fix: add finalizer to prevent volume leakage

[1978629634]

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 bug

What this PR does / why we need it:

Add a annotation volume.kubernetes.io/provisioning-consistency to pvc. When the annotation is set to enable, use a finalizer to ensure that the lifecycle of the PVC is consistent with the associated volume, preventing volume leakage.

The finalizer is removed under two conditions:

1.When the annotation volume.kubernetes.io/provisioning-consistency is set to disable on the PVC, or

2.When the associated PV has been provisioned successfully.

Removing the finalizer allows the PVC to be deleted safely without causing the volume to leak.

Which issue(s) this PR fixes:

Fixes #486

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

When the annotation volume.kubernetes.io/provisioning-consistency is added to a PVC with the value enable, a provisioning protection finalizer will be added before creating the volume and removed after setting pvc.spec.volumeName.

If the PVC is being deleted and volume.kubernetes.io/provisioning-consistency is set to disable, the finalizer will be removed, abandoning the provisioning process. A CSI driver may be provisioning the volume and this volume may leak.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: 1978629634 / name: Chen Pu (7eafefd)

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[APPROVALNOTIFIER] This PR is NOT APPROVED

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[jsafrane]

@1978629634 Thanks a lot for looking into this! I am afraid this is a complex problem and it will need more thoughts.

1. It probably belongs to https://github.com/kubernetes-sigs/sig-storage-lib-external-provisioner/
2. In ideal case, it should work as user friendly as possible. Today users can simply delete a PVC when it's stuck provisioning and create a new one with a different StorageClass. Kubernetes should do the right thing without leaks and magic annotations. The hard part is to find out how. Or if we expect users to change their behavior, we need really strong arguments.
   • Should there be a new PVC field instead of an annotation? Can we expect users to set it correctly? What prevents users from setting it to "disabled / I don't care about leaks"? It's cluster admin who will then need to deal with the leaks, not user. Do we as Kubernetes authors care?
   • Should the field be somewhere else, under admin control? Then users can still remove finalizers from their PVCs, creating leaks anyway.
   • Should we fix the provisioner in any other way, e.g. create a shadow object copying the PVC and continue calling Provision() until it gets a final response or cluster admin deletes this shadow object?

We need answers to these questions before we implement anything.
cc @msau42 @xing-yang

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PR needs rebase.

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