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Installing on IBM Power

OpenShift Container Platform 4.6

Installing OpenShift Container Platform IBM Power clusters

Red Hat OpenShift Documentation Team

Abstract

This document provides instructions for installing OpenShift Container Platform clusters on IBM Power.

Chapter 1. Installing on IBM Power

1.1. Installing a cluster on IBM Power Systems

In OpenShift Container Platform version 4.6, you can install a cluster on IBM Power Systems infrastructure that you provision.

Important

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.

Prerequisites

  • 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.
  • Provision persistent storage using NFS for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.
  • Review details about the OpenShift Container Platform installation and update processes.

  • If you use a firewall, you must configure it to allow the sites that your cluster requires access to.

    Note

    Be sure to also review this site list if you are configuring a proxy.

1.1.1. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.6, you require access to the Internet to install your cluster.

You must have Internet access to:

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

If your cluster cannot have direct Internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the content that is required and use it to populate a mirror registry with the packages that you need to install a cluster and generate the installation program. 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.

1.1.2. Machine requirements for a cluster with user-provisioned infrastructure

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

1.1.2.1. Required machines

The smallest OpenShift Container Platform clusters require the following hosts:

  • One temporary bootstrap machine
  • Three control plane, or master, machines
  • At least two compute machines, which are also known as worker machines.
Note

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.

Important

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

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS) or Red Hat Enterprise Linux (RHEL) 7.9.

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.

1.1.2.2. Network connectivity requirements

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config files from the Machine Config Server. During the initial boot, the machines require either a DHCP server or that static IP addresses be set in order to establish a network connection to download their Ignition config files. Additionally, each OpenShift Container Platform node in the cluster must have access to a Network Time Protocol (NTP) server. If a DHCP server provides NTP servers information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

1.1.2.3. Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

MachineOperating SystemvCPU [1]Virtual RAMStorageIOPS [2]

Bootstrap

RHCOS

2

16 GB

100 GB

300

Control plane

RHCOS

2

16 GB

100 GB

300

Compute

RHCOS

2

8 GB

100 GB

300

  1. One vCPU is equivalent to one physical core when simultaneous multithreading (SMT), or hyperthreading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.
  2. OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
1.1.2.4. 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.

1.1.3. Creating the user-provisioned infrastructure

Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Procedure

  1. Configure DHCP or set static IP addresses on each node.
  2. Provision the required load balancers.
  3. Configure the ports for your machines.
  4. Configure DNS.
  5. Ensure network connectivity.
1.1.3.1. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

During the initial boot, the machines require either a DHCP server or that static IP addresses be set on each host in the cluster in order to establish a network connection, which allows them to download their Ignition config files.

It is recommended to use the DHCP server to manage the machines for the cluster long-term. Ensure that the DHCP server is configured to provide persistent IP addresses and host names to the cluster machines.

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.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 1.1. All machines to all machines
ProtocolPortDescription

ICMP

N/A

Network reachability tests

TCP

1936

Metrics

9000-9999

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

10250-10259

The default ports that Kubernetes reserves

10256

openshift-sdn

UDP

4789

VXLAN and Geneve

6081

VXLAN and Geneve

9000-9999

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

TCP/UDP

30000-32767

Kubernetes node port

Table 1.2. All machines to control plane
ProtocolPortDescription

TCP

6443

Kubernetes API

Table 1.3. Control plane machines to control plane machines
ProtocolPortDescription

TCP

2379-2380

etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

Important

OpenShift Container Platform requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Load balancers

Before you install OpenShift Container Platform, you must provision two load balancers that meet the following requirements:

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

    • Layer 4 load balancing only. This can be referred to as Raw TCP, 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.
    Important

    Do not configure session persistence for an API load balancer.

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

    Table 1.4. API load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    6443

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

    X

    X

    Kubernetes API server

    22623

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

    X

    		 

    Machine config server

    Note

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

  2. Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. 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.

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

    Table 1.5. Application Ingress load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    443

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

    X

    X

    HTTPS traffic

    80

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

    X

    X

    HTTP traffic

Tip

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

Note

A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes.

NTP configuration

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

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

Additional resources

1.1.3.2. User-provisioned DNS requirements

DNS is used for name resolution and reverse name resolution. 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 host name for all the nodes. 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 an OpenShift Container Platform cluster that uses user-provisioned infrastructure. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 1.6. Required DNS records
ComponentRecordDescription

Kubernetes API

api.<cluster_name>.<base_domain>.

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

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

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. 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 host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

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

Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

Bootstrap

bootstrap.<cluster_name>.<base_domain>.

Add 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.

Master hosts

<master><n>.<cluster_name>.<base_domain>.

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

Worker hosts

<worker><n>.<cluster_name>.<base_domain>.

Add 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.

Tip

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

The following example of a BIND zone file shows sample A records for name resolution. The purpose of the example is to show the records that are needed. The example is not meant to provide advice for choosing one name resolution service over another.

Example 1.1. 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	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Example 1.2. 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.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.example.com.
5	IN	PTR	api-int.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

1.1.4. Generating an SSH private key and adding it to the agent

If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent and the installation program. You can use this key to access the bootstrap machine in a public cluster to troubleshoot installation issues.

Note

In a production environment, you require disaster recovery and debugging.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

Note

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

Procedure

  1. If you do not have an SSH key that is configured for password-less authentication on your computer, 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_rsa, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.

    Running this command generates an SSH key that does not require a password in the location that you specified.

    Note

    If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. Start the ssh-agent process as a background task: 

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

    Example output

    Agent pid 31874

    Note

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

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

    $ ssh-add <path>/<file_name> 1

    Example output

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

    1
    Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

  • When you install OpenShift Container Platform, provide the SSH public key to the installation program.

1.1.5. Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on a local computer.

Prerequisites

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

Procedure

  1. 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.
  2. Select your infrastructure provider.

