UPSTREAM: <carry>: non-cluster-aware informer integration test

Signed-off-by: Dr. Stefan Schimanski <[email protected]>

Author: sttts

pkg/cache/kcp_test.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2024 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 cache_test
+
+import (
+	"context"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	corev1 "k8s.io/api/core/v1"
+	"sigs.k8s.io/controller-runtime/pkg/cache"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+var _ = Describe("KCP cluster-unaware informer cache", func() {
+	// Test whether we can have a cluster-unaware informer cache against a single workspace.
+	// I.e. every object has a kcp.io/cluster annotation, but it should not be taken
+	// into consideration by the cache to compute the key.
+	It("should be able to get the default namespace despite kcp.io/cluster annotation", func() {
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		c, err := cache.New(cfg, cache.Options{})
+		Expect(err).NotTo(HaveOccurred())
+
+		By("Annotating the default namespace with kcp.io/cluster")
+		cl, err := client.New(cfg, client.Options{})
+		Expect(err).NotTo(HaveOccurred())
+		ns := &corev1.Namespace{}
+		err = cl.Get(ctx, client.ObjectKey{Name: "default"}, ns)
+		Expect(err).NotTo(HaveOccurred())
+		ns.Annotations = map[string]string{"kcp.io/cluster": "cluster1"}
+		err = cl.Update(ctx, ns)
+		Expect(err).NotTo(HaveOccurred())
+
+		go c.Start(ctx) //nolint:errcheck // Start is blocking, and error not relevant here.
+		c.WaitForCacheSync(ctx)
+
+		By("By getting the default namespace with the informer")
+		err = c.Get(ctx, client.ObjectKey{Name: "default"}, ns)
+		Expect(err).NotTo(HaveOccurred())
+	})
+})