False         False      37m
config-operator                            4.14.0    True        False         False      38m
console                                    4.14.0    True        False         False      26m
csi-snapshot-controller                    4.14.0    True        False         False      37m
dns                                        4.14.0    True        False         False      37m
etcd                                       4.14.0    True        False         False      36m
image-registry                             4.14.0    True        False         False      31m
ingress                                    4.14.0    True        False         False      30m
insights                                   4.14.0    True        False         False      31m
kube-apiserver                             4.14.0    True        False         False      26m
kube-controller-manager                    4.14.0    True        False         False      36m
kube-scheduler                             4.14.0    True        False         False      36m
kube-storage-version-migrator              4.14.0    True        False         False      37m
machine-api                                4.14.0    True        False         False      29m
machine-approver                           4.14.0    True        False         False      37m
machine-config                             4.14.0    True        False         False      36m
marketplace                                4.14.0    True        False         False      37m
monitoring                                 4.14.0    True        False         False      29m
network                                    4.14.0    True        False         False      38m
node-tuning                                4.14.0    True        False         False      37m
openshift-apiserver                        4.14.0    True        False         False      32m
openshift-controller-manager               4.14.0    True        False         False      30m
openshift-samples                          4.14.0    True        False         False      32m
operator-lifecycle-manager                 4.14.0    True        False         False      37m
operator-lifecycle-manager-catalog         4.14.0    True        False         False      37m
operator-lifecycle-manager-packageserver   4.14.0    True        False         False      32m
service-ca                                 4.14.0    True        False         False      38m
storage                                    4.14.0    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.

Confirm that the Kubernetes API server is communicating with the pods.

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
...

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.

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.

3.20. Telemetry access for OpenShift Container Platform

Additional resources

See About remote health monitoring for more information about the Telemetry service

3.21. Next steps

Validating an installation.
Customize your cluster.
If necessary, you can opt out of remote health reporting.
Set up your registry and configure registry storage.

Chapter 4. Installing a user-provisioned bare metal cluster on a restricted network

In OpenShift Container Platform 4.14, you can install a cluster on bare metal infrastructure that you provision in a restricted network.

Important

4.1. Prerequisites

You reviewed details about the OpenShift Container Platform installation and update processes.
You read the documentation on selecting a cluster installation method and preparing it for users.
You created a registry on your mirror host and obtained the imageContentSources data for your version of OpenShift Container Platform.
Important
Because the installation media is on the mirror host, you can use that computer to complete all installation steps.
You provisioned persistent storage for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.
If you use a firewall and plan to use the Telemetry service, you configured the firewall to allow the sites that your cluster requires access to.
Note
Be sure to also review this site list if you are configuring a proxy.

4.2. About installations in restricted networks

In OpenShift Container Platform 4.14, 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.

4.2.1. 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.

4.3. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.14, 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.

4.4. 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.

4.4.1. Required machines for cluster installation

The smallest OpenShift Container Platform clusters require the following hosts:

Table 4.1. Minimum required hosts
Hosts	Description
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

Important

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

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.

4.4.2. Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Table 4.2. Minimum resource requirements
Machine	Operating System	CPU ^[1]	RAM	Storage	Input/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

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.
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.
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

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 RHEL Architectures.

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

Optimizing storage

4.4.3. Certificate signing requests management

Additional resources

See Configuring a three-node cluster for details about deploying three-node clusters in bare metal environments.
See Approving the certificate signing requests for your machines for more information about approving cluster certificate signing requests after installation.

4.4.4. 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.

Note

4.4.4.1. Setting the cluster node hostnames through DHCP

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

4.4.4.2. Network connectivity requirements

This section provides details about the ports that are required.

Table 4.3. Ports used for all-machine to all-machine communications
Protocol	Port	Description
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
	`10256`	openshift-sdn
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 4.4. Ports used for all-machine to control plane communications
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 4.5. Ports used for control plane machine to control plane machine communications
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server and peer ports

NTP configuration for user-provisioned infrastructure

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

Configuring chrony time service

4.4.5. 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.

