To see recent information about hub cluster and managed cluster platforms, refer to the Red Hat Advanced Cluster Management 2.6 Support matrix.

You can access the Red Hat Advanced Cluster Management console from Mozilla Firefox, Google Chrome, Microsoft Edge, and Safari. See the following versions that are tested and supported:

Configure your network settings to allow the connections in the following sections.

The maximum number of clusters that Red Hat Advanced Cluster Management can manage varies based on several factors, including:

The following table shows the configuration information for the clusters on the Amazon Web Services cloud platform that were used during this testing:

For more information about infrastructure nodes, see, Installing the Red Hat Advanced Cluster Management hub cluster on infrastructure nodes. Also see Creating infrastructure machine sets.

The scalability of the Search component depends on the performance of the data store. The following variables are important when analyzing the search performance:

You need to plan your environment if you want to enable and use the observability service. The resource consumption later is for the OpenShift Container Platform project, where observability components are installed. Values that you plan to use are sums for all observability components.

Note: Data is based on the results from a lab environment at the time of testing. Your results might vary, depending on your environment, network speed, and changes to the product.

Each Red Hat Advanced Cluster Management for Kubernetes cluster is unique and the following guidelines provide sample deployment sizes for you. Recommendations are classified by size and purpose. Red Hat Advanced Cluster Management applies the following dimensions for sizing and placement of supporting services:

Important: For OpenShift Container Platform, distribute the master nodes of the cluster across three (3) availability zones.

Before you install Red Hat Advanced Cluster Management, see the following requirements:

You must have a supported OpenShift Container Platform version, including the registry and storage services, installed and working. For more information about installing OpenShift Container Platform, see the OpenShift Container Platform documentation.

You can proceed to install Red Hat Advanced Cluster Management from the console or the CLI. Both procedures are documented.

Best practice: From the Administrator view in your OpenShift Container Platform navigation, install the OperatorHub web console interface that is provided with OpenShift Container Platform.

If you are reinstalling Red Hat Advanced Cluster Management and the pods do not start, see Troubleshooting reinstallation failure for steps to work around this problem.

Notes:

An OpenShift Container Platform cluster can be configured to contain infrastructure nodes for running approved management components. Running components on infrastructure nodes avoids allocating OpenShift Container Platform subscription quota for the nodes that are running those management components.

After adding infrastructure nodes to your OpenShift Container Platform cluster, follow the Installing from the OpenShift Container Platform CLI instructions and add configurations to the Operator Lifecycle Manager subscription and MultiClusterHub custom resource.

metadata:
  labels:
    node-role.kubernetes.io/infra: ""
spec:
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/infra

spec:
  config:
    nodeSelector:
      node-role.kubernetes.io/infra: ""
    tolerations:
    - key: node-role.kubernetes.io/infra
      effect: NoSchedule
      operator: Exists

spec:
  nodeSelector:
    node-role.kubernetes.io/infra: ""

You must meet the following requirements before you install Red Hat Advanced Cluster Management for Kubernetes:

Open the URL in your browser and check the result. If the console URL displays console-openshift-console.router.default.svc.cluster.local, set the value for openshift_master_default_subdomain when you install OpenShift Container Platform.

Best practice: Use your existing mirror registry for the Operator Lifecycle Manager operator related content.

Installing Red Hat Advanced Cluster Management for Kubernetes in a disconnected environment involves the use of a local mirror image registry. Because you have already completed the installation of the OpenShift Container Platform cluster in your disconnected environment, you already set up a mirror registry for use during the Red Hat OpenShift Container Platform cluster installation.

If you do not already have a local image registry, create one by completing the procedure that is described in Mirroring images for a disconnected installation of the Red Hat OpenShift Container Platform documentation.

Because Red Hat Advanced Cluster Management for Kubernetes is packaged as an operator, installing is completed by using Operator Lifecycle Manager.

In disconnected environments, Operator Lifecycle Manager cannot access the standard operator sources that Red Hat provided operators can because they are hosted on image registries that are not accessible from a disconnected cluster. Instead, a cluster administrator can enable the installation and upgrade of operators in a disconnected environment by using mirrored image registries and operator catalogs.

