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In OpenShift Container Platform version 4.9, you can install a cluster on your VMware vSphere instance by using installer-provisioned infrastructure with customized network configuration options. By customizing your network configuration, your cluster can coexist with existing IP address allocations in your environment and integrate with existing MTU and VXLAN configurations. To customize the installation, you modify parameters in the install-config.yaml file before you install the cluster.

You must set most of the network configuration parameters during installation, and you can modify only kubeProxy configuration parameters in a running cluster.

Prerequisites

  • You reviewed details about the OpenShift Container Platform installation and update processes.

  • You read the documentation on selecting a cluster installation method and preparing it for users.

  • You provisioned persistent storage for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.

  • The OpenShift Container Platform installer requires access to port 443 on the vCenter and ESXi hosts. You verified that port 443 is accessible.

  • If you use a firewall, confirm with the administrator that port 443 is accessible. Control plane nodes must be able to reach vCenter and ESXi hosts on port 443 for the installation to succeed.

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

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

Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.9, you require access to the internet to install your cluster.

You must have internet access to:

  • Access the Red Hat OpenShift Cluster Manager page to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.

  • Access Quay.io to obtain the packages that are required to install your cluster.

  • Obtain the packages that are required to perform cluster updates.

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

VMware vSphere infrastructure requirements

You must install the OpenShift Container Platform cluster on a VMware vSphere version 6 or 7 instance that meets the requirements for the components that you use.

Table 1. Version requirements for vSphere virtual environments
Virtual environment product Required version

VM hardware version

13 or later

vSphere ESXi hosts

6.5 or later

vCenter host

6.5 or later

Installing a cluster on VMware vSphere version 6.7U2 or earlier and virtual hardware version 13 is now deprecated. These versions are still fully supported, but support will be removed in a future version of OpenShift Container Platform. Hardware version 15 is now the default for vSphere virtual machines in OpenShift Container Platform. To update the hardware version for your vSphere nodes, see the "Updating hardware on nodes running in vSphere" article.

Table 2. Minimum supported vSphere version for VMware components
Component Minimum supported versions Description

Hypervisor

vSphere 6.5 and later with HW version 13

This version is the minimum version that Red Hat Enterprise Linux CoreOS (RHCOS) supports. See the Red Hat Enterprise Linux 8 supported hypervisors list.

Storage with in-tree drivers

vSphere 6.5 and later

This plug-in creates vSphere storage by using the in-tree storage drivers for vSphere included in OpenShift Container Platform.

Optional: Networking (NSX-T)

vSphere 6.5U3 or vSphere 6.7U2 and later

vSphere 6.5U3 or vSphere 6.7U2+ are required for OpenShift Container Platform. VMware’s NSX Container Plug-in (NCP) is certified with OpenShift Container Platform 4.6 and NSX-T 3.x+.

If you use a vSphere version 6.5 instance, consider upgrading to 6.7U3 or 7.0 before you install OpenShift Container Platform.

You must ensure that the time on your ESXi hosts is synchronized before you install OpenShift Container Platform. See Edit Time Configuration for a Host in the VMware documentation.

Additional resources

vCenter requirements

Before you install an OpenShift Container Platform cluster on your vCenter that uses infrastructure that the installer provisions, you must prepare your environment.

Required vCenter account privileges

To install an OpenShift Container Platform cluster in a vCenter, the installation program requires access to an account with privileges to read and create the required resources. Using an account that has global administrative privileges is the simplest way to access all of the necessary permissions.

If you cannot use an account with global adminstrative privileges, you must create roles to grant the privileges necessary for OpenShift Container Platform cluster installation. While most of the privileges are always required, some are required only if you plan for the installation program to provision a folder to contain the OpenShift Container Platform cluster on your vCenter instance, which is the default behavior. You must create or amend vSphere roles for the specified objects to grant the required privileges.

An additional role is required if the installation program is to create a vSphere virtual machine folder.

Roles and privileges required for installation
vSphere object for role When required Required privileges

vSphere vCenter

Always

Cns.Searchable
InventoryService.Tagging.AttachTag
InventoryService.Tagging.CreateCategory
InventoryService.Tagging.CreateTag
InventoryService.Tagging.DeleteCategory
InventoryService.Tagging.DeleteTag
InventoryService.Tagging.EditCategory
InventoryService.Tagging.EditTag
Sessions.ValidateSession
StorageProfile.View

vSphere vCenter Cluster

Always

Host.Config.Storage
Resource.AssignVMToPool
VApp.AssignResourcePool
VApp.Import
VirtualMachine.Config.AddNewDisk

vSphere Datastore

Always

Datastore.AllocateSpace
Datastore.Browse
Datastore.FileManagement
InventoryService.Tagging.ObjectAttachable

