diff --git a/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go b/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go index bc6500909c3..d913154e000 100644 --- a/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go +++ b/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go @@ -482,6 +482,13 @@ func (c *Cacher) Delete( // Watch implements storage.Interface. func (c *Cacher) Watch(ctx context.Context, key string, opts storage.ListOptions) (watch.Interface, error) { pred := opts.Predicate + // If the resourceVersion is unset, ensure that the rv + // from which the watch is being served, is the latest + // one. "latest" is ensured by serving the watch from + // the underlying storage. + if opts.ResourceVersion == "" { + return c.storage.Watch(ctx, key, opts) + } watchRV, err := c.versioner.ParseResourceVersion(opts.ResourceVersion) if err != nil { return nil, err diff --git a/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher_whitebox_test.go b/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher_whitebox_test.go index 857fed8c6f7..a06ab757e6e 100644 --- a/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher_whitebox_test.go +++ b/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher_whitebox_test.go @@ -449,6 +449,37 @@ func TestGetCacheBypass(t *testing.T) { } } +func TestWatchCacheBypass(t *testing.T) { + backingStorage := &dummyStorage{} + cacher, _, err := newTestCacher(backingStorage) + if err != nil { + t.Fatalf("Couldn't create cacher: %v", err) + } + defer cacher.Stop() + + // Wait until cacher is initialized. + if err := cacher.ready.wait(); err != nil { + t.Fatalf("unexpected error waiting for the cache to be ready") + } + + // Inject error to underlying layer and check if cacher is not bypassed. + backingStorage.injectError(errDummy) + _, err = cacher.Watch(context.TODO(), "pod/ns", storage.ListOptions{ + ResourceVersion: "0", + }) + if err != nil { + t.Errorf("Watch with RV=0 should be served from cache: %v", err) + } + + // With unset RV, check if cacher is bypassed. + _, err = cacher.Watch(context.TODO(), "pod/ns", storage.ListOptions{ + ResourceVersion: "", + }) + if err != errDummy { + t.Errorf("Watch with unset RV should bypass cacher: %v", err) + } +} + func TestWatcherNotGoingBackInTime(t *testing.T) { backingStorage := &dummyStorage{} cacher, _, err := newTestCacher(backingStorage)