🐛 Fix dest pvc storage class check if existing

cmd/transfer-pvc/indirect.go

@@ -139,8 +139,8 @@ func (t *TransferPVCCommand) runIndirect() error {
 	// Create destination PVC
 	fmt.Fprintf(os.Stderr, "[2/6] Creating destination PVC ...\n")
 	destPVC := t.buildDestinationPVC(srcPVC)
-	err = destClient.Create(context.TODO(), destPVC, &client.CreateOptions{})
-	if err != nil && !errors.IsAlreadyExists(err) {
+	err = t.createDestinationPVC(context.TODO(), destClient, destPVC)
+	if err != nil {
 		log.Debugf("Unable to create destination PVC %s/%s: %v", destPVC.Namespace, destPVC.Name, err)
 		return fmt.Errorf("unable to create destination PVC: %w", err)
 	}

cmd/transfer-pvc/transfer-pvc.go

@@ -421,8 +421,8 @@ func (t *TransferPVCCommand) run() (retErr error) {
 	log.Infof("Phase 2: Creating destination PVC")
 	phases.Start("Creating destination PVC")
 	destPVC := t.buildDestinationPVC(srcPVC)
-	err = destClient.Create(context.TODO(), destPVC, &client.CreateOptions{})
-	if err != nil && !errors.IsAlreadyExists(err) {
+	err = t.createDestinationPVC(context.TODO(), destClient, destPVC)
+	if err != nil {
 		log.Errorf("Unable to create destination PVC %s/%s: %v", t.PVC.Namespace.destination, t.PVC.Name.destination, err)
 		return phases.Fail(err, "unable to create destination PVC")
 	}
@@ -1290,6 +1290,35 @@ func (t *TransferPVCCommand) buildDestinationPVC(sourcePVC *corev1.PersistentVol
 	return pvc
 }
 
+// createDestinationPVC creates the destination PVC, validating the storage
+// class of an existing PVC when --dest-storage-class was requested.
+func (t *TransferPVCCommand) createDestinationPVC(ctx context.Context, c client.Client, pvc *corev1.PersistentVolumeClaim) error {
+	if err := c.Create(ctx, pvc, &client.CreateOptions{}); err == nil {
+		return nil
+	} else if !errors.IsAlreadyExists(err) {
+		return fmt.Errorf("creating destination PVC %q: %w", pvc.Name, err)
+	}
+
+	if t.PVC.StorageClassName == "" {
+		return nil
+	}
+
+	existing := &corev1.PersistentVolumeClaim{}
+	if err := c.Get(ctx, client.ObjectKeyFromObject(pvc), existing); err != nil {
+		return fmt.Errorf("getting existing destination PVC %q: %w", pvc.Name, err)
+	}
+
+	existingStorageClass := ""
+	if existing.Spec.StorageClassName != nil {
+		existingStorageClass = *existing.Spec.StorageClassName
+	}
+	if existingStorageClass != t.PVC.StorageClassName {
+		return fmt.Errorf("destination PVC %q already exists with StorageClass %q but --dest-storage-class %q was requested; delete the existing PVC or omit --dest-storage-class to use the existing PVC as-is", pvc.Name, existingStorageClass, t.PVC.StorageClassName)
+	}
+
+	return nil
+}
+
 func stripServerManagedPVCAnnotations(annotations map[string]string) map[string]string {
 	if len(annotations) == 0 {
 		return nil

cmd/transfer-pvc/transfer-pvc_test.go

@@ -64,6 +64,53 @@ func newTestScheme() *runtime.Scheme {
 	return s
 }
 
+func TestCreateDestinationPVC(t *testing.T) {
+	storageClass := func(name string) *string { return &name }
+	tests := []struct {
+		name                  string
+		requestedStorageClass string
+		existingStorageClass  *string
+		wantErr               string
+	}{
+		{
+			name:                  "rejects existing PVC with a different requested storage class",
+			requestedStorageClass: "standard-v2",
+			existingStorageClass:  storageClass("crane-sc02-target"),
+			wantErr:               `destination PVC "test-pvc" already exists with StorageClass "crane-sc02-target" but --dest-storage-class "standard-v2" was requested`,
+		},
+		{
+			name:                  "accepts existing PVC with requested storage class",
+			requestedStorageClass: "standard-v2",
+			existingStorageClass:  storageClass("standard-v2"),
+		},
+		{
+			name:                 "accepts existing PVC when no storage class was requested",
+			existingStorageClass: storageClass("crane-sc02-target"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			existing := &corev1.PersistentVolumeClaim{
+				ObjectMeta: metav1.ObjectMeta{Name: "test-pvc", Namespace: "test-ns"},
+				Spec:       corev1.PersistentVolumeClaimSpec{StorageClassName: tt.existingStorageClass},
+			}
+			c := fake.NewClientBuilder().WithScheme(newTestScheme()).WithObjects(existing).Build()
+			cmd := &TransferPVCCommand{Flags: Flags{PVC: PvcFlags{StorageClassName: tt.requestedStorageClass}}}
+
+			err := cmd.createDestinationPVC(context.Background(), c, &corev1.PersistentVolumeClaim{
+				ObjectMeta: metav1.ObjectMeta{Name: "test-pvc", Namespace: "test-ns"},
+			})
+			if tt.wantErr == "" && err != nil {
+				t.Fatalf("createDestinationPVC() unexpected error = %v", err)
+			}
+			if tt.wantErr != "" && (err == nil || !strings.Contains(err.Error(), tt.wantErr)) {
+				t.Errorf("createDestinationPVC() error = %v, want to contain %q", err, tt.wantErr)
+			}
+		})
+	}
+}
+
 func Test_parseSourceDestinationMapping(t *testing.T) {
 	tests := []struct {
 		name            string