Add fallback to kubectl kustomize if kustomize binary isn't present

pkg/skaffold/deploy/kpt.go

@@ -226,7 +226,7 @@ func (k *KptDeployer) kustomizeBuild(ctx context.Context) error {
 		return nil
 	}
 
-	cmd := exec.CommandContext(ctx, "kustomize", buildCommandArgs([]string{"-o", filepath.Join(pipeline, k.Dir)}, k.Dir)...)
+	cmd := exec.CommandContext(ctx, "kustomize", append([]string{"build"}, buildCommandArgs([]string{"-o", filepath.Join(pipeline, k.Dir)}, k.Dir)...)...)
 	if _, err := util.RunCmdOut(cmd); err != nil {
 		return err
 	}

pkg/skaffold/deploy/kubectl/cli.go

@@ -93,6 +93,11 @@ func (c *CLI) Apply(ctx context.Context, out io.Writer, manifests ManifestList)
 	return nil
 }
 
+// Kustomize runs `kubectl kustomize` with the provided args
+func (c *CLI) Kustomize(ctx context.Context, args []string) ([]byte, error) {
+	return c.RunOut(ctx, "kustomize", c.args(nil, args...)...)
+}
+
 type getResult struct {
 	Items []struct {
 		Metadata struct {

pkg/skaffold/deploy/kustomize.go

@@ -44,6 +44,7 @@ var (
 	DefaultKustomizePath = "."
 	kustomizeFilePaths   = []string{"kustomization.yaml", "kustomization.yml", "Kustomization"}
 	basePath             = "base"
+	kustomizeBinaryCheck = kustomizeBinaryExists // For testing
 )
 
 // kustomization is the content of a kustomization.yaml file.
@@ -92,21 +93,49 @@ type secretGenerator struct {
 // KustomizeDeployer deploys workflows using kustomize CLI.
 type KustomizeDeployer struct {
 	*latest.KustomizeDeploy
-
-	kubectl            deploy.CLI
-	insecureRegistries map[string]bool
-	labels             map[string]string
-	globalConfig       string
+	kubectl             deploy.CLI
+	insecureRegistries  map[string]bool
+	labels              map[string]string
+	globalConfig        string
+	useKubectlKustomize bool
 }
 
 func NewKustomizeDeployer(cfg Config, labels map[string]string) *KustomizeDeployer {
+	kubectl := deploy.NewCLI(cfg, cfg.Pipeline().Deploy.KustomizeDeploy.Flags)
+
+	// if user has kustomize binary, prioritize that over kubectl kustomize
+	useKubectlKustomize := !kustomizeBinaryCheck() && kubectlVersionCheck(kubectl)
+
 	return &KustomizeDeployer{
-		KustomizeDeploy:    cfg.Pipeline().Deploy.KustomizeDeploy,
-		kubectl:            deploy.NewCLI(cfg, cfg.Pipeline().Deploy.KustomizeDeploy.Flags),
-		insecureRegistries: cfg.GetInsecureRegistries(),
-		globalConfig:       cfg.GlobalConfig(),
-		labels:             labels,
+		KustomizeDeploy:     cfg.Pipeline().Deploy.KustomizeDeploy,
+		kubectl:             kubectl,
+		insecureRegistries:  cfg.GetInsecureRegistries(),
+		globalConfig:        cfg.GlobalConfig(),
+		labels:              labels,
+		useKubectlKustomize: useKubectlKustomize,
+	}
+}
+
+// Check for existence of kustomize binary in user's PATH
+func kustomizeBinaryExists() bool {
+	if _, err := exec.LookPath("kustomize"); err != nil {
+		return false
+	}
+
+	return true
+}
+
+// Check that kubectl version is valid to use kubectl kustomize
+func kubectlVersionCheck(kubectl deploy.CLI) bool {
+	gt, err := kubectl.CompareVersionTo(context.Background(), 1, 14)
+	if err != nil {
+		return false
+	}
+	if gt == 1 {
+		return true
 	}
+
+	return false
 }
 
 // Deploy runs `kubectl apply` on the manifest generated by kustomize.
@@ -345,8 +374,16 @@ func pathExistsLocally(filename string, workingDir string) (bool, os.FileMode) {
 func (k *KustomizeDeployer) readManifests(ctx context.Context) (deploy.ManifestList, error) {
 	var manifests deploy.ManifestList
 	for _, kustomizePath := range k.KustomizePaths {
-		cmd := exec.CommandContext(ctx, "kustomize", buildCommandArgs(k.BuildArgs, kustomizePath)...)
-		out, err := util.RunCmdOut(cmd)
+		var out []byte
+		var err error
+
+		if k.useKubectlKustomize {
+			out, err = k.kubectl.Kustomize(ctx, buildCommandArgs(k.BuildArgs, kustomizePath))
+		} else {
+			cmd := exec.CommandContext(ctx, "kustomize", append([]string{"build"}, buildCommandArgs(k.BuildArgs, kustomizePath)...)...)
+			out, err = util.RunCmdOut(cmd)
+		}
+
 		if err != nil {
 			return nil, fmt.Errorf("kustomize build: %w", err)
 		}
@@ -361,7 +398,6 @@ func (k *KustomizeDeployer) readManifests(ctx context.Context) (deploy.ManifestL
 
 func buildCommandArgs(buildArgs []string, kustomizePath string) []string {
 	var args []string
-	args = append(args, "build")
 
 	if len(buildArgs) > 0 {
 		for _, v := range buildArgs {

pkg/skaffold/deploy/kustomize_test.go

@@ -33,14 +33,23 @@ import (
 	"github.com/GoogleContainerTools/skaffold/testutil"
 )
 
