Try splitting configmap package (#1851)

configmap/informer/informed_watcher.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package configmap
+package informer
 
 import (
 	"errors"
@@ -31,6 +31,7 @@ import (
 	"k8s.io/client-go/informers/internalinterfaces"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/cache"
+	"knative.dev/pkg/configmap"
 )
 
 // NewInformedWatcherFromFactory watches a Kubernetes namespace for ConfigMap changes.
@@ -38,7 +39,7 @@ func NewInformedWatcherFromFactory(sif informers.SharedInformerFactory, namespac
 	return &InformedWatcher{
 		sif:      sif,
 		informer: sif.Core().V1().ConfigMaps(),
-		ManualWatcher: ManualWatcher{
+		ManualWatcher: configmap.ManualWatcher{
 			Namespace: namespace,
 		},
 		defaults: make(map[string]*corev1.ConfigMap),
@@ -97,22 +98,22 @@ type InformedWatcher struct {
 	// Embedding this struct allows us to reuse the logic
 	// of registering and notifying observers. This simplifies the
 	// InformedWatcher to just setting up the Kubernetes informer.
-	ManualWatcher
+	configmap.ManualWatcher
 }
 
 // Asserts that InformedWatcher implements Watcher.
-var _ Watcher = (*InformedWatcher)(nil)
+var _ configmap.Watcher = (*InformedWatcher)(nil)
 
 // Asserts that InformedWatcher implements DefaultingWatcher.
-var _ DefaultingWatcher = (*InformedWatcher)(nil)
+var _ configmap.DefaultingWatcher = (*InformedWatcher)(nil)
 
 // WatchWithDefault implements DefaultingWatcher.
-func (i *InformedWatcher) WatchWithDefault(cm corev1.ConfigMap, o ...Observer) {
+func (i *InformedWatcher) WatchWithDefault(cm corev1.ConfigMap, o ...configmap.Observer) {
 	i.defaults[cm.Name] = &cm
 
-	i.m.Lock()
+	i.Lock()
 	started := i.started
-	i.m.Unlock()
+	i.Unlock()
 	if started {
 		// TODO make both Watch and WatchWithDefault work after the InformedWatcher has started.
 		// This likely entails changing this to `o(&cm)` and having Watch check started, if it has
@@ -130,11 +131,12 @@ func (i *InformedWatcher) Start(stopCh <-chan struct{}) error {
 	// Pretend that all the defaulted ConfigMaps were just created. This is done before we start
 	// the informer to ensure that if a defaulted ConfigMap does exist, then the real value is
 	// processed after the default one.
-	for k := range i.observers {
+	i.ForEach(func(k string, _ []configmap.Observer) error {
 		if def, ok := i.defaults[k]; ok {
 			i.addConfigMapEvent(def)
 		}
-	}
+		return nil
+	})
 
 	if err := i.registerCallbackAndStartInformer(stopCh); err != nil {
 		return err
@@ -149,8 +151,8 @@ func (i *InformedWatcher) Start(stopCh <-chan struct{}) error {
 }
 
 func (i *InformedWatcher) registerCallbackAndStartInformer(stopCh <-chan struct{}) error {
-	i.m.Lock()
-	defer i.m.Unlock()
+	i.Lock()
+	defer i.Unlock()
 	if i.started {
 		return errors.New("watcher already started")
 	}
@@ -168,19 +170,19 @@ func (i *InformedWatcher) registerCallbackAndStartInformer(stopCh <-chan struct{
 }
 
 func (i *InformedWatcher) checkObservedResourcesExist() error {
-	i.m.RLock()
-	defer i.m.RUnlock()
+	i.RLock()
+	defer i.RUnlock()
 	// Check that all objects with Observers exist in our informers.
-	for k := range i.observers {
+	return i.ForEach(func(k string, _ []configmap.Observer) error {
 		if _, err := i.informer.Lister().ConfigMaps(i.Namespace).Get(k); err != nil {
 			if _, ok := i.defaults[k]; ok && k8serrors.IsNotFound(err) {
 				// It is defaulted, so it is OK that it doesn't exist.
-				continue
+				return nil
 			}
 			return err
 		}
-	}
-	return nil
+		return nil
+	})
 }
 
 func (i *InformedWatcher) addConfigMapEvent(obj interface{}) {

configmap/informer/informed_watcher_test.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package configmap
+package informer
 
 import (
 	"context"

configmap/manual_watcher.go

@@ -27,7 +27,7 @@ type ManualWatcher struct {
 	Namespace string
 
 	// Guards observers
-	m         sync.RWMutex
+	sync.RWMutex
 	observers map[string][]Observer
 }
 
