Chapter 15. Installing with z/VM on IBM Z and LinuxONE
15.1. Preparing to install with z/VM on IBM Z and LinuxONE
15.1.1. 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.
15.1.2. Choosing a method to install OpenShift Container Platform with z/VM on IBM Z or LinuxONE
You can install a cluster with z/VM on IBM Z or LinuxONE infrastructure that you provision, by using one of the following methods:
- Installing a cluster with z/VM on IBM Z and LinuxONE: You can install OpenShift Container Platform with z/VM on IBM Z or LinuxONE infrastructure that you provision.
- Installing a cluster with z/VM on IBM Z and LinuxONE in a restricted network: You can install OpenShift Container Platform with z/VM on IBM Z or LinuxONE infrastructure that you provision in a restricted or disconnected network, by using an internal mirror of the installation release content. You can use this method to install a cluster that does not require an active internet connection to obtain the software components. You can also use this installation method to ensure that your clusters only use container images that satisfy your organizational controls on external content.
15.2. Installing a cluster with z/VM on IBM Z and LinuxONE
In OpenShift Container Platform version 4.10, you can install a cluster on IBM Z or LinuxONE infrastructure that you provision.
While this document refers only to IBM Z, all information in it also applies to LinuxONE.
Additional considerations exist for non-bare metal platforms. Review the information in the guidelines for deploying OpenShift Container Platform on non-tested platforms before you install an OpenShift Container Platform cluster.
15.2.1. 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.
- Before you begin the installation process, you must clean the installation directory. This ensures that the required installation files are created and updated during the installation process.
-
You provisioned persistent storage using OpenShift Data Foundation or other supported storage protocols for your cluster. To deploy a private image registry, you must set up persistent storage with
ReadWriteMany
access. - If you use a firewall, you configured it to allow the sites that your cluster requires access to.
Be sure to also review this site list if you are configuring a proxy.
15.2.2. Internet access for OpenShift Container Platform
In OpenShift Container Platform 4.10, 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.
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.
15.2.3. 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.
15.2.3.1. Required machines for cluster installation
The smallest OpenShift Container Platform clusters require the following 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. |
To improve high availability of your cluster, distribute the control plane machines over different z/VM instances on at least two physical machines.
The bootstrap, control plane, and compute machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.
Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.
15.2.3.2. Minimum resource requirements for cluster installation
Each cluster machine must meet the following minimum requirements:
Machine | Operating System | vCPU [1] | Virtual RAM | Storage | IOPS |
---|---|---|---|---|---|
Bootstrap | RHCOS | 4 | 16 GB | 100 GB | N/A |
Control plane | RHCOS | 4 | 16 GB | 100 GB | N/A |
Compute | RHCOS | 2 | 8 GB | 100 GB | N/A |
- One physical core (IFL) provides two logical cores (threads) when SMT-2 is enabled. The hypervisor can provide two or more vCPUs.
If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.
15.2.3.3. Minimum IBM Z system environment
You can install OpenShift Container Platform version 4.10 on the following IBM hardware:
- IBM z16 (all models), IBM z15 (all models), IBM z14 (all models), IBM z13, and IBM z13s
- LinuxONE, any version
Hardware requirements
- The equivalent of six Integrated Facilities for Linux (IFL), which are SMT2 enabled, for each cluster.
-
At least one network connection to both connect to the
LoadBalancer
service and to serve data for traffic outside the cluster.
You can use dedicated or shared IFLs to assign sufficient compute resources. Resource sharing is one of the key strengths of IBM Z. However, you must adjust capacity correctly on each hypervisor layer and ensure sufficient resources for every OpenShift Container Platform cluster.
Since the overall performance of the cluster can be impacted, the LPARs that are used to setup the OpenShift Container Platform clusters must provide sufficient compute capacity. In this context, LPAR weight management, entitlements, and CPU shares on the hypervisor level play an important role.
Operating system requirements
- One instance of z/VM 7.2 or later
On your z/VM instance, set up:
- Three guest virtual machines for OpenShift Container Platform control plane machines
- Two guest virtual machines for OpenShift Container Platform compute machines
- One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine
IBM Z network connectivity requirements
To install on IBM Z under z/VM, you require a single z/VM virtual NIC in layer 2 mode. You also need:
- A direct-attached OSA or RoCE network adapter
- A z/VM VSwitch set up. For a preferred setup, use OSA link aggregation.
Disk storage for the z/VM guest virtual machines
- FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV to ensure optimal performance.
- FCP attached disk storage
Storage / Main Memory
- 16 GB for OpenShift Container Platform control plane machines
- 8 GB for OpenShift Container Platform compute machines
- 16 GB for the temporary OpenShift Container Platform bootstrap machine
15.2.3.4. Preferred IBM Z system environment
Hardware requirements
- Three LPARS that each have the equivalent of six IFLs, which are SMT2 enabled, for each cluster.
-
Two network connections to both connect to the
LoadBalancer
service and to serve data for traffic outside the cluster. - HiperSockets, which are attached to a node either directly as a device or by bridging with one z/VM VSWITCH to be transparent to the z/VM guest. To directly connect HiperSockets to a node, you must set up a gateway to the external network via a RHEL 8 guest to bridge to the HiperSockets network.
Operating system requirements
- Two or three instances of z/VM 7.2 or later for high availability
On your z/VM instances, set up:
- Three guest virtual machines for OpenShift Container Platform control plane machines, one per z/VM instance.
- At least six guest virtual machines for OpenShift Container Platform compute machines, distributed across the z/VM instances.
- One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine.
-
To ensure the availability of integral components in an overcommitted environment, increase the priority of the control plane by using the CP command
SET SHARE
. Do the same for infrastructure nodes, if they exist. See SET SHARE in IBM Documentation.
IBM Z network connectivity requirements
To install on IBM Z under z/VM, you require a single z/VM virtual NIC in layer 2 mode. You also need:
- A direct-attached OSA or RoCE network adapter
- A z/VM VSwitch set up. For a preferred setup, use OSA link aggregation.
Disk storage for the z/VM guest virtual machines
- FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV and High Performance FICON (zHPF) to ensure optimal performance.
- FCP attached disk storage
Storage / Main Memory
- 16 GB for OpenShift Container Platform control plane machines
- 8 GB for OpenShift Container Platform compute machines
- 16 GB for the temporary OpenShift Container Platform bootstrap machine
15.2.3.5. 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 Bridging a HiperSockets LAN with a z/VM Virtual Switch in IBM Documentation.
- See Scaling HyperPAV alias devices on Linux guests on z/VM for performance optimization.
- See Topics in LPAR performance for LPAR weight management and entitlements.
- Recommended host practices for IBM Z & LinuxONE environments
15.2.3.6. 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 HTTP or HTTPS server to establish a network connection to download their Ignition config files.
The machines are configured with static IP addresses. No DHCP server is required. Ensure that the machines have persistent IP addresses and hostnames.
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.
15.2.3.6.1. 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.
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.
Protocol | Port | Description |
---|---|---|
ICMP | N/A | Network reachability tests |
TCP |
| Metrics |
|
Host level services, including the node exporter on ports | |
| The default ports that Kubernetes reserves | |
| openshift-sdn | |
UDP |
| VXLAN |
| Geneve | |
|
Host level services, including the node exporter on ports | |
| IPsec IKE packets | |
| IPsec NAT-T packets | |
TCP/UDP |
| Kubernetes node port |
ESP | N/A | IPsec Encapsulating Security Payload (ESP) |
Protocol | Port | Description |
---|---|---|
TCP |
| Kubernetes API |
Protocol | Port | Description |
---|---|---|
TCP |
| 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.
Additional resources
15.2.3.7. 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.
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>.
.
Component | Record | Description |
---|---|---|
Kubernetes API |
| 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. |
| 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 |
| 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, |
Bootstrap machine |
| 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 |
| 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 |
| 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. |
In OpenShift Container Platform 4.4 and later, you do not need to specify etcd host and SRV records in your DNS configuration.
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.
15.2.3.7.1. 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 15.1. 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 ; master0.ocp4.example.com. IN A 192.168.1.97 5 master1.ocp4.example.com. IN A 192.168.1.98 6 master2.ocp4.example.com. IN A 192.168.1.99 7 ; worker0.ocp4.example.com. IN A 192.168.1.11 8 worker1.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 15.2. 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 master0.ocp4.example.com. 4 98.1.168.192.in-addr.arpa. IN PTR master1.ocp4.example.com. 5 99.1.168.192.in-addr.arpa. IN PTR master2.ocp4.example.com. 6 ; 11.1.168.192.in-addr.arpa. IN PTR worker0.ocp4.example.com. 7 7.1.168.192.in-addr.arpa. IN PTR worker1.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.
A PTR record is not required for the OpenShift Container Platform application wildcard.
15.2.3.8. 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.
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, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
- A stateless load balancing algorithm. The options vary based on the load balancer implementation.
ImportantDo 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 15.7. 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
NoteThe 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, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the ingress routes.
- 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.
TipIf 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 15.8. 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
NoteIf 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.
15.2.3.8.1. 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.
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 15.3. 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 server bootstrap bootstrap.ocp4.example.com:6443 check inter 1s backup 2 server master0 master0.ocp4.example.com:6443 check inter 1s server master1 master1.ocp4.example.com:6443 check inter 1s server master2 master2.ocp4.example.com:6443 check inter 1s 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.NoteIf 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.