  3. Navigate to the page for your installation type, download the installation program for your operating system, and place the file in the directory where you will store the installation configuration files.

    Important

    The installation program creates several files on the computer that you use to install your cluster. You must keep the installation program and the files that the installation program creates after you finish installing the cluster. Both files are required to delete the cluster.

    Important

    Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OpenShift Container Platform uninstallation procedures for your specific cloud provider.

  4. 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
  5. 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.

1.1.6. Installing the OpenShift CLI by downloading the binary

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

Important

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.6. Download and install the new version of oc.

1.1.6.1. Installing the OpenShift CLI on Linux

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

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the appropriate version in the Version drop-down menu.
  3. Click Download Now next to the OpenShift v4.6 Linux Client entry and save the file.

  4. Unpack the archive: 

    $ tar xvzf <file>

  5. Place the oc binary in a directory that is on your PATH.

    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>
1.1.6.2. Installing the OpenShift CLI on Windows

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

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the appropriate version in the Version drop-down menu.
  3. Click Download Now next to the OpenShift v4.6 Windows Client entry and save the file.
  4. Unzip the archive with a ZIP program.

  5. Move the oc binary to a directory that is on your PATH.

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

    C:\> path

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

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

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

Procedure

  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
  2. Select the appropriate version in the Version drop-down menu.
  3. Click Download Now next to the OpenShift v4.6 MacOSX Client entry and save the file.
  4. Unpack and unzip the archive.

  5. Move the oc binary to a directory on your PATH.

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

    $ echo $PATH

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

$ oc <command>

1.1.7. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

  • Obtain the OpenShift Container Platform installation program and the access token for your cluster.

Procedure

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

    $ mkdir <installation_directory>
    Important

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

  2. Customize the following install-config.yaml file template and save it in the <installation_directory>.

    Note

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

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

    Important

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

1.1.7.1. Sample install-config.yaml file for IBM Power Systems

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 : ppc64le
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
  architecture : ppc64le
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 the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Only one control plane pool is used.
3 6
Whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note

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

Important

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

4
You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OpenShift Container Platform.
7
The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8
The cluster name that you specified in your DNS records.
9
A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
Note

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

10
The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs 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 Power Systems infrastructure.
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

The use of FIPS Validated / 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 public portion of the default SSH key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note

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

1.1.7.2. Configuring the cluster-wide proxy during installation

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

Prerequisites

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

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

    Note

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

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

Procedure

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

    apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> 1
  httpsProxy: https://<username>:<pswd>@<ip>:<port> 2
  noProxy: example.com 3
additionalTrustBundle: | 4
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...
    1
    A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
    2
    A proxy URL to use for creating HTTPS connections outside the cluster.
    3
    A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations.
    4
    If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace to hold the additional CA certificates. If you provide additionalTrustBundle and at least one proxy setting, the Proxy object is configured to reference the user-ca-bundle config map in the trustedCA field. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges the contents specified for the trustedCA parameter with the RHCOS trust bundle. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
    Note

    The installation program does not support the proxy readinessEndpoints field.

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

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

Note

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

1.1.8. 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 make its machines.

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

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

Prerequisites

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

Procedure

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

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

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

    1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
    2. Locate the mastersSchedulable parameter and ensure that it is set to false.
    3. Save and exit the file.

  3. To create the Ignition configuration files, run the following command from the directory that contains the installation program: 

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

    The following files are generated in the directory: 

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

1.1.9. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Before you install a cluster on IBM Power Systems infrastructure that you provision, you must create RHCOS machines for it to use. Follow either the steps to use an ISO image or network PXE booting to create the machines.

1.1.9.1. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines using an ISO image

Before you install a cluster on IBM Power Systems infrastructure that you provision, you must create RHCOS machines for it to use. You can use an ISO image to create the machines.

Prerequisites

  • Obtain the Ignition config files for your cluster.
  • Have access to an HTTP server that can be accessed from your computer, and from the machines that you create.

Procedure

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

    Important

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

  2. Obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page.

    Important

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

    ISO file names resemble the following example:

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

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

    • Burn the ISO image to a disk and boot it directly.
    • Use ISO redirection via a LOM interface.
  4. Boot the ISO image. You can interrupt the installation boot process to add kernel arguments. However, for this ISO procedure you should use the coreos-installer command instead of adding kernel arguments. If you run the live installer without options or interruption, the installer boots up to a shell prompt on the live system, ready for you to install RHCOS to disk.
  5. Review the Advanced RHCOS installation reference section for different ways of configuring features, such as networking and disk partitions, before running the coreos-installer.

  6. Run the coreos-installer command. At a minimum, you must identify the Ignition config file location for your node type, and the location of the disk you are installing to. Here is an example: 

    $ sudo coreos-installer install \
     --ignition-url=https://host/worker.ign /dev/sda
  7. After RHCOS installs, the system reboots. During the system reboot, it applies the Ignition config file that you specified.

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

    Important

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

1.1.9.1.1. 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.

Routing and bonding options at RHCOS boot prompt

If you install RHCOS from an ISO image, you can add kernel arguments manually when you boot that image to configure the node’s networking. If no networking arguments are used, the installation defaults to using DHCP.

Important

When adding networking arguments, you must also add the rd.neednet=1 kernel argument.

The following table describes how to use ip=, nameserver=, and bond= kernel arguments for live ISO installs.

Note

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

Routing and bonding options for ISO

The following table provides examples for configuring networking of your Red Hat Enterprise Linux CoreOS (RHCOS) nodes. These are networking options that 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.

DescriptionExamples

To configure an IP address, either use DHCP (ip=dhcp) or set an individual static IP address (ip=<host_ip>). Then identify the DNS server IP address (nameserver=<dns_ip>) on each node. This 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 
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
nameserver=4.4.4.41

Specify multiple network interfaces by specifying 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

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

If the additional network gateway is different from the primary network gateway, the default gateway must be the primary network gateway.

