Enhance storageclass validation for linkedclone volume creation

[deepakkinni]

What this PR does / why we need it:

Enhances LinkedClone PVC validation in guest clusters to compare supervisor storage class references instead of guest storage class names. This allows LinkedClone volumes to reference different guest storage classes as long as they point to the same supervisor storage class, providing more flexibility in storage class management.

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Testing done:

Precheckins:
WCP(PASS): https://jenkins-vcf-csifvt.devops.broadcom.net/job/wcp-instapp-e2e-pre-checkin/725/
VKS(PASS): https://jenkins-vcf-csifvt.devops.broadcom.net/job/vks-instapp-e2e-pre-checkin/665/

Modified the validation logic in validateGuestPVCOperation to fetch StorageClass objects and compare their parameters.svStorageClass values. Updated validation comments and error messages to reflect this change.

Added comprehensive unit tests covering five scenarios:

• LinkedClone with matching svStorageClass (same StorageClass)
• LinkedClone with different StorageClass names but same svStorageClass
• LinkedClone with mismatched svStorageClass
• LinkedClone with missing svStorageClass in source StorageClass
• LinkedClone with missing svStorageClass in LinkedClone StorageClass

Test results:

=== RUN   TestValidateGuestPVCOperation_LinkedClone_StorageClass
=== RUN   TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_matching_svStorageClass_should_succeed
=== RUN   TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_different_StorageClass_but_same_svStorageClass_should_succeed
=== RUN   TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_mismatched_svStorageClass_should_fail
=== RUN   TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_missing_svStorageClass_in_source_StorageClass_should_fail
=== RUN   TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_missing_svStorageClass_in_LinkedClone_StorageClass_should_fail
--- PASS: TestValidateGuestPVCOperation_LinkedClone_StorageClass (0.00s)
    --- PASS: TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_matching_svStorageClass_should_succeed (0.00s)
    --- PASS: TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_different_StorageClass_but_same_svStorageClass_should_succeed (0.00s)
    --- PASS: TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_mismatched_svStorageClass_should_fail (0.00s)
    --- PASS: TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_missing_svStorageClass_in_source_StorageClass_should_fail (0.00s)
    --- PASS: TestValidateGuestPVCOperation_LinkedClone_StorageClass/LinkedClone_with_missing_svStorageClass_in_LinkedClone_StorageClass_should_fail (0.00s)
PASS
ok  	sigs.k8s.io/vsphere-csi-driver/v3/pkg/syncer/admissionhandler	0.640s



Actual testbed testing:
root@localhost [ ~ ]# cat pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: src-pvc
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: wcpglobal-storage-profile

root@localhost [ ~ ]# cat vs-1.yaml
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: vs-1
spec:
  volumeSnapshotClassName: volumesnapshotclass-delete
  source:
    persistentVolumeClaimName: src-pvc
root@localhost [ ~ ]# cat lc-1.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  annotations:
     csi.vsphere.volume/fast-provisioning : "true"
  name: vs1-lc-1
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  dataSource:
    name: vs-1
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io
  storageClassName: wcpglobal-storage-profile
root@localhost [ ~ ]# cat lc-2.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  annotations:
     csi.vsphere.volume/fast-provisioning : "true"
  name: vs1-lc-2
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  dataSource:
    name: vs-1
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io
  storageClassName: wcpglobal-storage-profile-latebinding
root@localhost [ ~ ]# cat lc-3.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  annotations:
     csi.vsphere.volume/fast-provisioning : "true"
  name: vs1-lc-3
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  dataSource:
    name: vs-1
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io
  storageClassName: testpol


Regression LC creation:

root@localhost [ ~ ]# kubectl -n testns apply -f lc-1.yaml
persistentvolumeclaim/vs1-lc-1 created


Create LC with different WFFC version of storageclass:
root@localhost [ ~ ]# kubectl -n testns apply -f lc-2.yaml
persistentvolumeclaim/vs1-lc-2 created

Create LC with different storageclass:
root@localhost [ ~ ]# kubectl -n testns apply -f lc-3.yaml
Error from server: error when creating "lc-3.yaml": admission webhook "validation.csi.vsphere.vmware.com" denied the request: StorageClass svStorageClass mismatch, Namespace: testns, LinkedClone StorageClass: testpol (svStorageClass: testpol), source PVC StorageClass: wcpglobal-storage-profile (svStorageClass: wcpglobal-storage-profile)

Special notes for your reviewer:

The validation now retrieves StorageClass objects via the Kubernetes API to access their parameters. Error messages include both StorageClass names and their svStorageClass parameter values for better troubleshooting. The change is backward compatible and only affects LinkedClone PVC validation in guest clusters.

RBAC changes needed - this is covered in standard package

Release note:
NONE

[deepakkinni]

SUCCESS --- Jenkins Build #665

[deepakkinni]

Triggering CSI-WCP Pre-checkin Pipeline for this PR... Job takes approximately an hour to complete
Jenkins Build #722

[deepakkinni]

FAILED --- Jenkins Build #722

[deepakkinni]

SUCCESS --- Jenkins Build #725

[xing-yang]

/approve

[nikhilbarge]

/approve

[chethanv28]

/approve

Good to merge after fixing the linter errors

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: chethanv28, deepakkinni, nikhilbarge, xing-yang

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

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• OWNERS [chethanv28,deepakkinni,xing-yang]

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[deepakkinni]

/test pull-vsphere-csi-driver-verify-golangci-lint

[xing-yang]

/lgtm