Adding EndpointSliceMirroring controller

This will mirror custom Endpoints to EndpointSlices to ensure that
applications will not need to maintain both separately.

pkg/controller/endpointslicemirroring/utils_test.go

@@ -0,0 +1,93 @@
+/*
+Copyright 2020 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 endpointslicemirroring
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	v1 "k8s.io/api/core/v1"
+	discovery "k8s.io/api/discovery/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/rand"
+	"k8s.io/client-go/kubernetes/fake"
+	k8stesting "k8s.io/client-go/testing"
+)
+
+func TestNewEndpointSlice(t *testing.T) {
+	portName := "foo"
+	protocol := v1.ProtocolTCP
+
+	ports := []discovery.EndpointPort{{Name: &portName, Protocol: &protocol}}
+	addrType := discovery.AddressTypeIPv4
+
+	endpoints := v1.Endpoints{
+		ObjectMeta: metav1.ObjectMeta{Name: "foo", Namespace: "test"},
+		Subsets: []v1.EndpointSubset{{
+			Ports: []v1.EndpointPort{{Port: 80}},
+		}},
+	}
+
+	gvk := schema.GroupVersionKind{Version: "v1", Kind: "Endpoints"}
+	ownerRef := metav1.NewControllerRef(&endpoints, gvk)
+
+	expectedSlice := discovery.EndpointSlice{
+		ObjectMeta: metav1.ObjectMeta{
+			Labels: map[string]string{
+				discovery.LabelServiceName: endpoints.Name,
+				discovery.LabelManagedBy:   controllerName,
+			},
+			GenerateName:    fmt.Sprintf("%s-", endpoints.Name),
+			OwnerReferences: []metav1.OwnerReference{*ownerRef},
+			Namespace:       endpoints.Namespace,
+		},
+		Ports:       ports,
+		AddressType: addrType,
+		Endpoints:   []discovery.Endpoint{},
+	}
+	generatedSlice := newEndpointSlice(&endpoints, ports, addrType, "")
+
+	assert.EqualValues(t, expectedSlice, *generatedSlice)
+}
+
+// Test helpers
+
+func newClientset() *fake.Clientset {
+	client := fake.NewSimpleClientset()
+
+	client.PrependReactor("create", "endpointslices", k8stesting.ReactionFunc(func(action k8stesting.Action) (bool, runtime.Object, error) {
+		endpointSlice := action.(k8stesting.CreateAction).GetObject().(*discovery.EndpointSlice)
+
+		if endpointSlice.ObjectMeta.GenerateName != "" {
+			endpointSlice.ObjectMeta.Name = fmt.Sprintf("%s-%s", endpointSlice.ObjectMeta.GenerateName, rand.String(8))
+			endpointSlice.ObjectMeta.GenerateName = ""
+		}
+		endpointSlice.ObjectMeta.ResourceVersion = "100"
+
+		return false, endpointSlice, nil
+	}))
+	client.PrependReactor("update", "endpointslices", k8stesting.ReactionFunc(func(action k8stesting.Action) (bool, runtime.Object, error) {
+		endpointSlice := action.(k8stesting.CreateAction).GetObject().(*discovery.EndpointSlice)
+		endpointSlice.ObjectMeta.ResourceVersion = "200"
+		return false, endpointSlice, nil
+	}))
+
+	return client
+}