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.
15.2.4. 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, preparing a web server for the Ignition files, 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
- Set up static IP addresses.
- Set up an HTTP or HTTPS server to provide Ignition files to the cluster nodes.
- 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.
ImportantBy 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.
- Configure DNS name resolution for the Kubernetes API, the application wildcard, the bootstrap machine, the control plane machines, and the compute machines.
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.
- 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.
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.
Some load balancing solutions require the DNS name resolution for the cluster nodes to be in place before the load balancing is initialized.
15.2.5. Validating DNS resolution for user-provisioned infrastructure
You can validate your DNS configuration before installing OpenShift Container Platform on user-provisioned infrastructure.
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.
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. 0 IN A 192.168.1.5
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. 0 IN A 192.168.1.5
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. 0 IN A 192.168.1.5
NoteIn 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. 0 IN A 192.168.1.5
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. 0 IN A 192.168.1.96
- 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.
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. 0 IN PTR api-int.ocp4.example.com. 1 5.1.168.192.in-addr.arpa. 0 IN PTR api.ocp4.example.com. 2
NoteA 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.
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. 0 IN PTR bootstrap.ocp4.example.com.
- 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.
15.2.6. 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.
Do not skip this procedure in production environments, where disaster recovery and debugging is required.
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.
NoteIf you plan to install an OpenShift Container Platform cluster that uses FIPS validated or Modules In Process cryptographic libraries on the
x86_64
architecture, do not create a key that uses theed25519
algorithm. Instead, create a key that uses thersa
orecdsa
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.NoteOn some distributions, default SSH private key identities such as
~/.ssh/id_rsa
and~/.ssh/id_dsa
are managed automatically.If the
ssh-agent
process is not already running for your local user, start it as a background task:$ eval "$(ssh-agent -s)"
Example output
Agent pid 31874
NoteIf your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.
Add your SSH private key to the
ssh-agent
:$ 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.
15.2.7. Obtaining the installation program
Before you install OpenShift Container Platform, download the installation file on your provisioning machine.
Prerequisites
- You have a machine that runs Linux, for example Red Hat Enterprise Linux 8, with 500 MB of local disk space
Procedure
- Access the Infrastructure Provider page on the OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
- Select your infrastructure provider.
Navigate to the page for your installation type, download the installation program that corresponds with your host operating system and architecture, and place the file in the directory where you will store the installation configuration files.
ImportantThe 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 files are required to delete the cluster.
ImportantDeleting 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 the 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.
15.2.8. 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.
If you installed an earlier version of oc
, you cannot use it to complete all of the commands in OpenShift Container Platform 4.10. 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 appropriate version in the Version drop-down menu.
- Click Download Now next to the OpenShift v4.10 Linux Client entry and save the file.
Unpack the archive:
$ tar xvf <file>
Place the
oc
binary in a directory that is on yourPATH
.To check your
PATH
, execute the following command:$ echo $PATH
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 in the Version drop-down menu.
- Click Download Now next to the OpenShift v4.10 Windows Client entry and save the file.
- Unzip the archive with a ZIP program.
Move the
oc
binary to a directory that is on yourPATH
.To check your
PATH
, open the command prompt and execute the following command:C:\> path
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 in the Version drop-down menu.
- Click Download Now next to the OpenShift v4.10 MacOSX Client entry and save the file.
- 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
After you install the OpenShift CLI, it is available using the oc
command:
$ oc <command>
15.2.9. 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.
Procedure
Create an installation directory to store your required installation assets in:
$ mkdir <installation_directory>
ImportantYou 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>
.NoteYou must name this configuration file
install-config.yaml
.NoteFor some platform types, you can alternatively run
./openshift-install create install-config --dir <installation_directory>
to generate aninstall-config.yaml
file. You can provide details about your cluster configuration at the prompts.Back up the
install-config.yaml
file so that you can use it to install multiple clusters.ImportantThe
install-config.yaml
file is consumed during the next step of the installation process. You must back it up now.
15.2.9.1. Installation configuration parameters
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.
After installation, you cannot modify these parameters in the install-config.yaml
file.
15.2.9.1.1. Required configuration parameters
Required installation configuration parameters are described in the following table:
Parameter | Description | Values |
---|---|---|
|
The API version for the | String |
|
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 |
A fully-qualified domain or subdomain name, such as |
|
Kubernetes resource | Object |
|
The name of the cluster. DNS records for the cluster are all subdomains of |
String of lowercase letters, hyphens ( |
|
The configuration for the specific platform upon which to perform the installation: | Object |
| Get a pull secret from the 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" } } } |
15.2.9.1.2. 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.
Only IPv4 addresses are supported.
Parameter | Description | Values |
---|---|---|
| The configuration for the cluster network. | Object Note
You cannot modify parameters specified by the |
| The cluster network provider Container Network Interface (CNI) plugin to install. |
Either |
| The IP address blocks for pods.
The default value is 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 |
|
Required if you use An IPv4 network. |
An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between |
|
The subnet prefix length to assign to each individual node. For example, if | A subnet prefix.
The default value is |
|
The IP address block for services. The default value is The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network. | An array with an IP address block in CIDR format. For example: networking: serviceNetwork: - 172.30.0.0/16 |
| The IP address blocks for machines. If you specify multiple IP address blocks, the blocks must not overlap.
If you specify multiple IP kernel arguments, the | An array of objects. For example: networking: machineNetwork: - cidr: 10.0.0.0/16 |
|
Required if you use | An IP network block in CIDR notation.
For example, Note
Set the |
15.2.9.1.3. Optional configuration parameters
Optional installation configuration parameters are described in the following table:
Parameter | Description | Values |
---|---|---|
| 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 |
| Enables Linux control groups version 2 (cgroups v2) on specific nodes in your cluster. The OpenShift Container Platform process for enabling cgroups v2 disables all cgroup version 1 controllers and hierarchies. The OpenShift Container Platform cgroups version 2 feature is in Developer Preview and is not supported by Red Hat at this time. |
|
| The configuration for the machines that comprise the compute nodes. |
Array of |
|
Determines the instruction set architecture of the machines in the pool. Currently, heteregeneous clusters are not supported, so all pools must specify the same architecture. Valid values are | String |
|
Whether to enable or disable simultaneous multithreading, or Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance. |
|
|
Required if you use |
|
|
Required if you use |
|
| The number of compute machines, which are also known as worker machines, to provision. |
A positive integer greater than or equal to |
| The configuration for the machines that comprise the control plane. |
Array of |
|
Determines the instruction set architecture of the machines in the pool. Currently, heterogeneous clusters are not supported, so all pools must specify the same architecture. Valid values are | String |
|
Whether to enable or disable simultaneous multithreading, or Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance. |
|
|
Required if you use |
|
|
Required if you use |
|
| The number of control plane machines to provision. |
The only supported value is |
| The Cloud Credential Operator (CCO) mode. If no mode is specified, the CCO dynamically tries to determine the capabilities of the provided credentials, with a preference for mint mode on the platforms where multiple modes are supported. Note Not all CCO modes are supported for all cloud providers. For more information on CCO modes, see the Cloud Credential Operator entry in the Cluster Operators reference content. Note
If your AWS account has service control policies (SCP) enabled, you must configure the |
|
|
Enable or disable FIPS mode. The default is 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. The use of FIPS validated or Modules In Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the Note If you are using Azure File storage, you cannot enable FIPS mode. |
|
| Sources and repositories for the release-image content. |
Array of objects. Includes a |
|
Required if you use | String |
| Specify one or more repositories that may also contain the same images. | Array of strings |
| How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes. |
Setting this field to Important
If the value of the field is set to |
| The SSH key or keys to authenticate access 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 | One or more keys. For example: sshKey: <key1> <key2> <key3> |
15.2.9.2. Sample install-config.yaml file for IBM Z
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 architecture : s390x controlPlane: 5 hyperthreading: Enabled 6 name: master replicas: 3 7 architecture : s390x metadata: name: test 8 networking: clusterNetwork: - cidr: 10.128.0.0/14 9 hostPrefix: 23 10 networkType: OpenShiftSDN serviceNetwork: 11 - 172.30.0.0/16 platform: none: {} 12 fips: false 13 pullSecret: '{"auths": ...}' 14 sshKey: 'ssh-ed25519 AAAA...' 15
- 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 thecompute
section is a sequence of mappings. To meet the requirements of the different data structures, the first line of thecompute
section must begin with a hyphen,-
, and the first line of thecontrolPlane
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.NoteSimultaneous multithreading (SMT) is enabled by default. If SMT is not available on your OpenShift Container Platform nodes, the
hyperthreading
parameter has no effect.ImportantIf you disable
hyperthreading
, whether on your OpenShift Container Platform nodes or in theinstall-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.NoteIf 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 to23
, then each node is assigned a/23
subnet out of the givencidr
, 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 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.
- 12
- You must set the platform to
none
. You cannot provide additional platform configuration variables for IBM Z infrastructure.ImportantClusters 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. - 13
- 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. The use of FIPS validated or Modules In Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the
x86_64
architecture. - 14
- The pull secret from the 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.
- 15
- The SSH public key for the
core
user in Red Hat Enterprise Linux CoreOS (RHCOS).NoteFor 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.
15.2.9.3. 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.
