feat: block isbsvc deleting when there is linked pipeline

config/base/crds/full/numaflow.numaproj.io_interstepbufferservices.yaml

@@ -3174,6 +3174,7 @@ spec:
                 - Pending
                 - Running
                 - Failed
+                - Deleting
                 type: string
               type:
                 type: string

config/install.yaml

@@ -3173,6 +3173,7 @@ spec:
                 - Pending
                 - Running
                 - Failed
+                - Deleting
                 type: string
               type:
                 type: string

config/namespace-install.yaml

@@ -3173,6 +3173,7 @@ spec:
                 - Pending
                 - Running
                 - Failed
+                - Deleting
                 type: string
               type:
                 type: string

pkg/apis/numaflow/v1alpha1/isbsvc_types.go

@@ -20,14 +20,15 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
-// +kubebuilder:validation:Enum="";Pending;Running;Failed
+// +kubebuilder:validation:Enum="";Pending;Running;Failed;Deleting
 type ISBSvcPhase string
 
 const (
-	ISBSvcPhaseUnknown ISBSvcPhase = ""
-	ISBSvcPhasePending ISBSvcPhase = "Pending"
-	ISBSvcPhaseRunning ISBSvcPhase = "Running"
-	ISBSvcPhaseFailed  ISBSvcPhase = "Failed"
+	ISBSvcPhaseUnknown  ISBSvcPhase = ""
+	ISBSvcPhasePending  ISBSvcPhase = "Pending"
+	ISBSvcPhaseRunning  ISBSvcPhase = "Running"
+	ISBSvcPhaseFailed   ISBSvcPhase = "Failed"
+	ISBSvcPhaseDeleting ISBSvcPhase = "Deleting"
 
 	// ISBSvcConditionConfigured has the status True when the InterStepBufferService
 	// has valid configuration.
@@ -150,7 +151,8 @@ func (iss *InterStepBufferServiceStatus) SetObservedGeneration(value int64) {
 
 // IsHealthy indicates whether the InterStepBufferService is healthy or not
 func (iss *InterStepBufferServiceStatus) IsHealthy() bool {
-	if iss.Phase != ISBSvcPhaseRunning {
+	// Deleting is a special case, we don't want to mark it as unhealthy as Pipeline reconciliation relies on it
+	if iss.Phase != ISBSvcPhaseRunning && iss.Phase != ISBSvcPhaseDeleting {
 		return false
 	}
 	return iss.IsReady()

pkg/reconciler/isbsvc/controller.go

@@ -101,6 +101,7 @@ func (r *interStepBufferServiceReconciler) reconcile(ctx context.Context, isbSvc
 			// Finalizer logic should be added here.
 			if err := installer.Uninstall(ctx, isbSvc, r.client, r.kubeClient, r.config, log, r.recorder); err != nil {
 				log.Errorw("Failed to uninstall", zap.Error(err))
+				isbSvc.Status.SetPhase(dfv1.ISBSvcPhaseDeleting, err.Error())
 				return err
 			}
 			controllerutil.RemoveFinalizer(isbSvc, finalizerName)

