controllers: fix an idempotency bug in the portforward manager (#4771)

internal/controllers/core/kubernetesdiscovery/portforwards.go

@@ -40,7 +40,7 @@ func (r *Reconciler) manageOwnedPortForwards(ctx context.Context, nn types.Names
 			foundDesired = true
 
 			// If this PortForward is already in the APIServer, make sure it's up-to-date.
-			if apicmp.DeepEqual(pf.Spec, existingPF) {
+			if apicmp.DeepEqual(pf.Spec, existingPF.Spec) {
 				continue
 			}
 

internal/controllers/core/kubernetesdiscovery/portforwards_test.go

@@ -59,6 +59,47 @@ func TestPortForwardCreateAndUpdate(t *testing.T) {
 	assert.Equal(t, 4001, int(pf.Spec.Forwards[0].LocalPort))
 }
 
+func TestPortForwardIdempotent(t *testing.T) {
+	f := newFixture(t)
+
+	pod := f.buildPod("pod-ns", "pod", nil, nil)
+	key := types.NamespacedName{Name: "kd"}
+	kd := &v1alpha1.KubernetesDiscovery{
+		ObjectMeta: metav1.ObjectMeta{Name: "kd"},
+		Spec: v1alpha1.KubernetesDiscoverySpec{
+			Watches: []v1alpha1.KubernetesWatchRef{
+				{
+					UID:       string(pod.UID),
+					Namespace: pod.Namespace,
+					Name:      pod.Name,
+				},
+			},
+			PortForwardTemplateSpec: &v1alpha1.PortForwardTemplateSpec{
+				Forwards: []v1alpha1.Forward{
+					v1alpha1.Forward{LocalPort: 4000, ContainerPort: 4000},
+				},
+			},
+		},
+	}
+
+	f.Create(kd)
+	f.kClient.UpsertPod(pod)
+	f.requireObservedPods(key, ancestorMap{pod.UID: pod.UID})
+
+	// Simulate the reconcile (which would normally be invoked by the manager on status update).
+	f.MustReconcile(key)
+
+	var pf1 v1alpha1.PortForward
+	f.MustGet(types.NamespacedName{Name: "kd-pod"}, &pf1)
+
+	f.MustReconcile(key)
+
+	var pf2 v1alpha1.PortForward
+	f.MustGet(types.NamespacedName{Name: "kd-pod"}, &pf2)
+
+	assert.Equal(t, pf1.ObjectMeta, pf2.ObjectMeta)
+}
+
 func TestPortForwardCreateAndDelete(t *testing.T) {
 	f := newFixture(t)