e2e/apimachinery: Add an e2e test for the API Streaming feature

test/e2e/apimachinery/watchlist.go

@@ -0,0 +1,125 @@
+/*
+Copyright 2023 The Kubernetes 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 apimachinery
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"sort"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/onsi/ginkgo/v2"
+
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/kubernetes/test/e2e/framework"
+)
+
+var _ = SIGDescribe("API Streaming (aka. WatchList) [Serial] [Feature:WatchList]", func() {
+	f := framework.NewDefaultFramework("watchlist")
+	ginkgo.It("should be requested when ENABLE_CLIENT_GO_WATCH_LIST_ALPHA is set", func(ctx context.Context) {
+		prevWatchListEnvValue, wasWatchListEnvSet := os.LookupEnv("ENABLE_CLIENT_GO_WATCH_LIST_ALPHA")
+		os.Setenv("ENABLE_CLIENT_GO_WATCH_LIST_ALPHA", "true")
+		defer func() {
+			if !wasWatchListEnvSet {
+				os.Unsetenv("ENABLE_CLIENT_GO_WATCH_LIST_ALPHA")
+				return
+			}
+			os.Setenv("ENABLE_CLIENT_GO_WATCH_LIST_ALPHA", prevWatchListEnvValue)
+		}()
+		stopCh := make(chan struct{})
+		defer close(stopCh)
+		secretInformer := cache.NewSharedIndexInformer(
+			&cache.ListWatch{
+				ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
+					framework.Fail("Unexpected list call")
+					return nil, fmt.Errorf("unexpected list call")
+				},
+				WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
+					return f.ClientSet.CoreV1().Secrets(f.Namespace.Name).Watch(context.TODO(), options)
+				},
+			},
+			&v1.Secret{},
+			time.Duration(0),
+			nil,
+		)
+
+		ginkgo.By(fmt.Sprintf("Adding 5 secrets to %s namespace", f.Namespace.Name))
+		for i := 1; i <= 5; i++ {
+			_, err := f.ClientSet.CoreV1().Secrets(f.Namespace.Name).Create(ctx, newSecret(fmt.Sprintf("secret-%d", i)), metav1.CreateOptions{})
+			framework.ExpectNoError(err)
+		}
+
+		ginkgo.By("Starting the secret informer")
+		go secretInformer.Run(stopCh)
+
+		ginkgo.By("Waiting until the secret informer is fully synchronised")
+		err := wait.PollUntilContextTimeout(ctx, 100*time.Millisecond, 30*time.Second, false, func(context.Context) (done bool, err error) {
+			return secretInformer.HasSynced(), nil
+		})
+		framework.ExpectNoError(err, "Failed waiting for the secret informer in %s namespace to be synced", f.Namespace.Namespace)
+
+		ginkgo.By("Verifying if the secret informer was properly synchronised")
+		verifyStore(ctx, f, secretInformer.GetStore())
+
+		ginkgo.By("Modifying a secret and checking if the update was picked up by the secret informer")
+		secret, err := f.ClientSet.CoreV1().Secrets(f.Namespace.Name).Get(ctx, "secret-1", metav1.GetOptions{})
+		framework.ExpectNoError(err)
+		secret.StringData = map[string]string{"foo": "bar"}
+		_, err = f.ClientSet.CoreV1().Secrets(f.Namespace.Name).Update(ctx, secret, metav1.UpdateOptions{})
+		framework.ExpectNoError(err)
+		verifyStore(ctx, f, secretInformer.GetStore())
+	})
+})
+
+func verifyStore(ctx context.Context, f *framework.Framework, store cache.Store) {
+	ginkgo.By(fmt.Sprintf("Listing secrets directly from the server from %s namespace", f.Namespace.Name))
+	expectedSecretsList, err := f.ClientSet.CoreV1().Secrets(f.Namespace.Name).List(ctx, metav1.ListOptions{})
+	framework.ExpectNoError(err)
+	expectedSecrets := expectedSecretsList.Items
+
+	err = wait.PollUntilContextTimeout(ctx, 100*time.Millisecond, 30*time.Second, true, func(ctx context.Context) (done bool, err error) {
+		ginkgo.By("Comparing secrets retrieved directly from the server with the ones that have been streamed to the secret informer")
+		rawStreamedSecrets := store.List()
+		streamedSecrets := make([]v1.Secret, 0, len(rawStreamedSecrets))
+		for _, rawSecret := range rawStreamedSecrets {
+			streamedSecrets = append(streamedSecrets, *rawSecret.(*v1.Secret))
+		}
+		sort.Sort(byName(expectedSecrets))
+		sort.Sort(byName(streamedSecrets))
+		return cmp.Equal(expectedSecrets, streamedSecrets), nil
+	})
+	framework.ExpectNoError(err)
+}
+
+type byName []v1.Secret
+
+func (a byName) Len() int           { return len(a) }
+func (a byName) Less(i, j int) bool { return a[i].Name < a[j].Name }
+func (a byName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+func newSecret(name string) *v1.Secret {
+	return &v1.Secret{
+		ObjectMeta: metav1.ObjectMeta{Name: name},
+	}
+}