Installing a cluster on vSphere with customizations

In OKD version 4, you can install a cluster on your VMware vSphere instance by using installer-provisioned infrastructure. To customize the installation, you modify parameters in the install-config.yaml file before you install the cluster.

Prerequisites

• You reviewed details about the OKD 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 OKD installer requires access to port 443 on the vCenter and ESXi hosts. You verified that port 443 is accessible.

• If you use a firewall, you confirmed 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.

Generating a key pair for cluster node SSH access

During an OKD installation, you can provide an SSH public key to the installation program. The key is passed to the Fedora CoreOS (FCOS) 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 FCOS 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.

Procedure

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

   $ ssh-keygen -t ed25519 -N '' -f <path>/<file_name> (1)

   1	Specify the path and file name, such as ~/.ssh/id_ed25519, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.

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

2. View the public SSH key:

   $ cat <path>/<file_name>.pub

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

   $ cat ~/.ssh/id_ed25519.pub

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

   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_ed25519

   Example output

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

Next steps

• When you install OKD, provide the SSH public key to the installation program.

Obtaining the installation program

Before you install OKD, download the installation file on the host you are using for installation.

Prerequisites

• You have a machine that runs Linux, for example Red Hat Enterprise Linux 8, with 500 MB of local disk space.

  If you attempt to run the installation program on macOS, a known issue related to the golang compiler causes the installation of the OKD cluster to fail. For more information about this issue, see the section named “Known Issues” in the OKD 4 release notes document.

Procedure

1. Download installer from https://github.com/openshift/okd/releases

   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 OKD uninstallation procedures for your specific cloud provider.

2. 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

3. 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 OKD components.

   Using a pull secret from the Red Hat OpenShift Cluster Manager is not required. You can use a pull secret for another private registry. Or, if you do not need the cluster to pull images from a private registry, you can use {"auths":{"fake":{"auth":"aWQ6cGFzcwo="}}} as the pull secret when prompted during the installation.

   If you do not use the pull secret from the Red Hat OpenShift Cluster Manager:

   • Red Hat Operators are not available.

   • The Telemetry and Insights operators do not send data to Red Hat.

   • Content from the Red Hat Ecosystem Catalog Container images registry, such as image streams and Operators, are not available.

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 OKD 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

VMware vSphere region and zone enablement

You can deploy an OKD cluster to multiple vSphere datacenters that run in a single VMware vCenter. Each datacenter can run multiple clusters. This configuration reduces the risk of a hardware failure or network outage that can cause your cluster to fail.

The default installation configuration deploys a cluster to a single vSphere datacenter. If you want to deploy a cluster to multiple vSphere datacenters, you must create an installation configuration file that enables the region and zone feature.

The default install-config.yaml file includes vcenters and failureDomains fields, where you can specify multiple vSphere datacenters and clusters for your OKD cluster. You can leave these fields blank if you want to install an OKD cluster in a vSphere environment that consists of single datacenter.

The following list describes terms associated with defining zones and regions for your cluster:

• Failure domain: Establishes the relationships between a region and zone. You define a failure domain by using vCenter objects, such as a datastore object. A failure domain defines the vCenter location for OKD cluster nodes.

• Region: Specifies a vCenter datacenter. You define a region by using a tag from the openshift-region tag category.

• Zone: Specifies a vCenter cluster. You define a zone by using a tag from the openshift-zone tag category.

You must create a vCenter tag for each vCenter datacenter, which represents a region. Additionally, you must create a vCenter tag for each cluster than runs in a datacenter, which represents a zone. After you create the tags, you must attach each tag to their respective datacenters and clusters.

The following table outlines an example of the relationship among regions, zones, and tags for a configuration with multiple vSphere datacenters running in a single VMware vCenter.

Additional resources

• Additional VMware vSphere configuration parameters

• Deprecated VMware vSphere configuration parameters

• vSphere automatic migration

• VMware vSphere CSI Driver Operator

Creating the installation configuration file

You can customize the OKD cluster you install on VMware vSphere.

Prerequisites

• You have the OKD installation program and the pull secret for your cluster.

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.

      When specifying the directory:

      • Verify that the directory has the execute permission. This permission is required to run Terraform binaries under the installation directory.

      • Use an empty directory. Some installation assets, such as bootstrap X.509 certificates, have short expiration intervals, therefore 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 OKD version.

        Always delete the ~/.powervs directory to avoid reusing a stale configuration. Run the following command: $ rm -rf ~/.powervs

   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 OKD 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 data center in your vCenter instance to connect to.