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.

Table 4.6. Required DNS records
Component	Record	Description
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.
Kubernetes API	`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.

4.4.5.1. Example DNS configuration for user-provisioned clusters

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 4.1. 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 4.2. 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.

Additional resources

Validating DNS resolution for user-provisioned infrastructure

4.4.6. Load balancing requirements for user-provisioned infrastructure

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:

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

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

Table 4.7. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`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

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

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

Table 4.8. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`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

4.4.6.1. Example load balancer configuration for user-provisioned clusters

Note

Example 4.3. 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 worker0 worker0.ocp4.example.com:443 check inter 1s
  server worker1 worker1.ocp4.example.com:443 check inter 1s
listen ingress-router-80 6
  bind *:80
  mode tcp
  balance source
  server worker0 worker0.ocp4.example.com:80 check inter 1s
  server worker1 worker1.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.

4.5. Preparing the user-provisioned infrastructure

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

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

Prerequisites

You have reviewed the OpenShift Container Platform 4.x Tested Integrations page.
You have reviewed the infrastructure requirements detailed in the Requirements for a cluster with user-provisioned infrastructure section.

Procedure

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.
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.
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.
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.
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.
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.

Additional resources

Requirements for a cluster with user-provisioned infrastructure
Installing RHCOS and starting the OpenShift Container Platform bootstrap process
Setting the cluster node hostnames through DHCP
Advanced RHCOS installation configuration
Networking requirements for user-provisioned infrastructure
User-provisioned DNS requirements
Validating DNS resolution for user-provisioned infrastructure
Load balancing requirements for user-provisioned infrastructure

4.6. 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

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.
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.

Additional resources

User-provisioned DNS requirements
Load balancing requirements for user-provisioned infrastructure

4.7. Generating a key pair for cluster node SSH access

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 such as AWS key pairs.

Procedure

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.
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
```
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.
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

Verifying node health

4.8. Manually creating the installation configuration file

For user-provisioned installations of OpenShift Container Platform, you manually generate your 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

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.
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.
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.

Additional resources

Installation configuration parameters for bare metal

4.8.1. 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 supported values are OVNKubernetes and OpenShiftSDN. The default value is OVNKubernetes.

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 Installing the system in 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

See Load balancing requirements for user-provisioned infrastructure for more information on the API and application ingress load balancing requirements.

4.8.2. Configuring the cluster-wide proxy during installation

Note

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

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
```
Save the file and reference it when installing OpenShift Container Platform.

Note

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

4.8.3. Configuring a three-node cluster

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.

4.9. Creating the Kubernetes manifest and Ignition config files

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

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.
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.
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

See Recovering from expired control plane certificates for more information about recovering kubelet certificates.

4.10. 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

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: 4.14.0
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.
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
```
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
```

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

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

Note

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.

Note

As of OpenShift Container Platform 4.6, the RHCOS ISO and other installation artifacts provide support for installation on disks with 4K sectors.

4.11.1. 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

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.
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.

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.