vSphere Port Group

Always

Network.Assign

Virtual Machine Folder

Always

Resource.AssignVMToPool
VApp.Import
VirtualMachine.Config.AddExistingDisk
VirtualMachine.Config.AddNewDisk
VirtualMachine.Config.AddRemoveDevice
VirtualMachine.Config.AdvancedConfig
VirtualMachine.Config.Annotation
VirtualMachine.Config.CPUCount
VirtualMachine.Config.DiskExtend
VirtualMachine.Config.DiskLease
VirtualMachine.Config.EditDevice
VirtualMachine.Config.Memory
VirtualMachine.Config.RemoveDisk
VirtualMachine.Config.Rename
VirtualMachine.Config.ResetGuestInfo
VirtualMachine.Config.Resource
VirtualMachine.Config.Settings
VirtualMachine.Config.UpgradeVirtualHardware
VirtualMachine.Interact.GuestControl
VirtualMachine.Interact.PowerOff
VirtualMachine.Interact.PowerOn
VirtualMachine.Interact.Reset
VirtualMachine.Inventory.Create
VirtualMachine.Inventory.CreateFromExisting
VirtualMachine.Inventory.Delete
VirtualMachine.Provisioning.Clone

vSphere vCenter Datacenter

If the installation program creates the virtual machine folder

Resource.AssignVMToPool
VApp.Import
VirtualMachine.Config.AddExistingDisk
VirtualMachine.Config.AddNewDisk
VirtualMachine.Config.AddRemoveDevice
VirtualMachine.Config.AdvancedConfig
VirtualMachine.Config.Annotation
VirtualMachine.Config.CPUCount
VirtualMachine.Config.DiskExtend
VirtualMachine.Config.DiskLease
VirtualMachine.Config.EditDevice
VirtualMachine.Config.Memory
VirtualMachine.Config.RemoveDisk
VirtualMachine.Config.Rename
VirtualMachine.Config.ResetGuestInfo
VirtualMachine.Config.Resource
VirtualMachine.Config.Settings
VirtualMachine.Config.UpgradeVirtualHardware
VirtualMachine.Interact.GuestControl
VirtualMachine.Interact.PowerOff
VirtualMachine.Interact.PowerOn
VirtualMachine.Interact.Reset
VirtualMachine.Inventory.Create
VirtualMachine.Inventory.CreateFromExisting
VirtualMachine.Inventory.Delete
VirtualMachine.Provisioning.Clone
VirtualMachine.Provisioning.DeployTemplate
VirtualMachine.Provisioning.MarkAsTemplate
Folder.Create
Folder.Delete

Additionally, the user requires some ReadOnly permissions, and some of the roles require permission to propogate the permissions to child objects. These settings vary depending on whether or not you install the cluster into an existing folder.

Required permissions and propagation settings
vSphere object Folder type Propagate to children Permissions required

vSphere vCenter

Always

False

Listed required privileges

vSphere vCenter Datacenter

Existing folder

False

ReadOnly permission

Installation program creates the folder

True

Listed required privileges

vSphere vCenter Cluster

Always

True

Listed required privileges

vSphere vCenter Datastore

Always

False

Listed required privileges

vSphere Switch

Always

False

ReadOnly permission

vSphere Port Group

Always

False

Listed required privileges

vSphere vCenter Virtual Machine Folder

Existing folder

True

Listed required privileges

For more information about creating an account with only the required privileges, see vSphere Permissions and User Management Tasks in the vSphere documentation.

Using OpenShift Container Platform with vMotion

OpenShift Container Platform generally supports compute-only vMotion. Using Storage vMotion can cause issues and is not supported.

If you are using vSphere volumes in your pods, migrating a VM across datastores either manually or through Storage vMotion causes invalid references within OpenShift Container Platform persistent volume (PV) objects. These references prevent affected pods from starting up and can result in data loss.

Similarly, OpenShift Container Platform does not support selective migration of VMDKs across datastores, using datastore clusters for VM provisioning or for dynamic or static provisioning of PVs, or using a datastore that is part of a datastore cluster for dynamic or static provisioning of PVs.

Cluster resources

When you deploy an OpenShift Container Platform cluster that uses installer-provisioned infrastructure, the installation program must be able to create several resources in your vCenter instance.

A standard OpenShift Container Platform installation creates the following vCenter resources:

  • 1 Folder

  • 1 Tag category

  • 1 Tag

  • Virtual machines:

    • 1 template

    • 1 temporary bootstrap node

    • 3 control plane nodes

    • 3 compute machines

Although these resources use 856 GB of storage, the bootstrap node is destroyed during the cluster installation process. A minimum of 800 GB of storage is required to use a standard cluster.