         After you create the installation configuration file, you can modify the file to create a multiple vSphere datacenters environment. This means that you can deploy an OKD cluster to multiple vSphere datacenters that run in a single VMware vCenter. For more information about creating this environment, see the section named VMware vSphere region and zone enablement.

      6. Select the default vCenter datastore to use.

         You can specify the path of any datastore that exists in a datastore cluster. By default, Storage Distributed Resource Scheduler (SDRS), which uses Storage vMotion, is automatically enabled for a datastore cluster. Red Hat does not support Storage vMotion, so you must disable Storage DRS to avoid data loss issues for your OKD cluster. You cannot specify more than one datastore path. If you must specify VMs across multiple datastores, use a datastore object to specify a failure domain in your cluster’s install-config.yaml configuration file. For more information, see “VMware vSphere region and zone enablement”.

      7. Select the vCenter cluster to install the OKD 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 you enter must match the cluster name you specified when configuring the DNS records.

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

   If you are installing a three-node cluster, be sure to set the compute.replicas parameter to 0. This ensures that the cluster’s control planes are schedulable. For more information, see “Installing a three-node cluster on vSphere”.

2. 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.

Additional resources

• Installation configuration parameters

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 OKD cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com (1)
compute: (2)
- architecture: amd64
  name:  <worker_node>
  platform: {}
  replicas: 3
controlPlane: (2)
  architecture: amd64
  name: <parent_node>
  platform: {}
  replicas: 3
metadata:
  creationTimestamp: null
  name: test (3)
platform:
  vsphere: (4)
    apiVIPs:
      - 10.0.0.1
    failureDomains: (5)
    - name: <failure_domain_name>
      region: <default_region_name>
      server: <fully_qualified_domain_name>
      topology:
        computeCluster: "/<datacenter>/host/<cluster>"
        datacenter: <datacenter>
        datastore: "/<datacenter>/datastore/<datastore>" (6)
        networks:
        - <VM_Network_name>
        resourcePool: "/<datacenter>/host/<cluster>/Resources/<resourcePool>" (7)
        folder: "/<datacenter_name>/vm/<folder_name>/<subfolder_name>"
      zone: <default_zone_name>
    ingressVIPs:
    - 10.0.0.2
    vcenters:
    - datacenters:
      - <datacenter>
      password: <password>
      port: 443
      server: <fully_qualified_domain_name>
      user: administrator@vsphere.local
    diskType: thin (8)
pullSecret: '{"auths": ...}'
sshKey: 'ssh-ed25519 AAAA...'

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 OKD 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 OpenStack, the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

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

   apiVersion: v1
   baseDomain: my.domain.com
   proxy:
     httpProxy: http://<username>:<pswd>@<ip>:<port> (1)
     httpsProxy: https://<username>:<pswd>@<ip>:<port> (2)
     noProxy: example.com (3)
   additionalTrustBundle: | (4)
       -----BEGIN CERTIFICATE-----
       <MY_TRUSTED_CA_CERT>
       -----END CERTIFICATE-----
   additionalTrustBundlePolicy: <policy_to_add_additionalTrustBundle> (5)

   1	A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
   2	A proxy URL to use for creating HTTPS connections outside the cluster.
   3	A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations. 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 FCOS trust bundle. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the FCOS trust bundle.
   5	Optional: The policy to determine the configuration of the Proxy object to reference the user-ca-bundle config map in the trustedCA field. The allowed values are Proxyonly and Always. Use Proxyonly to reference the user-ca-bundle config map only when http/https proxy is configured. Use Always to always reference the user-ca-bundle config map. The default value is Proxyonly.

   The installation program does not support the proxy readinessEndpoints field.

   If the installer times out, restart and then complete the deployment by using the wait-for command of the installer. For example: $ ./openshift-install wait-for install-complete —log-level debug

2. Save the file and reference it when installing OKD.

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.

Configuring regions and zones for a VMware vCenter

You can modify the default installation configuration file, so that you can deploy an OKD cluster to multiple vSphere datacenters that run in a single VMware vCenter.

The default install-config.yaml file configuration from the previous release of OKD is deprecated. You can continue to use the deprecated default configuration, but the openshift-installer will prompt you with a warning message that indicates the use of deprecated fields in the configuration file.

