Isolated content of pkg/kustomize

pkg/commands/addpatch.go

@@ -0,0 +1,96 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/spf13/cobra"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+type addPatchOptions struct {
+	patchFilePath string
+}
+
+// newCmdAddPatch adds the name of a file containing a patch to the kustomization file.
+func newCmdAddPatch(out, errOut io.Writer, fsys fs.FileSystem) *cobra.Command {
+	var o addPatchOptions
+
+	cmd := &cobra.Command{
+		Use:   "patch",
+		Short: "Add the name of a file containing a patch to the kustomization file.",
+		Example: `
+		add patch {filepath}`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(args)
+			if err != nil {
+				return err
+			}
+			err = o.Complete(cmd, args)
+			if err != nil {
+				return err
+			}
+			return o.RunAddPatch(out, errOut, fsys)
+		},
+	}
+	return cmd
+}
+
+// Validate validates addPatch command.
+func (o *addPatchOptions) Validate(args []string) error {
+	if len(args) != 1 {
+		return errors.New("must specify a patch file")
+	}
+	o.patchFilePath = args[0]
+	return nil
+}
+
+// Complete completes addPatch command.
+func (o *addPatchOptions) Complete(cmd *cobra.Command, args []string) error {
+	return nil
+}
+
+// RunAddPatch runs addPatch command (do real work).
+func (o *addPatchOptions) RunAddPatch(out, errOut io.Writer, fsys fs.FileSystem) error {
+	_, err := fsys.Stat(o.patchFilePath)
+	if err != nil {
+		return err
+	}
+
+	mf, err := newKustomizationFile(constants.KustomizationFileName, fsys)
+	if err != nil {
+		return err
+	}
+
+	m, err := mf.read()
+	if err != nil {
+		return err
+	}
+
+	if stringInSlice(o.patchFilePath, m.Patches) {
+		return fmt.Errorf("patch %s already in kustomization file", o.patchFilePath)
+	}
+
+	m.Patches = append(m.Patches, o.patchFilePath)
+
+	return mf.write(m)
+}

pkg/commands/addpatch_test.go

@@ -0,0 +1,94 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"bytes"
+	"os"
+	"testing"
+
+	"strings"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+const (
+	patchFileName    = "myWonderfulPatch.yaml"
+	patchFileContent = `
+Lorem ipsum dolor sit amet, consectetur adipiscing elit,
+sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+`
+)
+
+func TestAddPatchHappyPath(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+	fakeFS.WriteFile(patchFileName, []byte(patchFileContent))
+	fakeFS.WriteFile(constants.KustomizationFileName, []byte(kustomizationContent))
+
+	cmd := newCmdAddPatch(buf, os.Stderr, fakeFS)
+	args := []string{patchFileName}
+	err := cmd.RunE(cmd, args)
+	if err != nil {
+		t.Errorf("unexpected cmd error: %v", err)
+	}
+	content, err := fakeFS.ReadFile(constants.KustomizationFileName)
+	if err != nil {
+		t.Errorf("unexpected read error: %v", err)
+	}
+	if !strings.Contains(string(content), patchFileName) {
+		t.Errorf("expected patch name in kustomization")
+	}
+}
+
+func TestAddPatchAlreadyThere(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+	fakeFS.WriteFile(patchFileName, []byte(patchFileContent))
+	fakeFS.WriteFile(constants.KustomizationFileName, []byte(kustomizationContent))
+
+	cmd := newCmdAddPatch(buf, os.Stderr, fakeFS)
+	args := []string{patchFileName}
+	err := cmd.RunE(cmd, args)
+	if err != nil {
+		t.Fatalf("unexpected cmd error: %v", err)
+	}
+
+	// adding an existing patch should return an error
+	err = cmd.RunE(cmd, args)
+	if err == nil {
+		t.Errorf("expected already there problem")
+	}
+	if err.Error() != "patch "+patchFileName+" already in kustomization file" {
+		t.Errorf("unexpected error %v", err)
+	}
+}
+
+func TestAddPatchNoArgs(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+
+	cmd := newCmdAddPatch(buf, os.Stderr, fakeFS)
+	err := cmd.Execute()
+	if err == nil {
+		t.Errorf("expected error: %v", err)
+	}
+	if err.Error() != "must specify a patch file" {
+		t.Errorf("incorrect error: %v", err.Error())
+	}
+}

pkg/commands/addresource.go

@@ -0,0 +1,96 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/spf13/cobra"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+type addResourceOptions struct {
+	resourceFilePath string
+}
+
+// newCmdAddResource adds the name of a file containing a resource to the kustomization file.
+func newCmdAddResource(out, errOut io.Writer, fsys fs.FileSystem) *cobra.Command {
+	var o addResourceOptions
+
+	cmd := &cobra.Command{
+		Use:   "resource",
+		Short: "Add the name of a file containing a resource to the kustomization file.",
+		Example: `
+		add resource {filepath}`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(args)
+			if err != nil {
+				return err
+			}
+			err = o.Complete(cmd, args)
+			if err != nil {
+				return err
+			}
+			return o.RunAddResource(out, errOut, fsys)
+		},
+	}
+	return cmd
+}
+
+// Validate validates addResource command.
+func (o *addResourceOptions) Validate(args []string) error {
+	if len(args) != 1 {
+		return errors.New("must specify a resource file")
+	}
+	o.resourceFilePath = args[0]
+	return nil
+}
+
+// Complete completes addResource command.
+func (o *addResourceOptions) Complete(cmd *cobra.Command, args []string) error {
+	return nil
+}
+
+// RunAddResource runs addResource command (do real work).
+func (o *addResourceOptions) RunAddResource(out, errOut io.Writer, fsys fs.FileSystem) error {
+	_, err := fsys.Stat(o.resourceFilePath)
+	if err != nil {
+		return err
+	}
+
+	mf, err := newKustomizationFile(constants.KustomizationFileName, fsys)
+	if err != nil {
+		return err
+	}
+
+	m, err := mf.read()
+	if err != nil {
+		return err
+	}
+
+	if stringInSlice(o.resourceFilePath, m.Resources) {
+		return fmt.Errorf("resource %s already in kustomization file", o.resourceFilePath)
+	}
+
+	m.Resources = append(m.Resources, o.resourceFilePath)
+
+	return mf.write(m)
+}