To configure the default gateway: 

ip=::10.10.10.254::::

To configure the route for the additional network: 

rd.route=20.20.20.0/24:20.20.20.254:enp2s0

Disable DHCP on a single interface, such as when there are two or more network interfaces and only one interface is being 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

You can combine DHCP and static IP configurations on systems with multiple network interfaces. 

ip=enp1s0:dhcp
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none

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: 

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: 

ip=enp2s0.100:dhcp
vlan=enp2s0.100:enp2s0

You can provide multiple DNS servers by adding a nameserver= entry for each server. 

nameserver=1.1.1.1
nameserver=8.8.8.8

Optional: Bonding multiple network interfaces to a single interface is supported using the bond= option. In these two examples:

  • The syntax for configuring a bonded interface is: bond=name[:network_interfaces][:options]
  • name is the bonding device name (bond0), network_interfaces represents a comma-separated list of physical (ethernet) interfaces (em1,em2), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.
  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

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

bond=bond0:em1,em2:mode=active-backup
ip=bond0:dhcp

To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: 

bond=bond0:em1,em2:mode=active-backup
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none

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

To configure the bonded interface with a VLAN and to use DHCP: 

ip=bond0.100:dhcp
bond=bond0:em1,em2:mode=active-backup
vlan=bond0.100:bond0

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

Optional: Network teaming can be used as an alternative to bonding by using the team= parameter. In this example:

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

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

Note

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

To configure a network team: 

team=team0:em1,em2
ip=team0:dhcp
1.1.9.2. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines by PXE or iPXE booting

Before you install a cluster that uses manually-provisioned RHCOS nodes, such as bare metal, you must create RHCOS machines for it to use. You can use PXE or iPXE booting to create the machines.

Prerequisites

  • Obtain the Ignition config files for your cluster.
  • Configure suitable PXE or iPXE infrastructure.
  • Have access to an HTTP server that you can access from your computer.

Procedure

  1. Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

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

  2. Obtain the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page.

    Important

    The RHCOS artifacts might not change with every release of OpenShift Container Platform. You must download artifacts with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate kernel, initramfs, and rootfs artifacts described below for this procedure. RHCOS qcow2 images are not supported for this installation type.

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

    • kernel: rhcos-<version>-live-kernel-<architecture>
    • initramfs: rhcos-<version>-live-initramfs.<architecture>.img
    • rootfs: rhcos-<version>-live-rootfs.<architecture>.img

  3. Upload the additional files that are required for your booting method:

    • For traditional PXE, upload the kernel and initramfs files to your TFTP server and the rootfs file to your HTTP server.

    • For iPXE, upload the kernel, initramfs, and rootfs files to your HTTP server.

      Important

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

  4. Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.

  5. Configure PXE or iPXE installation for the RHCOS images.

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

    • For PXE: 

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

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

    • For iPXE: 

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

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

  6. If you use PXE UEFI, perform the following actions:

    1. Provide the shimx64.efi and grubx64.efi EFI binaries and the grub.cfg file that are required for booting the system.

      • Extract the necessary EFI binaries by mounting the RHCOS ISO to your host and then mounting the images/efiboot.img file to your host: 

        $ mkdir -p /mnt/iso
        $ mkdir -p /mnt/efiboot
        $ mount -o loop rhcos-installer.x86_64.iso /mnt/iso
        $ mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot

      • From the efiboot.img mount point, copy the EFI/redhat/shimx64.efi and EFI/redhat/grubx64.efi files to your TFTP server: 

        $ cp /mnt/efiboot/EFI/redhat/shimx64.efi .
        $ cp /mnt/efiboot/EFI/redhat/grubx64.efi .
        $ umount /mnt/efiboot
        $ umount /mnt/iso
      • Copy the EFI/redhat/grub.cfg file that is included in the RHCOS ISO to your TFTP server.

    2. Edit the grub.cfg file to include arguments similar to the following: 

      menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os {
	linuxefi rhcos-<version>-live-kernel-<architecture> coreos.inst.install_dev=/dev/sda coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign
	initrdefi rhcos-<version>-live-initramfs.<architecture>.img
}

      where:

      rhcos-<version>-live-kernel-<architecture>
      Specifies the kernel file that you uploaded to your TFTP server.
      http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img
      Specifies the location of the live rootfs image that you uploaded to your HTTP server.
      http://<HTTP_server>/bootstrap.ign
      Specifies the location of the bootstrap Ignition config file that you uploaded to your HTTP server.
      rhcos-<version>-live-initramfs.<architecture>.img
      Specifies the location of the initramfs file that you uploaded to your TFTP server.
      Note

      For more information on how to configure a PXE server for UEFI boot, see the Red Hat Knowledgebase article: How to configure/setup a PXE server for UEFI boot for Red Hat Enterprise Linux?.

  7. Continue to create the machines for your cluster.

    Important

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

1.1.10. Creating the cluster

To create the OpenShift Container Platform cluster, you wait for the bootstrap process to complete on the machines that you provisioned by using the Ignition config files that you generated with the installation program.

Prerequisites

  • Create the required infrastructure for the cluster.
  • You obtained the installation program and generated the Ignition config files for your cluster.
  • You used the Ignition config files to create RHCOS machines for your cluster.
  • Your machines have direct Internet access or have an HTTP or HTTPS proxy available.

Procedure

  1. Monitor the bootstrap process: 

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

    Example output

    INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.19.0 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.

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

    Important

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

1.1.11. Logging in to the cluster by using the CLI

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

Prerequisites

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

Procedure

  1. Export the kubeadmin credentials: 

    $ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.

  2. Verify you can run oc commands successfully using the exported configuration: 

    $ oc whoami

    Example output

    system:admin

1.1.12. Approving the certificate signing requests for your machines

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

Prerequisites

  • You added machines to your cluster.