If you deploy more compute machines, the OpenShift Container Platform cluster will use more storage.

Cluster limits

Available resources vary between clusters. The number of possible clusters within a vCenter is limited primarily by available storage space and any limitations on the number of required resources. Be sure to consider both limitations to the vCenter resources that the cluster creates and the resources that you require to deploy a cluster, such as IP addresses and networks.

Networking requirements

You must use DHCP for the network and ensure that the DHCP server is configured to provide persistent IP addresses to the cluster machines. Additionally, you must create the following networking resources before you install the OpenShift Container Platform cluster:

It is recommended that each OpenShift Container Platform node in the cluster must have access to a Network Time Protocol (NTP) server that is discoverable via DHCP. Installation is possible without an NTP server. However, asynchronous server clocks will cause errors, which NTP server prevents.

Required IP Addresses

An installer-provisioned vSphere installation requires two static IP addresses:

  • The API address is used to access the cluster API.

  • The Ingress address is used for cluster ingress traffic.

You must provide these IP addresses to the installation program when you install the OpenShift Container Platform cluster.

DNS records

You must create DNS records for two static IP addresses in the appropriate DNS server for the vCenter instance that hosts your OpenShift Container Platform cluster. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify when you install the cluster. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 3. Required DNS records
Component Record Description

API VIP

api.<cluster_name>.<base_domain>.

This DNS A/AAAA or CNAME record must point to the load balancer for the control plane machines. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

Ingress VIP

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

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

Generating a key pair for cluster node SSH access

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

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

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

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

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 existing SSH key pair on your local machine to use for authentication onto your cluster nodes, create one. For example, on a computer that uses a Linux operating system, run the following command:

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

    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. View the public SSH key:

    $ cat <path>/<file_name>.pub

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

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

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

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

      $ eval "$(ssh-agent -s)"
      Example output
      Agent pid 31874

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

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

    $ ssh-add <path>/<file_name> (1)
    1 Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa
    Example output
    Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
Next steps
  • When you install OpenShift Container Platform, provide the SSH public key to the installation program.

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 Red Hat 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.

    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.

    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. From the Pull Secret page on the Red Hat OpenShift Cluster Manager site, download your installation pull secret. 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.

Adding vCenter root CA certificates to your system trust

Because the installation program requires access to your vCenter’s API, you must add your vCenter’s trusted root CA certificates to your system trust before you install an OpenShift Container Platform cluster.

Procedure
  1. From the vCenter home page, download the vCenter’s root CA certificates. Click Download trusted root CA certificates in the vSphere Web Services SDK section. The <vCenter>/certs/download.zip file downloads.

  2. Extract the compressed file that contains the vCenter root CA certificates. The contents of the compressed file resemble the following file structure:

    certs
    ├── lin
    │   ├── 108f4d17.0
    │   ├── 108f4d17.r1
    │   ├── 7e757f6a.0
    │   ├── 8e4f8471.0
    │   └── 8e4f8471.r0
    ├── mac
    │   ├── 108f4d17.0
    │   ├── 108f4d17.r1
    │   ├── 7e757f6a.0
    │   ├── 8e4f8471.0
    │   └── 8e4f8471.r0
    └── win
        ├── 108f4d17.0.crt
        ├── 108f4d17.r1.crl
        ├── 7e757f6a.0.crt
        ├── 8e4f8471.0.crt
        └── 8e4f8471.r0.crl
    
    3 directories, 15 files
  3. Add the files for your operating system to the system trust. For example, on a Fedora operating system, run the following command:

    # cp certs/lin/* /etc/pki/ca-trust/source/anchors
  4. Update your system trust. For example, on a Fedora operating system, run the following command:

    # update-ca-trust extract

Creating the installation configuration file

You can customize the OpenShift Container Platform cluster you install on VMware vSphere.

Prerequisites
  • Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.

  • Obtain service principal permissions at the subscription level.

Procedure
  1. Create the install-config.yaml file.

    1. Change to the directory that contains the installation program and run the following command:

      $ ./openshift-install create install-config --dir <installation_directory> (1)
      1 For <installation_directory>, specify the directory name to store the files that the installation program creates.

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

    2. At the prompts, provide the configuration details for your cloud:

      1. Optional: Select an SSH key to use to access your cluster machines.

        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.

      2. Select vsphere as the platform to target.

      3. Specify the name of your vCenter instance.

      4. Specify the user name and password for the vCenter account that has the required permissions to create the cluster.

        The installation program connects to your vCenter instance.

      5. Select the datacenter in your vCenter instance to connect to.

      6. Select the default vCenter datastore to use.

      7. Select the vCenter cluster to install the OpenShift Container Platform cluster in. The installation program uses the root resource pool of the vSphere cluster as the default resource pool.