pkg/commands/addresource_test.go

@@ -0,0 +1,110 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"bytes"
+	"os"
+	"testing"
+
+	"strings"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+const (
+	resourceFileName    = "myWonderfulResource.yaml"
+	resourceFileContent = `
+Lorem ipsum dolor sit amet, consectetur adipiscing elit,
+sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+`
+	kustomizationContent = `namePrefix: some-prefix
+# Labels to add to all objects and selectors.
+# These labels would also be used to form the selector for apply --prune
+# Named differently than “labels” to avoid confusion with metadata for this object
+commonLabels:
+  app: helloworld
+commonAnnotations:
+  note: This is an example annotation
+resources: []
+#- service.yaml
+#- ../some-dir/
+# There could also be configmaps in Base, which would make these overlays
+configMapGenerator: []
+# There could be secrets in Base, if just using a fork/rebase workflow
+secretGenerator: []
+`
+)
+
+func TestAddResourceHappyPath(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+	fakeFS.WriteFile(resourceFileName, []byte(resourceFileContent))
+	fakeFS.WriteFile(constants.KustomizationFileName, []byte(kustomizationContent))
+
+	cmd := newCmdAddResource(buf, os.Stderr, fakeFS)
+	args := []string{resourceFileName}
+	err := cmd.RunE(cmd, args)
+	if err != nil {
+		t.Errorf("unexpected cmd error: %v", err)
+	}
+	content, err := fakeFS.ReadFile(constants.KustomizationFileName)
+	if err != nil {
+		t.Errorf("unexpected read error: %v", err)
+	}
+	if !strings.Contains(string(content), resourceFileName) {
+		t.Errorf("expected resource name in kustomization")
+	}
+}
+
+func TestAddResourceAlreadyThere(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+	fakeFS.WriteFile(resourceFileName, []byte(resourceFileContent))
+	fakeFS.WriteFile(constants.KustomizationFileName, []byte(kustomizationContent))
+
+	cmd := newCmdAddResource(buf, os.Stderr, fakeFS)
+	args := []string{resourceFileName}
+	err := cmd.RunE(cmd, args)
+	if err != nil {
+		t.Fatalf("unexpected cmd error: %v", err)
+	}
+
+	// adding an existing resource should return an error
+	err = cmd.RunE(cmd, args)
+	if err == nil {
+		t.Errorf("expected already there problem")
+	}
+	if err.Error() != "resource "+resourceFileName+" already in kustomization file" {
+		t.Errorf("unexpected error %v", err)
+	}
+}
+
+func TestAddResourceNoArgs(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+
+	cmd := newCmdAddResource(buf, os.Stderr, fakeFS)
+	err := cmd.Execute()
+	if err == nil {
+		t.Errorf("expected error: %v", err)
+	}
+	if err.Error() != "must specify a resource file" {
+		t.Errorf("incorrect error: %v", err.Error())
+	}
+}

pkg/commands/build.go

@@ -0,0 +1,110 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+
+	"errors"
+
+	"k8s.io/kubectl/pkg/kustomize/app"
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	kutil "k8s.io/kubectl/pkg/kustomize/util"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+	"k8s.io/kubectl/pkg/loader"
+)
+
+type buildOptions struct {
+	kustomizationPath string
+}
+
+// newCmdBuild creates a new build command.
+func newCmdBuild(out, errOut io.Writer, fs fs.FileSystem) *cobra.Command {
+	var o buildOptions
+
+	cmd := &cobra.Command{
+		Use:   "build [path]",
+		Short: "Print current configuration per contents of " + constants.KustomizationFileName,
+		Example: "Use the file somedir/" + constants.KustomizationFileName +
+			" to generate a set of api resources:\nbuild somedir/",
+		Run: func(cmd *cobra.Command, args []string) {
+			err := o.Validate(args)
+			if err != nil {
+				fmt.Fprintf(errOut, "error: %v\n", err)
+				os.Exit(1)
+			}
+			err = o.RunBuild(out, errOut, fs)
+			if err != nil {
+				fmt.Fprintf(errOut, "error: %v\n", err)
+				os.Exit(1)
+			}
+		},
+	}
+	return cmd
+}
+
+// Validate validates build command.
+func (o *buildOptions) Validate(args []string) error {
+	if len(args) > 1 {
+		return errors.New("specify one path to " + constants.KustomizationFileName)
+	}
+	if len(args) == 0 {
+		o.kustomizationPath = "./"
+		return nil
+	}
+	o.kustomizationPath = args[0]
+	return nil
+}
+
+// RunBuild runs build command.
+func (o *buildOptions) RunBuild(out, errOut io.Writer, fs fs.FileSystem) error {
+	l := loader.Init([]loader.SchemeLoader{loader.NewFileLoader(fs)})
+
+	absPath, err := filepath.Abs(o.kustomizationPath)
+	if err != nil {
+		return err
+	}
+
+	rootLoader, err := l.New(absPath)
+	if err != nil {
+		return err
+	}
+
+	application, err := app.New(rootLoader)
+	if err != nil {
+		return err
+	}
+
+	allResources, err := application.Resources()
+
+	if err != nil {
+		return err
+	}
+
+	// Output the objects.
+	res, err := kutil.Encode(allResources)
+	if err != nil {
+		return err
+	}
+	_, err = out.Write(res)
+	return err
+}

