Link PVCs and PVs in VolumeGroupSnapshot and VolumeGroupSnapshotContent

leonardoce commented 5 months ago

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind api-change /kind bug /kind cleanup /kind design /kind documentation /kind failing-test /kind feature /kind flake

What this PR does / why we need it:

Following #1068 and the discussion in #969, this PR improves the snapshot controller and the CSI snapshotter sidecar to track which PVC and PVs are snapshotted by a VolumeGroupSnapshot.

With this PR applied, a VolumeGroupSnapshot will look like:

apiVersion: groupsnapshot.storage.k8s.io/v1alpha1
kind: VolumeGroupSnapshot
metadata:
  finalizers:
  - groupsnapshot.storage.kubernetes.io/volumegroupsnapshot-bound-protection
  generation: 1
  name: new-groupsnapshot
  namespace: default
  resourceVersion: "64488"
  uid: 02f28293-ff7e-4d1c-8ea8-c64fb2b45a26
spec:
  source:
    selector:
      matchLabels:
        cnpg.io/instanceName: cluster-example-1
  volumeGroupSnapshotClassName: csi-hostpath-groupsnapclass
status:
  boundVolumeGroupSnapshotContentName: groupsnapcontent-02f28293-ff7e-4d1c-8ea8-c64fb2b45a26
  creationTime: "2024-05-14T10:02:50Z"
  pvcVolumeSnapshotRefList:
  - persistentVolumeClaimRef:
      name: cluster-example-1
    volumeSnapshotRef:
      name: snapshot-219cbb76259445b14e5a1f0e11008cb976aacfb23bada2e4346d7d4da81d2d2b-2024-05-14-10.2.52
  - persistentVolumeClaimRef:
      name: cluster-example-1-wal
    volumeSnapshotRef:
      name: snapshot-8b65beb9db8573e67e31c3120401d13f1ccd83bf4974b546970799ce0b0016c3-2024-05-14-10.2.52
  readyToUse: true

The corresponding VolumeGroupSnapshotContent will look like:

apiVersion: groupsnapshot.storage.k8s.io/v1alpha1
kind: VolumeGroupSnapshotContent
metadata:
  creationTimestamp: "2024-05-14T10:02:50Z"
  finalizers:
  - groupsnapshot.storage.kubernetes.io/volumegroupsnapshotcontent-bound-protection
  generation: 1
  name: groupsnapcontent-02f28293-ff7e-4d1c-8ea8-c64fb2b45a26
  resourceVersion: "64482"
  uid: 7671dd61-0af3-4e53-a389-d7528fca5260
spec:
  deletionPolicy: Delete
  driver: hostpath.csi.k8s.io
  source:
    volumeHandles:
    - f4416324-1165-11ef-91b4-22776546f286
    - f440f487-1165-11ef-91b4-22776546f286
  volumeGroupSnapshotClassName: csi-hostpath-groupsnapclass
  volumeGroupSnapshotRef:
    apiVersion: groupsnapshot.storage.k8s.io/v1alpha1
    kind: VolumeGroupSnapshot
    name: new-groupsnapshot
    namespace: default
    resourceVersion: "64440"
    uid: 02f28293-ff7e-4d1c-8ea8-c64fb2b45a26
status:
  creationTime: 1715680970153290824
  pvVolumeSnapshotContentList:
  - persistentVolumeRef:
      name: pvc-e92d8114-160f-4a59-8c29-bb6fb42e345f
    volumeSnapshotContentRef:
      name: snapcontent-219cbb76259445b14e5a1f0e11008cb976aacfb23bada2e4346d7d4da81d2d2b-2024-05-14-10.2.52
  - persistentVolumeRef:
      name: pvc-7b7b185e-2c35-4973-959e-15593d5f74a5
    volumeSnapshotContentRef:
      name: snapcontent-8b65beb9db8573e67e31c3120401d13f1ccd83bf4974b546970799ce0b0016c3-2024-05-14-10.2.52
  readyToUse: true
  volumeGroupSnapshotHandle: 1f3e6247-11d9-11ef-a7bc-b25da50ff257

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Testing

To test this patch, I used the CSI host path driver. Having two PVCs and creating a VolumeGroupSnapshot matching them is enough to trigger the process.

Does this PR introduce a user-facing change?:

Link the snapshotted PVCs and the corresponding PVs in VolumeGroupSnapshot and VolumeGroupSnapshotContent to make restoring data easier.

k8s-ci-robot commented 5 months ago

Hi @leonardoce. Thanks for your PR.

I'm waiting for a kubernetes-csi member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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xing-yang commented 5 months ago

/ok-to-test

xing-yang commented 5 months ago

/assign

nixpanic commented 5 months ago

Once successfully created, maybe remove the groupsnapshot.storage.kubernetes.io/info annotation?

leonardoce commented 5 months ago

Once successfully created, maybe remove the groupsnapshot.storage.kubernetes.io/info annotation?

Yes. Nice idea, @nixpanic.

All the information in that annotation is in the status section of both VolumeGroupSnapshot and VolumeGroupSnapshotStatus. But this would require a new API server call.

More importantly, updateGroupSnapshotContentStatus and updateGroupSnapshotStatus won't be idempotent anymore as the annotation will be missing after removal. I need more experience in this codebase to judge this properly.

What's your opinion @xing-yang?

leonardoce commented 5 months ago

Thinking aloud, the VolumeGroupSnapshotContent resource would be more beautiful without that annotation...

xing-yang commented 5 months ago

/hold

xing-yang commented 5 months ago

I'd prefer the annotation gets removed.

leonardoce commented 4 months ago

I rebased it on the new master, removed the annotation, and updated the description of this PR with the latest resource definitions.