Procedure

  1. Confirm that the cluster recognizes the machines: 

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.19.0
master-1  Ready     master  63m  v1.19.0
master-2  Ready     master  64m  v1.19.0

    The output lists all of the machines that you created.

    Note

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

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

    $ oc get csr

    Example output

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

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

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

    Note

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

    Note

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

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

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.

    • To approve all pending CSRs, run the following command: 

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

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

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

    $ oc get csr

    Example output

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

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

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

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.

    • To approve all pending CSRs, run the following command: 

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve

  6. After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command: 

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

    Note

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

Additional information

1.1.13. Initial Operator configuration

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

Prerequisites

  • Your control plane has initialized.

Procedure

  1. Watch the cluster components come online: 

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.6.0   True        False         False      3h56m
cloud-credential                           4.6.0   True        False         False      29h
cluster-autoscaler                         4.6.0   True        False         False      29h
config-operator                            4.6.0   True        False         False      6h39m
console                                    4.6.0   True        False         False      3h59m
csi-snapshot-controller                    4.6.0   True        False         False      4h12m
dns                                        4.6.0   True        False         False      4h15m
etcd                                       4.6.0   True        False         False      29h
image-registry                             4.6.0   True        False         False      3h59m
ingress                                    4.6.0   True        False         False      4h30m
insights                                   4.6.0   True        False         False      29h
kube-apiserver                             4.6.0   True        False         False      29h
kube-controller-manager                    4.6.0   True        False         False      29h
kube-scheduler                             4.6.0   True        False         False      29h
kube-storage-version-migrator              4.6.0   True        False         False      4h2m
machine-api                                4.6.0   True        False         False      29h
machine-approver                           4.6.0   True        False         False      6h34m
machine-config                             4.6.0   True        False         False      3h56m
marketplace                                4.6.0   True        False         False      4h2m
monitoring                                 4.6.0   True        False         False      6h31m
network                                    4.6.0   True        False         False      29h
node-tuning                                4.6.0   True        False         False      4h30m
openshift-apiserver                        4.6.0   True        False         False      3h56m
openshift-controller-manager               4.6.0   True        False         False      4h36m
openshift-samples                          4.6.0   True        False         False      4h30m
operator-lifecycle-manager                 4.6.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.6.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.6.0   True        False         False      3h59m
service-ca                                 4.6.0   True        False         False      29h
storage                                    4.6.0   True        False         False      4h30m

  2. Configure the Operators that are not available.
1.1.13.1. 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.

1.1.13.1.1. Configuring registry storage for IBM Power Systems

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

Prerequisites

  • Cluster administrator permissions.
  • A cluster on IBM Power Systems.

  • Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.

    Important

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

  • Must have 100Gi capacity.

Procedure

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

    Note

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

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

    $ oc get pod -n openshift-image-registry
    Note

    If the storage type is emptyDIR, the replica number cannot be greater than 1.

  3. Check the registry configuration: 

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

    Example output

    storage:
  pvc:
    claim:

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

  4. Check the clusteroperator status: 

    $ oc get clusteroperator image-registry

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

    • Run: 

      $ oc edit configs.imageregistry/cluster

      Then, change the line 

      managementState: Removed

      to 

      managementState: Managed
1.1.13.1.2. 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":{}}}}'
    Warning

    Configure this option for only non-production clusters.

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

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

    Wait a few minutes and run the command again.

1.1.14. Completing installation on user-provisioned infrastructure

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

Prerequisites

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

Procedure

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

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.6.0   True        False         False      3h56m
cloud-credential                           4.6.0   True        False         False      29h
cluster-autoscaler                         4.6.0   True        False         False      29h
config-operator                            4.6.0   True        False         False      6h39m
console                                    4.6.0   True        False         False      3h59m
csi-snapshot-controller                    4.6.0   True        False         False      4h12m
dns                                        4.6.0   True        False         False      4h15m
etcd                                       4.6.0   True        False         False      29h
image-registry                             4.6.0   True        False         False      3h59m
ingress                                    4.6.0   True        False         False      4h30m
insights                                   4.6.0   True        False         False      29h
kube-apiserver                             4.6.0   True        False         False      29h
kube-controller-manager                    4.6.0   True        False         False      29h
kube-scheduler                             4.6.0   True        False         False      29h
kube-storage-version-migrator              4.6.0   True        False         False      4h2m
machine-api                                4.6.0   True        False         False      29h
machine-approver                           4.6.0   True        False         False      6h34m
machine-config                             4.6.0   True        False         False      3h56m
marketplace                                4.6.0   True        False         False      4h2m
monitoring                                 4.6.0   True        False         False      6h31m
network                                    4.6.0   True        False         False      29h
node-tuning                                4.6.0   True        False         False      4h30m
openshift-apiserver                        4.6.0   True        False         False      3h56m
openshift-controller-manager               4.6.0   True        False         False      4h36m
openshift-samples                          4.6.0   True        False         False      4h30m
operator-lifecycle-manager                 4.6.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.6.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.6.0   True        False         False      3h59m
service-ca                                 4.6.0   True        False         False      29h
storage                                    4.6.0   True        False         False      4h30m

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

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

    Example output

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

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

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

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

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

      $ oc get pods --all-namespaces

      Example output

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

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

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

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

1.1.15. Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.6, 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

1.1.16. Next steps

1.2. Installing a cluster on IBM Power Systems in a restricted network

In OpenShift Container Platform version 4.6, you can install a cluster on IBM Power Systems infrastructure that you provision in a restricted network.

Important

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.

Prerequisites

  • Create a mirror registry for installation in a restricted network and obtain 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.

    Important

    Ensure that installation steps are performed on a machine with access to the installation media.

  • Provision persistent storage for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.
  • Review details about the OpenShift Container Platform installation and update processes.

  • If you use a firewall and plan to use telemetry, you must configure the firewall to allow the sites that your cluster requires access to.

    Note

    Be sure to also review this site list if you are configuring a proxy.

1.2.1. About installations in restricted networks

In OpenShift Container Platform 4.6, 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.