pkg/commands/build_test.go

@@ -0,0 +1,152 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/ghodss/yaml"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+type buildTestCase struct {
+	Description string   `yaml:"description"`
+	Args        []string `yaml:"args"`
+	Filename    string   `yaml:"filename"`
+	// path to the file that contains the expected output
+	ExpectedStdout string `yaml:"expectedStdout"`
+	ExpectedError  string `yaml:"expectedError"`
+}
+
+func TestBuildValidate(t *testing.T) {
+	var cases = []struct {
+		name  string
+		args  []string
+		path  string
+		erMsg string
+	}{
+		{"noargs", []string{}, "./", ""},
+		{"file", []string{"beans"}, "beans", ""},
+		{"path", []string{"a/b/c"}, "a/b/c", ""},
+		{"path", []string{"too", "many"},
+			"", "specify one path to " + constants.KustomizationFileName},
+	}
+	for _, mycase := range cases {
+		opts := buildOptions{}
+		e := opts.Validate(mycase.args)
+		if len(mycase.erMsg) > 0 {
+			if e == nil {
+				t.Errorf("%s: Expected an error %v", mycase.name, mycase.erMsg)
+			}
+			if e.Error() != mycase.erMsg {
+				t.Errorf("%s: Expected error %s, but got %v", mycase.name, mycase.erMsg, e)
+			}
+			continue
+		}
+		if e != nil {
+			t.Errorf("%s: unknown error %v", mycase.name, e)
+			continue
+		}
+		if opts.kustomizationPath != mycase.path {
+			t.Errorf("%s: expected path '%s', got '%s'", mycase.name, mycase.path, opts.kustomizationPath)
+		}
+	}
+}
+
+func TestBuild(t *testing.T) {
+	const updateEnvVar = "UPDATE_KUSTOMIZE_EXPECTED_DATA"
+	updateKustomizeExpected := os.Getenv(updateEnvVar) == "true"
+	fs := fs.MakeRealFS()
+
+	testcases := sets.NewString()
+	filepath.Walk("testdata", func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if path == "testdata" {
+			return nil
+		}
+		name := filepath.Base(path)
+		if info.IsDir() {
+			if strings.HasPrefix(name, "testcase-") {
+				testcases.Insert(strings.TrimPrefix(name, "testcase-"))
+			}
+			return filepath.SkipDir
+		}
+		return nil
+	})
+	// sanity check that we found the right folder
+	if !testcases.Has("simple") {
+		t.Fatalf("Error locating testcases")
+	}
+
+	for _, testcaseName := range testcases.List() {
+		t.Run(testcaseName, func(t *testing.T) {
+			name := testcaseName
+			testcase := buildTestCase{}
+			testcaseDir := filepath.Join("testdata", "testcase-"+name)
+			testcaseData, err := ioutil.ReadFile(filepath.Join(testcaseDir, "test.yaml"))
+			if err != nil {
+				t.Fatalf("%s: %v", name, err)
+			}
+			if err := yaml.Unmarshal(testcaseData, &testcase); err != nil {
+				t.Fatalf("%s: %v", name, err)
+			}
+
+			ops := &buildOptions{
+				kustomizationPath: testcase.Filename,
+			}
+			buf := bytes.NewBuffer([]byte{})
+			err = ops.RunBuild(buf, os.Stderr, fs)
+			switch {
+			case err != nil && len(testcase.ExpectedError) == 0:
+				t.Errorf("unexpected error: %v", err)
+			case err != nil && len(testcase.ExpectedError) != 0:
+				if !strings.Contains(err.Error(), testcase.ExpectedError) {
+					t.Errorf("expected error to contain %q but got: %v", testcase.ExpectedError, err)
+				}
+				return
+			case err == nil && len(testcase.ExpectedError) != 0:
+				t.Errorf("unexpected no error")
+			}
+
+			actualBytes := buf.Bytes()
+			if !updateKustomizeExpected {
+				expectedBytes, err := ioutil.ReadFile(testcase.ExpectedStdout)
+				if err != nil {
+					t.Errorf("unexpected error: %v", err)
+				}
+				if !reflect.DeepEqual(actualBytes, expectedBytes) {
+					t.Errorf("%s\ndoesn't equal expected:\n%s\n", actualBytes, expectedBytes)
+				}
+			} else {
+				ioutil.WriteFile(testcase.ExpectedStdout, actualBytes, 0644)
+			}
+
+		})
+	}
+
+}

