Chapter 6. Preparing an Agent-based installed cluster for the multicluster engine for Kubernetes Operator You can install the multicluster engine Operator and deploy a hub cluster with the Agent-based OpenShift Container Platform Installer. The following procedure is partially automated and requires manual steps after the initial cluster is deployed. 6.1. Prerequisites You have read the following documentation: Cluster lifecycle with multicluster engine operator overview . Persistent storage using local volumes . Using GitOps ZTP to provision clusters at the network far edge . Preparing to install with the Agent-based Installer . About disconnected installation mirroring . You have access to the internet to obtain the necessary container images. You have installed the OpenShift CLI ( oc ). If you are installing in a disconnected environment, you must have a configured local mirror registry for disconnected installation mirroring. 6.2. Preparing an Agent-based cluster deployment for the multicluster engine for Kubernetes Operator while disconnected You can mirror the required OpenShift Container Platform container images, the multicluster engine Operator, and the Local Storage Operator (LSO) into your local mirror registry in a disconnected environment. Ensure that you note the local DNS hostname and port of your mirror registry. Note To mirror your OpenShift Container Platform image repository to your mirror registry, you can use either the oc adm release image or oc mirror command. In this procedure, the oc mirror command is used as an example. Procedure 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. 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-4.15 4 type: ocp additionalImages: - name: registry.redhat.io/ubi9/ubi:latest operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.15 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. To mirror a specific OpenShift Container Platform image repository, the multicluster engine, and the LSO, run the following command: USD oc mirror --dest-skip-tls --config ocp-mce-imageset.yaml docker://<your-local-registry-dns-name>:<your-local-registry-port> 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. Generate the cluster manifests by running the following command: USD openshift-install agent create cluster-manifests This command updates the cluster manifests folder to include a mirror folder that contains your mirror configuration. 6.3. Preparing an Agent-based cluster deployment for the multicluster engine for Kubernetes Operator while connected Create the required manifests for the multicluster engine Operator, the Local Storage Operator (LSO), and to deploy an agent-based OpenShift Container Platform cluster as a hub cluster. Procedure 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. 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. 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 Create the agent ISO image by running the following command: USD openshift-install agent create image --dir <assets_directory> When the image is ready, boot the target machine and wait for the installation to complete. To monitor the installation, run the following command: USD 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 USD oc apply -f <manifest-name> . The order of the manifest creation is important and where required, the waiting condition is displayed. 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 Use the following command to wait for the availability of the PVs, before applying the subsequent manifests: USD oc wait localvolume -n openshift-local-storage assisted-service --for condition=Available --timeout 10m Note Create a manifest for a multicluster engine instance. Example MultiClusterEngine.yaml apiVersion: multicluster.openshift.io/v1 kind: MultiClusterEngine metadata: name: multiclusterengine spec: {} 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 Create a manifest to deploy subsequently spoke clusters. Example clusterimageset.yaml apiVersion: hive.openshift.io/v1 kind: ClusterImageSet metadata: name: "4.15" spec: releaseImage: quay.io/openshift-release-dev/ocp-release:4.15.0-x86_64 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 Wait for the managed cluster to be created. USD oc wait -n multicluster-engine managedclusters local-cluster --for condition=ManagedClusterJoined=True --timeout 10m Verification To confirm that the managed cluster installation is successful, run the following command: USD oc get managedcluster NAME HUB ACCEPTED MANAGED CLUSTER URLS JOINED AVAILABLE AGE local-cluster true https://<your cluster url>:6443 True True 77m Additional resources The Local Storage Operator

Commands:
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-4.15 4 type: ocp additionalImages: - name: registry.redhat.io/ubi9/ubi:latest operators: - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.15 5 packages: 6 - name: multicluster-engine 7 - name: local-storage-operator 8
oc mirror --dest-skip-tls --config ocp-mce-imageset.yaml docker://<your-local-registry-dns-name>:<your-local-registry-port>
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"
additionalTrustBundle: | -----BEGIN CERTIFICATE----- zzzzzzzzzzz -----END CERTIFICATE-------
openshift-install agent create cluster-manifests
apiVersion: v1 kind: Namespace metadata: labels: openshift.io/cluster-monitoring: "true" name: multicluster-engine
apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: multicluster-engine-operatorgroup namespace: multicluster-engine spec: targetNamespaces: - multicluster-engine
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
apiVersion: v1 kind: Namespace metadata: annotations: openshift.io/cluster-monitoring: "true" name: openshift-local-storage
apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: local-operator-group namespace: openshift-local-storage spec: targetNamespaces: - openshift-local-storage
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
<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
openshift-install agent create image --dir <assets_directory>
openshift-install agent wait-for install-complete --dir <assets_directory>
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
oc wait localvolume -n openshift-local-storage assisted-service --for condition=Available --timeout 10m
The `devicePath` is an example and may vary depending on the actual hardware configuration used.
apiVersion: multicluster.openshift.io/v1 kind: MultiClusterEngine metadata: name: multiclusterengine spec: {}
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
apiVersion: hive.openshift.io/v1 kind: ClusterImageSet metadata: name: "4.15" spec: releaseImage: quay.io/openshift-release-dev/ocp-release:4.15.0-x86_64
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
oc wait -n multicluster-engine managedclusters local-cluster --for condition=ManagedClusterJoined=True --timeout 10m
oc get managedcluster NAME HUB ACCEPTED MANAGED CLUSTER URLS JOINED AVAILABLE AGE local-cluster true https://<your cluster url>:6443 True True 77m