Bug 2239140: Store application namespace as an annotation

controllers/drplacementcontrol.go

@@ -33,6 +33,9 @@ const (
 
 	// Annotation for the last cluster on which the application was running
 	LastAppDeploymentCluster = "drplacementcontrol.ramendr.openshift.io/last-app-deployment-cluster"
+
+	// Annotation for application namespace on the managed cluster
+	DRPCAppNamespace = "drplacementcontrol.ramendr.openshift.io/app-namespace"
 )
 
 var (

controllers/drplacementcontrol_controller.go

@@ -923,23 +923,32 @@ func (r *DRPlacementControlReconciler) getDRPolicy(ctx context.Context,
 	return drPolicy, nil
 }
 
-func (r DRPlacementControlReconciler) addLabelsAndFinalizers(ctx context.Context,
+// updateObjectMetadata updates drpc labels, annotations and finalizer, and also updates placementObj finalizer
+func (r DRPlacementControlReconciler) updateObjectMetadata(ctx context.Context,
 	drpc *rmn.DRPlacementControl, placementObj client.Object, log logr.Logger,
 ) error {
-	// add label and finalizer to DRPC
-	labelAdded := rmnutil.AddLabel(drpc, rmnutil.OCMBackupLabelKey, rmnutil.OCMBackupLabelValue)
-	finalizerAdded := rmnutil.AddFinalizer(drpc, DRPCFinalizer)
+	update := false
 
-	if labelAdded || finalizerAdded {
+	update = rmnutil.AddLabel(drpc, rmnutil.OCMBackupLabelKey, rmnutil.OCMBackupLabelValue)
+	update = rmnutil.AddFinalizer(drpc, DRPCFinalizer) || update
+
+	vrgNamespace, err := selectVRGNamespace(r.Client, r.Log, drpc, placementObj)
+	if err != nil {
+		return err
+	}
+
+	update = rmnutil.AddAnnotation(drpc, DRPCAppNamespace, vrgNamespace) || update
+
+	if update {
 		if err := r.Update(ctx, drpc); err != nil {
-			log.Error(err, "Failed to add label and finalizer to drpc")
+			log.Error(err, "Failed to add annotations, labels, or finalizer to drpc")
 
 			return fmt.Errorf("%w", err)
 		}
 	}
 
 	// add finalizer to User PlacementRule/Placement
-	finalizerAdded = rmnutil.AddFinalizer(placementObj, DRPCFinalizer)
+	finalizerAdded := rmnutil.AddFinalizer(placementObj, DRPCFinalizer)
 	if finalizerAdded {
 		if err := r.Update(ctx, placementObj); err != nil {
 			log.Error(err, "Failed to add finalizer to user placement rule")
@@ -1147,7 +1156,7 @@ func (r *DRPlacementControlReconciler) updateAndSetOwner(
 		return false, err
 	}
 
-	if err := r.addLabelsAndFinalizers(ctx, drpc, usrPlacement, log); err != nil {
+	if err := r.updateObjectMetadata(ctx, drpc, usrPlacement, log); err != nil {
 		return false, err
 	}
 
@@ -1960,6 +1969,10 @@ func selectVRGNamespace(
 	drpc *rmn.DRPlacementControl,
 	placementObj client.Object,
 ) (string, error) {
+	if drpc.GetAnnotations() != nil && drpc.GetAnnotations()[DRPCAppNamespace] != "" {
+		return drpc.GetAnnotations()[DRPCAppNamespace], nil
+	}
+
 	switch placementObj.(type) {
 	case *clrapiv1beta1.Placement:
 		vrgNamespace, err := getApplicationDestinationNamespace(client, log, placementObj)

controllers/drplacementcontrol_controller_test.go

@@ -1705,6 +1705,7 @@ func verifyInitialDRPCDeployment(userPlacement client.Object, preferredCluster s
 	_, condition := getDRPCCondition(&latestDRPC.Status, rmn.ConditionAvailable)
 	Expect(condition.Reason).To(Equal(string(rmn.Deployed)))
 	Expect(latestDRPC.GetAnnotations()[controllers.LastAppDeploymentCluster]).To(Equal(preferredCluster))
+	Expect(latestDRPC.GetAnnotations()[controllers.DRPCAppNamespace]).To(Equal(getVRGNameSpace()))
 }
 
 func verifyFailoverToSecondary(placementObj client.Object, toCluster string,

controllers/util/misc.go

@@ -72,6 +72,24 @@ func AddLabel(obj client.Object, key, value string) bool {
 	return !labelAdded
 }
 
+func AddAnnotation(obj client.Object, key, value string) bool {
+	const added = true
+
+	annotations := obj.GetAnnotations()
+	if annotations == nil {
+		annotations = map[string]string{}
+	}
+
+	if keyValue, ok := annotations[key]; !ok || keyValue != value {
+		annotations[key] = value
+		obj.SetAnnotations(annotations)
+
+		return added
+	}
+
+	return !added
+}
+
 func AddFinalizer(obj client.Object, finalizer string) bool {
 	const finalizerAdded = true