pkg/commands/commands.go

@@ -0,0 +1,126 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"flag"
+	"io"
+	"os"
+
+	"github.com/spf13/cobra"
+	"k8s.io/kubectl/cmd/kustomize/version"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+// NewDefaultCommand returns the default (aka root) command for kustomize command.
+func NewDefaultCommand() *cobra.Command {
+	fsys := fs.MakeRealFS()
+	stdOut, stdErr := os.Stdout, os.Stderr
+
+	c := &cobra.Command{
+		Use:   "kustomize",
+		Short: "kustomize manages declarative configuration of Kubernetes",
+		Long: `
+kustomize manages declarative configuration of Kubernetes.
+
+More info at https://github.com/kubernetes/kubectl/tree/master/cmd/kustomize
+`,
+	}
+
+	c.AddCommand(
+		newCmdBuild(stdOut, stdErr, fsys),
+		newCmdDiff(stdOut, stdErr, fsys),
+		newCmdEdit(stdOut, stdErr, fsys),
+		version.NewCmdVersion(stdOut),
+	)
+	c.PersistentFlags().AddGoFlagSet(flag.CommandLine)
+
+	// Workaround for this issue:
+	// https://github.com/kubernetes/kubernetes/issues/17162
+	flag.CommandLine.Parse([]string{})
+	return c
+}
+
+// newCmdEdit returns an instance of 'edit' subcommand.
+func newCmdEdit(stdOut, stdErr io.Writer, fsys fs.FileSystem) *cobra.Command {
+	c := &cobra.Command{
+		Use:   "edit",
+		Short: "Edits a kustomization file",
+		Long:  "",
+		Example: `
+	# Adds a configmap to the kustomization file
+	kustomize edit add configmap NAME --from-literal=k=v
+
+	# Sets the nameprefix field
+	kustomize edit set nameprefix <prefix-value>
+`,
+		Args: cobra.MinimumNArgs(1),
+	}
+	c.AddCommand(
+		newCmdAdd(stdOut, stdErr, fsys),
+		newCmdSet(stdOut, stdErr, fsys),
+	)
+	return c
+}
+
+// newAddCommand returns an instance of 'add' subcommand.
+func newCmdAdd(stdOut, stdErr io.Writer, fsys fs.FileSystem) *cobra.Command {
+	c := &cobra.Command{
+		Use:   "add",
+		Short: "Adds configmap/resource/secret to the kustomization file.",
+		Long:  "",
+		Example: `
+	# Adds a configmap to the kustomization file
+	kustomize edit add configmap NAME --from-literal=k=v
+
+	# Adds a secret to the kustomization file
+	kustomize edit add secret NAME --from-literal=k=v
+
+	# Adds a resource to the kustomization
+	kustomize edit add resource <filepath>
+
+	# Adds a patch to the kustomization
+	kustomize edit add patch <filepath>
+`,
+		Args: cobra.MinimumNArgs(1),
+	}
+	c.AddCommand(
+		newCmdAddResource(stdOut, stdErr, fsys),
+		newCmdAddPatch(stdOut, stdErr, fsys),
+		newCmdAddConfigMap(stdErr, fsys),
+	)
+	return c
+}
+
+// newSetCommand returns an instance of 'set' subcommand.
+func newCmdSet(stdOut, stdErr io.Writer, fsys fs.FileSystem) *cobra.Command {
+	c := &cobra.Command{
+		Use:   "set",
+		Short: "Sets the value of different fields in kustomization file.",
+		Long:  "",
+		Example: `
+	# Sets the nameprefix field
+	kustomize edit set nameprefix <prefix-value>
+`,
+		Args: cobra.MinimumNArgs(1),
+	}
+
+	c.AddCommand(
+		newCmdSetNamePrefix(stdOut, stdErr, fsys),
+	)
+	return c
+}

pkg/commands/configmap.go

@@ -0,0 +1,135 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/spf13/cobra"
+
+	"k8s.io/kubectl/pkg/kustomize/configmapandsecret"
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/types"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+func newCmdAddConfigMap(errOut io.Writer, fsys fs.FileSystem) *cobra.Command {
+	var config dataConfig
+	cmd := &cobra.Command{
+		Use:   "configmap NAME [--from-file=[key=]source] [--from-literal=key1=value1]",
+		Short: "Adds a configmap to the kustomization file.",
+		Long:  "",
+		Example: `
+	# Adds a configmap to the kustomization file (with a specified key)
+	kustomize edit add configmap my-configmap --from-file=my-key=file/path --from-literal=my-literal=12345
+
+	# Adds a configmap to the kustomization file (key is the filename)
+	kustomize edit add configmap my-configmap --from-file=file/path
+
+	# Adds a configmap from env-file
+	kustomize edit add configmap my-configmap --from-env-file=env/path.env
+`,
+		RunE: func(_ *cobra.Command, args []string) error {
+			err := config.Validate(args)
+			if err != nil {
+				return err
+			}
+
+			// Load in the kustomization file.
+			mf, err := newKustomizationFile(constants.KustomizationFileName, fsys)
+			if err != nil {
+				return err
+			}
+
+			m, err := mf.read()
+			if err != nil {
+				return err
+			}
+
+			// Add the config map to the kustomization file.
+			err = addConfigMap(m, config)
+			if err != nil {
+				return err
+			}
+
+			// Write out the kustomization file with added configmap.
+			return mf.write(m)
+		},
+	}
+
+	cmd.Flags().StringSliceVar(
+		&config.FileSources,
+		"from-file",
+		[]string{},
+		"Key file can be specified using its file path, in which case file basename will be used as configmap key, or optionally with a key and file path, in which case the given key will be used.  Specifying a directory will iterate each named file in the directory whose basename is a valid configmap key.")
+	cmd.Flags().StringArrayVar(
+		&config.LiteralSources,
+		"from-literal",
+		[]string{},
+		"Specify a key and literal value to insert in configmap (i.e. mykey=somevalue)")
+	cmd.Flags().StringVar(
+		&config.EnvFileSource,
+		"from-env-file",
+		"",
+		"Specify the path to a file to read lines of key=val pairs to create a configmap (i.e. a Docker .env file).")
+
+	return cmd
+}
+
+// addConfigMap updates a configmap within a kustomization file, using the data in config.
+// Note: error may leave kustomization file in an undefined state. Suggest passing a copy
+// of kustomization file.
+func addConfigMap(m *types.Kustomization, config dataConfig) error {
+	cm := getOrCreateConfigMap(m, config.Name)
+
+	err := mergeData(&cm.DataSources, config)
+	if err != nil {
+		return err
+	}
+
+	// Validate by trying to create corev1.configmap.
+	_, _, err = configmapandsecret.MakeConfigmapAndGenerateName(*cm)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func getOrCreateConfigMap(m *types.Kustomization, name string) *types.ConfigMapArgs {
+	for i, v := range m.ConfigMapGenerator {
+		if name == v.Name {
+			return &m.ConfigMapGenerator[i]
+		}
+	}
+	// config map not found, create new one and add it to the kustomization file.
+	cm := &types.ConfigMapArgs{Name: name}
+	m.ConfigMapGenerator = append(m.ConfigMapGenerator, *cm)
+	return &m.ConfigMapGenerator[len(m.ConfigMapGenerator)-1]
+}
+
+func mergeData(src *types.DataSources, config dataConfig) error {
+	src.LiteralSources = append(src.LiteralSources, config.LiteralSources...)
+	src.FileSources = append(src.FileSources, config.FileSources...)
+	if src.EnvSource != "" && src.EnvSource != config.EnvFileSource {
+		return fmt.Errorf("updating existing env source '%s' not allowed.", src.EnvSource)
+	}
+	src.EnvSource = config.EnvFileSource
+
+	return nil
+}

