Replaces Update with Patch for PersistentVolumeClaims

Signed-off-by: Grant Griffiths <ggriffiths@purestorage.com>

pkg/common-controller/snapshot_controller.go

@@ -911,7 +911,8 @@ func (ctrl *csiSnapshotCommonController) ensurePVCFinalizer(snapshot *crdv1.Volu
 		// If PVC is not being deleted and PVCFinalizer is not added yet, add the PVCFinalizer.
 		pvcClone := pvc.DeepCopy()
 		pvcClone.ObjectMeta.Finalizers = append(pvcClone.ObjectMeta.Finalizers, utils.PVCFinalizer)
-		_, err = ctrl.client.CoreV1().PersistentVolumeClaims(pvcClone.Namespace).Update(context.TODO(), pvcClone, metav1.UpdateOptions{})
+
+		_, err = utils.PatchPersistentVolumeClaim(ctrl.client, pvc, pvcClone, true)
 		if err != nil {
 			klog.Errorf("cannot add finalizer on claim [%s/%s] for snapshot [%s/%s]: [%v]", pvc.Namespace, pvc.Name, snapshot.Namespace, snapshot.Name, err)
 			return newControllerUpdateError(pvcClone.Name, err.Error())
@@ -930,7 +931,7 @@ func (ctrl *csiSnapshotCommonController) removePVCFinalizer(pvc *v1.PersistentVo
 	pvcClone := pvc.DeepCopy()
 	pvcClone.ObjectMeta.Finalizers = utils.RemoveString(pvcClone.ObjectMeta.Finalizers, utils.PVCFinalizer)
 
-	_, err := ctrl.client.CoreV1().PersistentVolumeClaims(pvcClone.Namespace).Update(context.TODO(), pvcClone, metav1.UpdateOptions{})
+	_, err := utils.PatchPersistentVolumeClaim(ctrl.client, pvc, pvcClone, true)
 	if err != nil {
 		return newControllerUpdateError(pvcClone.Name, err.Error())
 	}

pkg/utils/patch.go

@@ -3,12 +3,19 @@ package utils
 import (
 	"context"
 	"encoding/json"
+	"fmt"
+
 	crdv1alpha1 "github.com/kubernetes-csi/external-snapshotter/client/v6/apis/volumegroupsnapshot/v1alpha1"
 
 	crdv1 "github.com/kubernetes-csi/external-snapshotter/client/v6/apis/volumesnapshot/v1"
 	clientset "github.com/kubernetes-csi/external-snapshotter/client/v6/clientset/versioned"
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/strategicpatch"
+	"k8s.io/client-go/kubernetes"
 )
 
 // PatchOp represents a json patch operation
@@ -77,3 +84,72 @@ func PatchVolumeGroupSnapshotContent(
 
 	return newGroupSnapshotContent, nil
 }
+
+func PatchPersistentVolumeClaim(client kubernetes.Interface, oldPVC, newPVC *v1.PersistentVolumeClaim, addResourceVersionCheck bool) (*v1.PersistentVolumeClaim, error) {
+	patchBytes, err := GetPVCPatchData(oldPVC, newPVC, addResourceVersionCheck)
+	if err != nil {
+		return oldPVC, fmt.Errorf("can't patch status of PVC %s as generate path data failed: %v", PVCKey(oldPVC), err)
+	}
+	updatedClaim, updateErr := client.CoreV1().PersistentVolumeClaims(oldPVC.Namespace).
+		Patch(context.TODO(), oldPVC.Name, types.StrategicMergePatchType, patchBytes, metav1.PatchOptions{}, "status")
+	if updateErr != nil {
+		return oldPVC, fmt.Errorf("can't patch status of  PVC %s with %v", PVCKey(oldPVC), updateErr)
+	}
+
+	return updatedClaim, nil
+}
+
+// PVCKey returns an unique key of a PVC object,
+func PVCKey(pvc *v1.PersistentVolumeClaim) string {
+	return fmt.Sprintf("%s/%s", pvc.Namespace, pvc.Name)
+}
+
+func GetPVCPatchData(oldPVC, newPVC *v1.PersistentVolumeClaim, addResourceVersionCheck bool) ([]byte, error) {
+	patchBytes, err := GetPatchData(oldPVC, newPVC)
+	if err != nil {
+		return patchBytes, err
+	}
+
+	if addResourceVersionCheck {
+		patchBytes, err = addResourceVersion(patchBytes, oldPVC.ResourceVersion)
+		if err != nil {
+			return nil, fmt.Errorf("apply ResourceVersion to patch data failed: %v", err)
+		}
+	}
+	return patchBytes, nil
+}
+
+func GetPatchData(oldObj, newObj interface{}) ([]byte, error) {
+	oldData, err := json.Marshal(oldObj)
+	if err != nil {
+		return nil, fmt.Errorf("marshal old object failed: %v", err)
+	}
+	newData, err := json.Marshal(newObj)
+	if err != nil {
+		return nil, fmt.Errorf("marshal new object failed: %v", err)
+	}
+	patchBytes, err := strategicpatch.CreateTwoWayMergePatch(oldData, newData, oldObj)
+	if err != nil {
+		return nil, fmt.Errorf("CreateTwoWayMergePatch failed: %v", err)
+	}
+	return patchBytes, nil
+}
+
+func addResourceVersion(patchBytes []byte, resourceVersion string) ([]byte, error) {
+	var patchMap map[string]interface{}
+	err := json.Unmarshal(patchBytes, &patchMap)
+	if err != nil {
+		return nil, fmt.Errorf("error unmarshalling patch with %v", err)
+	}
+	u := unstructured.Unstructured{Object: patchMap}
+	a, err := meta.Accessor(&u)
+	if err != nil {
+		return nil, fmt.Errorf("error creating accessor with  %v", err)
+	}
+	a.SetResourceVersion(resourceVersion)
+	versionBytes, err := json.Marshal(patchMap)
+	if err != nil {
+		return nil, fmt.Errorf("error marshalling json patch with %v", err)
+	}
+	return versionBytes, nil
+}