✨ Allow to use builder.OnlyMetadata option with Watches

pkg/builder/controller.go

@@ -116,9 +116,10 @@ func (blder *Builder) Owns(object client.Object, opts ...OwnsOption) *Builder {
 
 // WatchesInput represents the information set by Watches method.
 type WatchesInput struct {
-	src          source.Source
-	eventhandler handler.EventHandler
-	predicates   []predicate.Predicate
+	src              source.Source
+	eventhandler     handler.EventHandler
+	predicates       []predicate.Predicate
+	objectProjection objectProjection
 }
 
 // Watches exposes the lower-level ControllerManagedBy Watches functions through the builder.  Consider using
@@ -255,10 +256,19 @@ func (blder *Builder) doWatch() error {
 	for _, w := range blder.watchesInput {
 		allPredicates := append([]predicate.Predicate(nil), blder.globalPredicates...)
 		allPredicates = append(allPredicates, w.predicates...)
+
+		// If the source of this watch is of type *source.Kind, project it.
+		if srckind, ok := w.src.(*source.Kind); ok {
+			typeForSrc, err := blder.project(srckind.Type, w.objectProjection)
+			if err != nil {
+				return err
+			}
+			srckind.Type = typeForSrc
+		}
+
 		if err := blder.ctrl.Watch(w.src, w.eventhandler, allPredicates...); err != nil {
 			return err
 		}
-
 	}
 	return nil
 }

pkg/builder/controller_test.go

@@ -371,14 +371,61 @@ var _ = Describe("application", func() {
 			Expect(err).NotTo(HaveOccurred())
 		})
 
-		It("should support watching For & Owns as metadata", func() {
+		It("should support watching For, Owns, and Watch as metadata", func() {
+			statefulSetMaps := make(chan *metav1.PartialObjectMetadata)
+
 			bldr := ControllerManagedBy(mgr).
 				For(&appsv1.Deployment{}, OnlyMetadata).
-				Owns(&appsv1.ReplicaSet{}, OnlyMetadata)
+				Owns(&appsv1.ReplicaSet{}, OnlyMetadata).
+				Watches(&source.Kind{Type: &appsv1.StatefulSet{}},
+					handler.EnqueueRequestsFromMapFunc(func(o client.Object) []reconcile.Request {
+						ometa := o.(*metav1.PartialObjectMetadata)
+						statefulSetMaps <- ometa
+						return nil
+					}),
+					OnlyMetadata)
 
 			ctx, cancel := context.WithCancel(context.Background())
 			defer cancel()
 			doReconcileTest(ctx, "8", bldr, mgr, true)
+
+			By("Creating a new stateful set")
+			set := &appsv1.StatefulSet{
+				ObjectMeta: metav1.ObjectMeta{
+					Namespace: "default",
+					Name:      "test1",
+					Labels: map[string]string{
+						"foo": "bar",
+					},
+				},
+				Spec: appsv1.StatefulSetSpec{
+					Selector: &metav1.LabelSelector{
+						MatchLabels: map[string]string{"foo": "bar"},
+					},
+					Template: corev1.PodTemplateSpec{
+						ObjectMeta: metav1.ObjectMeta{Labels: map[string]string{"foo": "bar"}},
+						Spec: corev1.PodSpec{
+							Containers: []corev1.Container{
+								{
+									Name:  "nginx",
+									Image: "nginx",
+								},
+							},
+						},
+					},
+				},
+			}
+			err := mgr.GetClient().Create(context.TODO(), set)
+			Expect(err).NotTo(HaveOccurred())
+
+			By("Checking that the mapping function has been called")
+			Eventually(func() bool {
+				metaSet := <-statefulSetMaps
+				Expect(metaSet.Name).To(Equal(set.Name))
+				Expect(metaSet.Namespace).To(Equal(set.Namespace))
+				Expect(metaSet.Labels).To(Equal(set.Labels))
+				return true
+			}).Should(BeTrue())
 		})
 	})
 })

pkg/builder/options.go

@@ -94,6 +94,11 @@ func (p projectAs) ApplyToOwns(opts *OwnsInput) {
 	opts.objectProjection = objectProjection(p)
 }
 
+// ApplyToWatches applies this configuration to the given WatchesInput options.
+func (p projectAs) ApplyToWatches(opts *WatchesInput) {
+	opts.objectProjection = objectProjection(p)
+}
+
 var (
 	// OnlyMetadata tells the controller to *only* cache metadata, and to watch
 	// the the API server in metadata-only form.  This is useful when watching
@@ -104,8 +109,9 @@ var (
 	// unstructured cache.
 	OnlyMetadata = projectAs(projectAsMetadata)
 
-	_ ForOption  = OnlyMetadata
-	_ OwnsOption = OnlyMetadata
+	_ ForOption     = OnlyMetadata
+	_ OwnsOption    = OnlyMetadata
+	_ WatchesOption = OnlyMetadata
 )
 
 // }}}