Chapter 15. ClusterClaims

A ClusterClaim is a cluster-scoped custom resource definition (CRD) on a managed cluster. A ClusterClaim represents a piece of information that a managed cluster claims. The following example shows a claim that is identified in the YAML file: 

apiVersion: cluster.open-cluster-management.io/v1alpha1
kind: ClusterClaim
metadata:
  name: id.openshift.io
spec:
  value: 95f91f25-d7a2-4fc3-9237-2ef633d8451c

The following table shows the defined ClusterClaims that might be on a cluster that Red Hat Advanced Cluster Management for Kubernetes manages:

Claim nameReservedMutableDescription

id.k8s.io

true

false

ClusterID defined in upstream proposal

kubeversion.open-cluster-management.io

true

true

Kubernetes version

platform.open-cluster-management.io

true

false

Platform the managed cluster is running on, like AWS, GCE, and Equinix Metal

product.open-cluster-management.io

true

false

Product name, like OpenShift, Anthos, EKS and GKE

id.openshift.io

false

false

OpenShift Container Platform external ID, which is only available for an OpenShift Container Platform cluster

consoleurl.openshift.io

false

true

URL of the management console, which is only available for an OpenShift Container Platform cluster

version.openshift.io

false

true

OpenShift Container Platform version, which is only available for an OpenShift Container Platform cluster

If any of the previous claims are deleted or updated on managed cluster, they are restored or rolled back to a previous version automatically.

After the managed cluster joins the hub, the ClusterClaims that are created on a managed cluster are synchronized with the status of the ManagedCluster resource on the hub. A managed cluster with ClusterClaims might look similar to the following example: 

apiVersion: cluster.open-cluster-management.io/v1
kind: ManagedCluster
metadata:
  labels:
    cloud: Amazon
    clusterID: 95f91f25-d7a2-4fc3-9237-2ef633d8451c
    installer.name: multiclusterhub
    installer.namespace: open-cluster-management
    name: cluster1
    vendor: OpenShift
  name: cluster1
spec:
  hubAcceptsClient: true
  leaseDurationSeconds: 60
status:
  allocatable:
    cpu: '15'
    memory: 65257Mi
  capacity:
    cpu: '18'
    memory: 72001Mi
  clusterClaims:
    - name: id.k8s.io
      value: cluster1
    - name: kubeversion.open-cluster-management.io
      value: v1.18.3+6c42de8
    - name: platform.open-cluster-management.io
      value: AWS
    - name: product.open-cluster-management.io
      value: OpenShift
    - name: id.openshift.io
      value: 95f91f25-d7a2-4fc3-9237-2ef633d8451c
    - name: consoleurl.openshift.io
      value: 'https://console-openshift-console.apps.xxxx.dev04.red-chesterfield.com'
    - name: version.openshift.io
      value: '4.5'
  conditions:
    - lastTransitionTime: '2020-10-26T07:08:49Z'
      message: Accepted by hub cluster admin
      reason: HubClusterAdminAccepted
      status: 'True'
      type: HubAcceptedManagedCluster
    - lastTransitionTime: '2020-10-26T07:09:18Z'
      message: Managed cluster joined
      reason: ManagedClusterJoined
      status: 'True'
      type: ManagedClusterJoined
    - lastTransitionTime: '2020-10-30T07:20:20Z'
      message: Managed cluster is available
      reason: ManagedClusterAvailable
      status: 'True'
      type: ManagedClusterConditionAvailable
  version:
    kubernetes: v1.18.3+6c42de8

15.1. List existing ClusterClaims

You can use the kubectl command to list the ClusterClaims that apply to your managed cluster. This is helpful when you want to compare your ClusterClaim to an error message.

Note: Make sure you have list permission on resource clusterclaims.cluster.open-cluster-management.io.

Run the following command to list all existing ClusterClaims that are on the managed cluster: 

kubectl get clusterclaims.cluster.open-cluster-management.io

15.2. Create custom ClusterClaims

You can create ClusterClaims with custom names on a managed cluster, which makes it easier to identify them. The custom ClusterClaims are synchronized with the status of the ManagedCluster resource on the hub cluster. The following content shows an example of a definition for a customized ClusterClaim: 

apiVersion: cluster.open-cluster-management.io/v1alpha1
kind: ClusterClaim
metadata:
  name: <custom_claim_name>
spec:
  value: <custom_claim_value>

The max length of field spec.value is 1024. The create permission on resource clusterclaims.cluster.open-cluster-management.io is required to create a ClusterClaim.