pkg/reconciler/isbsvc/installer/installer.go

@@ -91,10 +91,37 @@ func getInstaller(isbSvc *dfv1.InterStepBufferService, client client.Client, kub
 //
 // It could also be used to check if the ISB Service object can be safely deleted.
 func Uninstall(ctx context.Context, isbSvc *dfv1.InterStepBufferService, client client.Client, kubeClient kubernetes.Interface, config *reconciler.GlobalConfig, logger *zap.SugaredLogger, recorder record.EventRecorder) error {
+	pls, err := referencedPipelines(ctx, client, isbSvc)
+	if err != nil {
+		return fmt.Errorf("failed to check if there is any pipeline using this InterStepBufferService, %w", err)
+	}
+	if pls > 0 {
+		return fmt.Errorf("can not delete InterStepBufferService %q which has %d pipelines connected", isbSvc.Name, pls)
+	}
 	installer, err := getInstaller(isbSvc, client, kubeClient, config, logger, recorder)
 	if err != nil {
 		logger.Errorw("Failed to get an installer", zap.Error(err))
 		return err
 	}
 	return installer.Uninstall(ctx)
 }
+
+func referencedPipelines(ctx context.Context, c client.Client, isbSvc *dfv1.InterStepBufferService) (int, error) {
+	pipelines := &dfv1.PipelineList{}
+	if err := c.List(ctx, pipelines, &client.ListOptions{
+		Namespace: isbSvc.Namespace,
+	}); err != nil {
+		return 0, err
+	}
+	result := 0
+	for _, pl := range pipelines.Items {
+		isbSvcName := pl.Spec.InterStepBufferServiceName
+		if isbSvcName == "" {
+			isbSvcName = dfv1.DefaultISBSvcName
+		}
+		if isbSvcName == isbSvc.Name {
+			result++
+		}
+	}
+	return result, nil
+}

pkg/reconciler/isbsvc/installer/installer_test.go

@@ -250,4 +250,71 @@ func TestUnInstall(t *testing.T) {
 		err := Uninstall(ctx, testObj, cl, kubeClient, fakeConfig, zaptest.NewLogger(t).Sugar(), record.NewFakeRecorder(64))
 		assert.NoError(t, err)
 	})
+
+	t.Run("test has pl connected", func(t *testing.T) {
+		testPipeline := &dfv1.Pipeline{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test-pl",
+				Namespace: testNamespace,
+			},
+			Spec: dfv1.PipelineSpec{
+				InterStepBufferServiceName: testISBSName,
+			},
+		}
+		err := cl.Create(ctx, testPipeline)
+		assert.NoError(t, err)
+		testObj := testJetStreamIsbSvc.DeepCopy()
+		err = Uninstall(ctx, testObj, cl, kubeClient, fakeConfig, zaptest.NewLogger(t).Sugar(), record.NewFakeRecorder(64))
+		assert.Error(t, err)
+		assert.Contains(t, err.Error(), "connected")
+	})
+}
+
+func Test_referencedPipelines(t *testing.T) {
+	cl := fake.NewClientBuilder().Build()
+	ctx := context.TODO()
+
+	t.Run("test no referenced pls", func(t *testing.T) {
+		testObj := testJetStreamIsbSvc.DeepCopy()
+		pls, err := referencedPipelines(ctx, cl, testObj)
+		assert.NoError(t, err)
+		assert.Equal(t, 0, pls)
+	})
+
+	t.Run("test having referenced pls - non default isbsvc", func(t *testing.T) {
+		testPipeline := &dfv1.Pipeline{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test-pl",
+				Namespace: testNamespace,
+			},
+			Spec: dfv1.PipelineSpec{
+				InterStepBufferServiceName: testISBSName,
+			},
+		}
+		err := cl.Create(ctx, testPipeline)
+		assert.NoError(t, err)
+		testObj := testJetStreamIsbSvc.DeepCopy()
+		pls, err := referencedPipelines(ctx, cl, testObj)
+		assert.NoError(t, err)
+		assert.Equal(t, 1, pls)
+	})
+
+	t.Run("test having referenced pls - default isbsvc", func(t *testing.T) {
+		testPipeline := &dfv1.Pipeline{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test-pl-1",
+				Namespace: testNamespace,
+			},
+			Spec: dfv1.PipelineSpec{
+				InterStepBufferServiceName: "",
+			},
+		}
+		err := cl.Create(ctx, testPipeline)
+		assert.NoError(t, err)
+		testObj := testJetStreamIsbSvc.DeepCopy()
+		testObj.Name = "default"
+		pls, err := referencedPipelines(ctx, cl, testObj)
+		assert.NoError(t, err)
+		assert.Equal(t, 1, pls)
+	})
 }