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-4.14-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso",
"location": "<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso",
"location": "<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso",
"location": "<url>/art/storage/releases/rhcos-4.14/<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
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.
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.
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
```
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.
After RHCOS installs, you must reboot the system. During the system reboot, it applies the Ignition config file that you specified.

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

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.

4.11.2. 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

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.

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.

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

Example output

"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-kernel-aarch64"
"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-initramfs.aarch64.img"
"<url>/art/storage/releases/rhcos-4.14-aarch64/<release>/aarch64/rhcos-<release>-live-rootfs.aarch64.img"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/49.84.202110081256-0/ppc64le/rhcos-<release>-live-kernel-ppc64le"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live-initramfs.ppc64le.img"
"<url>/art/storage/releases/rhcos-4.14-ppc64le/<release>/ppc64le/rhcos-<release>-live-rootfs.ppc64le.img"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-kernel-s390x"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-initramfs.s390x.img"
"<url>/art/storage/releases/rhcos-4.14-s390x/<release>/s390x/rhcos-<release>-live-rootfs.s390x.img"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-kernel-x86_64"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-initramfs.x86_64.img"
"<url>/art/storage/releases/rhcos-4.14/<release>/x86_64/rhcos-<release>-live-rootfs.x86_64.img"

Important

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

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.
Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
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.
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.
After RHCOS installs, the system reboots. During reboot, the system applies the Ignition config file that you specified.

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

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.

4.11.3. Advanced RHCOS installation configuration

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

4.11.3.1. Using advanced networking options for PXE and ISO installations

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

Boot the ISO installer.
From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.
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.
Reboot into the installed system.

Additional resources

See Getting started with nmcli and Getting started with nmtui in the RHEL 8 documentation for more information about the nmcli and nmtui tools.

4.11.3.2. Disk partitioning

Important

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, /.

Important

4.11.3.2.1. Creating a separate `/var` partition

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.

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.

Procedure

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>
```
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: 4.14.0
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.
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
```
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.

4.11.3.2.2. Retaining existing 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

4.11.3.3. 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.

4.11.3.4. Default console configuration

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.

4.11.3.5. Enabling the serial console for PXE and ISO installations

Procedure

Boot the ISO installer.
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.
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.

4.11.3.6. Customizing a live RHCOS ISO or PXE install

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.

4.11.3.7. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.
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.

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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.
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.

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

Note

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

4.11.3.7.3. 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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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
```
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
```
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.

4.11.3.8. 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

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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.

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

Note

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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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.

4.11.3.8.3. 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

Procedure

Download the coreos-installer binary from the coreos-installer image mirror page.
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
```
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
```
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
```

$ 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

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.

4.11.3.9. Advanced RHCOS installation reference

4.11.3.9.1. Networking and bonding options for ISO installations

Important

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

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

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

Configuring an IP address without a static hostname

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

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

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

Important

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

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:

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.
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

4.11.3.9.2. `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 4.9. 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.

4.11.3.9.3. `coreos.inst` boot options for ISO or PXE installations

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 4.10. coreos.inst boot options
Argument	Description
`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.

4.11.4. 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.

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

Important

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

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.
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".
Reboot into the installed system.

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.

4.11.4.1. 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

Create a Butane config with information similar to the following:

Example multipath-config.bu

variant: openshift
version: 4.14.0
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.

Create the Ignition configuration by running the following command:

$ butane --pretty --strict multipath-config.bu > multipath-config.ign

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.

4.12. Waiting 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

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 v1.27.3 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.
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

See Monitoring installation progress for more information about monitoring the installation logs and retrieving diagnostic data if installation issues arise.

4.13. Logging in to the cluster by using the CLI

Prerequisites

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

Procedure

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.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

4.14. Approving the certificate signing requests for your machines

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:
```
$ oc get nodes
```
Example output
```
NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.27.3
master-1  Ready     master  63m  v1.27.3
master-2  Ready     master  64m  v1.27.3
```
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.

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.

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.

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
...