+func kustomizeAbsent() bool {
+	return false
+}
+
+func kustomizePresent() bool {
+	return true
+}
+
 func TestKustomizeDeploy(t *testing.T) {
 	tests := []struct {
-		description string
-		kustomize   latest.KustomizeDeploy
-		builds      []build.Artifact
-		commands    util.Command
-		shouldErr   bool
-		forceDeploy bool
+		description        string
+		kustomize          latest.KustomizeDeploy
+		builds             []build.Artifact
+		commands           util.Command
+		shouldErr          bool
+		forceDeploy        bool
+		kustomizeCmdAbsent bool
 	}{
 		{
 			description: "no manifest",
@@ -90,10 +99,38 @@ func TestKustomizeDeploy(t *testing.T) {
 			},
 			forceDeploy: true,
 		},
+		{
+			description: "built-in kubectl kustomize",
+			kustomize: latest.KustomizeDeploy{
+				KustomizePaths: []string{"a", "b"},
+			},
+			commands: testutil.
+				CmdRunOut("kubectl version --client -ojson", kubectlVersion118).
+				AndRunOut("kubectl --context kubecontext --namespace testNamespace kustomize a", deploymentWebYAML).
+				AndRunOut("kubectl --context kubecontext --namespace testNamespace kustomize b", deploymentAppYAML).
+				AndRunInputOut("kubectl --context kubecontext --namespace testNamespace get -f - --ignore-not-found -ojson", deploymentWebYAMLv1+"\n---\n"+deploymentAppYAMLv1, "").
+				AndRun("kubectl --context kubecontext --namespace testNamespace apply -f - --force --grace-period=0"),
+			builds: []build.Artifact{
+				{
+					ImageName: "leeroy-web",
+					Tag:       "leeroy-web:v1",
+				},
+				{
+					ImageName: "leeroy-app",
+					Tag:       "leeroy-app:v1",
+				},
+			},
+			forceDeploy:        true,
+			kustomizeCmdAbsent: true,
+		},
 	}
+
 	for _, test := range tests {
 		testutil.Run(t, test.description, func(t *testutil.T) {
 			t.Override(&util.DefaultExecCommand, test.commands)
+			if test.kustomizeCmdAbsent {
+				t.Override(&kustomizeBinaryCheck, kustomizeAbsent)
+			}
 			t.NewTempDir().
 				Chdir()
 
@@ -157,17 +194,15 @@ func TestKustomizeCleanup(t *testing.T) {
 			kustomize: latest.KustomizeDeploy{
 				KustomizePaths: []string{tmpDir.Root()},
 			},
-			commands: testutil.CmdRunOutErr(
-				"kustomize build "+tmpDir.Root(),
-				"",
-				errors.New("BUG"),
-			),
+			commands: testutil.
+				CmdRunOutErr("kustomize build "+tmpDir.Root(), "", errors.New("BUG")),
 			shouldErr: true,
 		},
 	}
 	for _, test := range tests {
 		testutil.Run(t, test.description, func(t *testutil.T) {
 			t.Override(&util.DefaultExecCommand, test.commands)
+			t.Override(&kustomizeBinaryCheck, kustomizePresent)
 
 			k := NewKustomizeDeployer(&kustomizeConfig{
 				workingDir: tmpDir.Root(),
@@ -396,49 +431,49 @@ func TestKustomizeBuildCommandArgs(t *testing.T) {
 			description:   "no BuildArgs, empty KustomizePaths ",
 			buildArgs:     []string{},
 			kustomizePath: "",
-			expectedArgs:  []string{"build"},
+			expectedArgs:  nil,
 		},
 		{
 			description:   "One BuildArg, empty KustomizePaths",
 			buildArgs:     []string{"--foo"},
 			kustomizePath: "",
-			expectedArgs:  []string{"build", "--foo"},
+			expectedArgs:  []string{"--foo"},
 		},
 		{
 			description:   "no BuildArgs, non-empty KustomizePaths",
 			buildArgs:     []string{},
 			kustomizePath: "foo",
-			expectedArgs:  []string{"build", "foo"},
+			expectedArgs:  []string{"foo"},
 		},
 		{
 			description:   "One BuildArg, non-empty KustomizePaths",
 			buildArgs:     []string{"--foo"},
 			kustomizePath: "bar",
-			expectedArgs:  []string{"build", "--foo", "bar"},
+			expectedArgs:  []string{"--foo", "bar"},
 		},
 		{
 			description:   "Multiple BuildArg, empty KustomizePaths",
 			buildArgs:     []string{"--foo", "--bar"},
 			kustomizePath: "",
-			expectedArgs:  []string{"build", "--foo", "--bar"},
+			expectedArgs:  []string{"--foo", "--bar"},
 		},
 		{
 			description:   "Multiple BuildArg with spaces, empty KustomizePaths",
 			buildArgs:     []string{"--foo bar", "--baz"},
 			kustomizePath: "",
-			expectedArgs:  []string{"build", "--foo", "bar", "--baz"},
+			expectedArgs:  []string{"--foo", "bar", "--baz"},
 		},
 		{
 			description:   "Multiple BuildArg with spaces, non-empty KustomizePaths",
 			buildArgs:     []string{"--foo bar", "--baz"},
 			kustomizePath: "barfoo",
-			expectedArgs:  []string{"build", "--foo", "bar", "--baz", "barfoo"},
+			expectedArgs:  []string{"--foo", "bar", "--baz", "barfoo"},
 		},
 		{
 			description:   "Multiple BuildArg no spaces, non-empty KustomizePaths",
 			buildArgs:     []string{"--foo", "bar", "--baz"},
 			kustomizePath: "barfoo",
-			expectedArgs:  []string{"build", "--foo", "bar", "--baz", "barfoo"},
+			expectedArgs:  []string{"--foo", "bar", "--baz", "barfoo"},
 		},
 	}