To complete a restricted network installation, you must create a registry that mirrors the contents of the OpenShift Container Platform registry and contains the installation media. You can create this registry on a mirror host, which can access both the Internet and your closed network, or by using other methods that meet your restrictions.

Important

Because of the complexity of the configuration for user-provisioned installations, consider completing a standard user-provisioned infrastructure installation before you attempt a restricted network installation using user-provisioned infrastructure. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network.

1.2.1.1. Additional limits

Clusters in restricted networks have the following additional limitations and restrictions:

  • The ClusterVersion status includes an Unable to retrieve available updates error.
  • By default, you cannot use the contents of the Developer Catalog because you cannot access the required image stream tags.

1.2.2. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.6, 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.
Important

If your cluster cannot have direct Internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the content that is required and use it to populate a mirror registry with the packages that you need to install a cluster and generate the installation program. 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.

1.2.3. Machine requirements for a cluster with user-provisioned infrastructure

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

1.2.3.1. Required machines

The smallest OpenShift Container Platform clusters require the following hosts:

  • One temporary bootstrap machine
  • Three control plane, or master, machines
  • At least two compute machines, which are also known as worker machines.
Note

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.

Important

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

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS) or Red Hat Enterprise Linux (RHEL) 7.9.

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.

1.2.3.2. Network connectivity requirements

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config files from the Machine Config Server. During the initial boot, the machines require either a DHCP server or that static IP addresses be set in order to establish a network connection to download their Ignition config files. Additionally, each OpenShift Container Platform node in the cluster must have access to a Network Time Protocol (NTP) server. If a DHCP server provides NTP servers information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

1.2.3.3. Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

MachineOperating SystemvCPU [1]Virtual RAMStorageIOPS [2]

Bootstrap

RHCOS

2

16 GB

100 GB

300

Control plane

RHCOS

2

16 GB

100 GB

300

Compute

RHCOS

2

8 GB

100 GB

300

  1. One vCPU is equivalent to one physical core when simultaneous multithreading (SMT), or hyperthreading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.
  2. OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
1.2.3.4. 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.

1.2.4. Creating the user-provisioned infrastructure

Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Procedure

  1. Configure DHCP or set static IP addresses on each node.
  2. Provision the required load balancers.
  3. Configure the ports for your machines.
  4. Configure DNS.
  5. Ensure network connectivity.
1.2.4.1. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

During the initial boot, the machines require either a DHCP server or that static IP addresses be set on each host in the cluster in order to establish a network connection, which allows them to download their Ignition config files.

It is recommended to use the DHCP server to manage the machines for the cluster long-term. Ensure that the DHCP server is configured to provide persistent IP addresses and host names to the cluster machines.

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.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 1.7. All machines to all machines
ProtocolPortDescription

ICMP

N/A

Network reachability tests

TCP

1936

Metrics

9000-9999

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

10250-10259

The default ports that Kubernetes reserves

10256

openshift-sdn

UDP

4789

VXLAN and Geneve

6081

VXLAN and Geneve

9000-9999

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

TCP/UDP

30000-32767

Kubernetes node port

Table 1.8. All machines to control plane
ProtocolPortDescription

TCP

6443

Kubernetes API

Table 1.9. Control plane machines to control plane machines
ProtocolPortDescription

TCP

2379-2380

etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

Load balancers

Before you install OpenShift Container Platform, you must provision two load balancers that meet the following requirements:

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

    • Layer 4 load balancing only. This can be referred to as Raw TCP, 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.
    Important

    Do not configure session persistence for an API load balancer.

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

    Table 1.10. API load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    6443

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

    X

    X

    Kubernetes API server

    22623

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

    X

    		 

    Machine config server

    Note

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

  2. Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. 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.

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

    Table 1.11. Application Ingress load balancer
    PortBack-end machines (pool members)InternalExternalDescription

    443

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

    X

    X

    HTTPS traffic

    80

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

    X

    X

    HTTP traffic

Tip

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

Note

A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes.

NTP configuration

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

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

Additional resources

1.2.4.2. User-provisioned DNS requirements

DNS is used for name resolution and reverse name resolution. 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 host name for all the nodes. 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 an OpenShift Container Platform cluster that uses user-provisioned infrastructure. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 1.12. Required DNS records
ComponentRecordDescription

Kubernetes API

api.<cluster_name>.<base_domain>.

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

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

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. 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 host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

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

Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

Bootstrap

bootstrap.<cluster_name>.<base_domain>.

Add 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.

Master hosts

<master><n>.<cluster_name>.<base_domain>.

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

Worker hosts

<worker><n>.<cluster_name>.<base_domain>.

Add 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.

Tip

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

The following example of a BIND zone file shows sample A records for name resolution. The purpose of the example is to show the records that are needed. The example is not meant to provide advice for choosing one name resolution service over another.

Example 1.3. 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	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Example 1.4. 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.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.example.com.
5	IN	PTR	api-int.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

1.2.5. Generating an SSH private key and adding it to the agent

If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent and the installation program. You can use this key to access the bootstrap machine in a public cluster to troubleshoot installation issues.

Note

In a production environment, you require disaster recovery and debugging.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

Note

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

Procedure

  1. If you do not have an SSH key that is configured for password-less authentication on your computer, 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_rsa, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.

    Running this command generates an SSH key that does not require a password in the location that you specified.

    Note

    If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. Start the ssh-agent process as a background task: 

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

    Example output

    Agent pid 31874

    Note

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

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

    $ ssh-add <path>/<file_name> 1

    Example output

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

    1
    Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

  • When you install OpenShift Container Platform, provide the SSH public key to the installation program.

1.2.6. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

  • Obtain the OpenShift Container Platform installation program and the access token for your cluster.
  • Obtain the imageContentSources section from the output of the command to mirror the repository.
  • Obtain the contents of the certificate for your mirror registry.