Prerequisites

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

  You must specify at least one failure domain for your OKD cluster, so that you can provision datacenter objects for your VMware vCenter server. Consider specifying multiple failure domains if you need to provision virtual machine nodes in different datacenters, clusters, datastores, and other components.

Procedure

1. Enter the following govc command-line tool commands to create the openshift-region and openshift-zone vCenter tag categories:

   If you specify different names for the openshift-region and openshift-zone vCenter tag categories, the installation of the OKD cluster fails.

   $ govc tags.category.create -d "OpenShift region" openshift-region

   $ govc tags.category.create -d "OpenShift zone" openshift-zone

2. To create a region tag for each region vSphere datacenter where you want to deploy your cluster, enter the following command in your terminal:

   $ govc tags.create -c <region_tag_category> <region_tag>

3. To create a zone tag for each vSphere cluster where you want to deploy your cluster, enter the following command:

   $ govc tags.create -c <zone_tag_category> <zone_tag>

4. Attach region tags to each vCenter datacenter object by entering the following command:

   $ govc tags.attach -c <region_tag_category> <region_tag_1> /<datacenter_1>

5. Attach the zone tags to each vCenter datacenter object by entering the following command:

   $ govc tags.attach -c <zone_tag_category> <zone_tag_1> /<datacenter_1>/host/vcs-mdcnc-workload-1

6. Change to the directory that contains the installation program and initialize the cluster deployment according to your chosen installation requirements.

Sample install-config.yaml file with multiple datacenters defined in a vSphere center

---
compute:
---
  vsphere:
      zones:
        - "<machine_pool_zone_1>"
        - "<machine_pool_zone_2>"
---
controlPlane:
---
vsphere:
      zones:
        - "<machine_pool_zone_1>"
        - "<machine_pool_zone_2>"
---
platform:
  vsphere:
    vcenters:
---
    datacenters:
      - <datacenter1_name>
      - <datacenter2_name>
    failureDomains:
    - name: <machine_pool_zone_1>
      region: <region_tag_1>
      zone: <zone_tag_1>
      server: <fully_qualified_domain_name>
      topology:
        datacenter: <datacenter1>
        computeCluster: "/<datacenter1>/host/<cluster1>"
        networks:
        - <VM_Network1_name>
        datastore: "/<datacenter1>/datastore/<datastore1>"
        resourcePool: "/<datacenter1>/host/<cluster1>/Resources/<resourcePool1>"
        folder: "/<datacenter1>/vm/<folder1>"
    - name: <machine_pool_zone_2>
      region: <region_tag_2>
      zone: <zone_tag_2>
      server: <fully_qualified_domain_name>
      topology:
        datacenter: <datacenter2>
        computeCluster: "/<datacenter2>/host/<cluster2>"
        networks:
        - <VM_Network2_name>
        datastore: "/<datacenter2>/datastore/<datastore2>"
        resourcePool: "/<datacenter2>/host/<cluster2>/Resources/<resourcePool2>"
        folder: "/<datacenter2>/vm/<folder2>"
---

Deploying the cluster

You can install OKD on a compatible cloud platform.

Prerequisites

• You have the OKD installation program and the pull secret for your cluster.

• You have verified that the cloud provider account on your host has the correct permissions to deploy the cluster. An account with incorrect permissions causes the installation process to fail with an error message that displays the missing permissions.

• Optional: Before you create the cluster, configure an external load balancer in place of the default load balancer.

  You do not need to specify API and Ingress static addresses for your installation program. If you choose this configuration, you must take additional actions to define network targets that accept an IP address from each referenced vSphere subnet. See the section “Configuring an external load balancer”.

Procedure

• 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.

Verification

When the cluster deployment completes successfully:

• The terminal displays directions for accessing your cluster, including a link to the web console and credentials for the kubeadmin user.

• Credential information also outputs to <installation_directory>/.openshift_install.log.

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: "password"
INFO Time elapsed: 36m22s

Installing the OpenShift CLI by downloading the binary

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

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 https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

2. Download oc.tar.gz.

3. Unpack the archive:

   $ tar xvf <file>

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

   To check your PATH, execute the following command:

   $ echo $PATH

Verification

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

  $ oc <command>

Installing the OpenShift CLI on Windows

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

Procedure

1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

2. Download oc.zip.

3. Unzip the archive with a ZIP program.

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

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

   C:\> path

Verification

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

  C:\> oc <command>

Installing the OpenShift CLI on macOS

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

Procedure

1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

2. Download oc.tar.gz.

3. Unpack and unzip the archive.

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

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

   $ echo $PATH

Verification

• 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 OKD installation.