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’sspec.noProxy
field to bypass the proxy if necessary.NoteThe
Proxy
objectstatus.noProxy
field is populated with the values of thenetworking.machineNetwork[].cidr
,networking.clusterNetwork[].cidr
, andnetworking.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
objectstatus.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----- ...
- 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
matchesx.y.com
, but noty.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 theopenshift-config
namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates atrusted-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 thetrustedCA
field of theProxy
object. TheadditionalTrustBundle
field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
NoteThe installation program does not support the proxy
readinessEndpoints
field.NoteIf 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
.
Only the Proxy
object named cluster
is supported, and no additional proxies can be created.
15.2.9.4. Configuring a three-node cluster
Optionally, you can deploy zero compute machines in a minimal three node 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 yourinstall-config.yaml
file, as shown in the followingcompute
stanza:compute: - name: worker platform: {} replicas: 0
NoteYou must set the value of the
replicas
parameter for the compute machines to0
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.NoteThe preferred resource for control plane nodes is six vCPUs and 21 GB. For three control plane nodes this is the memory + vCPU equivalent of a minimum five-node cluster. You should back the three nodes, each installed on a 120 GB disk, with three IFLs that are SMT2 enabled. The minimum tested setup is three vCPUs and 10 GB on a 120 GB disk for each control plane node.
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 totrue
. 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.
15.2.10. 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 and these fields cannot be changed:
clusterNetwork
- IP address pools from which pod IP addresses are allocated.
serviceNetwork
- IP address pool for services.
defaultNetwork.type
- Cluster network provider, such as OpenShift SDN or OVN-Kubernetes.
You can specify the cluster network provider configuration for your cluster by setting the fields for the defaultNetwork
object in the CNO object named cluster
.
15.2.10.1. Cluster Network Operator configuration object
The fields for the Cluster Network Operator (CNO) are described in the following table:
Field | Type | Description |
---|---|---|
|
|
The name of the CNO object. This name is always |
|
| 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
You can customize this field only in the |
|
| A block of IP addresses for services. The OpenShift SDN and OVN-Kubernetes Container Network Interface (CNI) network providers 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 |
|
| Configures the Container Network Interface (CNI) cluster network provider for the cluster network. |
|
| The fields for this object specify the kube-proxy configuration. If you are using the OVN-Kubernetes cluster network provider, the kube-proxy configuration has no effect. |
defaultNetwork object configuration
The values for the defaultNetwork
object are defined in the following table:
Field | Type | Description |
---|---|---|
|
|
Either Note OpenShift Container Platform uses the OpenShift SDN Container Network Interface (CNI) cluster network provider by default. |
|
| This object is only valid for the OpenShift SDN cluster network provider. |
|
| This object is only valid for the OVN-Kubernetes cluster network provider. |
Configuration for the OpenShift SDN CNI cluster network provider
The following table describes the configuration fields for the OpenShift SDN Container Network Interface (CNI) cluster network provider.
Field | Type | Description |
---|---|---|
|
|
Configures the network isolation mode for OpenShift SDN. The default value is
The values |
|
| 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 This value cannot be changed after cluster installation. |
|
|
The port to use for all VXLAN packets. The default value is 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 |
Example OpenShift SDN configuration
defaultNetwork: type: OpenShiftSDN openshiftSDNConfig: mode: NetworkPolicy mtu: 1450 vxlanPort: 4789
Configuration for the OVN-Kubernetes CNI cluster network provider
The following table describes the configuration fields for the OVN-Kubernetes CNI cluster network provider.
Field | Type | Description |
---|---|---|
|
| 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 |
|
|
The port to use for all Geneve packets. The default value is |
|
| Specify an empty object to enable IPsec encryption. This value cannot be changed after cluster installation. |
|
| Specify a configuration object for customizing network policy audit logging. If unset, the defaults audit log settings are used. |
|
| 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. |
Field | Type | Description |
---|---|---|
| integer |
The maximum number of messages to generate every second per node. The default value is |
| integer |
The maximum size for the audit log in bytes. The default value is |
| string | One of the following additional audit log targets:
|
| string |
The syslog facility, such as |
Field | Type | Description |
---|---|---|
|
|
Set this field to
This field has an interaction with the Open vSwitch hardware offloading feature. If you set this field to |
Example OVN-Kubernetes configuration with IPSec enabled
defaultNetwork: type: OVNKubernetes ovnKubernetesConfig: mtu: 1400 genevePort: 6081 ipsecConfig: {}
kubeProxyConfig object configuration
The values for the kubeProxyConfig
object are defined in the following table:
Field | Type | Description |
---|---|---|
|
|
The refresh period for Note
Because of performance improvements introduced in OpenShift Container Platform 4.3 and greater, adjusting the |
|
|
The minimum duration before refreshing kubeProxyConfig: proxyArguments: iptables-min-sync-period: - 0s |
15.2.11. Creating the Kubernetes manifest and Ignition config files
Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to configure the machines.
The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to configure the cluster machines.
-
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.
The installation program that generates the manifest and Ignition files is architecture specific and can be obtained from the client image mirror. The Linux version of the installation program runs on s390x only. This installer program is also available as a Mac OS version.
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 theinstall-config.yaml
file you created.
WarningIf you are installing a three-node cluster, skip the following step to allow the control plane nodes to be schedulable.
ImportantWhen you configure control plane nodes from the default unschedulable to schedulable, additional subscriptions are required. This is because control plane nodes then become worker nodes.
Check that the
mastersSchedulable
parameter in the<installation_directory>/manifests/cluster-scheduler-02-config.yml
Kubernetes manifest file is set tofalse
. This setting prevents pods from being scheduled on the control plane machines:-
Open the
<installation_directory>/manifests/cluster-scheduler-02-config.yml
file. -
Locate the
mastersSchedulable
parameter and ensure that it is set tofalse
. - Save and exit the file.
-
Open the
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
andkubeconfig
files are created in the./<installation_directory>/auth
directory:. ├── auth │ ├── kubeadmin-password │ └── kubeconfig ├── bootstrap.ign ├── master.ign ├── metadata.json └── worker.ign
15.2.12. Installing RHCOS and starting the OpenShift Container Platform bootstrap process
To install OpenShift Container Platform on IBM Z infrastructure that you provision, you must install Red Hat Enterprise Linux CoreOS (RHCOS) on z/VM guest virtual 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 z/VM guest virtual machines have rebooted.
Complete the following steps to create the machines.
Prerequisites
- An HTTP or HTTPS server running on your provisioning machine that is accessible to the machines you create.
Procedure
- Log in to Linux on your provisioning machine.
Obtain the Red Hat Enterprise Linux CoreOS (RHCOS) kernel, initramfs, and rootfs files from the RHCOS image mirror.
ImportantThe 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. Only use the appropriate kernel, initramfs, and rootfs artifacts described in the following procedure.
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
NoteThe rootfs image is the same for FCP and DASD.
-
kernel:
Create parameter files. The following parameters are specific for a particular virtual machine:
For
ip=
, specify the following seven entries:- The IP address for the machine.
- An empty string.
- The gateway.
- The netmask.
-
The machine host and domain name in the form
hostname.domainname
. Omit this value to let RHCOS decide. - The network interface name. Omit this value to let RHCOS decide.
-
If you use static IP addresses, specify
none
.
-
For
coreos.inst.ignition_url=
, specify the Ignition file for the machine role. Usebootstrap.ign
,master.ign
, orworker.ign
. Only HTTP and HTTPS protocols are supported. -
For
coreos.live.rootfs_url=
, specify the matching rootfs artifact for the kernel and initramfs you are booting. Only HTTP and HTTPS protocols are supported. For installations on DASD-type disks, complete the following tasks:
-
For
coreos.inst.install_dev=
, specifydasda
. -
Use
rd.dasd=
to specify the DASD where RHCOS is to be installed. Leave all other parameters unchanged.
Example parameter file,
bootstrap-0.parm
, for the bootstrap machine:rd.neednet=1 \ console=ttysclp0 \ coreos.inst.install_dev=dasda \ coreos.live.rootfs_url=http://cl1.provide.example.com:8080/assets/rhcos-live-rootfs.s390x.img \ coreos.inst.ignition_url=http://cl1.provide.example.com:8080/ignition/bootstrap.ign \ ip=172.18.78.2::172.18.78.1:255.255.255.0:::none nameserver=172.18.78.1 \ rd.znet=qeth,0.0.bdf0,0.0.bdf1,0.0.bdf2,layer2=1,portno=0 \ zfcp.allow_lun_scan=0 \ rd.dasd=0.0.3490
Write all options in the parameter file as a single line and make sure you have no newline characters.
-
For
For installations on FCP-type disks, complete the following tasks:
Use
rd.zfcp=<adapter>,<wwpn>,<lun>
to specify the FCP disk where RHCOS is to be installed. For multipathing repeat this step for each additional path.NoteWhen you install with multiple paths, you must enable multipathing directly after the installation, not at a later point in time, as this can cause problems.
Set the install device as:
coreos.inst.install_dev=sda
.NoteIf additional LUNs are configured with NPIV, FCP requires
zfcp.allow_lun_scan=0
. If you must enablezfcp.allow_lun_scan=1
because you use a CSI driver, for example, you must configure your NPIV so that each node cannot access the boot partition of another node.Leave all other parameters unchanged.