Procedure

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

    $ mkdir <installation_directory>
    Important

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

  2. Customize the following install-config.yaml file template and save it in the <installation_directory>.

    Note

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

    • Unless you use a registry that RHCOS trusts by default, such as docker.io, you must provide the contents of the certificate for your mirror repository in the additionalTrustBundle section. In most cases, you must provide the certificate for your mirror.
    • You must include the imageContentSources section from the output of the command to mirror the repository.

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

    Important

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

1.2.6.1. Sample install-config.yaml file for IBM Power Systems

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 : ppc64le
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
  architecture : ppc64le
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_registry>/<local_repository_name>/release
  source: quay.io/openshift-release-dev/ocp-release
- mirrors:
  - <local_registry>/<local_repository_name>/release
  source: quay.io/openshift-release-dev/ocp-v4.0-art-dev
1
The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 5
The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Only one control plane pool is used.
3 6
Whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note

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

Important

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

4
You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OpenShift Container Platform.
7
The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8
The cluster name that you specified in your DNS records.
9
A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
Note

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

10
The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs 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 Power Systems infrastructure.
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

The use of FIPS Validated / 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 or registry.example.com:5000. For <credentials>, specify the base64-encoded user name and password for your mirror registry.
15
The public portion of the default SSH key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note

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

16
Provide the contents of the certificate file that you used for your mirror registry.
17
Provide the imageContentSources section from the output of the command to mirror the repository.
1.2.6.2. Configuring the cluster-wide proxy during installation

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

Prerequisites

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

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

    Note

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

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

Procedure

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

    apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> 1
  httpsProxy: https://<username>:<pswd>@<ip>:<port> 2
  noProxy: example.com 3
additionalTrustBundle: | 4
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...
    1
    A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
    2
    A proxy URL to use for creating HTTPS connections outside the cluster.
    3
    A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations.
    4
    If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace to hold the additional CA certificates. If you provide additionalTrustBundle and at least one proxy setting, the Proxy object is configured to reference the user-ca-bundle config map in the trustedCA field. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges the contents specified for the trustedCA parameter with the RHCOS trust bundle. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
    Note

    The installation program does not support the proxy readinessEndpoints field.

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

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

Note

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

1.2.7. 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 make its machines.

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

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

Prerequisites

  • You obtained the OpenShift Container Platform installation program. For a restricted network installation, these files are on your mirror host.
  • You created the install-config.yaml installation configuration file.

Procedure

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

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

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

    1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
    2. Locate the mastersSchedulable parameter and ensure that it is set to false.
    3. Save and exit the file.

  3. To create the Ignition configuration files, run the following command from the directory that contains the installation program: 

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

    The following files are generated in the directory: 

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

1.2.8. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Before you install a cluster on IBM Power Systems infrastructure that you provision, you must create RHCOS machines for it to use. Follow either the steps to use an ISO image or network PXE booting to create the machines.

1.2.8.1. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines using an ISO image

Before you install a cluster on IBM Power Systems infrastructure that you provision, you must create RHCOS machines for it to use. You can use an ISO image to create the machines.

Prerequisites

  • Obtain the Ignition config files for your cluster.
  • Have access to an HTTP server that can be accessed from your computer, and from the machines that you create.

Procedure

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

    Important

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

  2. Obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page.

    Important

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

    ISO file names resemble the following example:

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

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

    • Burn the ISO image to a disk and boot it directly.
    • Use ISO redirection via a LOM interface.
  4. Boot the ISO image. You can interrupt the installation boot process to add kernel arguments. However, for this ISO procedure you should use the coreos-installer command instead of adding kernel arguments. If you run the live installer without options or interruption, the installer boots up to a shell prompt on the live system, ready for you to install RHCOS to disk.
  5. Review the Advanced RHCOS installation reference section for different ways of configuring features, such as networking and disk partitions, before running the coreos-installer.

  6. Run the coreos-installer command. At a minimum, you must identify the Ignition config file location for your node type, and the location of the disk you are installing to. Here is an example: 

    $ sudo coreos-installer install \
     --ignition-url=https://host/worker.ign /dev/sda
  7. After RHCOS installs, the system reboots. During the system reboot, it applies the Ignition config file that you specified.

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

    Important

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

1.2.8.1.1. 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.

Routing and bonding options at RHCOS boot prompt

If you install RHCOS from an ISO image, you can add kernel arguments manually when you boot that image to configure the node’s networking. If no networking arguments are used, the installation defaults to using DHCP.

Important

When adding networking arguments, you must also add the rd.neednet=1 kernel argument.

The following table describes how to use ip=, nameserver=, and bond= kernel arguments for live ISO installs.

Note

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

Routing and bonding options for ISO

The following table provides examples for configuring networking of your Red Hat Enterprise Linux CoreOS (RHCOS) nodes. These are networking options that 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.

DescriptionExamples

To configure an IP address, either use DHCP (ip=dhcp) or set an individual static IP address (ip=<host_ip>). Then identify the DNS server IP address (nameserver=<dns_ip>) on each node. This 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 
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
nameserver=4.4.4.41

Specify multiple network interfaces by specifying 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

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

If the additional network gateway is different from the primary network gateway, the default gateway must be the primary network gateway.

To configure the default gateway: 

ip=::10.10.10.254::::

To configure the route for the additional network: 

rd.route=20.20.20.0/24:20.20.20.254:enp2s0

Disable DHCP on a single interface, such as when there are two or more network interfaces and only one interface is being 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

You can combine DHCP and static IP configurations on systems with multiple network interfaces. 

ip=enp1s0:dhcp
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none

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: 

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: 

ip=enp2s0.100:dhcp
vlan=enp2s0.100:enp2s0

You can provide multiple DNS servers by adding a nameserver= entry for each server. 

nameserver=1.1.1.1
nameserver=8.8.8.8

Optional: Bonding multiple network interfaces to a single interface is supported using the bond= option. In these two examples:

  • The syntax for configuring a bonded interface is: bond=name[:network_interfaces][:options]
  • name is the bonding device name (bond0), network_interfaces represents a comma-separated list of physical (ethernet) interfaces (em1,em2), and options is a comma-separated list of bonding options. Enter modinfo bonding to see available options.
  • When you create a bonded interface using bond=, you must specify how the IP address is assigned and other information for the bonded interface.

