Add field in status to show the actual state of the back-end image

[iamniting]

As of now, we have one field (State) in the status of volume replication CR which shows the state as replicating/Failed/Resyncing. But it does not tell us the actual state of the VR. We need one more field which tells us about the actual state of the Image at the backend. Adding one more field will give the user more clarity about the actual state in those scenarios when the user has edited the CR.

For example:

1. User has created a CR as Image State Primary. We will mark the State as replicating until reconcile failed.
2. User has edited the CR to change the image state as Secondary and reconcile failed we are going to mark the state as Failed. In this case, it is difficult for the user to know the state when he edits the CR many times.

[Madhu-1]

cc @ShyamsundarR @leseb

[leseb]

As example, this is what Rook reports at the pool levels it in the CephBlockPool CRD status field:

status:
  info:
    rbdMirrorBootstrapPeerSecretName: pool-peer-token-replicapool
  mirroringInfo:
    lastChecked: "2021-03-12T15:16:10Z"
    mode: image
    site_name: 94824460-9eea-4d9c-b702-d7e2d30550e5-rook-ceph
  mirroringStatus:
    lastChecked: "2021-03-12T15:16:10Z"
    summary:
      daemon_health: UNKNOWN
      health: UNKNOWN
      image_health: OK
      states: {}
  phase: Ready
  snapshotScheduleStatus:
    lastChecked: "2021-03-12T15:16:10Z"
    snapshotSchedules:
    - image: '-'
      items:
      - interval: 12h
        start_time: 12:00:00-05:00
      - interval: 1d
        start_time: 14:00:00-05:00
      namespace: '-'
      pool: replicapool

So it makes sense to report rbd mirror pool info/status outputs.

[ShyamsundarR]

So it makes sense to report rbd mirror pool info/status outputs.

This makes it RBD specific, whereas VolumeReplication status is ideally for any storage provider.

We may want to add additional status via the rbd info/status, but will have to represent it more generically in status as such.