To prepare your disconnected cluster for installing Red Hat Advanced Cluster Management for Kubernetes, follow the procedure that is described in Using Operator Lifecycle Manager on restricted networks in the OpenShift Container Platform documentation.

apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: my-mirror-catalog-source
  namespace: openshift-marketplace
spec:
  image: myregistry.example.com:5000/mirror/my-operator-index:v4.10
  sourceType: grpc

Operator Lifecycle Manager polls catalog sources for available packages on a regular timed interval. After Operator Lifecycle Manager polls the catalog source for your mirrored catalog, you can verify that the required packages are available from on your disconnected cluster by querying the available PackageManifest resources.

Run the following command, directed at your disconnected cluster:

oc -n openshift-marketplace get packagemanifests

The list that is displayed should include entries showing that the following packages are supplied by the catalog source for your mirror catalog:

In order to have your cluster obtain container images for the Red Hat Advanced Cluster Management for Kubernetes operator from your mirror registry, rather than from the internet-hosted registries, you must configure an ImageContentSourcePolicy on your disconnected cluster to redirect image references to your mirror registry.

If you mirrored your catalog using the oc adm catalog mirror command, the needed image content source policy configuration is in the imageContentSourcePolicy.yaml file inside of the manifests-* directory that is created by that command.

If you used the oc-mirror plugin to mirror your catalog instead, the imageContentSourcePolicy.yaml file is within the oc-mirror-workspace/results-* directory create by the oc-mirror plugin.

In either case, you can apply the policies to your disconnected command using an oc apply or oc replace command such as:

oc replace -f ./<path>/imageContentSourcePolicy.yaml

The required image content source policy statements can vary based on how you created your mirror registry, but are similar to this example:

apiVersion: operator.openshift.io/v1alpha1
kind: ImageContentSourcePolicy
metadata:
  labels:
    operators.openshift.org/catalog: "true"
  name: operator-0
spec:
  repositoryDigestMirrors:
  - mirrors:
    - myregistry.example.com:5000/rhacm2
    source: registry.redhat.io/rhacm2
  - mirrors:
    - myregistry.example.com:5000/multicluster-engine
    source: registry.redhat.io/multicluster-engine
  - mirrors:
    - myregistry.example.com:5000/openshift4
    source: registry.redhat.io/openshift4
  - mirrors:
    - myregistry.example.com:5000/redhat
    source: registry.redhat.io/redhat

After you have configured Operator Lifecycle Manager and Red Hat OpenShift Container Platform as previously described, you can install Red Hat Advanced Cluster Management for Kubernetes by using either the OperatorHub console or a CLI. Follow the same guidance described in the Installing while connected online topic.

Important: Creating the MulticlusterHub resource is the beginning of the installation process of your hub cluster.

Because operator installation on a cluster requires the use of a non-default catalog source for the mirror catalog, a special annotation is needed in the MulticlusterHub resource to provide the name of the mirror catalog source to the operator. The following example displays the required mce-subscription-spec annotation:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
   namespace: open-cluster-management
   name: hub
   annotations:
      installer.open-cluster-management.io/mce-subscription-spec: '{"source": "my-mirror-catalog-source"}'
spec: {}

If you are creating the resource with a CLI, include the mce-subscription-spec annotation in the YAML that you apply with the oc apply command to create the MulticlusterHub resource.

If you create the resource by using the OperatorHub console, switch to the YAML view and insert the annotation as previously displayed. Important: There is no field in the OperatorHub console for the annotation in the the Field view panel to create the MulticlusterHub.

Complete the following additional steps when using governance policies with disconnected Red Hat OpenShift Container Platform clusters:

If you plan to import Kubernetes clusters that were not created by OpenShift Container Platform or Red Hat Advanced Cluster Management, generate a secret that contains your OpenShift Container Platform pull secret information to access the entitled content from the distribution registry.

The secret requirements for OpenShift Container Platform clusters are automatically resolved by OpenShift Container Platform and Red Hat Advanced Cluster Management, so you do not have to create the secret if you are not importing other types of Kubernetes clusters to be managed. Your OpenShift Container Platform pull secret is associated with your Red Hat Customer Portal ID, and is the same across all Kubernetes providers.