pkg/commands/configmap_test.go

@@ -0,0 +1,129 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"testing"
+
+	"k8s.io/kubectl/pkg/kustomize/types"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+func TestNewAddConfigMapIsNotNil(t *testing.T) {
+	if newCmdAddConfigMap(nil, fs.MakeFakeFS()) == nil {
+		t.Fatal("newCmdAddConfigMap shouldn't be nil")
+	}
+}
+
+func TestGetOrCreateConfigMap(t *testing.T) {
+	cmName := "test-config-name"
+
+	kustomization := &types.Kustomization{
+		NamePrefix: "test-name-prefix",
+	}
+
+	if len(kustomization.ConfigMapGenerator) != 0 {
+		t.Fatal("Initial kustomization should not have any configmaps")
+	}
+	cm := getOrCreateConfigMap(kustomization, cmName)
+
+	if cm == nil {
+		t.Fatalf("ConfigMap should always be non-nil")
+	}
+
+	if len(kustomization.ConfigMapGenerator) != 1 {
+		t.Fatalf("Kustomization should have newly created configmap")
+	}
+
+	if &kustomization.ConfigMapGenerator[len(kustomization.ConfigMapGenerator)-1] != cm {
+		t.Fatalf("Pointer address for newly inserted configmap should be same")
+	}
+
+	existingCM := getOrCreateConfigMap(kustomization, cmName)
+
+	if existingCM != cm {
+		t.Fatalf("should have returned an existing cm with name: %v", cmName)
+	}
+
+	if len(kustomization.ConfigMapGenerator) != 1 {
+		t.Fatalf("Should not insert configmap for an existing name: %v", cmName)
+	}
+}
+
+func TestMergeData_LiteralSources(t *testing.T) {
+	ds := &types.DataSources{}
+
+	err := mergeData(ds, dataConfig{LiteralSources: []string{"k1=v1"}})
+	if err != nil {
+		t.Fatalf("Merge initial literal source should not return error")
+	}
+
+	if len(ds.LiteralSources) != 1 {
+		t.Fatalf("Initial literal source should have been added")
+	}
+
+	err = mergeData(ds, dataConfig{LiteralSources: []string{"k2=v2"}})
+	if err != nil {
+		t.Fatalf("Merge second literal source should not return error")
+	}
+
+	if len(ds.LiteralSources) != 2 {
+		t.Fatalf("Second literal source should have been added")
+	}
+}
+
+func TestMergeData_FileSources(t *testing.T) {
+	ds := &types.DataSources{}
+
+	err := mergeData(ds, dataConfig{FileSources: []string{"file1"}})
+	if err != nil {
+		t.Fatalf("Merge initial file source should not return error")
+	}
+
+	if len(ds.FileSources) != 1 {
+		t.Fatalf("Initial file source should have been added")
+	}
+
+	err = mergeData(ds, dataConfig{FileSources: []string{"file2"}})
+	if err != nil {
+		t.Fatalf("Merge second file source should not return error")
+	}
+
+	if len(ds.FileSources) != 2 {
+		t.Fatalf("Second file source should have been added")
+	}
+}
+
+func TestMergeData_EnvSource(t *testing.T) {
+	envFileName := "env1"
+	envFileName2 := "env2"
+	ds := &types.DataSources{}
+
+	err := mergeData(ds, dataConfig{EnvFileSource: envFileName})
+	if err != nil {
+		t.Fatalf("Merge initial env source should not return error")
+	}
+
+	if ds.EnvSource != envFileName {
+		t.Fatalf("Initial env source filename should have been added")
+	}
+
+	err = mergeData(ds, dataConfig{EnvFileSource: envFileName2})
+	if err == nil {
+		t.Fatalf("Updating env source should return an error")
+	}
+}

pkg/commands/data_config.go

@@ -0,0 +1,50 @@
+/*
+Copyright 2018 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 commands
+
+import (
+	"fmt"
+)
+
+// dataConfig encapsulates the options for add configmap/Secret commands.
+type dataConfig struct {
+	// Name of configMap/Secret (required)
+	Name string
+	// FileSources to derive the configMap/Secret from (optional)
+	FileSources []string
+	// LiteralSources to derive the configMap/Secret from (optional)
+	LiteralSources []string
+	// EnvFileSource to derive the configMap/Secret from (optional)
+	// TODO: Rationalize this name with Generic.EnvSource
+	EnvFileSource string
+}
+
+// Validate validates required fields are set to support structured generation.
+func (a *dataConfig) Validate(args []string) error {
+	if len(args) != 1 {
+		return fmt.Errorf("name must be specified once")
+	}
+	a.Name = args[0]
+	if len(a.EnvFileSource) == 0 && len(a.FileSources) == 0 && len(a.LiteralSources) == 0 {
+		return fmt.Errorf("at least from-env-file, or from-file or from-literal must be set")
+	}
+	if len(a.EnvFileSource) > 0 && (len(a.FileSources) > 0 || len(a.LiteralSources) > 0) {
+		return fmt.Errorf("from-env-file cannot be combined with from-file or from-literal")
+	}
+	// TODO: Should we check if the path exists? if it's valid, if it's within the same (sub-)directory?
+	return nil
+}