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

bond=bond0:em1,em2:mode=active-backup
ip=bond0:dhcp

To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: 

bond=bond0:em1,em2:mode=active-backup
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none

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

To configure the bonded interface with a VLAN and to use DHCP: 

ip=bond0.100:dhcp
bond=bond0:em1,em2:mode=active-backup
vlan=bond0.100:bond0

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

Optional: Network teaming can be used as an alternative to bonding by using the team= parameter. In this example:

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

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

Note

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

To configure a network team: 

team=team0:em1,em2
ip=team0:dhcp
1.2.8.2. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines by PXE or iPXE booting

Before you install a cluster that uses manually-provisioned RHCOS nodes, such as bare metal, you must create RHCOS machines for it to use. You can use PXE or iPXE booting to create the machines.

Prerequisites

  • Obtain the Ignition config files for your cluster.
  • Configure suitable PXE or iPXE infrastructure.
  • Have access to an HTTP server that you can access from your computer.

Procedure

  1. Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

    Important

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

  2. Obtain the RHCOS kernel, initramfs and rootfs files from the RHCOS image mirror page.

    Important

    The RHCOS artifacts might not change with every release of OpenShift Container Platform. You must download artifacts with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate kernel, initramfs, and rootfs artifacts described below for this procedure. RHCOS qcow2 images are not supported for this installation type.

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

    • kernel: rhcos-<version>-live-kernel-<architecture>
    • initramfs: rhcos-<version>-live-initramfs.<architecture>.img
    • rootfs: rhcos-<version>-live-rootfs.<architecture>.img

  3. Upload the additional files that are required for your booting method:

    • For traditional PXE, upload the kernel and initramfs files to your TFTP server and the rootfs file to your HTTP server.

    • For iPXE, upload the kernel, initramfs, and rootfs files to your HTTP server.

      Important

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

  4. Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.

  5. Configure PXE or iPXE installation for the RHCOS images.

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

    • For PXE: 

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

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

    • For iPXE: 

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

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

  6. If you use PXE UEFI, perform the following actions:

    1. Provide the shimx64.efi and grubx64.efi EFI binaries and the grub.cfg file that are required for booting the system.

      • Extract the necessary EFI binaries by mounting the RHCOS ISO to your host and then mounting the images/efiboot.img file to your host: 

        $ mkdir -p /mnt/iso
        $ mkdir -p /mnt/efiboot
        $ mount -o loop rhcos-installer.x86_64.iso /mnt/iso
        $ mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot

      • From the efiboot.img mount point, copy the EFI/redhat/shimx64.efi and EFI/redhat/grubx64.efi files to your TFTP server: 

        $ cp /mnt/efiboot/EFI/redhat/shimx64.efi .
        $ cp /mnt/efiboot/EFI/redhat/grubx64.efi .
        $ umount /mnt/efiboot
        $ umount /mnt/iso
      • Copy the EFI/redhat/grub.cfg file that is included in the RHCOS ISO to your TFTP server.

    2. Edit the grub.cfg file to include arguments similar to the following: 

      menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os {
	linuxefi rhcos-<version>-live-kernel-<architecture> coreos.inst.install_dev=/dev/sda coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign
	initrdefi rhcos-<version>-live-initramfs.<architecture>.img
}

      where:

      rhcos-<version>-live-kernel-<architecture>
      Specifies the kernel file that you uploaded to your TFTP server.
      http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img
      Specifies the location of the live rootfs image that you uploaded to your HTTP server.
      http://<HTTP_server>/bootstrap.ign
      Specifies the location of the bootstrap Ignition config file that you uploaded to your HTTP server.
      rhcos-<version>-live-initramfs.<architecture>.img
      Specifies the location of the initramfs file that you uploaded to your TFTP server.
      Note

      For more information on how to configure a PXE server for UEFI boot, see the Red Hat Knowledgebase article: How to configure/setup a PXE server for UEFI boot for Red Hat Enterprise Linux?.

  7. Continue to create the machines for your cluster.

    Important

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

1.2.9. Creating the cluster

To create the OpenShift Container Platform cluster, you wait for the bootstrap process to complete on the machines that you provisioned by using the Ignition config files that you generated with the installation program.

Prerequisites

  • Create the required infrastructure for the cluster.
  • You obtained the installation program and generated the Ignition config files for your cluster.
  • You used the Ignition config files to create RHCOS machines for your cluster.

Procedure

  1. Monitor the bootstrap process: 

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

    Example output

    INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.19.0 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.

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

    Important

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

1.2.10. Logging in to the cluster by using the CLI

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

Prerequisites

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

Procedure

  1. Export the kubeadmin credentials: 

    $ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
    1
    For <installation_directory>, specify the path to the directory that you stored the installation files in.

  2. Verify you can run oc commands successfully using the exported configuration: 

    $ oc whoami

    Example output

    system:admin

1.2.11. Approving the certificate signing requests for your machines

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

Prerequisites

  • You added machines to your cluster.

Procedure

  1. Confirm that the cluster recognizes the machines: 

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.19.0
master-1  Ready     master  63m  v1.19.0
master-2  Ready     master  64m  v1.19.0

    The output lists all of the machines that you created.

    Note

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

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

    $ oc get csr

    Example output

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

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

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

    Note

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

    Note

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

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

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.

    • To approve all pending CSRs, run the following command: 

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

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

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

    $ oc get csr

    Example output

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

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

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

      $ oc adm certificate approve <csr_name> 1
      1
      <csr_name> is the name of a CSR from the list of current CSRs.