ImportantAdditional post-installation steps are required to fully enable multipathing. For more information, see “Enabling multipathing with kernel arguments on RHCOS" in Post-installation machine configuration tasks.
The following is an example parameter file
worker-1.parm
for a worker node with multipathing:rd.neednet=1 \ console=ttysclp0 \ coreos.inst.install_dev=sda \ coreos.live.rootfs_url=http://cl1.provide.example.com:8080/assets/rhcos-live-rootfs.s390x.img \ coreos.inst.ignition_url=http://cl1.provide.example.com:8080/ignition/worker.ign \ ip=172.18.78.2::172.18.78.1:255.255.255.0:::none nameserver=172.18.78.1 \ rd.znet=qeth,0.0.bdf0,0.0.bdf1,0.0.bdf2,layer2=1,portno=0 \ zfcp.allow_lun_scan=0 \ rd.zfcp=0.0.1987,0x50050763070bc5e3,0x4008400B00000000 \ rd.zfcp=0.0.19C7,0x50050763070bc5e3,0x4008400B00000000 \ rd.zfcp=0.0.1987,0x50050763071bc5e3,0x4008400B00000000 \ rd.zfcp=0.0.19C7,0x50050763071bc5e3,0x4008400B00000000
Write all options in the parameter file as a single line and make sure you have no newline characters.
- Transfer the initramfs, kernel, parameter files, and RHCOS images to z/VM, for example with FTP. For details about how to transfer the files with FTP and boot from the virtual reader, see Installing under Z/VM.
Punch the files to the virtual reader of the z/VM guest virtual machine that is to become your bootstrap node.
See PUNCH in IBM Documentation.
TipYou can use the CP PUNCH command or, if you use Linux, the vmur command to transfer files between two z/VM guest virtual machines.
- Log in to CMS on the bootstrap machine.
IPL the bootstrap machine from the reader:
$ ipl c
See IPL in IBM Documentation.
- Repeat this procedure for the other machines in the cluster.
15.2.12.1. 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.
15.2.12.1.1. 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.
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 table 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.
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
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.
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. Entermodinfo 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,fail_over_mac=1 ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Always set option fail_over_mac=1
in active-backup mode, to avoid problems when shared OSA/RoCE cards are used.
Bonding multiple network interfaces to a single interface
Optional: You can configure VLANs on bonded interfaces by using the vlan=
parameter and to use DHCP, for example:
ip=bond0.100:dhcp bond=bond0:em1,em2:mode=active-backup vlan=bond0.100:bond0
Use the following example to configure the bonded interface with a VLAN and to use a static IP address:
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0.100:none bond=bond0:em1,em2:mode=active-backup vlan=bond0.100:bond0
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
).
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
15.2.13. Waiting for the bootstrap process to complete
The OpenShift Container Platform bootstrap process begins after the cluster nodes first boot into the persistent RHCOS environment that has been installed to disk. The configuration information provided through the Ignition config files is used to initialize the bootstrap process and install OpenShift Container Platform on the machines. You must wait for the bootstrap process to complete.
Prerequisites
- You have created the Ignition config files for your cluster.
- You have configured suitable network, DNS and load balancing infrastructure.
- You have obtained the installation program and generated the Ignition config files for your cluster.
- You installed RHCOS on your cluster machines and provided the Ignition config files that the OpenShift Container Platform installation program generated.
- Your machines have direct internet access or have an HTTP or HTTPS proxy available.
Procedure
Monitor the bootstrap process:
$ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ 1 --log-level=info 2
Example output
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443... INFO API v1.23.0 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 bootstrap process is complete, remove the bootstrap machine from the load balancer.
ImportantYou must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the bootstrap machine itself.
15.2.14. Logging in to the cluster by using the CLI
You can log in to your cluster as a default system user by exporting the cluster kubeconfig
file. The kubeconfig
file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server. The file is specific to a cluster and is created during OpenShift Container Platform installation.
Prerequisites
- You deployed an OpenShift Container Platform cluster.
-
You installed the
oc
CLI.
Procedure
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
15.2.15. Approving the certificate signing requests for your machines
When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.
Prerequisites
- You added machines to your cluster.
Procedure
Confirm that the cluster recognizes the machines:
$ oc get nodes
Example output
NAME STATUS ROLES AGE VERSION master-0 Ready master 63m v1.23.0 master-1 Ready master 63m v1.23.0 master-2 Ready master 64m v1.23.0
The output lists all of the machines that you created.
NoteThe 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
orApproved
status for each machine that you added to the cluster:$ oc get csr
Example output
NAME AGE REQUESTOR CONDITION csr-mddf5 20m system:node:master-01.example.com Approved,Issued csr-z5rln 16m system:node:worker-21.example.com Approved,Issued
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:NoteBecause 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.NoteFor 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
, andoc 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 thenode-bootstrapper
service account in thesystem:node
orsystem: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
NoteSome 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 v1.23.0 master-1 Ready master 73m v1.23.0 master-2 Ready master 74m v1.23.0 worker-0 Ready worker 11m v1.23.0 worker-1 Ready worker 11m v1.23.0
NoteIt 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.
15.2.16. Initial Operator configuration
After the control plane initializes, you must immediately configure some Operators so that they all become available.
Prerequisites
- Your control plane has initialized.
Procedure
Watch the cluster components come online:
$ watch -n5 oc get clusteroperators
Example output
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE authentication 4.10.0 True False False 19m baremetal 4.10.0 True False False 37m cloud-credential 4.10.0 True False False 40m cluster-autoscaler 4.10.0 True False False 37m config-operator 4.10.0 True False False 38m console 4.10.0 True False False 26m csi-snapshot-controller 4.10.0 True False False 37m dns 4.10.0 True False False 37m etcd 4.10.0 True False False 36m image-registry 4.10.0 True False False 31m ingress 4.10.0 True False False 30m insights 4.10.0 True False False 31m kube-apiserver 4.10.0 True False False 26m kube-controller-manager 4.10.0 True False False 36m kube-scheduler 4.10.0 True False False 36m kube-storage-version-migrator 4.10.0 True False False 37m machine-api 4.10.0 True False False 29m machine-approver 4.10.0 True False False 37m machine-config 4.10.0 True False False 36m marketplace 4.10.0 True False False 37m monitoring 4.10.0 True False False 29m network 4.10.0 True False False 38m node-tuning 4.10.0 True False False 37m openshift-apiserver 4.10.0 True False False 32m openshift-controller-manager 4.10.0 True False False 30m openshift-samples 4.10.0 True False False 32m operator-lifecycle-manager 4.10.0 True False False 37m operator-lifecycle-manager-catalog 4.10.0 True False False 37m operator-lifecycle-manager-packageserver 4.10.0 True False False 32m service-ca 4.10.0 True False False 38m storage 4.10.0 True False False 37m
- Configure the Operators that are not available.
15.2.16.1. 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.
15.2.16.1.1. Configuring registry storage for IBM Z
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 on IBM Z.
You have provisioned persistent storage for your cluster, such as Red Hat OpenShift Data Foundation.
ImportantOpenShift Container Platform supports
ReadWriteOnce
access for image registry storage when you have only one replica.ReadWriteOnce
access also requires that the registry uses theRecreate
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 theconfigs.imageregistry/cluster
resource.NoteWhen using 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 resourses found in openshift-image-registry namespace
NoteIf 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 animage-registry-storage
PVC.Check the
clusteroperator
status:$ oc get clusteroperator image-registry
Example output
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE MESSAGE image-registry 4.10 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
15.2.16.1.2. 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":{}}}}'
WarningConfigure 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.
15.2.17. Completing installation on user-provisioned infrastructure
After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.
Prerequisites
- Your control plane has initialized.
- You have completed the initial Operator configuration.
Procedure
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 4.10.0 True False False 19m baremetal 4.10.0 True False False 37m cloud-credential 4.10.0 True False False 40m cluster-autoscaler 4.10.0 True False False 37m config-operator 4.10.0 True False False 38m console 4.10.0 True False False 26m csi-snapshot-controller 4.10.0 True False False 37m dns 4.10.0 True False False 37m etcd 4.10.0 True False False 36m image-registry 4.10.0 True False False 31m ingress 4.10.0 True False False 30m insights 4.10.0 True False False 31m kube-apiserver 4.10.0 True False False 26m kube-controller-manager 4.10.0 True False False 36m kube-scheduler 4.10.0 True False False 36m kube-storage-version-migrator 4.10.0 True False False 37m machine-api 4.10.0 True False False 29m machine-approver 4.10.0 True False False 37m machine-config 4.10.0 True False False 36m marketplace 4.10.0 True False False 37m monitoring 4.10.0 True False False 29m network 4.10.0 True False False 38m node-tuning 4.10.0 True False False 37m openshift-apiserver 4.10.0 True False False 32m openshift-controller-manager 4.10.0 True False False 30m openshift-samples 4.10.0 True False False 32m operator-lifecycle-manager 4.10.0 True False False 37m operator-lifecycle-manager-catalog 4.10.0 True False False 37m operator-lifecycle-manager-packageserver 4.10.0 True False False 32m service-ca 4.10.0 True False False 38m storage 4.10.0 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 Post-installation machine configuration tasks documentation for more information.
15.2.18. Telemetry access for OpenShift Container Platform
In OpenShift Container Platform 4.10, 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
- How to generate SOSREPORT within OpenShift4 nodes without SSH.
