Do not assume storageclass is still in-tree after csi migration

[ialidzhikov]

What type of PR is this?
/kind bug

What this PR does / why we need it:
Volume expand controller is responsible for setting the volume.kubernetes.io/storage-resizer annotation for migrated volume. However currently the controller relies that the PVC StorageClass will be still the in-tree (legacy) one. Basically it currently tries to fetch the PVC StorageClass, it gets the StorageClass provisioner (and assumes that it is the in-tree one), then tries to get the csi plugin name by in-tree plugin name.
Often after csi migration users replace their legacy StorageClasses with the new out-of-tree. If that is the case, the volume_expand controller fails to set the volume.kubernetes.io/storage-resizer annotation and volume resize for a migrated volume fails. I couldn't find a statement that deleting the legacy storageclass and recreating the out-of-tree one with the same name is forbidden and not supposed to happen by the csi contract. Feel free to correct me if it is.

With the PR, volume expand controller is adapted to get the in-tree plugin name from the PV spec (not from the PVC StorageClass provisioner).

Which issue(s) this PR fixes:

Fixes #94189

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

An issues preventing volume expand controller to annotate the PVC with `volume.kubernetes.io/storage-resizer` when the PVC StorageClass is already updated to the out-of-tree provisioner is now fixed.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

Hi @ialidzhikov. Thanks for your PR.

I'm waiting for a kubernetes 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.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[ialidzhikov]

/sig storage
/assign @gnufied @leakingtapan @msau42

[ialidzhikov]

/priority important-soon

[msau42]

I think there's a general problem that users can recreate storageclasses with the same name, but completely change the contents of the StorageClass, which may invalidate the PV.spec.storageclassname on existing PVs.

This is why we do not rely on StorageClass after PV creation, and perhaps this StorageClass.allowVolumeExpansion field is flawed in that regard.

[ialidzhikov]

This is why we do not rely on StorageClass after PV creation,

Yep, I agree. This PR improves the volume expand controller wrt that.

[ialidzhikov]

@gnufied , @leakingtapan , @msau42 did you managed to check this PR?
I want also to cherry-pick this change into v1.17, v1.18, v1.19.

[ialidzhikov]

@msau42 , if you don't have objections, can we add /milestone v1.20?

[msau42]

/milestone v1.20

Will let @gnufied review

[ialidzhikov]

/assign @deads2k

[ialidzhikov]

ping @gnufied @deads2k

[gnufied]

/lgtm

[ialidzhikov]

@msau42 , I think we are back to you (or someone else that can assist with review/approval).

[msau42]

/approve

[msau42]

/assign @deads2k

for controller manager approval

[deads2k]

kcm change lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: deads2k, ialidzhikov, msau42

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• cmd/kube-controller-manager/OWNERS [deads2k]
• pkg/controller/volume/expand/OWNERS [deads2k,msau42]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ialidzhikov]

/test pull-kubernetes-bazel-test