Add test cases to check cache sync timeouts

Co-authored-by: Alvaro Aleman <alvaroaleman@users.noreply.github.com>

pkg/internal/controller/controller.go

@@ -79,7 +79,7 @@ type Controller struct {
 	// undergo a major refactoring and redesign to allow for context to not be stored in a struct.
 	ctx context.Context
 
-	// CacheSyncTimeout refers to the time limit set on waiting cache to sync
+	// CacheSyncTimeout refers to the time limit set on waiting for cache to sync
 	// Defaults to 2 minutes if not set.
 	CacheSyncTimeout time.Duration
 
@@ -146,10 +146,6 @@ func (c *Controller) Start(ctx context.Context) error {
 	// Set the internal context.
 	c.ctx = ctx
 
-	// use a context with timeout for launching sources and syncing caches.
-	sourceStartCtx, cancel := context.WithTimeout(ctx, c.CacheSyncTimeout)
-	defer cancel()
-
 	c.Queue = c.MakeQueue()
 	defer c.Queue.ShutDown() // needs to be outside the iife so that we shutdown after the stop channel is closed
 
@@ -164,7 +160,10 @@ func (c *Controller) Start(ctx context.Context) error {
 		// caches.
 		for _, watch := range c.startWatches {
 			c.Log.Info("Starting EventSource", "source", watch.src)
-			if err := watch.src.Start(sourceStartCtx, watch.handler, c.Queue, watch.predicates...); err != nil {
+
+			watchStartCtx, cancel := context.WithTimeout(ctx, c.CacheSyncTimeout)
+			defer cancel()
+			if err := watch.src.Start(watchStartCtx, watch.handler, c.Queue, watch.predicates...); err != nil {
 				return err
 			}
 		}
@@ -177,9 +176,14 @@ func (c *Controller) Start(ctx context.Context) error {
 			if !ok {
 				continue
 			}
+
+			// use a context with timeout for launching sources and syncing caches.
+			sourceStartCtx, cancel := context.WithTimeout(ctx, c.CacheSyncTimeout)
+			defer cancel()
+
+			// WaitForSync waits for a definitive timeout, and returns if there
+			// is an error or a timeout
 			if err := syncingSource.WaitForSync(sourceStartCtx); err != nil {
-				// This code is unreachable in case of kube watches since WaitForCacheSync will never return an error
-				// Leaving it here because that could happen in the future
 				err := fmt.Errorf("failed to wait for %s caches to sync: %w", c.Name, err)
 				c.Log.Error(err, "Could not wait for Cache to sync")
 				return err

pkg/internal/controller/controller_test.go

@@ -124,15 +124,12 @@ var _ = Describe("controller", func() {
 
 		It("should error when cache sync timeout occurs", func(done Done) {
 			ctrl.CacheSyncTimeout = 10 * time.Nanosecond
+
 			c, err := cache.New(cfg, cache.Options{})
 			Expect(err).NotTo(HaveOccurred())
-			_, err = c.GetInformer(context.TODO(), &appsv1.Deployment{})
-			Expect(err).NotTo(HaveOccurred())
-			sync := false
+
 			ctrl.startWatches = []watchDescription{{
-				src: source.NewKindWithCache(&appsv1.Deployment{}, &informertest.FakeInformers{
-					Synced: &sync,
-				}),
+				src: source.NewKindWithCache(&appsv1.Deployment{}, c),
 			}}
 
 			err = ctrl.Start(context.TODO())
@@ -142,39 +139,35 @@ var _ = Describe("controller", func() {
 			close(done)
 		})
 
-		It("should not error when cache sync time out is of reasonable value", func(done Done) {
+		It("should not error when cache sync timeout is of sufficiently high", func(done Done) {
 			ctrl.CacheSyncTimeout = 1 * time.Second
+
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+
+			sourceSynced := make(chan struct{})
 			c, err := cache.New(cfg, cache.Options{})
 			Expect(err).NotTo(HaveOccurred())
 			ctrl.startWatches = []watchDescription{{
-				src: source.NewKindWithCache(&appsv1.Deployment{}, c),
+				src: &singnallingSourceWrapper{
+					SyncingSource: source.NewKindWithCache(&appsv1.Deployment{}, c),
+					cacheSyncDone: sourceSynced,
+				},
 			}}
 
-			By("running the cache and waiting for it to sync")
 			go func() {
 				defer GinkgoRecover()
-				Expect(c.Start(context.TODO())).To(Succeed())
+				Expect(c.Start(ctx)).To(Succeed())
 			}()
-			close(done)
-		})
 
-		It("should error when timeout is set to a very low value such that cache cannot sync", func(done Done) {
-			ctrl.CacheSyncTimeout = 1 * time.Nanosecond
-			c, err := cache.New(cfg, cache.Options{})
-			Expect(err).NotTo(HaveOccurred())
-			ctrl.startWatches = []watchDescription{{
-				src: source.NewKindWithCache(&appsv1.Deployment{}, c),
-			}}
-
-			By("running the cache and waiting for it to sync")
 			go func() {
 				defer GinkgoRecover()
-				err = ctrl.Start(context.TODO())
-				Expect(err).To(HaveOccurred())
-				Expect(err.Error()).To(ContainSubstring("cache did not sync"))
+				Expect(ctrl.Start(ctx)).To(Succeed())
 			}()
+
+			<-sourceSynced
 			close(done)
-		})
+		}, 10.0)
 
 		It("should call Start on sources with the appropriate EventHandler, Queue, and Predicates", func() {
 			pr1 := &predicate.Funcs{}
@@ -865,3 +858,15 @@ func (f *fakeReconciler) Reconcile(_ context.Context, r reconcile.Request) (reco
 	}
 	return res.Result, res.Err
 }
+
+type singnallingSourceWrapper struct {
+	cacheSyncDone chan struct{}
+	source.SyncingSource
+}
+
+func (s *singnallingSourceWrapper) WaitForSync(ctx context.Context) error {
+	defer func() {
+		close(s.cacheSyncDone)
+	}()
+	return s.SyncingSource.WaitForSync(ctx)
+}