Fix PV.Spec.ClaimRef.Kind validation

When comparing PVs, skip comparing unset "Spec.ClaimRef.kind". This
breaks validation when using KubeVirt VM, and actual resources in the
system do not match the backed up resources in the s3 store. It is
correct to ignore unset kind since this is an optional field[1].

Previously we failed with:

    Failed to restore PVs: failed to restore ClusterData for VolRep
    (failed to restore PVs and PVCs using profile list
    ([s3profile-perf8-ocs-storagecluster]): failed to restore all
    []v1.PersistentVolume. Total/Restored 1/0)

And then the VRG will not make any progress. Now we consider unset
"kind" as equal and continue the flow normally.

[1] https://github.com/kubernetes/api/blob/f3648a53522eb60ea75d70d36a50c799f7e4e23b/core/v1/types.go#L6381

Bug: https://bugzilla.redhat.com/2262455
Signed-off-by: Nir Soffer <[email protected]>

Author: nirs

controllers/util/misc.go

@@ -115,3 +115,8 @@ func UpdateStringMap(dst *map[string]string, src map[string]string) {
 		(*dst)[key] = val
 	}
 }
+
+// OptionalEqual returns True if optional field values are equal, or one of them is unset.
+func OptionalEqual(a, b string) bool {
+	return a == "" || b == "" || a == b
+}

controllers/vrg_volrep.go

@@ -2162,7 +2162,7 @@ func (v *VRGInstance) pvMatches(x, y *corev1.PersistentVolume) bool {
 			"y", y.Spec.PersistentVolumeSource.CSI.FSType)
 
 		return false
-	case x.Spec.ClaimRef.Kind != y.Spec.ClaimRef.Kind:
+	case !rmnutil.OptionalEqual(x.Spec.ClaimRef.Kind, y.Spec.ClaimRef.Kind):
 		v.log.Info("PVs ClaimRef.Kind mismatch", "x", x.Spec.ClaimRef.Kind, "y", y.Spec.ClaimRef.Kind)
 
 		return false