pkg/commands/data_config_test.go

@@ -0,0 +1,83 @@
+/*
+Copyright 2018 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 commands
+
+import (
+	"testing"
+)
+
+func TestDataConfigValidation_NoName(t *testing.T) {
+	config := dataConfig{}
+
+	if config.Validate([]string{}) == nil {
+		t.Fatal("Validation should fail if no name is specified")
+	}
+}
+
+func TestDataConfigValidation_MoreThanOneName(t *testing.T) {
+	config := dataConfig{}
+
+	if config.Validate([]string{"name", "othername"}) == nil {
+		t.Fatal("Validation should fail if more than one name is specified")
+	}
+}
+
+func TestDataConfigValidation_Flags(t *testing.T) {
+	tests := []struct {
+		name       string
+		config     dataConfig
+		shouldFail bool
+	}{
+		{
+			name: "env-file-source and literal are both set",
+			config: dataConfig{
+				LiteralSources: []string{"one", "two"},
+				EnvFileSource:  "three",
+			},
+			shouldFail: true,
+		},
+		{
+			name: "env-file-source and from-file are both set",
+			config: dataConfig{
+				FileSources:   []string{"one", "two"},
+				EnvFileSource: "three",
+			},
+			shouldFail: true,
+		},
+		{
+			name:       "we don't have any option set",
+			config:     dataConfig{},
+			shouldFail: true,
+		},
+		{
+			name: "we have from-file and literal ",
+			config: dataConfig{
+				LiteralSources: []string{"one", "two"},
+				FileSources:    []string{"three", "four"},
+			},
+			shouldFail: false,
+		},
+	}
+
+	for _, test := range tests {
+		if test.config.Validate([]string{"name"}) == nil && test.shouldFail {
+			t.Fatalf("Validation should fail if %s", test.name)
+		} else if test.config.Validate([]string{"name"}) != nil && !test.shouldFail {
+			t.Fatalf("Validation should succeed if %s", test.name)
+		}
+	}
+}

pkg/commands/diff.go

@@ -0,0 +1,130 @@
+/*
+Copyright 2018 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 commands
+
+import (
+	"errors"
+	"io"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+
+	"k8s.io/kubectl/pkg/kustomize/app"
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+	"k8s.io/kubectl/pkg/loader"
+	"k8s.io/utils/exec"
+)
+
+type diffOptions struct {
+	kustomizationPath string
+}
+
+// newCmdDiff makes the diff command.
+func newCmdDiff(out, errOut io.Writer, fs fs.FileSystem) *cobra.Command {
+	var o diffOptions
+
+	cmd := &cobra.Command{
+		Use:     "diff",
+		Short:   "diff between transformed resources and untransformed resources",
+		Long:    "diff between transformed resources and untransformed resources and the subpackages are all transformed.",
+		Example: `diff -f .`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(cmd, args)
+			if err != nil {
+				return err
+			}
+			err = o.Complete(cmd, args)
+			if err != nil {
+				return err
+			}
+			return o.RunDiff(out, errOut, fs)
+		},
+	}
+
+	cmd.Flags().StringVarP(
+		&o.kustomizationPath,
+		"filename",
+		"f",
+		"",
+		"Specify a directory containing "+constants.KustomizationFileName)
+	cmd.MarkFlagRequired("filename")
+	return cmd
+}
+
+// Validate validates diff command.
+func (o *diffOptions) Validate(cmd *cobra.Command, args []string) error {
+	if len(args) > 0 {
+		return errors.New("The diff command takes no arguments.")
+	}
+	return nil
+}
+
+// Complete completes diff command.
+func (o *diffOptions) Complete(cmd *cobra.Command, args []string) error {
+	return nil
+}
+
+// RunDiff gets the differences between Application.Resources() and Application.RawResources().
+func (o *diffOptions) RunDiff(out, errOut io.Writer, fs fs.FileSystem) error {
+	printer := util.Printer{}
+	diff := util.DiffProgram{
+		Exec:   exec.New(),
+		Stdout: out,
+		Stderr: errOut,
+	}
+
+	l := loader.Init([]loader.SchemeLoader{loader.NewFileLoader(fs)})
+
+	absPath, err := filepath.Abs(o.kustomizationPath)
+	if err != nil {
+		return err
+	}
+
+	rootLoader, err := l.New(absPath)
+	if err != nil {
+		return err
+	}
+
+	application, err := app.New(rootLoader)
+	if err != nil {
+		return err
+	}
+	resources, err := application.Resources()
+	if err != nil {
+		return err
+	}
+	rawResources, err := application.RawResources()
+	if err != nil {
+		return err
+	}
+
+	transformedDir, err := util.WriteToDir(resources, "transformed", printer)
+	if err != nil {
+		return err
+	}
+	defer transformedDir.Delete()
+
+	noopDir, err := util.WriteToDir(rawResources, "noop", printer)
+	if err != nil {
+		return err
+	}
+	defer noopDir.Delete()
+
+	return diff.Run(noopDir.Name, transformedDir.Name)
+}