15.2.19. Next steps
- Enabling multipathing with kernel arguments on RHCOS.
- Customize your cluster.
- If necessary, you can opt out of remote health reporting.
15.3. Installing a cluster with z/VM on IBM Z and LinuxONE in a restricted network
In OpenShift Container Platform version 4.10, you can install a cluster on IBM Z and LinuxONE infrastructure that you provision in a restricted network.
While this document refers to only IBM Z, all information in it also applies to LinuxONE.
Additional considerations exist for non-bare metal platforms. Review the information in the guidelines for deploying OpenShift Container Platform on non-tested platforms before you install an OpenShift Container Platform cluster.
15.3.1. 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.
-
You created a mirror registry for installation in a restricted network and obtained the
imageContentSources
data for your version of OpenShift Container Platform. Before you begin the installation process, you must move or remove any existing installation files. This ensures that the required installation files are created and updated during the installation process.
ImportantEnsure that installation steps are done from a machine with access to the installation media.
-
You provisioned persistent storage using OpenShift Data Foundation or other supported storage protocols for your cluster. To deploy a private image registry, you must set up persistent storage with
ReadWriteMany
access. 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.
NoteBe sure to also review this site list if you are configuring a proxy.
15.3.2. About installations in restricted networks
In OpenShift Container Platform 4.10, 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 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.
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.
15.3.2.1. Additional limits
Clusters in restricted networks have the following additional limitations and restrictions:
-
The
ClusterVersion
status includes anUnable 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.
15.3.3. Internet access for OpenShift Container Platform
In OpenShift Container Platform 4.10, 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.
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.
15.3.4. Requirements for a cluster with user-provisioned infrastructure
For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.
This section describes the requirements for deploying OpenShift Container Platform on user-provisioned infrastructure.
15.3.4.1. Required machines for cluster installation
The smallest OpenShift Container Platform clusters require the following 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. |
To improve high availability of your cluster, distribute the control plane machines over different z/VM instances on at least two physical machines.
The bootstrap, control plane, and compute machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.
Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.
15.3.4.2. Minimum resource requirements for cluster installation
Each cluster machine must meet the following minimum requirements:
Machine | Operating System | vCPU [1] | Virtual RAM | Storage | IOPS |
---|---|---|---|---|---|
Bootstrap | RHCOS | 4 | 16 GB | 100 GB | N/A |
Control plane | RHCOS | 4 | 16 GB | 100 GB | N/A |
Compute | RHCOS | 2 | 8 GB | 100 GB | N/A |
- One physical core (IFL) provides two logical cores (threads) when SMT-2 is enabled. The hypervisor can provide two or more vCPUs.
If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.
15.3.4.3. Minimum IBM Z system environment
You can install OpenShift Container Platform version 4.10 on the following IBM hardware:
- IBM z16 (all models), IBM z15 (all models), IBM z14 (all models), IBM z13, and IBM z13s
- LinuxONE, any version
Hardware requirements
- The equivalent of six Integrated Facilities for Linux (IFL), which are SMT2 enabled, for each cluster.
-
At least one network connection to both connect to the
LoadBalancer
service and to serve data for traffic outside the cluster.
You can use dedicated or shared IFLs to assign sufficient compute resources. Resource sharing is one of the key strengths of IBM Z. However, you must adjust capacity correctly on each hypervisor layer and ensure sufficient resources for every OpenShift Container Platform cluster.
Since the overall performance of the cluster can be impacted, the LPARs that are used to setup the OpenShift Container Platform clusters must provide sufficient compute capacity. In this context, LPAR weight management, entitlements, and CPU shares on the hypervisor level play an important role.
Operating system requirements
- One instance of z/VM 7.2 or later
On your z/VM instance, set up:
- Three guest virtual machines for OpenShift Container Platform control plane machines
- Two guest virtual machines for OpenShift Container Platform compute machines
- One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine
IBM Z network connectivity requirements
To install on IBM Z under z/VM, you require a single z/VM virtual NIC in layer 2 mode. You also need:
- A direct-attached OSA or RoCE network adapter
- A z/VM VSwitch set up. For a preferred setup, use OSA link aggregation.
Disk storage for the z/VM guest virtual machines
- FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV to ensure optimal performance.
- FCP attached disk storage
Storage / Main Memory
- 16 GB for OpenShift Container Platform control plane machines
- 8 GB for OpenShift Container Platform compute machines
- 16 GB for the temporary OpenShift Container Platform bootstrap machine
15.3.4.4. Preferred IBM Z system environment
Hardware requirements
- Three LPARS that each have the equivalent of six IFLs, which are SMT2 enabled, for each cluster.
-
Two network connections to both connect to the
LoadBalancer
service and to serve data for traffic outside the cluster. - HiperSockets, which are attached to a node either directly as a device or by bridging with one z/VM VSWITCH to be transparent to the z/VM guest. To directly connect HiperSockets to a node, you must set up a gateway to the external network via a RHEL 8 guest to bridge to the HiperSockets network.
Operating system requirements
- Two or three instances of z/VM 7.2 or later for high availability
On your z/VM instances, set up:
- Three guest virtual machines for OpenShift Container Platform control plane machines, one per z/VM instance.
- At least six guest virtual machines for OpenShift Container Platform compute machines, distributed across the z/VM instances.
- One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine.
-
To ensure the availability of integral components in an overcommitted environment, increase the priority of the control plane by using the CP command
SET SHARE
. Do the same for infrastructure nodes, if they exist. See SET SHARE in IBM Documentation.
IBM Z network connectivity requirements
To install on IBM Z under z/VM, you require a single z/VM virtual NIC in layer 2 mode. You also need:
- A direct-attached OSA or RoCE network adapter
- A z/VM VSwitch set up. For a preferred setup, use OSA link aggregation.
Disk storage for the z/VM guest virtual machines
- FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV and High Performance FICON (zHPF) to ensure optimal performance.
- FCP attached disk storage
Storage / Main Memory
- 16 GB for OpenShift Container Platform control plane machines
- 8 GB for OpenShift Container Platform compute machines
- 16 GB for the temporary OpenShift Container Platform bootstrap machine
15.3.4.5. 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 Bridging a HiperSockets LAN with a z/VM Virtual Switch in IBM Documentation.
- See Scaling HyperPAV alias devices on Linux guests on z/VM for performance optimization.
- See Topics in LPAR performance for LPAR weight management and entitlements.
- Recommended host practices for IBM Z & LinuxONE environments
15.3.4.6. 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.
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.
15.3.4.6.1. 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.
15.3.4.6.2. 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.
Protocol | Port | Description |
---|---|---|
ICMP | N/A | Network reachability tests |
TCP |
| Metrics |
|
Host level services, including the node exporter on ports | |
| The default ports that Kubernetes reserves | |
| openshift-sdn | |
UDP |
| VXLAN |
| Geneve | |
|
Host level services, including the node exporter on ports | |
| IPsec IKE packets | |
| IPsec NAT-T packets | |
TCP/UDP |
| Kubernetes node port |
ESP | N/A | IPsec Encapsulating Security Payload (ESP) |
Protocol | Port | Description |
---|---|---|
TCP |
| Kubernetes API |
Protocol | Port | Description |
---|---|---|
TCP |
| 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.
Additional resources
15.3.4.7. 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.
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>.
.
Component | Record | Description |
---|---|---|
Kubernetes API |
| 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. |
| 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 |
| 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, |
Bootstrap machine |
| 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 |
| 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 |
| 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. |
In OpenShift Container Platform 4.4 and later, you do not need to specify etcd host and SRV records in your DNS configuration.
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.
15.3.4.7.1. 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 15.4. Sample DNS zone database
$TTL 1W @ IN SOA ns1.example.com. root ( 2019070700 ; serial 3H ; refresh (3 hours) 30M ; retry (30 minutes) 2W ; expiry (2 weeks) 1W ) ; minimum (1 week) IN NS ns1.example.com. IN MX 10 smtp.example.com. ; ; ns1.example.com. IN A 192.168.1.5 smtp.example.com. IN A 192.168.1.5 ; helper.example.com. IN A 192.168.1.5 helper.ocp4.example.com. IN A 192.168.1.5 ; api.ocp4.example.com. IN A 192.168.1.5 1 api-int.ocp4.example.com. IN A 192.168.1.5 2 ; *.apps.ocp4.example.com. IN A 192.168.1.5 3 ; bootstrap.ocp4.example.com. IN A 192.168.1.96 4 ; master0.ocp4.example.com. IN A 192.168.1.97 5 master1.ocp4.example.com. IN A 192.168.1.98 6 master2.ocp4.example.com. IN A 192.168.1.99 7 ; worker0.ocp4.example.com. IN A 192.168.1.11 8 worker1.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 15.5. Sample DNS zone database for reverse records
$TTL 1W @ IN SOA ns1.example.com. root ( 2019070700 ; serial 3H ; refresh (3 hours) 30M ; retry (30 minutes) 2W ; expiry (2 weeks) 1W ) ; minimum (1 week) IN NS ns1.example.com. ; 5.1.168.192.in-addr.arpa. IN PTR api.ocp4.example.com. 1 5.1.168.192.in-addr.arpa. IN PTR api-int.ocp4.example.com. 2 ; 96.1.168.192.in-addr.arpa. IN PTR bootstrap.ocp4.example.com. 3 ; 97.1.168.192.in-addr.arpa. IN PTR master0.ocp4.example.com. 4 98.1.168.192.in-addr.arpa. IN PTR master1.ocp4.example.com. 5 99.1.168.192.in-addr.arpa. IN PTR master2.ocp4.example.com. 6 ; 11.1.168.192.in-addr.arpa. IN PTR worker0.ocp4.example.com. 7 7.1.168.192.in-addr.arpa. IN PTR worker1.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.