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
```

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  v1.27.3
master-1  Ready     master  73m  v1.27.3
master-2  Ready     master  74m  v1.27.3
worker-0  Ready     worker  11m  v1.27.3
worker-1  Ready     worker  11m  v1.27.3

Note

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

Additional information

For more information on CSRs, see Certificate Signing Requests.

4.15. 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

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.14.0    True        False         False      19m
baremetal                                  4.14.0    True        False         False      37m
cloud-credential                           4.14.0    True        False         False      40m
cluster-autoscaler                         4.14.0    True        False         False      37m
config-operator                            4.14.0    True        False         False      38m
console                                    4.14.0    True        False         False      26m
csi-snapshot-controller                    4.14.0    True        False         False      37m
dns                                        4.14.0    True        False         False      37m
etcd                                       4.14.0    True        False         False      36m
image-registry                             4.14.0    True        False         False      31m
ingress                                    4.14.0    True        False         False      30m
insights                                   4.14.0    True        False         False      31m
kube-apiserver                             4.14.0    True        False         False      26m
kube-controller-manager                    4.14.0    True        False         False      36m
kube-scheduler                             4.14.0    True        False         False      36m
kube-storage-version-migrator              4.14.0    True        False         False      37m
machine-api                                4.14.0    True        False         False      29m
machine-approver                           4.14.0    True        False         False      37m
machine-config                             4.14.0    True        False         False      36m
marketplace                                4.14.0    True        False         False      37m
monitoring                                 4.14.0    True        False         False      29m
network                                    4.14.0    True        False         False      38m
node-tuning                                4.14.0    True        False         False      37m
openshift-apiserver                        4.14.0    True        False         False      32m
openshift-controller-manager               4.14.0    True        False         False      30m
openshift-samples                          4.14.0    True        False         False      32m
operator-lifecycle-manager                 4.14.0    True        False         False      37m
operator-lifecycle-manager-catalog         4.14.0    True        False         False      37m
operator-lifecycle-manager-packageserver   4.14.0    True        False         False      32m
service-ca                                 4.14.0    True        False         False      38m
storage                                    4.14.0    True        False         False      37m

Configure the Operators that are not available.

Additional resources

See Gathering logs from a failed installation for details about gathering data in the event of a failed OpenShift Container Platform installation.
See Troubleshooting Operator issues for steps to check Operator pod health across the cluster and gather Operator logs for diagnosis.

4.15.1. 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 Administration → Cluster Settings → Configuration → OperatorHub page, click the Sources tab, where you can create, update, delete, disable, and enable individual sources.

4.15.2. Image registry storage configuration

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

4.15.2.1. 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"}}'

4.15.2.2. 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

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.
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.
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.

Check the clusteroperator status:

$ oc get clusteroperator image-registry

Example output

NAME             VERSION              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
image-registry   4.14                 True        False         False      6h50m

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
```

4.15.2.3. Configuring storage for the image registry in non-production clusters

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.

4.15.2.4. 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

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

Procedure

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}}'
```
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
```
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.

4.16. 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

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                             4.14.0    True        False         False      19m
baremetal                                  4.14.0    True        False         False      37m
cloud-credential                           4.14.0    True        False         False      40m
cluster-autoscaler                         4.14.0    True        False         False      37m
config-operator                            4.14.0    True        False         False      38m
console                                    4.14.0    True        False         False      26m
csi-snapshot-controller                    4.14.0    True        False         False      37m
dns                                        4.14.0    True        False         False      37m
etcd                                       4.14.0    True        False         False      36m
image-registry                             4.14.0    True        False         False      31m
ingress                                    4.14.0    True        False         False      30m
insights                                   4.14.0    True        False         False      31m
kube-apiserver                             4.14.0    True        False         False      26m
kube-controller-manager                    4.14.0    True        False         False      36m
kube-scheduler                             4.14.0    True        False         False      36m
kube-storage-version-migrator              4.14.0    True        False         False      37m
machine-api                                4.14.0    True        False         False      29m
machine-approver                           4.14.0    True        False         False      37m
machine-config                             4.14.0    True        False         False      36m
marketplace                                4.14.0    True        False         False      37m
monitoring                                 4.14.0    True        False         False      29m
network                                    4.14.0    True        False         False      38m
node-tuning                                4.14.0    True        False         False      37m
openshift-apiserver                        4.14.0    True        False         False      32m
openshift-controller-manager               4.14.0    True        False         False      30m
openshift-samples                          4.14.0    True        False         False      32m
operator-lifecycle-manager                 4.14.0    True        False         False      37m
operator-lifecycle-manager-catalog         4.14.0    True        False         False      37m
operator-lifecycle-manager-packageserver   4.14.0    True        False         False      32m
service-ca                                 4.14.0    True        False         False      38m
storage                                    4.14.0    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.

Confirm that the Kubernetes API server is communicating with the pods.

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
...

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.

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.
Register your cluster on the Cluster registration page.