      8. Select the network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured.

      9. Enter the virtual IP address that you configured for control plane API access.

      10. Enter the virtual IP address that you configured for cluster ingress.

      11. Enter the base domain. This base domain must be the same one that you used in the DNS records that you configured.

      12. Enter a descriptive name for your cluster. The cluster name must be the same one that you used in the DNS records that you configured.

      13. Paste the pull secret that you obtained from the Pull Secret page on the Red Hat OpenShift Cluster Manager site.

  2. Modify the install-config.yaml file. You can find more information about the available parameters in the "Installation configuration parameters" section.

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

    The install-config.yaml file is consumed during the installation process. If you want to reuse the file, you must back it up now.

Installation configuration parameters

Before you deploy an OpenShift Container Platform cluster, you provide parameter values to describe your account on the cloud platform that hosts your cluster and optionally customize your cluster’s platform. When you create the install-config.yaml installation configuration file, you provide values for the required parameters through the command line. If you customize your cluster, you can modify the install-config.yaml file to provide more details about the platform.

After installation, you cannot modify these parameters in the install-config.yaml file.

The openshift-install command does not validate field names for parameters. If an incorrect name is specified, the related file or object is not created, and no error is reported. Ensure that the field names for any parameters that are specified are correct.

Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 4. Required parameters
Parameter Description Values

apiVersion

The API version for the install-config.yaml content. The current version is v1. The installer may also support older API versions.

String

baseDomain

The base domain of your cloud provider. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the baseDomain and metadata.name parameter values that uses the <metadata.name>.<baseDomain> format.

A fully-qualified domain or subdomain name, such as example.com.

metadata

Kubernetes resource ObjectMeta, from which only the name parameter is consumed.

Object

metadata.name

The name of the cluster. DNS records for the cluster are all subdomains of {{.metadata.name}}.{{.baseDomain}}.

String of lowercase letters, hyphens (-), and periods (.), such as dev.

platform

The configuration for the specific platform upon which to perform the installation: aws, baremetal, azure, openstack, ovirt, vsphere, or {}. For additional information about platform.<platform> parameters, consult the table for your specific platform that follows.

Object

pullSecret

Get a pull secret from https://console.redhat.com/openshift/install/pull-secret to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io.

{
   "auths":{
      "cloud.openshift.com":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      },
      "quay.io":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      }
   }
}

Network configuration parameters

You can customize your installation configuration based on the requirements of your existing network infrastructure. For example, you can expand the IP address block for the cluster network or provide different IP address blocks than the defaults.

Only IPv4 addresses are supported.

Table 5. Network parameters
Parameter Description Values

networking

The configuration for the cluster network.

Object

You cannot modify parameters specified by the networking object after installation.

networking.networkType

The cluster network provider Container Network Interface (CNI) plug-in to install.

Either OpenShiftSDN or OVNKubernetes. The default value is OpenShiftSDN.

networking.clusterNetwork

The IP address blocks for pods.

The default value is 10.128.0.0/14 with a host prefix of /23.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23

networking.clusterNetwork.cidr

Required if you use networking.clusterNetwork. An IP address block.

An IPv4 network.

An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between 0 and 32.

networking.clusterNetwork.hostPrefix

The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23 then each node is assigned a /23 subnet out of the given cidr. A hostPrefix value of 23 provides 510 (2^(32 - 23) - 2) pod IP addresses.

A subnet prefix.

The default value is 23.

networking.serviceNetwork

The IP address block for services. The default value is 172.30.0.0/16.

The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network.

An array with an IP address block in CIDR format. For example:

networking:
  serviceNetwork:
   - 172.30.0.0/16

networking.machineNetwork

The IP address blocks for machines.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  machineNetwork:
  - cidr: 10.0.0.0/16

networking.machineNetwork.cidr

Required if you use networking.machineNetwork. An IP address block. The default value is 10.0.0.0/16 for all platforms other than libvirt. For libvirt, the default value is 192.168.126.0/24.

An IP network block in CIDR notation.

For example, 10.0.0.0/16.

Set the networking.machineNetwork to match the CIDR that the preferred NIC resides in.

Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Table 6. Optional parameters
Parameter Description Values

additionalTrustBundle

A PEM-encoded X.509 certificate bundle that is added to the nodes' trusted certificate store. This trust bundle may also be used when a proxy has been configured.

String

compute

The configuration for the machines that comprise the compute nodes.

Array of MachinePool objects.

compute.architecture

Determines the instruction set architecture of the machines in the pool. Currently, heteregeneous clusters are not supported, so all pools must specify the same architecture. Valid values are amd64 (the default).