A PTR record is not required for the OpenShift Container Platform application wildcard.
15.3.4.8. 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.
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, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
- A stateless load balancing algorithm. The options vary based on the load balancer implementation.
ImportantDo 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 15.25. 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
NoteThe 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, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the ingress routes.
- 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.
TipIf 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 15.26. 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
NoteIf 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.
15.3.4.8.1. 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.
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 15.6. Sample API and application Ingress load balancer configuration
global log 127.0.0.1 local2 pidfile /var/run/haproxy.pid maxconn 4000 daemon defaults mode http log global option dontlognull option http-server-close option redispatch retries 3 timeout http-request 10s timeout queue 1m timeout connect 10s timeout client 1m timeout server 1m timeout http-keep-alive 10s timeout check 10s maxconn 3000 listen api-server-6443 1 bind *:6443 mode tcp server bootstrap bootstrap.ocp4.example.com:6443 check inter 1s backup 2 server master0 master0.ocp4.example.com:6443 check inter 1s server master1 master1.ocp4.example.com:6443 check inter 1s server master2 master2.ocp4.example.com:6443 check inter 1s 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.NoteIf 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.
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.
15.3.5. Preparing the user-provisioned infrastructure
Before you install OpenShift Container Platform on user-provisioned infrastructure, you must prepare the underlying infrastructure.
This section provides details about the high-level steps required to set up your cluster infrastructure in preparation for an OpenShift Container Platform installation. This includes configuring IP networking and network connectivity for your cluster nodes, preparing a web server for the Ignition files, 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
- Set up static IP addresses.
- Set up an HTTP or HTTPS server to provide Ignition files to the cluster nodes.
- 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.
ImportantBy 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.
- Configure DNS name resolution for the Kubernetes API, the application wildcard, the bootstrap machine, the control plane machines, and the compute machines.
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.
- 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.
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.
Some load balancing solutions require the DNS name resolution for the cluster nodes to be in place before the load balancing is initialized.
15.3.6. Validating DNS resolution for user-provisioned infrastructure
You can validate your DNS configuration before installing OpenShift Container Platform on user-provisioned infrastructure.
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.
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. 0 IN A 192.168.1.5
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. 0 IN A 192.168.1.5
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. 0 IN A 192.168.1.5
NoteIn 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. 0 IN A 192.168.1.5
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. 0 IN A 192.168.1.96
- 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.
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. 0 IN PTR api-int.ocp4.example.com. 1 5.1.168.192.in-addr.arpa. 0 IN PTR api.ocp4.example.com. 2
NoteA 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.
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. 0 IN PTR bootstrap.ocp4.example.com.
- 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.
15.3.7. Generating a key pair for cluster node SSH access
During an OpenShift Container Platform installation, you can provide an SSH public key to the installation program. The key is passed to the Red Hat Enterprise Linux CoreOS (RHCOS) nodes through their Ignition config files and is used to authenticate SSH access to the nodes. The key is added to the ~/.ssh/authorized_keys
list for the core
user on each node, which enables password-less authentication.
After the key is passed to the nodes, you can use the key pair to SSH in to the RHCOS nodes as the user core
. To access the nodes through SSH, the private key identity must be managed by SSH for your local user.
If you want to SSH in to your cluster nodes to perform installation debugging or disaster recovery, you must provide the SSH public key during the installation process. The ./openshift-install gather
command also requires the SSH public key to be in place on the cluster nodes.
Do not skip this procedure in production environments, where disaster recovery and debugging is required.
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.
NoteIf you plan to install an OpenShift Container Platform cluster that uses FIPS validated or Modules In Process cryptographic libraries on the
x86_64
architecture, do not create a key that uses theed25519
algorithm. Instead, create a key that uses thersa
orecdsa
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.NoteOn some distributions, default SSH private key identities such as
~/.ssh/id_rsa
and~/.ssh/id_dsa
are managed automatically.If the
ssh-agent
process is not already running for your local user, start it as a background task:$ eval "$(ssh-agent -s)"
Example output
Agent pid 31874
NoteIf your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.
Add your SSH private key to the
ssh-agent
:$ 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.
15.3.8. 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.
Procedure
Create an installation directory to store your required installation assets in:
$ mkdir <installation_directory>
ImportantYou 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>
.NoteYou must name this configuration file
install-config.yaml
.NoteFor some platform types, you can alternatively run
./openshift-install create install-config --dir <installation_directory>
to generate aninstall-config.yaml
file. You can provide details about your cluster configuration at the prompts.Back up the
install-config.yaml
file so that you can use it to install multiple clusters.ImportantThe
install-config.yaml
file is consumed during the next step of the installation process. You must back it up now.
15.3.8.1. Installation configuration parameters
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.
After installation, you cannot modify these parameters in the install-config.yaml
file.
15.3.8.1.1. Required configuration parameters
Required installation configuration parameters are described in the following table:
Parameter | Description | Values |
---|---|---|
|
The API version for the | String |
|
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 |
A fully-qualified domain or subdomain name, such as |
|
Kubernetes resource | Object |
|
The name of the cluster. DNS records for the cluster are all subdomains of |
String of lowercase letters, hyphens ( |
|
The configuration for the specific platform upon which to perform the installation: | Object |
| Get a pull secret from the 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" } } } |
15.3.8.1.2. 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.
Only IPv4 addresses are supported.
Parameter | Description | Values |
---|---|---|
| The configuration for the cluster network. | Object Note
You cannot modify parameters specified by the |
| The cluster network provider Container Network Interface (CNI) plugin to install. |
Either |
| The IP address blocks for pods.
The default value is 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 |
|
Required if you use An IPv4 network. |
An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between |
|
The subnet prefix length to assign to each individual node. For example, if | A subnet prefix.
The default value is |
|
The IP address block for services. The default value is The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network. | An array with an IP address block in CIDR format. For example: networking: serviceNetwork: - 172.30.0.0/16 |
| The IP address blocks for machines. If you specify multiple IP address blocks, the blocks must not overlap.
If you specify multiple IP kernel arguments, the | An array of objects. For example: networking: machineNetwork: - cidr: 10.0.0.0/16 |
|
Required if you use | An IP network block in CIDR notation.
For example, Note
Set the |
15.3.8.1.3. Optional configuration parameters
Optional installation configuration parameters are described in the following table:
Parameter | Description | Values |
---|---|---|
| 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 |
| Enables Linux control groups version 2 (cgroups v2) on specific nodes in your cluster. The OpenShift Container Platform process for enabling cgroups v2 disables all cgroup version 1 controllers and hierarchies. The OpenShift Container Platform cgroups version 2 feature is in Developer Preview and is not supported by Red Hat at this time. |
|
| The configuration for the machines that comprise the compute nodes. |
Array of |
|
Determines the instruction set architecture of the machines in the pool. Currently, heteregeneous clusters are not supported, so all pools must specify the same architecture. Valid values are | String |
|
Whether to enable or disable simultaneous multithreading, or Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance. |
|
|
Required if you use |
|
|
Required if you use |
|
| The number of compute machines, which are also known as worker machines, to provision. |
A positive integer greater than or equal to |
| The configuration for the machines that comprise the control plane. |
Array of |
|
Determines the instruction set architecture of the machines in the pool. Currently, heterogeneous clusters are not supported, so all pools must specify the same architecture. Valid values are | String |
|
Whether to enable or disable simultaneous multithreading, or Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance. |
|
|
Required if you use |
|
|
Required if you use |
|
| The number of control plane machines to provision. |
The only supported value is |
| The Cloud Credential Operator (CCO) mode. If no mode is specified, the CCO dynamically tries to determine the capabilities of the provided credentials, with a preference for mint mode on the platforms where multiple modes are supported. Note Not all CCO modes are supported for all cloud providers. For more information on CCO modes, see the Cloud Credential Operator entry in the Cluster Operators reference content. Note
If your AWS account has service control policies (SCP) enabled, you must configure the |
|
|
Enable or disable FIPS mode. The default is 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. The use of FIPS validated or Modules In Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the Note If you are using Azure File storage, you cannot enable FIPS mode. |
|
| Sources and repositories for the release-image content. |
Array of objects. Includes a |
|
Required if you use | String |
| Specify one or more repositories that may also contain the same images. | Array of strings |
| How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes. |
Setting this field to Important
If the value of the field is set to |
| The SSH key or keys to authenticate access 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 | One or more keys. For example: sshKey: <key1> <key2> <key3> |
15.3.8.2. Sample install-config.yaml file for IBM Z
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 architecture : s390x controlPlane: 5 hyperthreading: Enabled 6 name: master replicas: 3 7 architecture : s390x metadata: name: test 8 networking: clusterNetwork: - cidr: 10.128.0.0/14 9 hostPrefix: 23 10 networkType: OpenShiftSDN serviceNetwork: 11 - 172.30.0.0/16 platform: none: {} 12 fips: false 13 pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' 14 sshKey: 'ssh-ed25519 AAAA...' 15 additionalTrustBundle: | 16 -----BEGIN CERTIFICATE----- ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ -----END CERTIFICATE----- imageContentSources: 17 - mirrors: - <local_repository>/ocp4/openshift4 source: quay.io/openshift-release-dev/ocp-release - mirrors: - <local_repository>/ocp4/openshift4 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 thecompute
section is a sequence of mappings. To meet the requirements of the different data structures, the first line of thecompute
section must begin with a hyphen,-
, and the first line of thecontrolPlane
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.NoteSimultaneous multithreading (SMT) is enabled by default. If SMT is not available on your OpenShift Container Platform nodes, the
hyperthreading
parameter has no effect.ImportantIf you disable
hyperthreading
, whether on your OpenShift Container Platform nodes or in theinstall-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.NoteIf 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 to23
, then each node is assigned a/23
subnet out of the givencidr
, 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 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.