Important: These secrets are namespace-specific, so make sure that you are in the namespace that you use for your hub cluster.

The following example displays the spec.imagePullSecret template to use if you want to use a custom pull secret. Replace secret with the name of your pull secret:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  imagePullSecret: <secret>

The Red Hat Advanced Cluster Management hub cluster has two availabilities: High and Basic. By default, the hub cluster has an availability of High, which gives hub cluster components a replicaCount of 2. This provides better support in cases of failover but consumes more resources than the Basic availability, which gives components a replicaCount of 1.

The following examples shows the spec.availabilityConfig template with Basic availability:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  availabilityConfig: "Basic"

You can define a set of node selectors in the Red Hat Advanced Cluster Management hub cluster to install to specific nodes on your cluster. The following example shows spec.nodeSelector to assign Red Hat Advanced Cluster Management pods to nodes with the label node-role.kubernetes.io/infra:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  nodeSelector:
    node-role.kubernetes.io/infra: ""

You can define a list of tolerations to allow the Red Hat Advanced Cluster Management hub cluster to tolerate specific taints defined on the cluster.

The following example shows a spec.tolerations that matches a node-role.kubernetes.io/infra taint:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  tolerations:
  - key: node-role.kubernetes.io/infra
    effect: NoSchedule
    operator: Exists

The previous infra-node toleration is set on pods by default without specifying any tolerations in the configuration. Customizing tolerations in the configuration replaces this default.

By default, the Red Hat Advanced Cluster Management hub cluster is automatically imported and managed by itself. This managed hub cluster is named, local-cluster.

Note: On a Red Hat Advanced Cluster Management hub cluster that is managing a multicluster engine for Kubernetes operator cluster, any previous manual configurations are replaced by this action.

If you do not want the Red Hat Advanced Cluster Management hub cluster to manage itself, you need to change the setting for spec. disableHubSelfManagement from false to true. If the setting is not included in the YAML file that defines the custom resource, you need to add it. The hub cluster can only be managed with this option.

Setting this option to true and attempting to manage the hub manually leads to unexpected behavior.

The following example shows the default template to use if you want to disable the hub cluster self-management feature. Replace namespace with the name of your project:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  disableHubSelfManagement: true

To enable the default local-cluster, return the setting to false, or remove this setting.

If you want to ensure that you use the same release image for all of your clusters, you can create your own custom list of release images that are available when you create a cluster.

See the following instructions in Maintaining a custom list of release images when connected to manage your available release images and to set the spec.disableUpdateClusterImageSets attribute, which stops the custom image list from being overwritten.

The following example shows the default template that disables updates to the cluster image set. Replace namespace with the name of your project:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  disableUpdateClusterImageSets: true

By default, Red Hat OpenShift Container Platform uses the Ingress Operator to create an internal CA.

The following example shows the default template used to provide a customized OpenShift Container Platform default ingress CA certificate to Red Hat Advanced Cluster Management. Replace namespace with the name of your project. Replace the spec.customCAConfigmap value with the name of your ConfigMap:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  customCAConfigmap: <configmap>

By default, the Red Hat Advanced Cluster Management hub cluster includes the full list of supported SSL ciphers.

The following example shows the default spec.ingress.sslCiphers template that is used to list sslCiphers for the management ingress. Replace namespace with the name of your project:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  ingress:
    sslCiphers:
    - "ECDHE-ECDSA-AES128-GCM-SHA256"
    - "ECDHE-RSA-AES128-GCM-SHA256"

The enableClusterBackup field is no longer supported and is replaced by this component.