@@ -35,8 +35,8 @@ var _ Watcher = (*ManualWatcher)(nil)
 
 // Watch implements Watcher
 func (w *ManualWatcher) Watch(name string, o ...Observer) {
-	w.m.Lock()
-	defer w.m.Unlock()
+	w.Lock()
+	defer w.Unlock()
 
 	if w.observers == nil {
 		w.observers = make(map[string][]Observer, 1)
@@ -44,6 +44,16 @@ func (w *ManualWatcher) Watch(name string, o ...Observer) {
 	w.observers[name] = append(w.observers[name], o...)
 }
 
+// Watch implements Watcher
+func (w *ManualWatcher) ForEach(f func(string, []Observer) error) error {
+	for k, v := range w.observers {
+		if err := f(k, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // Start implements Watcher
 func (w *ManualWatcher) Start(<-chan struct{}) error {
 	return nil
@@ -55,8 +65,8 @@ func (w *ManualWatcher) OnChange(configMap *corev1.ConfigMap) {
 		return
 	}
 	// Within our namespace, take the lock and see if there are any registered observers.
-	w.m.RLock()
-	defer w.m.RUnlock()
+	w.RLock()
+	defer w.RUnlock()
 	// Iterate over the observers and invoke their callbacks.
 	for _, o := range w.observers[configMap.Name] {
 		o(configMap)

configmap/manual_watcher_test.go

@@ -17,12 +17,35 @@ limitations under the License.
 package configmap
 
 import (
+	"sync"
 	"testing"
 
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+type counter struct {
+	name string
+	mu   sync.RWMutex
+	cfg  []*corev1.ConfigMap
+	wg   *sync.WaitGroup
+}
+
+func (c *counter) callback(cm *corev1.ConfigMap) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.cfg = append(c.cfg, cm)
+	if c.wg != nil {
+		c.wg.Done()
+	}
+}
+
+func (c *counter) count() int {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return len(c.cfg)
+}
+
 func TestManualStartNOOP(t *testing.T) {
 	watcher := ManualWatcher{
 		Namespace: "default",

configmap/nodep_test.go

@@ -0,0 +1,29 @@
+/*
+Copyright 2020 The Knative Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package configmap_test
+
+import (
+	"testing"
+
+	"knative.dev/pkg/depcheck"
+)
+
+func TestNoDeps(t *testing.T) {
+	depcheck.AssertNoDependency(t, map[string][]string{
+		"knative.dev/pkg/configmap": depcheck.KnownHeavyDependencies,
+	})
+}

injection/sharedmain/main.go

@@ -38,7 +38,7 @@ import (
 	"k8s.io/client-go/rest"
 
 	kubeclient "knative.dev/pkg/client/injection/kube/client"
-	"knative.dev/pkg/configmap"
+	cminformer "knative.dev/pkg/configmap/informer"
 	"knative.dev/pkg/controller"
 	"knative.dev/pkg/injection"
 	"knative.dev/pkg/leaderelection"
@@ -290,12 +290,12 @@ func CheckK8sClientMinimumVersionOrDie(ctx context.Context, logger *zap.SugaredL
 