pkg/commands/diff_test.go

@@ -0,0 +1,124 @@
+/*
+Copyright 2018 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 commands
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"regexp"
+	"strings"
+	"testing"
+
+	"github.com/ghodss/yaml"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+type DiffTestCase struct {
+	Description string   `yaml:"description"`
+	Args        []string `yaml:"args"`
+	Filename    string   `yaml:"filename"`
+	// path to the file that contains the expected output
+	ExpectedDiff  string `yaml:"expectedDiff"`
+	ExpectedError string `yaml:"expectedError"`
+}
+
+func TestDiff(t *testing.T) {
+	const updateEnvVar = "UPDATE_KUSTOMIZE_EXPECTED_DATA"
+	updateKustomizeExpected := os.Getenv(updateEnvVar) == "true"
+
+	noopDir, _ := regexp.Compile(`/tmp/noop-[0-9]*/`)
+	transformedDir, _ := regexp.Compile(`/tmp/transformed-[0-9]*/`)
+	timestamp, _ := regexp.Compile(`[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1]) (2[0-3]|[01][0-9]):[0-5][0-9]:[0-5][0-9].[0-9]* [+-]{1}[0-9]{4}`)
+
+	fs := fs.MakeRealFS()
+
+	testcases := sets.NewString()
+	filepath.Walk("testdata", func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if path == "testdata" {
+			return nil
+		}
+		name := filepath.Base(path)
+		if info.IsDir() {
+			if strings.HasPrefix(name, "testcase-") {
+				testcases.Insert(strings.TrimPrefix(name, "testcase-"))
+			}
+			return filepath.SkipDir
+		}
+		return nil
+	})
+	// sanity check that we found the right folder
+	if !testcases.Has("simple") {
+		t.Fatalf("Error locating testcases")
+	}
+
+	for _, testcaseName := range testcases.List() {
+		t.Run(testcaseName, func(t *testing.T) {
+			name := testcaseName
+			testcase := DiffTestCase{}
+			testcaseDir := filepath.Join("testdata", "testcase-"+name)
+			testcaseData, err := ioutil.ReadFile(filepath.Join(testcaseDir, "test.yaml"))
+			if err != nil {
+				t.Fatalf("%s: %v", name, err)
+			}
+			if err := yaml.Unmarshal(testcaseData, &testcase); err != nil {
+				t.Fatalf("%s: %v", name, err)
+			}
+
+			diffOps := &diffOptions{
+				kustomizationPath: testcase.Filename,
+			}
+			buf := bytes.NewBuffer([]byte{})
+			err = diffOps.RunDiff(buf, os.Stderr, fs)
+			switch {
+			case err != nil && len(testcase.ExpectedError) == 0:
+				t.Errorf("unexpected error: %v", err)
+			case err != nil && len(testcase.ExpectedError) != 0:
+				if !strings.Contains(err.Error(), testcase.ExpectedError) {
+					t.Errorf("expected error to contain %q but got: %v", testcase.ExpectedError, err)
+				}
+				return
+			case err == nil && len(testcase.ExpectedError) != 0:
+				t.Errorf("unexpected no error")
+			}
+
+			actualString := string(buf.Bytes())
+			actualString = noopDir.ReplaceAllString(actualString, "/tmp/noop/")
+			actualString = transformedDir.ReplaceAllString(actualString, "/tmp/transformed/")
+			actualString = timestamp.ReplaceAllString(actualString, "YYYY-MM-DD HH:MM:SS")
+			actualBytes := []byte(actualString)
+			if !updateKustomizeExpected {
+				expectedBytes, err := ioutil.ReadFile(testcase.ExpectedDiff)
+				if err != nil {
+					t.Errorf("unexpected error: %v", err)
+				}
+				if !reflect.DeepEqual(actualBytes, expectedBytes) {
+					t.Errorf("%s\ndoesn't equal expected:\n%s\n", actualBytes, expectedBytes)
+				}
+			} else {
+				ioutil.WriteFile(testcase.ExpectedDiff, actualBytes, 0644)
+			}
+
+		})
+	}
+}

pkg/commands/init.go

@@ -0,0 +1,96 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"fmt"
+	"io"
+
+	"errors"
+
+	"github.com/spf13/cobra"
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+const kustomizationTemplate = `
+namePrefix: some-prefix
+# Labels to add to all objects and selectors.
+# These labels would also be used to form the selector for apply --prune
+# Named differently than “labels” to avoid confusion with metadata for this object
+commonLabels:
+  app: helloworld
+commonAnnotations:
+  note: This is an example annotation
+resources: []
+#- service.yaml
+#- ../some-dir/
+# There could also be configmaps in Base, which would make these overlays
+configMapGenerator: []
+# There could be secrets in Base, if just using a fork/rebase workflow
+secretGenerator: []
+`
+
+type initOptions struct {
+}
+
+// NewCmdInit makes the init command.
+func newCmdInit(out, errOut io.Writer, fs fs.FileSystem) *cobra.Command {
+	var o initOptions
+
+	cmd := &cobra.Command{
+		Use:   "init",
+		Short: "Creates a file called \"" + constants.KustomizationFileName + "\" in the current directory",
+		Long: "Creates a file called \"" +
+			constants.KustomizationFileName + "\" in the current directory with example values.",
+		Example:      `init`,
+		SilenceUsage: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(cmd, args)
+			if err != nil {
+				return err
+			}
+			err = o.Complete(cmd, args)
+			if err != nil {
+				return err
+			}
+			return o.RunInit(out, errOut, fs)
+		},
+	}
+	return cmd
+}
+
+// Validate validates init command.
+func (o *initOptions) Validate(cmd *cobra.Command, args []string) error {
+	if len(args) > 0 {
+		return errors.New("The init command takes no arguments.")
+	}
+	return nil
+}
+
+// Complete completes init command.
+func (o *initOptions) Complete(cmd *cobra.Command, args []string) error {
+	return nil
+}
+
+// RunInit writes a kustomization file.
+func (o *initOptions) RunInit(out, errOut io.Writer, fs fs.FileSystem) error {
+	if _, err := fs.Stat(constants.KustomizationFileName); err == nil {
+		return fmt.Errorf("%q already exists", constants.KustomizationFileName)
+	}
+	return fs.WriteFile(constants.KustomizationFileName, []byte(kustomizationTemplate))
+}