String

compute.hyperthreading

Whether to enable or disable simultaneous multithreading, or hyperthreading, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

compute.name

Required if you use compute. The name of the machine pool.

worker

compute.platform

Required if you use compute. Use this parameter to specify the cloud provider to host the worker machines. This parameter value must match the controlPlane.platform parameter value.

aws, azure, gcp, openstack, ovirt, vsphere, or {}

compute.replicas

The number of compute machines, which are also known as worker machines, to provision.

A positive integer greater than or equal to 2. The default value is 3.

controlPlane

The configuration for the machines that comprise the control plane.

Array of MachinePool objects.

controlPlane.architecture

Determines the instruction set architecture of the machines in the pool. Currently, heterogeneous clusters are not supported, so all pools must specify the same architecture. Valid values are amd64 (the default).

String

controlPlane.hyperthreading

Whether to enable or disable simultaneous multithreading, or hyperthreading, on control plane machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

controlPlane.name

Required if you use controlPlane. The name of the machine pool.

master

controlPlane.platform

Required if you use controlPlane. Use this parameter to specify the cloud provider that hosts the control plane machines. This parameter value must match the compute.platform parameter value.

aws, azure, gcp, openstack, ovirt, vsphere, or {}

controlPlane.replicas

The number of control plane machines to provision.

The only supported value is 3, which is the default value.

credentialsMode

The Cloud Credential Operator (CCO) mode. If no mode is specified, the CCO dynamically tries to determine the capabilities of the provided credentials, with a preference for mint mode on the platforms where multiple modes are supported.

Not all CCO modes are supported for all cloud providers. For more information on CCO modes, see the Cloud Credential Operator entry in the Red Hat Operators reference content.

Mint, Passthrough, Manual, or an empty string ("").

fips

Enable or disable FIPS mode. The default is false (disabled). If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.

The use of FIPS Validated / Modules in Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the x86_64 architecture.

If you are using Azure File storage, you cannot enable FIPS mode.

false or true

imageContentSources

Sources and repositories for the release-image content.

Array of objects. Includes a source and, optionally, mirrors, as described in the following rows of this table.

imageContentSources.source

Required if you use imageContentSources. Specify the repository that users refer to, for example, in image pull specifications.

String

imageContentSources.mirrors

Specify one or more repositories that may also contain the same images.

Array of strings

publish

How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes.

Internal or External. The default value is External.

Setting this field to Internal is not supported on non-cloud platforms.

sshKey

The SSH key or keys to authenticate access your cluster machines.

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.

One or more keys. For example:

sshKey:
  <key1>
  <key2>
  <key3>

Additional VMware vSphere configuration parameters

Additional VMware vSphere configuration parameters are described in the following table:

Table 7. Additional VMware vSphere cluster parameters
Parameter Description Values

platform.vsphere.vCenter

The fully-qualified hostname or IP address of the vCenter server.

String

platform.vsphere.username

The user name to use to connect to the vCenter instance with. This user must have at least the roles and privileges that are required for static or dynamic persistent volume provisioning in vSphere.

String

platform.vsphere.password

The password for the vCenter user name.

String

platform.vsphere.datacenter

The name of the datacenter to use in the vCenter instance.

String

platform.vsphere.defaultDatastore

The name of the default datastore to use for provisioning volumes.

String

platform.vsphere.folder

Optional. The absolute path of an existing folder where the installation program creates the virtual machines. If you do not provide this value, the installation program creates a folder that is named with the infrastructure ID in the datacenter virtual machine folder.

String, for example, /<datacenter_name>/vm/<folder_name>/<subfolder_name>.

platform.vsphere.network

The network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured.

String

platform.vsphere.cluster

The vCenter cluster to install the OpenShift Container Platform cluster in.

String

platform.vsphere.apiVIP

The virtual IP (VIP) address that you configured for control plane API access.

An IP address, for example 128.0.0.1.

platform.vsphere.ingressVIP

The virtual IP (VIP) address that you configured for cluster ingress.

An IP address, for example 128.0.0.1.

Optional VMware vSphere machine pool configuration parameters

Optional VMware vSphere machine pool configuration parameters are described in the following table:

Table 8. Optional VMware vSphere machine pool parameters
Parameter Description Values

platform.vsphere.clusterOSImage

The location from which the installer downloads the RHCOS image. You must set this parameter to perform an installation in a restricted network.

An HTTP or HTTPS URL, optionally with a SHA-256 checksum. For example, https://mirror.openshift.com/images/rhcos-<version>-vmware.<architecture>.ova.

platform.vsphere.osDisk.diskSizeGB

The size of the disk in gigabytes.

Integer

platform.vsphere.cpus

The total number of virtual processor cores to assign a virtual machine.

