Track colliding child resources that are not owned (#569)

When creating a child resource with a fixed name, it's possible there
already exists a resource with the same that blocks the creation of
the new resource. If this resource isn't owned by our resource, and owner
relationship are utilized, that creates a blind spot where changes to
that resource will not trigger a new reconcile.

We now track resources in this very specific case. When the target
child resource is deleted the parent resource will now be reconciled.

Signed-off-by: Scott Andrews <[email protected]>

reconcilers/child.go

@@ -168,6 +168,7 @@ func (r *ChildReconciler[T, CT, CLT]) SetupWithManager(ctx context.Context, mgr
 
 	if !r.SkipOwnerReference {
 		bldr.Owns(r.ChildType)
+		bldr.Watches(r.ChildType, EnqueueTracked(ctx))
 	}
 
 	if err := r.ChildObjectManager.SetupWithManager(ctx, mgr, bldr); err != nil {
@@ -240,6 +241,10 @@ func (r *ChildReconciler[T, CT, CLT]) Reconcile(ctx context.Context, resource T)
 				return Result{}, err
 			}
 			log.Info("unable to reconcile child, not owned", "child", namespaceName(conflicted), "ownerRefs", conflicted.GetOwnerReferences())
+			if !r.SkipOwnerReference {
+				// manually track to watch for deletion since the existing resource is not owned by us
+				c.Tracker.TrackObject(conflicted, resource)
+			}
 			r.ReflectChildStatusOnParent(ctx, resource, child, err)
 			return Result{}, nil
 		case apierrs.IsInvalid(err):

reconcilers/child_test.go

@@ -413,6 +413,12 @@ func TestChildReconciler(t *testing.T) {
 					d.AddField("foo", "bar")
 				}).
 				DieReleasePtr(),
+			APIGivenObjects: []client.Object{
+				configMapGiven.
+					MetadataDie(func(d *diemetav1.ObjectMetaDie) {
+						d.OwnerReferences()
+					}),
+			},
 			WithReactors: []rtesting.ReactionFunc{
 				rtesting.InduceFailure("create", "ConfigMap", rtesting.InduceFailureOpts{
 					Error: apierrs.NewAlreadyExists(schema.GroupResource{}, testName),
@@ -437,6 +443,9 @@ func TestChildReconciler(t *testing.T) {
 			ExpectCreates: []client.Object{
 				configMapCreate,
 			},
+			ExpectTracks: []rtesting.TrackRequest{
+				rtesting.NewTrackRequest(configMapGiven, resource, scheme),
+			},
 		},
 		"child name collision, stale informer cache": {
 			Resource: resourceReady.
@@ -908,6 +917,12 @@ func TestChildReconciler_Unstructured(t *testing.T) {
 					d.AddField("foo", "bar")
 				}).
 				DieReleaseUnstructured(),
+			APIGivenObjects: []client.Object{
+				configMapGiven.
+					MetadataDie(func(d *diemetav1.ObjectMetaDie) {
+						d.OwnerReferences()
+					}).DieReleaseUnstructured(),
+			},
 			WithReactors: []rtesting.ReactionFunc{
 				rtesting.InduceFailure("create", "ConfigMap", rtesting.InduceFailureOpts{
 					Error: apierrs.NewAlreadyExists(schema.GroupResource{}, testName),
@@ -932,6 +947,9 @@ func TestChildReconciler_Unstructured(t *testing.T) {
 			ExpectCreates: []client.Object{
 				configMapCreate.DieReleaseUnstructured(),
 			},
+			ExpectTracks: []rtesting.TrackRequest{
+				rtesting.NewTrackRequest(configMapGiven, resource, scheme),
+			},
 		},
 		"child name collision, stale informer cache": {
 			Resource: resourceReady.