Prerequisites

• You deployed an OKD 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

Creating registry storage

After you install the cluster, you must create storage for the registry Operator.

Image registry removed during installation

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

After installation, you must edit the Image Registry Operator configuration to switch the managementState from Removed to Managed.

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.

Configuring registry storage for VMware vSphere

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

Prerequisites

• Cluster administrator permissions.

• A cluster on VMware vSphere.

• Persistent storage provisioned for your cluster, such as Red Hat OpenShift Data Foundation.

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

• Must have “100Gi” capacity.

Procedure

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

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

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

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

   Example output

   No resourses found in openshift-image-registry namespace

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

3. Check the registry configuration:

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

   Example output

   storage:
     pvc:
       claim: (1)

   1

   Leave the claim field blank to allow the automatic creation of an image-registry-storage persistent volume claim (PVC). The PVC is generated based on the default storage class. However, be aware that the default storage class might provide ReadWriteOnce (RWO) volumes, such as a RADOS Block Device (RBD), which can cause issues when you replicate to more than one replica.

4. Check the clusteroperator status:

   $ oc get clusteroperator image-registry

   Example output

   NAME             VERSION                              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
   image-registry   4.7                                  True        False         False      6h50m

Configuring block registry storage for VMware vSphere

To allow the image registry to use block storage types such as vSphere Virtual Machine Disk (VMDK) during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Procedure

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

   $ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'

2. Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.

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

      kind: PersistentVolumeClaim
      apiVersion: v1
      metadata:
        name: image-registry-storage (1)
        namespace: openshift-image-registry (2)
      spec:
        accessModes:
        - ReadWriteOnce (3)
        resources:
          requests:
            storage: 100Gi (4)

      1	A unique name that represents the PersistentVolumeClaim object.
      2	The namespace for the PersistentVolumeClaim object, which is openshift-image-registry.
      3	The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node.
      4	The size of the persistent volume claim.

   2. Enter the following command to create the PersistentVolumeClaim object from the file:

      $ oc create -f pvc.yaml -n openshift-image-registry

3. Enter the following command to edit the registry configuration so that it references the correct PVC:

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

   Example output

   storage:
     pvc:
       claim: (1)

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

For instructions about configuring registry storage so that it references the correct PVC, see Configuring the registry for vSphere.

Additional resources

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

Configuring an external load balancer

You can configure an OKD cluster to use an external load balancer in place of the default load balancer.

Red Hat supports the following services for an external load balancer:

• Ingress Controller

• OpenShift API

• OpenShift MachineConfig API

You can choose whether you want to configure one or all of these services for an external load balancer. Configuring only the Ingress Controller service is a common configuration option. To better understand each service, view the following diagrams:

Figure 1. Example network workflow that shows an Ingress Controller operating in an OKD environment

Figure 2. Example network workflow that shows an OpenShift API operating in an OKD environment

Figure 3. Example network workflow that shows an OpenShift MachineConfig API operating in an OKD environment

The following configuration options are supported for external load balancers:

• Use a node selector to map the Ingress Controller to a specific set of nodes. You must assign a static IP address to each node in this set, or configure each node to receive the same IP address from the Dynamic Host Configuration Protocol (DHCP). Infrastructure nodes commonly receive this type of configuration.

• Target all IP addresses on a subnet. This configuration can reduce maintenance overhead, because you can create and destroy nodes within those networks without reconfiguring the load balancer targets. If you deploy your ingress pods by using a machine set on a smaller network, such as a /27 or /28, you can simplify your load balancer targets.

  You can list all IP addresses that exist in a network by checking the machine config pool’s resources.

Considerations

• For a front-end IP address, you can use the same IP address for the front-end IP address, the Ingress Controller’s load balancer, and API load balancer. Check the vendor’s documentation for this capability.

• For a back-end IP address, ensure that an IP address for an OKD control plane node does not change during the lifetime of the external load balancer. You can achieve this by completing one of the following actions:

  • Assign a static IP address to each control plane node.

  • Configure each node to receive the same IP address from the DHCP every time the node requests a DHCP lease. Depending on the vendor, the DHCP lease might be in the form of an IP reservation or a static DHCP assignment.

• Manually define each node that runs the Ingress Controller in the external load balancer for the Ingress Controller back-end service. For example, if the Ingress Controller moves to an undefined node, a connection outage can occur.