Integer

platform.vsphere.coresPerSocket

The number of cores per socket in a virtual machine. The number of virtual sockets on the virtual machine is platform.vsphere.cpus/platform.vsphere.coresPerSocket. The default value is 1

Integer

platform.vsphere.memoryMB

The size of a virtual machine’s memory in megabytes.

Integer

Sample install-config.yaml file for an installer-provisioned VMware vSphere cluster

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: 3
  platform:
    vsphere: (4)
      cpus: 2
      coresPerSocket: 2
      memoryMB: 8196
      osDisk:
        diskSizeGB: 120
controlPlane: (2)
  hyperthreading: Enabled (3)
  name: master
  replicas: 3
  platform:
    vsphere: (4)
      cpus: 4
      coresPerSocket: 2
      memoryMB: 16384
      osDisk:
        diskSizeGB: 120
metadata:
  name: cluster (5)
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 10.0.0.0/16
  networkType: OpenShiftSDN
  serviceNetwork:
  - 172.30.0.0/16
platform:
  vsphere:
    vcenter: your.vcenter.server
    username: username
    password: password
    datacenter: datacenter
    defaultDatastore: datastore
    folder: folder
    network: VM_Network
    cluster: vsphere_cluster_name (6)
    apiVIP: api_vip
    ingressVIP: ingress_vip
fips: false
pullSecret: '{"auths": ...}'
sshKey: 'ssh-ed25519 AAAA...'
1 The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 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. Although both sections currently define a single machine pool, it is possible that future versions of OpenShift Container Platform will support defining multiple compute pools during installation. Only one control plane pool is used.
3 Whether to enable or disable simultaneous multithreading, or hyperthreading. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable simultaneous multithreading in some cluster machines, you must disable it in all cluster machines.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance. Your machines must use at least 8 CPUs and 32 GB of RAM if you disable simultaneous multithreading.

4 Optional: Provide additional configuration for the machine pool parameters for the compute and control plane machines.
5 The cluster name that you specified in your DNS records.
6 The vSphere cluster to install the OpenShift Container Platform cluster in. The installation program uses the root resource pool of the vSphere cluster as the default resource pool.

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.

    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).

  • If your cluster is on AWS, you added the ec2.<region>.amazonaws.com, elasticloadbalancing.<region>.amazonaws.com, and s3.<region>.amazonaws.com endpoints to your VPC endpoint. These endpoints are required to complete requests from the nodes to the AWS EC2 API. Because the proxy works on the container level, not the node level, you must route these requests to the AWS EC2 API through the AWS private network. Adding the public IP address of the EC2 API to your allowlist in your proxy server is not sufficient.

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. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpProxy value.
    2 A proxy URL to use for creating HTTPS connections outside the cluster. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpsProxy value.
    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. You must include vCenter’s IP address and the IP range that you use for its machines.
    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. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must provide the MITM CA certificate.

    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.

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

Network configuration phases

There are two phases prior to OpenShift Container Platform installation where you can customize the network configuration.

Phase 1

You can customize the following network-related fields in the install-config.yaml file before you create the manifest files:

  • networking.networkType

  • networking.clusterNetwork

  • networking.serviceNetwork

  • networking.machineNetwork

    For more information on these fields, refer to Installation configuration parameters.

    Set the networking.machineNetwork to match the CIDR that the preferred NIC resides in.

Phase 2

After creating the manifest files by running openshift-install create manifests, you can define a customized Cluster Network Operator manifest with only the fields you want to modify. You can use the manifest to specify advanced network configuration.

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

Specifying advanced network configuration

You can use advanced network configuration for your cluster network provider to integrate your cluster into your existing network environment. You can specify advanced network configuration only before you install the cluster.

Customizing your network configuration by modifying the OpenShift Container Platform manifest files created by the installation program is not supported. Applying a manifest file that you create, as in the following procedure, is supported.

Prerequisites
  • You have created the install-config.yaml file and completed any modifications to it.

Procedure
  1. Change to the directory that contains the installation program and create the manifests:

    $ ./openshift-install create manifests --dir <installation_directory> (1)
    1 <installation_directory> specifies the name of the directory that contains the install-config.yaml file for your cluster.
  2. Create a stub manifest file for the advanced network configuration that is named cluster-network-03-config.yml in the <installation_directory>/manifests/ directory:

    apiVersion: operator.openshift.io/v1
    kind: Network
    metadata:
      name: cluster
    spec:
  3. Specify the advanced network configuration for your cluster in the cluster-network-03-config.yml file, such as in the following examples:

    Specify a different VXLAN port for the OpenShift SDN network provider
    apiVersion: operator.openshift.io/v1
    kind: Network
    metadata:
      name: cluster
    spec:
      defaultNetwork:
        openshiftSDNConfig:
          vxlanPort: 4800
    Enable IPsec for the OVN-Kubernetes network provider
    apiVersion: operator.openshift.io/v1
    kind: Network
    metadata:
      name: cluster
    spec:
      defaultNetwork:
        ovnKubernetesConfig:
          ipsecConfig: {}
  4. Optional: Back up the manifests/cluster-network-03-config.yml file. The installation program consumes the manifests/ directory when you create the Ignition config files.