 // SetupConfigMapWatchOrDie establishes a watch of the configmaps in the system
 // namespace that are labeled to be watched or dies by calling log.Fatalw.
-func SetupConfigMapWatchOrDie(ctx context.Context, logger *zap.SugaredLogger) *configmap.InformedWatcher {
+func SetupConfigMapWatchOrDie(ctx context.Context, logger *zap.SugaredLogger) *cminformer.InformedWatcher {
 	kc := kubeclient.Get(ctx)
 	// Create ConfigMaps watcher with optional label-based filter.
 	var cmLabelReqs []labels.Requirement
 	if cmLabel := system.ResourceLabel(); cmLabel != "" {
-		req, err := configmap.FilterConfigByLabelExists(cmLabel)
+		req, err := cminformer.FilterConfigByLabelExists(cmLabel)
 		if err != nil {
 			logger.Fatalw("Failed to generate requirement for label "+cmLabel, zap.Error(err))
 		}
@@ -303,13 +303,13 @@ func SetupConfigMapWatchOrDie(ctx context.Context, logger *zap.SugaredLogger) *c
 		cmLabelReqs = append(cmLabelReqs, *req)
 	}
 	// TODO(mattmoor): This should itself take a context and be injection-based.
-	return configmap.NewInformedWatcher(kc, system.Namespace(), cmLabelReqs...)
+	return cminformer.NewInformedWatcher(kc, system.Namespace(), cmLabelReqs...)
 }
 
 // WatchLoggingConfigOrDie establishes a watch of the logging config or dies by
 // calling log.Fatalw. Note, if the config does not exist, it will be defaulted
 // and this method will not die.
-func WatchLoggingConfigOrDie(ctx context.Context, cmw *configmap.InformedWatcher, logger *zap.SugaredLogger, atomicLevel zap.AtomicLevel, component string) {
+func WatchLoggingConfigOrDie(ctx context.Context, cmw *cminformer.InformedWatcher, logger *zap.SugaredLogger, atomicLevel zap.AtomicLevel, component string) {
 	if _, err := kubeclient.Get(ctx).CoreV1().ConfigMaps(system.Namespace()).Get(ctx, logging.ConfigMapName(),
 		metav1.GetOptions{}); err == nil {
 		cmw.Watch(logging.ConfigMapName(), logging.UpdateLevelFromConfigMap(logger, atomicLevel, component))
@@ -321,7 +321,7 @@ func WatchLoggingConfigOrDie(ctx context.Context, cmw *configmap.InformedWatcher
 // WatchObservabilityConfigOrDie establishes a watch of the observability config
 // or dies by calling log.Fatalw. Note, if the config does not exist, it will be
 // defaulted and this method will not die.
-func WatchObservabilityConfigOrDie(ctx context.Context, cmw *configmap.InformedWatcher, profilingHandler *profiling.Handler, logger *zap.SugaredLogger, component string) {
+func WatchObservabilityConfigOrDie(ctx context.Context, cmw *cminformer.InformedWatcher, profilingHandler *profiling.Handler, logger *zap.SugaredLogger, component string) {
 	if _, err := kubeclient.Get(ctx).CoreV1().ConfigMaps(system.Namespace()).Get(ctx, metrics.ConfigMapName(),
 		metav1.GetOptions{}); err == nil {
 		cmw.Watch(metrics.ConfigMapName(),
@@ -351,7 +351,7 @@ func SecretFetcher(ctx context.Context) metrics.SecretFetcher {
 // ControllersAndWebhooksFromCtors returns a list of the controllers and a list
 // of the webhooks created from the given constructors.
 func ControllersAndWebhooksFromCtors(ctx context.Context,
-	cmw *configmap.InformedWatcher,
+	cmw *cminformer.InformedWatcher,
 	ctors ...injection.ControllerConstructor) ([]*controller.Impl, []interface{}) {
 
 	// Check whether the context has been infused with a leader elector builder.

tracing/setup.go

@@ -42,7 +42,7 @@ func SetupStaticPublishing(logger *zap.SugaredLogger, serviceName string, cfg *c
 // just ensures that if generated, they are collected appropriately. This is normally done by using
 // tracing.HTTPSpanMiddleware as a middleware HTTP handler. The configuration will be dynamically
 // updated when the ConfigMap is updated.
-func SetupDynamicPublishing(logger *zap.SugaredLogger, configMapWatcher *configmap.InformedWatcher, serviceName, tracingConfigName string) error {
+func SetupDynamicPublishing(logger *zap.SugaredLogger, configMapWatcher configmap.Watcher, serviceName, tracingConfigName string) error {
 	oct := NewOpenCensusTracer(WithExporter(serviceName, logger))
 
 	tracerUpdater := func(name string, value interface{}) {