Added unit tests for mutatingwebhook.go

go.mod

@@ -8,6 +8,7 @@ require (
 	cloud.google.com/go/storage v1.34.1
 	github.com/container-storage-interface/spec v1.9.0
 	github.com/go-logr/logr v1.3.0
+	github.com/google/go-cmp v0.6.0
 	github.com/google/uuid v1.4.0
 	github.com/kubernetes-csi/csi-lib-utils v0.15.0
 	github.com/kubernetes-csi/csi-test/v5 v5.1.0
@@ -62,7 +63,6 @@ require (
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/cel-go v0.16.1 // indirect
 	github.com/google/gnostic-models v0.6.8 // indirect
-	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/google/gofuzz v1.2.1-0.20210504230335-f78f29fc09ea // indirect
 	github.com/google/pprof v0.0.0-20231101202521-4ca4178f5c7a // indirect
 	github.com/google/s2a-go v0.1.7 // indirect

pkg/webhook/mutatingwebhook_test.go

@@ -0,0 +1,195 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+Copyright 2022 Google LLC
+
+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
+
+    https://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 webhook
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+	v1 "k8s.io/api/admission/v1"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/utils/ptr"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
+)
+
+func TestValidateMutatingWebhookResponse(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name         string
+		inputPod     *corev1.Pod
+		operation    v1.Operation
+		wantResponse admission.Response
+	}{
+		{
+			name:         "Empty request test.",
+			inputPod:     nil,
+			wantResponse: admission.Errored(http.StatusBadRequest, fmt.Errorf("there is no content to decode")),
+		},
+		{
+			name:      "Different operation test.",
+			operation: v1.Update,
+			inputPod: &corev1.Pod{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{GetSidecarContainerSpec(FakeConfig())},
+					Volumes:    GetSidecarContainerVolumeSpec(),
+				},
+			},
+			wantResponse: admission.Allowed(fmt.Sprintf("No injection required for operation %v.", v1.Update)),
+		},
+		{
+			name:      "Annotation key not found test",
+			operation: v1.Create,
+			inputPod: &corev1.Pod{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{GetSidecarContainerSpec(FakeConfig())},
+					Volumes:    GetSidecarContainerVolumeSpec(),
+				},
+			},
+			wantResponse: admission.Allowed(fmt.Sprintf("The annotation key %q is not found, no injection required.", AnnotationGcsfuseVolumeEnableKey)),
+		},
+		{
+			name:      "Sidecar already injected test.",
+			operation: v1.Create,
+			inputPod: &corev1.Pod{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{GetSidecarContainerSpec(FakeConfig())},
+					Volumes:    GetSidecarContainerVolumeSpec(),
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Annotations: map[string]string{
+						"gke-gcsfuse/volumes": "true",
+					},
+				},
+			},
+			wantResponse: admission.Allowed("The sidecar container was injected, no injection required."),
+		},
+		{
+			name:         "Injection successful test.",
+			operation:    v1.Create,
+			inputPod:     validInputPod(),
+			wantResponse: wantResponse(t),
+		},
+	}
+
+	for n, tc := range testCases {
+		t.Logf("test case %v: %s", n+1, tc.name)
+		si := SidecarInjector{
+			Client:  nil,
+			Config:  FakeConfig(),
+			Decoder: admission.NewDecoder(runtime.NewScheme()),
+		}
+		request := &admission.Request{
+			AdmissionRequest: v1.AdmissionRequest{
+				Operation: tc.operation,
+			},
+		}
+		if tc.inputPod != nil {
+			request.Object = runtime.RawExtension{
+				Raw: serialize(t, tc.inputPod),
+			}
+		}
+
+		gotResponse := si.Handle(context.Background(), *request)
+
+		if err := compareResponses(tc.wantResponse, gotResponse); err != nil {
+			t.Errorf("\nGot injection result: %v, but want: %v.", gotResponse, tc.wantResponse)
+			t.Error("Details: ", err)
+		}
+	}
+}
+
+func serialize(t *testing.T, obj any) []byte {
+	t.Helper()
+	b, err := json.Marshal(obj)
+	if err != nil {
+		t.Errorf("Error serializing object %o.", obj)
+
+		return nil
+	}
+
+	return b
+}
+
+func compareResponses(wantResponse, gotResponse admission.Response) error {
+	if diff := cmp.Diff(gotResponse.String(), wantResponse.String()); diff != "" {
+		return fmt.Errorf("request args differ (-got, +want)\n%s", diff)
+	}
+	if len(wantResponse.Patches) != len(gotResponse.Patches) {
+		return fmt.Errorf("expecting %d patches, got %d patches", len(wantResponse.Patches), len(gotResponse.Patches))
+	}
+	var wantPaths, gotPaths []string
+	for i := 0; i < len(wantResponse.Patches); i++ {
+		wantPaths = append(wantPaths, wantResponse.Patches[i].Path)
+		gotPaths = append(gotPaths, gotResponse.Patches[i].Path)
+	}
+
+	if len(wantPaths) > 0 && len(gotPaths) > 0 {
+		less := func(a, b string) bool { return a > b }
+		if diff := cmp.Diff(wantPaths, gotPaths, cmpopts.SortSlices(less)); diff != "" {
+			return fmt.Errorf("unexpected pod args (-got, +want)\n%s", diff)
+		}
+	}
+
+	return nil
+}
+
+func validInputPod() *corev1.Pod {
+	return &corev1.Pod{
+		Spec: corev1.PodSpec{
+			Containers: []corev1.Container{
+				{
+					Name: "FakeContainer1",
+				},
+				{
+					Name: "FakeContainer2",
+				},
+			},
+			Volumes: []corev1.Volume{
+				{
+					Name: "FakeVolume1",
+				},
+				{
+					Name: "FakeVolume2",
+				},
+			},
+			TerminationGracePeriodSeconds: ptr.To[int64](60),
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Annotations: map[string]string{
+				"gke-gcsfuse/volumes": "true",
+			},
+		},
+	}
+}
+
+func wantResponse(t *testing.T) admission.Response {
+	t.Helper()
+	newPod := validInputPod()
+	newPod.Spec.Containers = append([]corev1.Container{GetSidecarContainerSpec(FakeConfig())}, newPod.Spec.Containers...)
+	newPod.Spec.Volumes = append(GetSidecarContainerVolumeSpec(), newPod.Spec.Volumes...)
+
+	return admission.PatchResponseFromRaw(serialize(t, validInputPod()), serialize(t, newPod))
+}