4.17. Telemetry access for OpenShift Container Platform

Additional resources

See About remote health monitoring for more information about the Telemetry service

4.18. Next steps

Validating an installation.
Customize your cluster.
Configure image streams for the Cluster Samples Operator and the must-gather tool.
Learn how to use Operator Lifecycle Manager (OLM) on restricted networks.
If the mirror registry that you used to install your cluster has a trusted CA, add it to the cluster by configuring additional trust stores.
If necessary, you can opt out of remote health reporting.
If necessary, see Registering your disconnected cluster

Chapter 5. 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.

5.1. 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 hosts 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.

5.1.1. 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.

5.1.2. 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.

5.2. 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

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 4.14 does not support enabling a provisioning network when you scale a user-provisioned cluster by using the Bare Metal Operator.

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

5.3. 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

To provision bare-metal hosts to the cluster by using the BMO, you must set the spec.externallyProvisioned specification in the BareMetalHost custom resource to false.

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

Create the Secret CR and the BareMetalHost CR.

Save the following YAML in the bmh.yaml file:

---
apiVersion: v1
kind: Secret
metadata:
  name: worker1-bmc
  namespace: openshift-machine-api
type: Opaque
data:
  username: <base64_of_uid>
  password: <base64_of_pwd>
---
apiVersion: metal3.io/v1alpha1
kind: BareMetalHost
metadata:
  name: worker1
  namespace: openshift-machine-api
spec:
  bmc:
    address: <protocol>://<bmc_url> 1
    credentialsName: "worker1-bmc"
  bootMACAddress: <nic1_mac_address>
  externallyProvisioned: false 2
  customDeploy:
    method: install_coreos
  online: true
  userData:
    name: worker-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 spec.externallyProvisioned specification in the BareMetalHost custom resource to false. The default value is false.

Create the bare-metal host object by running the following command:

$ oc create -f bmh.yaml

Example output

secret/worker1-bmc created
baremetalhost.metal3.io/worker1 created

Approve all certificate signing requests (CSRs).

Verify that the provisioning state of the host is provisioned 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             5m25s
openshift-machine-api   worker1       provisioned                         true             4m45s

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

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

5.4. 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

Create the Secret CR and the BareMetalHost CR.

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.

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

5.5. 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

Cordon and drain the host 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

Delete the customDeploy specification from the BareMetalHost CR.

Edit the BareMetalHost CR for the host by running the following command:
```
$ oc edit bmh -n openshift-machine-api <host_name>
```
Delete the lines spec.customDeploy and spec.customDeploy.method:
```
...
  customDeploy:
    method: install_coreos
```

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

Delete the node by running the following command:
```
$ oc delete node <node_name>
```

Verification

Verify the node is deleted by running the following command:

$ oc get nodes

Example output

NAME          STATUS   ROLES           AGE     VERSION
controller1   Ready    master,worker   2d23h   v1.24.0+dc5a2fd

Chapter 6. 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.

6.1. 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.

6.1.1. Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 6.1. Required parameters
Parameter	Description	Values
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: `alibabacloud`, `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" } } }

6.1.2. 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.

If you use the Red Hat OpenShift Networking OVN-Kubernetes network plugin, both IPv4 and IPv6 address families are supported.
If you use the Red Hat OpenShift Networking OpenShift SDN network plugin, only the IPv4 address family is supported.

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

Note

Globalnet is not supported with Red Hat OpenShift Data Foundation disaster recovery solutions. For regional disaster recovery scenarios, ensure that you use a nonoverlapping range of private IP addresses for the cluster and service networks in each cluster.

Table 6.2. Network parameters
Parameter	Description	Values
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.	Either `OpenShiftSDN` or `OVNKubernetes`. `OpenShiftSDN` is a CNI plugin for all-Linux networks. `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 OpenShift SDN network plugin, specify an IPv4 network. 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 OpenShift SDN and OVN-Kubernetes network plugins support 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.