The following example shows the spec.overrides default template used to enable ClusterBackup. Replace namespace with the name of your project:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  overrides:
    components:
    - name: cluster-backup
      enabled: true

Alternatively, you can run the following command. Replace namespace with the name of your project.

oc patch MultiClusterHub multiclusterhub -n <namespace> --type=json -p='[{"op": "add", "path": "/spec/overrides/components/-","value":{"name":"cluster-backup","enabled":true}}]'

The following example shows the spec.overrides default template used to enable ManagedServiceAccount. Replace namespace with the name of your project:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  overrides:
    components:
    - name: managedserviceaccount-preview
      enabled: true

Alternatively, you can run the following command. Replace namespace with the name of your project.

oc patch MultiClusterHub multiclusterhub -n <namespace> --type=json -p='[{"op": "add", "path": "/spec/overrides/components/-","value":{"name":"managedserviceaccount-preview","enabled":true}}]'

The following example shows the spec.overrides default template used to enable Hypershift. Replace namespace with the name of your project:

apiVersion: operator.open-cluster-management.io/v1
kind: MultiClusterHub
metadata:
  name: multiclusterhub
  namespace: <namespace>
spec:
  overrides:
    components:
    - name: hypershift-preview
      enabled: true

Alternatively, you can run the following command. Replace namespace with the name of your project.

oc patch MultiClusterHub multiclusterhub -n <namespace> --type=json -p='[{"op": "add", "path": "/spec/overrides/components/-","value":{"name":"hypershift-preview","enabled":true}}]'

If you are Managing cluster pools (Technology Preview), you need further configuration to stop automatic management of these cluster pools after upgrade.

Set cluster.open-cluster-management.io/createmanagedcluster: "false" in the ClusterClaim metadata.annotations.

All existing cluster claims are automatically imported when the product is upgraded unless you change this setting.

During your installation, or upgrade, of Red Hat Advanced Cluster Management for Kubernetes to release 2.5 or later, you encountered important information that is related to the interdependency between the Red Hat Advanced Cluster Management for Kubernetes and multicluster engine for Kubernetes operators. See Install in disconnected network environments. Similar considerations are required when you upgrade.

As is the case for upgrading in a connected network environment, the upgrade process is started by changing the upgrade channel in your Operator Lifecycle Manager subscription for Red Hat Advanced Cluster Management for Kubernetes to the upgrade channel for the new release.

However, because of the special characteristics of the disconnected environment, you need to address the following mirroring requirements before changing the update channel to start the upgrade process:

Red Hat Advanced Cluster Management for Kubernetes release 2.5 and later uses the related multicluster engine for Kubernetes operator functionality to provide foundational services that previously were delivered as part of Red Hat Advanced Cluster Management for Kubernetes. Releases 2.5 and later of the Red Hat Advanced Cluster Management for Kubernetes operator automatically install and manage the required multicluster engine for Kubernetes operator and MulticlusterEngine resource instance as part of the hub cluster installation and upgrade.

In connected network environments, the cluster administrator can install or upgrade Red Hat Advanced Cluster Management for Kubernetes without special mirror catalogs and catalog sources. However, because installation of any Operator Lifecycle Manager operator in a disconnected environment involves the use of special mirror catalogs and catalog sources (as described in the earlier sections), some additional steps are necessary beyond installation.

Important: If you begin an upgrade from release 2.4 to release 2.5 before you add the annotation, the upgrade begins but stalls when the operator attempts to install a subscription to multicluster-engine in the background. The status of the MulticlusterHub resource continues to display upgrading during this time.

To resolve this issue, run oc edit to add the mce-subscription-spec annotation as shown previously.

Before you uninstall the Red Hat Advanced Cluster Management hub cluster, you must detach all of the clusters that are managed by that hub cluster. To resolve errors, detach all clusters that are still managed by the hub cluster, then try to uninstall again.

❯ oc get csv
NAME                                 DISPLAY                                      VERSION   REPLACES   PHASE
advanced-cluster-management.v2.4.0   Advanced Cluster Management for Kubernetes   2.4.0                Succeeded

❯ oc delete clusterserviceversion advanced-cluster-management.v2.4.0

❯ oc get sub
NAME                        PACKAGE                       SOURCE                CHANNEL
acm-operator-subscription   advanced-cluster-management   acm-custom-registry   release-2.5

❯ oc delete sub acm-operator-subscription

Note: The name of the subscription and version of the CSV might differ.

When you use the Red Hat OpenShift Container Platform console to uninstall, you remove the operator. Complete the following steps to uninstall by using the console: