Chapter 6. Preparing an Agent-based installed cluster for the multicluster engine for Kubernetes Operator

Procedure

1. Create an <assets_directory> folder to contain valid install-config.yaml and agent-config.yaml files. This directory is used to store all the assets.

2. To mirror an OpenShift Container Platform image repository, the multicluster engine, and the LSO, create a ImageSetConfiguration.yaml file with the following settings:

   Example ImageSetConfiguration.yaml

     kind: ImageSetConfiguration
     apiVersion: mirror.openshift.io/v1alpha2
     archiveSize: 4 

   1

   
     storageConfig: 

   2

   
       imageURL: <your-local-registry-dns-name>:<your-local-registry-port>/mirror/oc-mirror-metadata 

   3

   
       skipTLS: true
     mirror:
       platform:
         architectures:
           - "amd64"
         channels:
           - name: stable-4.16 

   4

   
             type: ocp
       additionalImages:
         - name: registry.redhat.io/ubi9/ubi:latest
       operators:
         - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.16 

   5

   
           packages: 

   6

   
             - name: multicluster-engine 

   7

   
             - name: local-storage-operator 

   8

   1

   Specify the maximum size, in GiB, of each file within the image set.

   2

   Set the back-end location to receive the image set metadata. This location can be a registry or local directory. It is required to specify storageConfig values.

   3

   Set the registry URL for the storage backend.

   4

   Set the channel that contains the OpenShift Container Platform images for the version you are installing.

   5

   Set the Operator catalog that contains the OpenShift Container Platform images that you are installing.

   6

   Specify only certain Operator packages and channels to include in the image set. Remove this field to retrieve all packages in the catalog.

   7

   The multicluster engine packages and channels.

   8

   The LSO packages and channels.

   Note

   This file is required by the oc mirror command when mirroring content.

3. To mirror a specific OpenShift Container Platform image repository, the multicluster engine, and the LSO, run the following command:

   $ oc mirror --dest-skip-tls --config ocp-mce-imageset.yaml docker://<your-local-registry-dns-name>:<your-local-registry-port>

4. Update the registry and certificate in the install-config.yaml file:

   Example imageContentSources.yaml

     imageContentSources:
       - source: "quay.io/openshift-release-dev/ocp-release"
         mirrors:
           - "<your-local-registry-dns-name>:<your-local-registry-port>/openshift/release-images"
       - source: "quay.io/openshift-release-dev/ocp-v4.0-art-dev"
         mirrors:
           - "<your-local-registry-dns-name>:<your-local-registry-port>/openshift/release"
       - source: "registry.redhat.io/ubi9"
         mirrors:
           - "<your-local-registry-dns-name>:<your-local-registry-port>/ubi9"
       - source: "registry.redhat.io/multicluster-engine"
         mirrors:
           - "<your-local-registry-dns-name>:<your-local-registry-port>/multicluster-engine"
       - source: "registry.redhat.io/rhel8"
         mirrors:
           - "<your-local-registry-dns-name>:<your-local-registry-port>/rhel8"
       - source: "registry.redhat.io/redhat"
         mirrors:
           - "<your-local-registry-dns-name>:<your-local-registry-port>/redhat"

   Additionally, ensure your certificate is present in the additionalTrustBundle field of the install-config.yaml.

   Example install-config.yaml

   additionalTrustBundle: |
     -----BEGIN CERTIFICATE-----
     zzzzzzzzzzz
     -----END CERTIFICATE-------

   Important

   The oc mirror command creates a folder called oc-mirror-workspace with several outputs. This includes the imageContentSourcePolicy.yaml file that identifies all the mirrors you need for OpenShift Container Platform and your selected Operators.

5. Generate the cluster manifests by running the following command:

   $ openshift-install agent create cluster-manifests

   This command updates the cluster manifests folder to include a mirror folder that contains your mirror configuration.

Procedure

1. Create a sub-folder named openshift in the <assets_directory> folder. This sub-folder is used to store the extra manifests that will be applied during the installation to further customize the deployed cluster. The <assets_directory> folder contains all the assets including the install-config.yaml and agent-config.yaml files.

   Note

   The installer does not validate extra manifests.

2. For the multicluster engine, create the following manifests and save them in the <assets_directory>/openshift folder:

   Example mce_namespace.yaml

     apiVersion: v1
     kind: Namespace
     metadata:
       labels:
         openshift.io/cluster-monitoring: "true"
       name: multicluster-engine

   Example mce_operatorgroup.yaml

     apiVersion: operators.coreos.com/v1
     kind: OperatorGroup
     metadata:
       name: multicluster-engine-operatorgroup
       namespace: multicluster-engine
     spec:
       targetNamespaces:
       - multicluster-engine

   Example mce_subscription.yaml

     apiVersion: operators.coreos.com/v1alpha1
     kind: Subscription
     metadata:
       name: multicluster-engine
       namespace: multicluster-engine
     spec:
       channel: "stable-2.3"
       name: multicluster-engine
       source: redhat-operators
       sourceNamespace: openshift-marketplace

   Note

   You can install a distributed unit (DU) at scale with the Red Hat Advanced Cluster Management (RHACM) using the assisted installer (AI). These distributed units must be enabled in the hub cluster. The AI service requires persistent volumes (PVs), which are manually created.

3. For the AI service, create the following manifests and save them in the <assets_directory>/openshift folder:

   Example lso_namespace.yaml

     apiVersion: v1
     kind: Namespace
     metadata:
       annotations:
         openshift.io/cluster-monitoring: "true"
       name: openshift-local-storage

   Example lso_operatorgroup.yaml

     apiVersion: operators.coreos.com/v1
     kind: OperatorGroup
     metadata:
       name: local-operator-group
       namespace: openshift-local-storage
     spec:
       targetNamespaces:
         - openshift-local-storage

   Example lso_subscription.yaml

     apiVersion: operators.coreos.com/v1alpha1
     kind: Subscription
     metadata:
       name: local-storage-operator
       namespace: openshift-local-storage
     spec:
       installPlanApproval: Automatic
       name: local-storage-operator
       source: redhat-operators
       sourceNamespace: openshift-marketplace

   Note

   After creating all the manifests, your filesystem must display as follows:

   Example Filesystem

   <assets_directory>
       ├─ install-config.yaml
       ├─ agent-config.yaml
       └─ /openshift
           ├─ mce_namespace.yaml
           ├─ mce_operatorgroup.yaml
           ├─ mce_subscription.yaml
           ├─ lso_namespace.yaml
           ├─ lso_operatorgroup.yaml
           └─ lso_subscription.yaml

4. Create the agent ISO image by running the following command:

   $ openshift-install agent create image --dir <assets_directory>

5. When the image is ready, boot the target machine and wait for the installation to complete.

6. To monitor the installation, run the following command:

   $ openshift-install agent wait-for install-complete --dir <assets_directory>

   Note

   To configure a fully functional hub cluster, you must create the following manifests and manually apply them by running the command $ oc apply -f <manifest-name>. The order of the manifest creation is important and where required, the waiting condition is displayed.

7. For the PVs that are required by the AI service, create the following manifests:

     apiVersion: local.storage.openshift.io/v1
     kind: LocalVolume
     metadata:
      name: assisted-service
      namespace: openshift-local-storage
     spec:
      logLevel: Normal
      managementState: Managed
      storageClassDevices:
        - devicePaths:
            - /dev/vda
            - /dev/vdb
          storageClassName: assisted-service
          volumeMode: Filesystem

8. Use the following command to wait for the availability of the PVs, before applying the subsequent manifests:

   $ oc wait localvolume -n openshift-local-storage assisted-service --for condition=Available --timeout 10m

   Note

   The `devicePath` is an example and may vary depending on the actual hardware configuration used.

9. Create a manifest for a multicluster engine instance.

   Example MultiClusterEngine.yaml

     apiVersion: multicluster.openshift.io/v1
     kind: MultiClusterEngine
     metadata:
       name: multiclusterengine
     spec: {}

10. Create a manifest to enable the AI service.

    Example agentserviceconfig.yaml

      apiVersion: agent-install.openshift.io/v1beta1
      kind: AgentServiceConfig
      metadata:
        name: agent
        namespace: assisted-installer
      spec:
       databaseStorage:
        storageClassName: assisted-service
        accessModes:
        - ReadWriteOnce
        resources:
         requests:
          storage: 10Gi
       filesystemStorage:
        storageClassName: assisted-service
        accessModes:
        - ReadWriteOnce
        resources:
         requests:
          storage: 10Gi

11. Create a manifest to deploy subsequently spoke clusters.

    Example clusterimageset.yaml

      apiVersion: hive.openshift.io/v1
      kind: ClusterImageSet
      metadata:
        name: "4.16"
      spec:
        releaseImage: quay.io/openshift-release-dev/ocp-release:4.16.0-x86_64

12. Create a manifest to import the agent installed cluster (that hosts the multicluster engine and the Assisted Service) as the hub cluster.

    Example autoimport.yaml

      apiVersion: cluster.open-cluster-management.io/v1
      kind: ManagedCluster
      metadata:
       labels:
         local-cluster: "true"
         cloud: auto-detect
         vendor: auto-detect
       name: local-cluster
      spec:
       hubAcceptsClient: true

13. Wait for the managed cluster to be created.

    $ oc wait -n multicluster-engine managedclusters local-cluster --for condition=ManagedClusterJoined=True --timeout 10m