- 12
- You must set the platform to
none
. You cannot provide additional platform configuration variables for IBM Z infrastructure.ImportantClusters 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. - 13
- 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. The use of FIPS validated or Modules In Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the
x86_64
architecture. - 14
- 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
orregistry.example.com:5000
. For<credentials>
, specify the base64-encoded user name and password for your mirror registry. - 15
- The SSH public key for the
core
user in Red Hat Enterprise Linux CoreOS (RHCOS).NoteFor 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. - 16
- Add the
additionalTrustBundle
parameter and value. The value must be the contents of the certificate file that you used for your mirror registry. The certificate file can be an existing, trusted certificate authority or the self-signed certificate that you generated for the mirror registry. - 17
- Provide the
imageContentSources
section from the output of the command to mirror the repository.
15.3.8.3. 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.
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’sspec.noProxy
field to bypass the proxy if necessary.NoteThe
Proxy
objectstatus.noProxy
field is populated with the values of thenetworking.machineNetwork[].cidr
,networking.clusterNetwork[].cidr
, andnetworking.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
objectstatus.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----- ...
- 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
matchesx.y.com
, but noty.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 theopenshift-config
namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates atrusted-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 thetrustedCA
field of theProxy
object. TheadditionalTrustBundle
field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
NoteThe installation program does not support the proxy
readinessEndpoints
field.NoteIf 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
.
Only the Proxy
object named cluster
is supported, and no additional proxies can be created.
15.3.8.4. Configuring a three-node cluster
Optionally, you can deploy zero compute machines in a minimal three node 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 yourinstall-config.yaml
file, as shown in the followingcompute
stanza:compute: - name: worker platform: {} replicas: 0
NoteYou must set the value of the
replicas
parameter for the compute machines to0
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.NoteThe preferred resource for control plane nodes is six vCPUs and 21 GB. For three control plane nodes this is the memory + vCPU equivalent of a minimum five-node cluster. You should back the three nodes, each installed on a 120 GB disk, with three IFLs that are SMT2 enabled. The minimum tested setup is three vCPUs and 10 GB on a 120 GB disk for each control plane node.
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 totrue
. 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.
15.3.9. 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 and these fields cannot be changed:
clusterNetwork
- IP address pools from which pod IP addresses are allocated.
serviceNetwork
- IP address pool for services.
defaultNetwork.type
- Cluster network provider, such as OpenShift SDN or OVN-Kubernetes.
You can specify the cluster network provider configuration for your cluster by setting the fields for the defaultNetwork
object in the CNO object named cluster
.
15.3.9.1. Cluster Network Operator configuration object
The fields for the Cluster Network Operator (CNO) are described in the following table:
Field | Type | Description |
---|---|---|
|
|
The name of the CNO object. This name is always |
|
| 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
You can customize this field only in the |
|
| A block of IP addresses for services. The OpenShift SDN and OVN-Kubernetes Container Network Interface (CNI) network providers 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 |
|
| Configures the Container Network Interface (CNI) cluster network provider for the cluster network. |
|
| The fields for this object specify the kube-proxy configuration. If you are using the OVN-Kubernetes cluster network provider, the kube-proxy configuration has no effect. |
defaultNetwork object configuration
The values for the defaultNetwork
object are defined in the following table:
Field | Type | Description |
---|---|---|
|
|
Either Note OpenShift Container Platform uses the OpenShift SDN Container Network Interface (CNI) cluster network provider by default. |
|
| This object is only valid for the OpenShift SDN cluster network provider. |
|
| This object is only valid for the OVN-Kubernetes cluster network provider. |
Configuration for the OpenShift SDN CNI cluster network provider
The following table describes the configuration fields for the OpenShift SDN Container Network Interface (CNI) cluster network provider.
Field | Type | Description |
---|---|---|
|
|
Configures the network isolation mode for OpenShift SDN. The default value is
The values |
|
| 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 This value cannot be changed after cluster installation. |
|
|
The port to use for all VXLAN packets. The default value is 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 |
Example OpenShift SDN configuration
defaultNetwork: type: OpenShiftSDN openshiftSDNConfig: mode: NetworkPolicy mtu: 1450 vxlanPort: 4789
Configuration for the OVN-Kubernetes CNI cluster network provider
The following table describes the configuration fields for the OVN-Kubernetes CNI cluster network provider.
Field | Type | Description |
---|---|---|
|
| 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 |
|
|
The port to use for all Geneve packets. The default value is |
|
| Specify an empty object to enable IPsec encryption. This value cannot be changed after cluster installation. |
|
| Specify a configuration object for customizing network policy audit logging. If unset, the defaults audit log settings are used. |
|
| 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. |
Field | Type | Description |
---|---|---|
| integer |
The maximum number of messages to generate every second per node. The default value is |
| integer |
The maximum size for the audit log in bytes. The default value is |
| string | One of the following additional audit log targets:
|
| string |
The syslog facility, such as |
Field | Type | Description |
---|---|---|
|
|
Set this field to
This field has an interaction with the Open vSwitch hardware offloading feature. If you set this field to |
Example OVN-Kubernetes configuration with IPSec enabled
defaultNetwork: type: OVNKubernetes ovnKubernetesConfig: mtu: 1400 genevePort: 6081 ipsecConfig: {}
kubeProxyConfig object configuration
The values for the kubeProxyConfig
object are defined in the following table:
Field | Type | Description |
---|---|---|
|
|
The refresh period for Note
Because of performance improvements introduced in OpenShift Container Platform 4.3 and greater, adjusting the |
|
|
The minimum duration before refreshing kubeProxyConfig: proxyArguments: iptables-min-sync-period: - 0s |
15.3.10. Creating the Kubernetes manifest and Ignition config files
Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to configure the machines.
The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to configure the cluster machines.
-
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.
The installation program that generates the manifest and Ignition files is architecture specific and can be obtained from the client image mirror. The Linux version of the installation program runs on s390x only. This installer program is also available as a Mac OS version.
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 theinstall-config.yaml
file you created.
WarningIf you are installing a three-node cluster, skip the following step to allow the control plane nodes to be schedulable.
ImportantWhen you configure control plane nodes from the default unschedulable to schedulable, additional subscriptions are required. This is because control plane nodes then become worker nodes.
Check that the
mastersSchedulable
parameter in the<installation_directory>/manifests/cluster-scheduler-02-config.yml
Kubernetes manifest file is set tofalse
. This setting prevents pods from being scheduled on the control plane machines:-
Open the
<installation_directory>/manifests/cluster-scheduler-02-config.yml
file. -
Locate the
mastersSchedulable
parameter and ensure that it is set tofalse
. - Save and exit the file.
-
Open the
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
andkubeconfig
files are created in the./<installation_directory>/auth
directory:. ├── auth │ ├── kubeadmin-password │ └── kubeconfig ├── bootstrap.ign ├── master.ign ├── metadata.json └── worker.ign
15.3.11. Installing RHCOS and starting the OpenShift Container Platform bootstrap process
To install OpenShift Container Platform on IBM Z infrastructure that you provision, you must install Red Hat Enterprise Linux CoreOS (RHCOS) on z/VM guest virtual 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 z/VM guest virtual machines have rebooted.
Complete the following steps to create the machines.
Prerequisites
- An HTTP or HTTPS server running on your provisioning machine that is accessible to the machines you create.
Procedure
- Log in to Linux on your provisioning machine.
Obtain the Red Hat Enterprise Linux CoreOS (RHCOS) kernel, initramfs, and rootfs files from the RHCOS image mirror.
ImportantThe 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. Only use the appropriate kernel, initramfs, and rootfs artifacts described in the following procedure.
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
NoteThe rootfs image is the same for FCP and DASD.
-
kernel:
Create parameter files. The following parameters are specific for a particular virtual machine:
For
ip=
, specify the following seven entries:- The IP address for the machine.
- An empty string.
- The gateway.
- The netmask.
-
The machine host and domain name in the form
hostname.domainname
. Omit this value to let RHCOS decide. - The network interface name. Omit this value to let RHCOS decide.
-
If you use static IP addresses, specify
none
.
-
For
coreos.inst.ignition_url=
, specify the Ignition file for the machine role. Usebootstrap.ign
,master.ign
, orworker.ign
. Only HTTP and HTTPS protocols are supported. -
For
coreos.live.rootfs_url=
, specify the matching rootfs artifact for the kernel and initramfs you are booting. Only HTTP and HTTPS protocols are supported. For installations on DASD-type disks, complete the following tasks:
-
For
coreos.inst.install_dev=
, specifydasda
. -
Use
rd.dasd=
to specify the DASD where RHCOS is to be installed. Leave all other parameters unchanged.