Cluster Network Operator configuration

The configuration for the cluster network is specified as part of the Cluster Network Operator (CNO) configuration and stored in a custom resource (CR) object that is named cluster. The CR specifies the fields for the Network API in the operator.openshift.io API group.

The CNO configuration inherits the following fields during cluster installation from the Network API in the Network.config.openshift.io API group and these fields cannot be changed:

clusterNetwork

IP address pools from which pod IP addresses are allocated.

serviceNetwork

IP address pool for services.

defaultNetwork.type

Cluster network provider, such as OpenShift SDN or OVN-Kubernetes.

You can specify the cluster network provider configuration for your cluster by setting the fields for the defaultNetwork object in the CNO object named cluster.

Cluster Network Operator configuration object

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

Table 9. Cluster Network Operator configuration object
Field Type Description

metadata.name

string

The name of the CNO object. This name is always cluster.

spec.clusterNetwork

array

A list specifying the blocks of IP addresses from which pod IP addresses are allocated and the subnet prefix length assigned to each individual node in the cluster. For example:

spec:
  clusterNetwork:
  - cidr: 10.128.0.0/19
    hostPrefix: 23
  - cidr: 10.128.32.0/19
    hostPrefix: 23

You can customize this field only in the install-config.yaml file before you create the manifests. The value is read-only in the manifest file.

spec.serviceNetwork

array

A block of IP addresses for services. The OpenShift SDN and OVN-Kubernetes Container Network Interface (CNI) network providers support only a single IP address block for the service network. For example:

spec:
  serviceNetwork:
  - 172.30.0.0/14

You can customize this field only in the install-config.yaml file before you create the manifests. The value is read-only in the manifest file.

spec.defaultNetwork

object

Configures the Container Network Interface (CNI) cluster network provider for the cluster network.

spec.kubeProxyConfig

object

The fields for this object specify the kube-proxy configuration. If you are using the OVN-Kubernetes cluster network provider, the kube-proxy configuration has no effect.

defaultNetwork object configuration

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

Table 10. defaultNetwork object
Field Type Description

type

string

Either OpenShiftSDN or OVNKubernetes. The cluster network provider is selected during installation. This value cannot be changed after cluster installation.

OpenShift Container Platform uses the OpenShift SDN Container Network Interface (CNI) cluster network provider by default.

openshiftSDNConfig

object

This object is only valid for the OpenShift SDN cluster network provider.

ovnKubernetesConfig

object

This object is only valid for the OVN-Kubernetes cluster network provider.

Configuration for the OpenShift SDN CNI cluster network provider

The following table describes the configuration fields for the OpenShift SDN Container Network Interface (CNI) cluster network provider.

Table 11. openshiftSDNConfig object
Field Type Description

mode

string

Configures the network isolation mode for OpenShift SDN. The default value is NetworkPolicy.

The values Multitenant and Subnet are available for backwards compatibility with OpenShift Container Platform 3.x but are not recommended. This value cannot be changed after cluster installation.

mtu

integer

The maximum transmission unit (MTU) for the VXLAN overlay network. This is detected automatically based on the MTU of the primary network interface. You do not normally need to override the detected MTU.

If the auto-detected value is not what you expect it to be, confirm that the MTU on the primary network interface on your nodes is correct. You cannot use this option to change the MTU value of the primary network interface on the nodes.

If your cluster requires different MTU values for different nodes, you must set this value to 50 less than the lowest MTU value in your cluster. For example, if some nodes in your cluster have an MTU of 9001, and some have an MTU of 1500, you must set this value to 1450.

This value cannot be changed after cluster installation.

vxlanPort

integer

The port to use for all VXLAN packets. The default value is 4789. This value cannot be changed after cluster installation.

If you are running in a virtualized environment with existing nodes that are part of another VXLAN network, then you might be required to change this. For example, when running an OpenShift SDN overlay on top of VMware NSX-T, you must select an alternate port for the VXLAN, because both SDNs use the same default VXLAN port number.

On Amazon Web Services (AWS), you can select an alternate port for the VXLAN between port 9000 and port 9999.

Example OpenShift SDN configuration
defaultNetwork:
  type: OpenShiftSDN
  openshiftSDNConfig:
    mode: NetworkPolicy
    mtu: 1450
    vxlanPort: 4789
Configuration for the OVN-Kubernetes CNI cluster network provider

The following table describes the configuration fields for the OVN-Kubernetes CNI cluster network provider.

Table 12. ovnKubernetesConfig object
Field Type Description

mtu

integer

The maximum transmission unit (MTU) for the Geneve (Generic Network Virtualization Encapsulation) overlay network. This is detected automatically based on the MTU of the primary network interface. You do not normally need to override the detected MTU.

If the auto-detected value is not what you expect it to be, confirm that the MTU on the primary network interface on your nodes is correct. You cannot use this option to change the MTU value of the primary network interface on the nodes.

If your cluster requires different MTU values for different nodes, you must set this value to 100 less than the lowest MTU value in your cluster. For example, if some nodes in your cluster have an MTU of 9001, and some have an MTU of 1500, you must set this value to 1400.

This value cannot be changed after cluster installation.

genevePort

integer

The port to use for all Geneve packets. The default value is 6081. This value cannot be changed after cluster installation.

ipsecConfig

object

Specify an empty object to enable IPsec encryption. This value cannot be changed after cluster installation.

policyAuditConfig

object

Specify a configuration object for customizing network policy audit logging. If unset, the defaults audit log settings are used.

Table 13. policyAuditConfig object
Field Type Description

rateLimit

integer

The maximum number of messages to generate every second per node. The default value is 20 messages per second.

maxFileSize

integer

The maximum size for the audit log in bytes. The default value is 50000000 or 50 MB.

destination

string

One of the following additional audit log targets:

libc

The libc syslog() function of the journald process on the host.

udp:<host>:<port>

A syslog server. Replace <host>:<port> with the host and port of the syslog server.

unix:<file>

A Unix Domain Socket file specified by <file>.

null

Do not send the audit logs to any additional target.

syslogFacility

string

The syslog facility, such as kern, as defined by RFC5424. The default value is local0.

Example OVN-Kubernetes configuration
defaultNetwork:
  type: OVNKubernetes
  ovnKubernetesConfig:
    mtu: 1400
    genevePort: 6081
    ipsecConfig: {}

kubeProxyConfig object configuration

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

Table 14. kubeProxyConfig object
Field Type Description

iptablesSyncPeriod

string

The refresh period for iptables rules. The default value is 30s. Valid suffixes include s, m, and h and are described in the Go time package documentation.

Because of performance improvements introduced in OpenShift Container Platform 4.3 and greater, adjusting the iptablesSyncPeriod parameter is no longer necessary.

proxyArguments.iptables-min-sync-period

array

The minimum duration before refreshing iptables rules. This field ensures that the refresh does not happen too frequently. Valid suffixes include s, m, and h and are described in the Go time package. The default value is:

kubeProxyConfig:
  proxyArguments:
    iptables-min-sync-period:
    - 0s

Deploying the cluster

You can install OpenShift Container Platform on a compatible cloud platform.

You can run the create cluster command of the installation program only once, during initial installation.

Prerequisites
  • Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.

Procedure
  1. Change to the directory that contains the installation program and initialize the cluster deployment:

    $ ./openshift-install create cluster --dir <installation_directory> \ (1)
        --log-level=info (2)
    
    1 For <installation_directory>, specify the location of your customized ./install-config.yaml file.
    2 To view different installation details, specify warn, debug, or error instead of info.

    If the cloud provider account that you configured on your host does not have sufficient permissions to deploy the cluster, the installation process stops, and the missing permissions are displayed.

    When the cluster deployment completes, directions for accessing your cluster, including a link to its web console and credentials for the kubeadmin user, display in your terminal.

    Example output
    ...
    INFO Install complete!
    INFO To access the cluster as the system:admin user when using 'oc', run 'export KUBECONFIG=/home/myuser/install_dir/auth/kubeconfig'
    INFO Access the OpenShift web-console here: https://console-openshift-console.apps.mycluster.example.com
    INFO Login to the console with user: "kubeadmin", and password: "4vYBz-Ee6gm-ymBZj-Wt5AL"
    INFO Time elapsed: 36m22s

    The cluster access and credential information also outputs to <installation_directory>/.openshift_install.log when an installation succeeds.

    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.

    You must not delete the installation program or the files that the installation program creates. Both are required to delete the cluster.

Installing the OpenShift CLI by downloading the binary

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

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.9. Download and install the new version of oc.

Installing the OpenShift CLI on Linux

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

Procedure
  1. Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.

  2. Select the appropriate version in the Version drop-down menu.

  3. Click Download Now next to the OpenShift v4.9 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>

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 v4.9 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>

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 v4.9 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>

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