Installing a cluster with customizations - Installing on vSphere | Installing

Prerequisites
VMware vSphere region and zone enablement
Creating the installation configuration file
Deploying the cluster
Logging in to the cluster by using the CLI
Creating registry storage
- Image registry removed during installation
- Image registry storage configuration
Services for an external load balancer
- Configuring an external load balancer
Next steps

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.

OKD supports deploying a cluster to a single VMware vCenter only. Deploying a cluster with machines/machine sets on multiple vCenters is not supported.

Prerequisites

You have completed the tasks in Preparing to install a cluster using installer-provisioned infrastructure.
You reviewed your VMware platform licenses. Red Hat does not place any restrictions on your VMware licenses, but some VMware infrastructure components require licensing.
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.

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. To enable regions and zones, you must define multiple failure domains for your OKD cluster.

The VMware vSphere region and zone enablement feature requires the vSphere Container Storage Interface (CSI) driver as the default storage driver in the cluster. As a result, the feature is only available on a newly installed cluster.

For a cluster that was upgraded from a previous release, you must enable CSI automatic migration for the cluster. You can then configure multiple regions and zones for the upgraded cluster.

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.

If you plan on specifying more than one failure domain in your install-config.yaml file, you must create tag categories, zone tags, and region tags in advance of creating the configuration file.

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.

Datacenter (region)	Cluster (zone)	Tags
us-east	us-east-1	us-east-1a
us-east-1b
us-east-2	us-east-2a
us-east-2b
us-west	us-west-1	us-west-1a
us-west-1b
us-west-2	us-west-2a
us-west-2b

Datacenter (region)

Cluster (zone)

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

Create the install-config.yaml file.

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.

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

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.
Select vsphere as the platform to target.
Specify the name of your vCenter instance.
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.

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.

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".

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.
Select the network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured.
Enter the virtual IP address that you configured for control plane API access.
Enter the virtual IP address that you configured for cluster ingress.
Enter the base domain. This base domain must be the same one that you used in the DNS records that you configured.
Enter a descriptive name for your cluster.

The cluster name you enter must match the cluster name you specified when configuring the DNS records.

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".

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...'

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. Only one control plane pool is used.

3 The cluster name that you specified in your DNS records.

4 Optional: Provides additional configuration for the machine pool parameters for the compute and control plane machines.

5 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.

The path to the vSphere datastore that holds virtual machine files, templates, and ISO images.

You can specify the path of any datastore that exists in a datastore cluster. By default, Storage vMotion is automatically enabled for a datastore cluster. Red Hat does not support Storage vMotion, so you must disable Storage vMotion to avoid data loss issues for your OKD cluster.

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 Optional: Provides an existing resource pool for machine creation. If you do not specify a value, the installation program uses the root resource pool of the vSphere cluster.

8 The vSphere disk provisioning method.

In OKD 4.12 and later, the apiVIP and ingressVIP configuration settings are deprecated. Instead, use a list format to enter values in the apiVIPs and ingressVIPs configuration settings.

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

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

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.

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

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.

The example uses the govc command. The govc command is an open source command available from VMware; it is not available from Red Hat. The Red Hat support team does not maintain the govc command. Instructions for downloading and installing govc are found on the VMware documentation website

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. To enable regions and zones, you must define multiple failure domains for your OKD cluster.

Procedure

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
```
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>
```
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>
```
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>
```

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

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.

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

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.

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

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

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

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

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig (1)
```
1 For <installation_directory>, specify the path to the directory that you stored the installation files in.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

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.

Testing shows issues with using the NFS server on RHEL as storage backend for core services. This includes the OpenShift Container Registry and Quay, Prometheus for monitoring storage, and Elasticsearch for logging storage. Therefore, using RHEL NFS to back PVs used by core services is not recommended.

Other NFS implementations on the marketplace might not have these issues. Contact the individual NFS implementation vendor for more information on any testing that was possibly completed against these OKD core components.

Procedure

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.
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.

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.

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.

Block storage volumes are supported but not recommended for use with image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica.

Procedure

Enter the following command to set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy, and runs with only 1 replica:
```
$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
```

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

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.

Enter the following command to create the PersistentVolumeClaim object from the file:
```
$ oc create -f pvc.yaml -n openshift-image-registry
```

Enter the following command to edit the registry configuration so that it references the correct PVC:
```
$ oc edit config.imageregistry.operator.openshift.io -o yaml
```
Example output
```
storage:
  pvc:
    claim: (1)
```
1 By creating a custom PVC, you can leave the claim field blank for the default automatic creation of an image-registry-storage PVC.

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

Services for an external load balancer

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

Configuring an external load balancer depends on your vendor’s load balancer.

The information and examples in this section are for guideline purposes only. Consult the vendor documentation for more specific information about the vendor’s 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:

An image that shows an example network workflow of an Ingress Controller operating in an OKD environment.

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

An image that shows an example network workflow of an OpenShift API operating in an OKD environment.

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

An image that shows an example network workflow of an OpenShift MachineConfig 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.

Before you configure an external load balancer for your OKD cluster, consider the following information:

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.

Configuring an external load balancer

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

Before you configure an external load balancer, ensure that you read the "Services for an external load balancer" section.

Read the following prerequisites that apply to the service that you want to configure for your external load balancer.

MetalLB, that runs on a cluster, functions as an external load balancer.

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

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 192.168.1.100:22623
    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-2 192.168.1.101:22623 check inter 10s rise 2 fall 2
    server my-cluster-master-0 192.168.1.102:22623 check inter 10s rise 2 fall 2
    server my-cluster-master-1 192.168.1.103:22623 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
# ...

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

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"
}

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
```

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

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

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.

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

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"
  }

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
```

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

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.

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`.

Installing a cluster on vSphere with customizations

Prerequisites

VMware vSphere region and zone enablement

Creating the installation configuration file

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

Configuring the cluster-wide proxy during installation

Configuring regions and zones for a VMware vCenter

Deploying the cluster

Logging in to the cluster by using the CLI

Creating registry storage

Image registry removed during installation

Image registry storage configuration

Configuring registry storage for VMware vSphere

Configuring block registry storage for VMware vSphere

Services for an external load balancer

Configuring an external load balancer

Next steps