OpenShift API prerequisites

• You defined a front-end IP address.

• TCP ports 6443 and 22623 are exposed on the front-end IP address of your load balancer. Check the following items:

  • Port 6443 provides access to the OpenShift API service.

  • Port 22623 can provide ignition startup configurations to nodes.

• The front-end IP address and port 6443 are reachable by all users of your system with a location external to your OKD cluster.

• The front-end IP address and port 22623 are reachable only by OKD nodes.

• The load balancer backend can communicate with OKD control plane nodes on port 6443 and 22623.

Ingress Controller prerequisites

• You defined a front-end IP address.

• TCP ports 443 and 80 are exposed on the front-end IP address of your load balancer.

• The front-end IP address, port 80 and port 443 are be reachable by all users of your system with a location external to your OKD cluster.

• The front-end IP address, port 80 and port 443 are reachable to all nodes that operate in your OKD cluster.

• The load balancer backend can communicate with OKD nodes that run the Ingress Controller on ports 80, 443, and 1936.

Prerequisite for health check URL specifications

You can configure most load balancers by setting health check URLs that determine if a service is available or unavailable. OKD provides these health checks for the OpenShift API, Machine Configuration API, and Ingress Controller backend services.

The following examples demonstrate health check specifications for the previously listed backend services:

Example of a Kubernetes API health check specification

Path: HTTPS:6443/readyz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10

Example of a Machine Config API health check specification

Path: HTTPS:22623/healthz
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 10
Interval: 10

Example of an Ingress Controller health check specification

Path: HTTP:1936/healthz/ready
Healthy threshold: 2
Unhealthy threshold: 2
Timeout: 5
Interval: 10

Procedure

1. Configure the HAProxy Ingress Controller, so that you can enable access to the cluster from your load balancer on ports 6443, 443, and 80:

   Example HAProxy configuration

   #...
   listen my-cluster-api-6443
       bind 192.168.1.100:6443
       mode tcp
       balance roundrobin
     option httpchk
     http-check connect
     http-check send meth GET uri /readyz
     http-check expect status 200
       server my-cluster-master-2 192.168.1.101:6443 check inter 10s rise 2 fall 2
       server my-cluster-master-0 192.168.1.102:6443 check inter 10s rise 2 fall 2
       server my-cluster-master-1 192.168.1.103:6443 check inter 10s rise 2 fall 2
   listen my-cluster-machine-config-api-22623
       bind 192.168.1.1000.0.0.0:22623
       mode tcp
       balance roundrobin
     option httpchk
     http-check connect
     http-check send meth GET uri /healthz
     http-check expect status 200
       server my-cluster-master-2 192.0168.21.2101:22623 check inter 10s rise 2 fall 2
       server my-cluster-master-0 192.168.1.1020.2.3:22623 check inter 10s rise 2 fall 2
       server my-cluster-master-1 192.168.1.1030.2.1:22623 check inter 10s rise 2 fall 2
   listen my-cluster-apps-443
           bind 192.168.1.100:443
           mode tcp
           balance roundrobin
       option httpchk
       http-check connect
       http-check send meth GET uri /healthz/ready
       http-check expect status 200
           server my-cluster-worker-0 192.168.1.111:443 check port 1936 inter 10s rise 2 fall 2
           server my-cluster-worker-1 192.168.1.112:443 check port 1936 inter 10s rise 2 fall 2
           server my-cluster-worker-2 192.168.1.113:443 check port 1936 inter 10s rise 2 fall 2
   listen my-cluster-apps-80
           bind 192.168.1.100:80
           mode tcp
           balance roundrobin
       option httpchk
       http-check connect
       http-check send meth GET uri /healthz/ready
       http-check expect status 200
           server my-cluster-worker-0 192.168.1.111:80 check port 1936 inter 10s rise 2 fall 2
           server my-cluster-worker-1 192.168.1.112:80 check port 1936 inter 10s rise 2 fall 2
           server my-cluster-worker-2 192.168.1.113:80 check port 1936 inter 10s rise 2 fall 2
   # ...

