Value Statement

In order to support epic https://issues.redhat.com/browse/ACM-11041, the hypershift addon agent is going to become the discovery agent to discover hosted clusters from MCE and create DiscoveredCluster resources in MCE's namespace in the ACM hub cluster. The hypershift addon agent will create, update and remove these DiscoveredCluster resources. Here is the sample DiscoveredCluster resource.

apiVersion: discovery.open-cluster-management.io/v1
kind: DiscoveredCluster
metadata:
  creationTimestamp: "2024-05-09T01:31:49Z"
  generation: 2
  labels:
    hypershift.open-cluster-management.io/hc-name: rj-0508a
    hypershift.open-cluster-management.io/hc-namespace: clusters
  name: rj-0508a
  namespace: local-cluster
  resourceVersion: "51271683"
  uid: ae3ed948-53e8-4a4c-8a60-1535331ee6bf
spec:
  apiUrl: https://ad444596dab354e0b9fe2b8751c84479-464d8264d7f96e8d.elb.us-east-2.amazonaws.com:6443
  cloudProvider: aws
  creationTimestamp: "2024-05-09T01:28:49Z"
  credential: {}
  displayName: local-cluster-rj-0508a
  isManagedCluster: false
  importAsManagedCluster: false
  name: rj-0508a
  openshiftVersion: 4.15.12
  type: MultiClusterEngineHCP 

The discover controller should handle MultiClusterEngineHCP type DiscoveredCluster differently when importAsManagedCluster is set to true.

It should create a KlusterletConfig resource to get the klusterlet installed in a non-default namespace for the discovered cluster. This can be shared for all DiscoveredCluster resources from the same MCE namespace.

apiVersion: config.open-cluster-management.io/v1alpha1
kind: KlusterletConfig
metadata:
  name: <DiscoveredClusterNamespace>-config
spec:
  # has to be prefix of open-cluster-management- and less than 57 character
  agentInstallNamespace: open-cluster-management-<DiscoveredClusterNamespace>

It should create a ManagedCluster resource with special annotations.

    apiVersion: cluster.open-cluster-management.io/v1
    kind: ManagedCluster
    metadata:  
      annotations:    
        import.open-cluster-management.io/hosting-cluster-name: <DiscoveredClusterNamespace>    
        import.open-cluster-management.io/klusterlet-deploy-mode: Hosted
        open-cluster-management/created-via: hypershift  
        agent.open-cluster-management.io/klusterlet-config: <DiscoveredClusterNamespace>-config
       name: $CLUSTER_NAME
    spec:  
      hubAcceptsClient: true  
      leaseDurationSeconds: 60 

Create a klusterletaddonconfig resource that overrides the addon installation namespace. (still need to find out how from Qiu Jian)

Definition of Done for Engineering Story Owner (Checklist)

• ...

Development Complete

• The code is complete.
• Functionality is working.
• Any required downstream Docker file changes are made.

Tests Automated

• [ ] Unit/function tests have been automated and incorporated into the
  build.
• [ ] 100% automated unit/function test coverage for new or changed APIs.

Secure Design

• [ ] Security has been assessed and incorporated into your threat model.

Multidisciplinary Teams Readiness

• [ ] Create an informative documentation issue using the [Customer
  Portal_doc_issue template](
  https://github.com/stolostron/backlog/issues/new?assignees=&labels=squad%3Adoc&template=doc_issue.md&title=),
  and ensure doc acceptance criteria is met. Link the development issue to
  the doc issue.
• [ ] Provide input to the QE team, and ensure QE acceptance criteria
  (established between story owner and QE focal) are met.

Support Readiness

• [ ] The must-gather script has been updated.