    • To approve all pending CSRs, run the following command: 

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve

  6. After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command: 

    $ oc get nodes

    Example output

    NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

    Note

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

Additional information

1.2.12. Initial Operator configuration

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

Prerequisites

  • Your control plane has initialized.

Procedure

  1. Watch the cluster components come online: 

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.6.0   True        False         False      3h56m
cloud-credential                           4.6.0   True        False         False      29h
cluster-autoscaler                         4.6.0   True        False         False      29h
config-operator                            4.6.0   True        False         False      6h39m
console                                    4.6.0   True        False         False      3h59m
csi-snapshot-controller                    4.6.0   True        False         False      4h12m
dns                                        4.6.0   True        False         False      4h15m
etcd                                       4.6.0   True        False         False      29h
image-registry                             4.6.0   True        False         False      3h59m
ingress                                    4.6.0   True        False         False      4h30m
insights                                   4.6.0   True        False         False      29h
kube-apiserver                             4.6.0   True        False         False      29h
kube-controller-manager                    4.6.0   True        False         False      29h
kube-scheduler                             4.6.0   True        False         False      29h
kube-storage-version-migrator              4.6.0   True        False         False      4h2m
machine-api                                4.6.0   True        False         False      29h
machine-approver                           4.6.0   True        False         False      6h34m
machine-config                             4.6.0   True        False         False      3h56m
marketplace                                4.6.0   True        False         False      4h2m
monitoring                                 4.6.0   True        False         False      6h31m
network                                    4.6.0   True        False         False      29h
node-tuning                                4.6.0   True        False         False      4h30m
openshift-apiserver                        4.6.0   True        False         False      3h56m
openshift-controller-manager               4.6.0   True        False         False      4h36m
openshift-samples                          4.6.0   True        False         False      4h30m
operator-lifecycle-manager                 4.6.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.6.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.6.0   True        False         False      3h59m
service-ca                                 4.6.0   True        False         False      29h
storage                                    4.6.0   True        False         False      4h30m

  2. Configure the Operators that are not available.
1.2.12.1. 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 the OperatorHub object: 

    $ oc patch OperatorHub cluster --type json \
    -p '[{"op": "add", "path": "/spec/disableAllDefaultSources", "value": true}]'
Tip

Alternatively, you can use the web console to manage catalog sources. From the Administration → Cluster Settings → Global Configuration → OperatorHub page, click the Sources tab, where you can create, delete, disable, and enable individual sources.

1.2.12.2. 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.

1.2.12.2.1. Changing the image registry’s management state

To start the image registry, you must change the Image Registry Operator configuration’s managementState from Removed to Managed.

Procedure

  • Change managementState Image Registry Operator configuration from Removed to Managed. For example: 

    $ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"managementState":"Managed"}}'
1.2.12.2.2. Configuring registry storage for IBM Power Systems

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

Prerequisites

  • Cluster administrator permissions.
  • A cluster on IBM Power Systems.

  • Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.

    Important

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

  • Must have 100Gi capacity.

Procedure

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

    Note

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

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

    $ oc get pod -n openshift-image-registry
    Note

    If the storage type is emptyDIR, the replica number cannot be greater than 1.

  3. Check the registry configuration: 

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

    Example output

    storage:
  pvc:
    claim:

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

  4. Check the clusteroperator status: 

    $ oc get clusteroperator image-registry

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

    • Run: 

      $ oc edit configs.imageregistry/cluster

      Then, change the line 

      managementState: Removed

      to 

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

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

Procedure

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

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

    Configure this option for only non-production clusters.

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

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

    Wait a few minutes and run the command again.

1.2.13. Completing installation on user-provisioned infrastructure

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

Prerequisites

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

Procedure

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

    $ watch -n5 oc get clusteroperators

    Example output

    NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.6.0   True        False         False      3h56m
cloud-credential                           4.6.0   True        False         False      29h
cluster-autoscaler                         4.6.0   True        False         False      29h
config-operator                            4.6.0   True        False         False      6h39m
console                                    4.6.0   True        False         False      3h59m
csi-snapshot-controller                    4.6.0   True        False         False      4h12m
dns                                        4.6.0   True        False         False      4h15m
etcd                                       4.6.0   True        False         False      29h
image-registry                             4.6.0   True        False         False      3h59m
ingress                                    4.6.0   True        False         False      4h30m
insights                                   4.6.0   True        False         False      29h
kube-apiserver                             4.6.0   True        False         False      29h
kube-controller-manager                    4.6.0   True        False         False      29h
kube-scheduler                             4.6.0   True        False         False      29h
kube-storage-version-migrator              4.6.0   True        False         False      4h2m
machine-api                                4.6.0   True        False         False      29h
machine-approver                           4.6.0   True        False         False      6h34m
machine-config                             4.6.0   True        False         False      3h56m
marketplace                                4.6.0   True        False         False      4h2m
monitoring                                 4.6.0   True        False         False      6h31m
network                                    4.6.0   True        False         False      29h
node-tuning                                4.6.0   True        False         False      4h30m
openshift-apiserver                        4.6.0   True        False         False      3h56m
openshift-controller-manager               4.6.0   True        False         False      4h36m
openshift-samples                          4.6.0   True        False         False      4h30m
operator-lifecycle-manager                 4.6.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.6.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.6.0   True        False         False      3h59m
service-ca                                 4.6.0   True        False         False      29h
storage                                    4.6.0   True        False         False      4h30m

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

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

    Example output

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

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

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

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

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

      $ oc get pods --all-namespaces

      Example output

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

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

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

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

1.2.14. Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.6, 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

1.2.15. Next steps

Legal Notice

Copyright © 2024 Red Hat, Inc.

OpenShift documentation is licensed under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0).

Modified versions must remove all Red Hat trademarks.

Portions adapted from https://github.com/kubernetes-incubator/service-catalog/ with modifications by Red Hat.

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