Example parameter file,
bootstrap-0.parm
, for the bootstrap machine:rd.neednet=1 \ console=ttysclp0 \ coreos.inst.install_dev=dasda \ coreos.live.rootfs_url=http://cl1.provide.example.com:8080/assets/rhcos-live-rootfs.s390x.img \ coreos.inst.ignition_url=http://cl1.provide.example.com:8080/ignition/bootstrap.ign \ ip=172.18.78.2::172.18.78.1:255.255.255.0:::none nameserver=172.18.78.1 \ rd.znet=qeth,0.0.bdf0,0.0.bdf1,0.0.bdf2,layer2=1,portno=0 \ zfcp.allow_lun_scan=0 \ rd.dasd=0.0.3490
Write all options in the parameter file as a single line and make sure you have no newline characters.
-
For
For installations on FCP-type disks, complete the following tasks:
Use
rd.zfcp=<adapter>,<wwpn>,<lun>
to specify the FCP disk where RHCOS is to be installed. For multipathing repeat this step for each additional path.NoteWhen you install with multiple paths, you must enable multipathing directly after the installation, not at a later point in time, as this can cause problems.
Set the install device as:
coreos.inst.install_dev=sda
.NoteIf additional LUNs are configured with NPIV, FCP requires
zfcp.allow_lun_scan=0
. If you must enablezfcp.allow_lun_scan=1
because you use a CSI driver, for example, you must configure your NPIV so that each node cannot access the boot partition of another node.Leave all other parameters unchanged.
ImportantAdditional post-installation steps are required to fully enable multipathing. For more information, see “Enabling multipathing with kernel arguments on RHCOS" in Post-installation machine configuration tasks.
The following is an example parameter file
worker-1.parm
for a worker node with multipathing:rd.neednet=1 \ console=ttysclp0 \ coreos.inst.install_dev=sda \ coreos.live.rootfs_url=http://cl1.provide.example.com:8080/assets/rhcos-live-rootfs.s390x.img \ coreos.inst.ignition_url=http://cl1.provide.example.com:8080/ignition/worker.ign \ ip=172.18.78.2::172.18.78.1:255.255.255.0:::none nameserver=172.18.78.1 \ rd.znet=qeth,0.0.bdf0,0.0.bdf1,0.0.bdf2,layer2=1,portno=0 \ zfcp.allow_lun_scan=0 \ rd.zfcp=0.0.1987,0x50050763070bc5e3,0x4008400B00000000 \ rd.zfcp=0.0.19C7,0x50050763070bc5e3,0x4008400B00000000 \ rd.zfcp=0.0.1987,0x50050763071bc5e3,0x4008400B00000000 \ rd.zfcp=0.0.19C7,0x50050763071bc5e3,0x4008400B00000000
Write all options in the parameter file as a single line and make sure you have no newline characters.
- Transfer the initramfs, kernel, parameter files, and RHCOS images to z/VM, for example with FTP. For details about how to transfer the files with FTP and boot from the virtual reader, see Installing under Z/VM.
Punch the files to the virtual reader of the z/VM guest virtual machine that is to become your bootstrap node.
See PUNCH in IBM Documentation.
TipYou can use the CP PUNCH command or, if you use Linux, the vmur command to transfer files between two z/VM guest virtual machines.
- Log in to CMS on the bootstrap machine.
IPL the bootstrap machine from the reader:
$ ipl c
See IPL in IBM Documentation.
- Repeat this procedure for the other machines in the cluster.
15.3.11.1. 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.
15.3.11.1.1. 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.
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 table 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.
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
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.
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. Entermodinfo 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,fail_over_mac=1 ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
Always set option fail_over_mac=1
in active-backup mode, to avoid problems when shared OSA/RoCE cards are used.
Bonding multiple network interfaces to a single interface
Optional: You can configure VLANs on bonded interfaces by using the vlan=
parameter and to use DHCP, for example:
ip=bond0.100:dhcp bond=bond0:em1,em2:mode=active-backup vlan=bond0.100:bond0
Use the following example to configure the bonded interface with a VLAN and to use a static IP address:
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0.100:none bond=bond0:em1,em2:mode=active-backup vlan=bond0.100:bond0
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
).
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
15.3.12. 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.
Procedure
Monitor the bootstrap process:
$ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ 1 --log-level=info 2
Example output
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443... INFO API v1.23.0 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 bootstrap process is complete, remove the bootstrap machine from the load balancer.
ImportantYou must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the bootstrap machine itself.
15.3.13. 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
15.3.14. 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 v1.23.0 master-1 Ready master 63m v1.23.0 master-2 Ready master 64m v1.23.0
The output lists all of the machines that you created.
NoteThe 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
orApproved
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:NoteBecause 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.NoteFor 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
, andoc 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 thenode-bootstrapper
service account in thesystem:node
orsystem: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
NoteSome 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 v1.23.0 master-1 Ready master 73m v1.23.0 master-2 Ready master 74m v1.23.0 worker-0 Ready worker 11m v1.23.0 worker-1 Ready worker 11m v1.23.0
NoteIt 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.
15.3.15. 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 4.10.0 True False False 19m baremetal 4.10.0 True False False 37m cloud-credential 4.10.0 True False False 40m cluster-autoscaler 4.10.0 True False False 37m config-operator 4.10.0 True False False 38m console 4.10.0 True False False 26m csi-snapshot-controller 4.10.0 True False False 37m dns 4.10.0 True False False 37m etcd 4.10.0 True False False 36m image-registry 4.10.0 True False False 31m ingress 4.10.0 True False False 30m insights 4.10.0 True False False 31m kube-apiserver 4.10.0 True False False 26m kube-controller-manager 4.10.0 True False False 36m kube-scheduler 4.10.0 True False False 36m kube-storage-version-migrator 4.10.0 True False False 37m machine-api 4.10.0 True False False 29m machine-approver 4.10.0 True False False 37m machine-config 4.10.0 True False False 36m marketplace 4.10.0 True False False 37m monitoring 4.10.0 True False False 29m network 4.10.0 True False False 38m node-tuning 4.10.0 True False False 37m openshift-apiserver 4.10.0 True False False 32m openshift-controller-manager 4.10.0 True False False 30m openshift-samples 4.10.0 True False False 32m operator-lifecycle-manager 4.10.0 True False False 37m operator-lifecycle-manager-catalog 4.10.0 True False False 37m operator-lifecycle-manager-packageserver 4.10.0 True False False 32m service-ca 4.10.0 True False False 38m storage 4.10.0 True False False 37m
- Configure the Operators that are not available.
15.3.15.1. Disabling the default OperatorHub 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 theOperatorHub
object:$ oc patch OperatorHub cluster --type json \ -p '[{"op": "add", "path": "/spec/disableAllDefaultSources", "value": true}]'
Alternatively, you can use the web console to manage catalog sources. From the Administration
15.3.15.2. 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.
15.3.15.2.1. Configuring registry storage for IBM Z
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 on IBM Z.
You have provisioned persistent storage for your cluster, such as Red Hat OpenShift Data Foundation.
ImportantOpenShift Container Platform supports
ReadWriteOnce
access for image registry storage when you have only one replica.ReadWriteOnce
access also requires that the registry uses theRecreate
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 theconfigs.imageregistry/cluster
resource.NoteWhen using 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 resourses found in openshift-image-registry namespace
NoteIf 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 animage-registry-storage
PVC.Check the
clusteroperator
status:$ oc get clusteroperator image-registry
Example output
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE MESSAGE image-registry 4.10 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
15.3.15.2.2. 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":{}}}}'
WarningConfigure 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.
15.3.16. 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 4.10.0 True False False 19m baremetal 4.10.0 True False False 37m cloud-credential 4.10.0 True False False 40m cluster-autoscaler 4.10.0 True False False 37m config-operator 4.10.0 True False False 38m console 4.10.0 True False False 26m csi-snapshot-controller 4.10.0 True False False 37m dns 4.10.0 True False False 37m etcd 4.10.0 True False False 36m image-registry 4.10.0 True False False 31m ingress 4.10.0 True False False 30m insights 4.10.0 True False False 31m kube-apiserver 4.10.0 True False False 26m kube-controller-manager 4.10.0 True False False 36m kube-scheduler 4.10.0 True False False 36m kube-storage-version-migrator 4.10.0 True False False 37m machine-api 4.10.0 True False False 29m machine-approver 4.10.0 True False False 37m machine-config 4.10.0 True False False 36m marketplace 4.10.0 True False False 37m monitoring 4.10.0 True False False 29m network 4.10.0 True False False 38m node-tuning 4.10.0 True False False 37m openshift-apiserver 4.10.0 True False False 32m openshift-controller-manager 4.10.0 True False False 30m openshift-samples 4.10.0 True False False 32m operator-lifecycle-manager 4.10.0 True False False 37m operator-lifecycle-manager-catalog 4.10.0 True False False 37m operator-lifecycle-manager-packageserver 4.10.0 True False False 32m service-ca 4.10.0 True False False 38m storage 4.10.0 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 Post-installation machine configuration tasks documentation for more information.
- Register your cluster on the Cluster registration page.
15.3.17. Next steps
- Customize your cluster.
- 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