6.1.3. Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Table 6.3. Optional parameters
Parameter	Description	Values
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.	`alibabacloud`, `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.	`alibabacloud`, `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.	`Mint`, `Passthrough`, `Manual` or an empty string (`""`). ^[1]
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 Installing the system in 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..`.

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.

Legal Notice

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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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Installing on bare metal

Installing 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

1.3. NIC partitioning for SR-IOV devices (Technology Preview)

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

1.4.1. Installing a cluster on installer-provisioned infrastructure

1.4.2. Installing a cluster on user-provisioned infrastructure

Chapter 2. Installing a user-provisioned cluster on bare metal

2.1. Prerequisites

2.2. Internet access for OpenShift Container Platform

2.3. Requirements for a cluster with user-provisioned infrastructure

2.3.1. Required machines for cluster installation

2.3.2. Minimum resource requirements for cluster installation

2.3.3. Certificate signing requests management

2.3.4. Requirements for baremetal clusters on vSphere

2.3.5. Networking requirements for user-provisioned infrastructure

2.3.5.1. Setting the cluster node hostnames through DHCP

2.3.5.2. Network connectivity requirements

NTP configuration for user-provisioned infrastructure

2.3.6. User-provisioned DNS requirements

2.3.6.1. Example DNS configuration for user-provisioned clusters

2.3.7. Load balancing requirements for user-provisioned infrastructure

2.3.7.1. Example load balancer configuration for user-provisioned clusters

2.4. Preparing the user-provisioned infrastructure

2.5. Validating DNS resolution for user-provisioned infrastructure

2.6. Generating a key pair for cluster node SSH access

2.7. Obtaining the installation program

2.8. Installing the OpenShift CLI by downloading the binary

Installing the OpenShift CLI on Linux

Installing the OpenShift CLI on Windows

Installing the OpenShift CLI on macOS

2.9. Manually creating the installation configuration file

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

2.9.2. Configuring the cluster-wide proxy during installation

2.9.3. Configuring a three-node cluster

2.10. Creating the Kubernetes manifest and Ignition config files

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

2.11.1. Installing RHCOS by using an ISO image

2.11.2. Installing RHCOS by using PXE or iPXE booting

2.11.3. Advanced RHCOS installation configuration

2.11.3.1. Using advanced networking options for PXE and ISO installations

2.11.3.2. Disk partitioning

2.11.3.2.1. Creating a separate /var partition

2.11.3.2.2. Retaining existing partitions

2.11.3.3. Identifying Ignition configs

2.11.3.4. Default console configuration

2.11.3.5. Enabling the serial console for PXE and ISO installations

2.11.3.6. Customizing a live RHCOS ISO or PXE install

2.11.3.7. Customizing a live RHCOS ISO image

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

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

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

2.11.3.8. Customizing a live RHCOS PXE environment

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

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

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

2.11.3.9. Advanced RHCOS installation reference

2.11.3.9.1. Networking and bonding options for ISO installations

Configuring DHCP or static IP addresses

Configuring an IP address without a static hostname

Specifying multiple network interfaces

Configuring default gateway and route

Disabling DHCP on a single interface

Combining DHCP and static IP configurations

Configuring VLANs on individual interfaces

Providing multiple DNS servers

Bonding multiple network interfaces to a single interface

Bonding multiple SR-IOV network interfaces to a dual port NIC interface

Using network teaming

2.11.3.9.2. coreos-installer options for ISO and PXE installations

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

2.11.4. Enabling multipathing with kernel arguments on RHCOS

2.11.4.1. Enabling multipathing on secondary disks

2.12. Waiting for the bootstrap process to complete

2.13. Logging in to the cluster by using the CLI

2.14. Approving the certificate signing requests for your machines

2.15. Initial Operator configuration

2.15.1. Image registry removed during installation

2.11.3.2.1. Creating a separate `/var` partition

2.11.3.9.2. `coreos-installer` options for ISO and PXE installations

2.11.3.9.3. `coreos.inst` boot options for ISO or PXE installations

3.14.3.2.1. Creating a separate `/var` partition