2. Use the curl CLI command to verify that the external load balancer and its resources are operational:

   1. Verify that the cluster machine configuration API is accessible to the Kubernetes API server resource, by running the following command and observing the response:

      $ curl https://<loadbalancer_ip_address>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
        "major": "1",
        "minor": "11+",
        "gitVersion": "v1.11.0+ad103ed",
        "gitCommit": "ad103ed",
        "gitTreeState": "clean",
        "buildDate": "2019-01-09T06:44:10Z",
        "goVersion": "go1.10.3",
        "compiler": "gc",
        "platform": "linux/amd64"
      }

   2. Verify that the cluster machine configuration API is accessible to the Machine config server resource, by running the following command and observing the output:

      $ curl -v https://<loadbalancer_ip_address>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      Content-Length: 0

   3. Verify that the controller is accessible to the Ingress Controller resource on port 80, by running the following command and observing the output:

      $ curl -I -L -H "Host: console-openshift-console.apps.<cluster_name>.<base_domain>" http://<load_balancer_front_end_IP_address>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
      content-length: 0
      location: https://console-openshift-console.apps.ocp4.private.opequon.net/
      cache-control: no-cache

   4. Verify that the controller is accessible to the Ingress Controller resource on port 443, by running the following command and observing the output:

      $ curl -I -L --insecure --resolve console-openshift-console.apps.<cluster_name>.<base_domain>:443:<Load Balancer Front End IP Address> https://console-openshift-console.apps.<cluster_name>.<base_domain>

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Wed, 04 Oct 2023 16:29:38 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private

3. Configure the DNS records for your cluster to target the front-end IP addresses of the external load balancer. You must update records to your DNS server for the cluster API and applications over the load balancer.

   Examples of modified DNS records

   <load_balancer_ip_address>  A  api.<cluster_name>.<base_domain>
   A record pointing to Load Balancer Front End

   <load_balancer_ip_address>   A apps.<cluster_name>.<base_domain>
   A record pointing to Load Balancer Front End

   DNS propagation might take some time for each DNS record to become available. Ensure that each DNS record propagates before validating each record.

4. Use the curl CLI command to verify that the external load balancer and DNS record configuration are operational:

   1. Verify that you can access the cluster API, by running the following command and observing the output:

      $ curl https://api.<cluster_name>.<base_domain>:6443/version --insecure

      If the configuration is correct, you receive a JSON object in response:

      {
        "major": "1",
        "minor": "11+",
        "gitVersion": "v1.11.0+ad103ed",
        "gitCommit": "ad103ed",
        "gitTreeState": "clean",
        "buildDate": "2019-01-09T06:44:10Z",
        "goVersion": "go1.10.3",
        "compiler": "gc",
        "platform": "linux/amd64"
        }

   2. Verify that you can access the cluster machine configuration, by running the following command and observing the output:

      $ curl -v https://api.<cluster_name>.<base_domain>:22623/healthz --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      Content-Length: 0

   3. Verify that you can access each cluster application on port, by running the following command and observing the output:

      $ curl http://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 302 Found
      content-length: 0
      location: https://console-openshift-console.apps.<cluster-name>.<base domain>/
      cache-control: no-cacheHTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=39HoZgztDnzjJkq/JuLJMeoKNXlfiVv2YgZc09c3TBOBU4NI6kDXaJH1LdicNhN1UsQWzon4Dor9GWGfopaTEQ==; Path=/; Secure
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Tue, 17 Nov 2020 08:42:10 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=9b714eb87e93cf34853e87a92d6894be; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private

   4. Verify that you can access each cluster application on port 443, by running the following command and observing the output:

      $ curl https://console-openshift-console.apps.<cluster_name>.<base_domain> -I -L --insecure

      If the configuration is correct, the output from the command shows the following response:

      HTTP/1.1 200 OK
      referrer-policy: strict-origin-when-cross-origin
      set-cookie: csrf-token=UlYWOyQ62LWjw2h003xtYSKlh1a0Py2hhctw0WmV2YEdhJjFyQwWcGBsja261dGLgaYO0nxzVErhiXt6QepA7g==; Path=/; Secure; SameSite=Lax
      x-content-type-options: nosniff
      x-dns-prefetch-control: off
      x-frame-options: DENY
      x-xss-protection: 1; mode=block
      date: Wed, 04 Oct 2023 16:29:38 GMT
      content-type: text/html; charset=utf-8
      set-cookie: 1e2670d92730b515ce3a1bb65da45062=1bf5e9573c9a2760c964ed1659cc1673; path=/; HttpOnly; Secure; SameSite=None
      cache-control: private

Next steps

• Customize your cluster.

• If necessary, you can opt out of remote health reporting.

• Set up your registry and configure registry storage.

• Optional: View the events from the vSphere Problem Detector Operator to determine if the cluster has permission or storage configuration issues.