pkg/commands/set_name_prefix.go

@@ -0,0 +1,88 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"errors"
+	"io"
+
+	"github.com/spf13/cobra"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+type setNamePrefixOptions struct {
+	prefix string
+}
+
+// newCmdSetNamePrefix sets the value of the namePrefix field in the kustomization.
+func newCmdSetNamePrefix(out, errOut io.Writer, fsys fs.FileSystem) *cobra.Command {
+	var o setNamePrefixOptions
+
+	cmd := &cobra.Command{
+		Use:   "nameprefix",
+		Short: "Sets the value of the namePrefix field in the kustomization file.",
+		Example: `
+The command
+  set nameprefix acme-
+will add the field "namePrefix: acme-" to the kustomization file if it doesn't exist,
+and overwrite the value with "acme-" if the field does exist.
+`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			err := o.Validate(args)
+			if err != nil {
+				return err
+			}
+			err = o.Complete(cmd, args)
+			if err != nil {
+				return err
+			}
+			return o.RunSetNamePrefix(out, errOut, fsys)
+		},
+	}
+	return cmd
+}
+
+// Validate validates setNamePrefix command.
+func (o *setNamePrefixOptions) Validate(args []string) error {
+	if len(args) != 1 {
+		return errors.New("must specify exactly one prefix value")
+	}
+	// TODO: add further validation on the value.
+	o.prefix = args[0]
+	return nil
+}
+
+// Complete completes setNamePrefix command.
+func (o *setNamePrefixOptions) Complete(cmd *cobra.Command, args []string) error {
+	return nil
+}
+
+// RunSetNamePrefix runs setNamePrefix command (does real work).
+func (o *setNamePrefixOptions) RunSetNamePrefix(out, errOut io.Writer, fsys fs.FileSystem) error {
+	mf, err := newKustomizationFile(constants.KustomizationFileName, fsys)
+	if err != nil {
+		return err
+	}
+	m, err := mf.read()
+	if err != nil {
+		return err
+	}
+	m.NamePrefix = o.prefix
+	return mf.write(m)
+}

pkg/commands/set_name_prefix_test.go

@@ -0,0 +1,66 @@
+/*
+Copyright 2017 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 commands
+
+import (
+	"bytes"
+	"os"
+	"testing"
+
+	"strings"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+const (
+	goodPrefixValue = "acme-"
+)
+
+func TestSetNamePrefixHappyPath(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+	fakeFS.WriteFile(constants.KustomizationFileName, []byte(kustomizationContent))
+
+	cmd := newCmdSetNamePrefix(buf, os.Stderr, fakeFS)
+	args := []string{goodPrefixValue}
+	err := cmd.RunE(cmd, args)
+	if err != nil {
+		t.Errorf("unexpected cmd error: %v", err)
+	}
+	content, err := fakeFS.ReadFile(constants.KustomizationFileName)
+	if err != nil {
+		t.Errorf("unexpected read error: %v", err)
+	}
+	if !strings.Contains(string(content), goodPrefixValue) {
+		t.Errorf("expected prefix value in kustomization file")
+	}
+}
+
+func TestSetNamePrefixNoArgs(t *testing.T) {
+	buf := bytes.NewBuffer([]byte{})
+	fakeFS := fs.MakeFakeFS()
+
+	cmd := newCmdSetNamePrefix(buf, os.Stderr, fakeFS)
+	err := cmd.Execute()
+	if err == nil {
+		t.Errorf("expected error: %v", err)
+	}
+	if err.Error() != "must specify exactly one prefix value" {
+		t.Errorf("incorrect error: %v", err.Error())
+	}
+}

pkg/commands/testdata/testcase-base-only/expected.diff

@@ -0,0 +1,58 @@
+diff -u -N /tmp/noop/apps_v1beta2_Deployment_nginx.yaml /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml
+--- /tmp/noop/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
+@@ -1,14 +1,27 @@
+ apiVersion: apps/v1beta2
+ kind: Deployment
+ metadata:
++  annotations:
++    note: This is a test annotation
+   labels:
+-    app: nginx
+-  name: nginx
++    app: mynginx
++    org: example.com
++    team: foo
++  name: team-foo-nginx
+ spec:
++  selector:
++    matchLabels:
++      app: mynginx
++      org: example.com
++      team: foo
+   template:
+     metadata:
++      annotations:
++        note: This is a test annotation
+       labels:
+-        app: nginx
++        app: mynginx
++        org: example.com
++        team: foo
+     spec:
+       containers:
+       - image: nginx
+diff -u -N /tmp/noop/v1_Service_nginx.yaml /tmp/transformed/v1_Service_nginx.yaml
+--- /tmp/noop/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
+@@ -1,11 +1,17 @@
+ apiVersion: v1
+ kind: Service
+ metadata:
++  annotations:
++    note: This is a test annotation
+   labels:
+-    app: nginx
+-  name: nginx
++    app: mynginx
++    org: example.com
++    team: foo
++  name: team-foo-nginx
+ spec:
+   ports:
+   - port: 80
+   selector:
+-    app: nginx
++    app: mynginx
++    org: example.com
++    team: foo

pkg/commands/testdata/testcase-base-only/expected.yaml

@@ -0,0 +1,46 @@
+apiVersion: v1
+kind: Service
+metadata:
+  annotations:
+    note: This is a test annotation
+  labels:
+    app: mynginx
+    org: example.com
+    team: foo
+  name: team-foo-nginx
+spec:
+  ports:
+  - port: 80
+  selector:
+    app: mynginx
+    org: example.com
+    team: foo
+---
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  annotations:
+    note: This is a test annotation
+  labels:
+    app: mynginx
+    org: example.com
+    team: foo
+  name: team-foo-nginx
+spec:
+  selector:
+    matchLabels:
+      app: mynginx
+      org: example.com
+      team: foo
+  template:
+    metadata:
+      annotations:
+        note: This is a test annotation
+      labels:
+        app: mynginx
+        org: example.com
+        team: foo
+    spec:
+      containers:
+      - image: nginx
+        name: nginx

pkg/commands/testdata/testcase-base-only/in/deployment.yaml

@@ -0,0 +1,15 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  template:
+    metadata:
+      labels:
+        app: nginx
+    spec:
+      containers:
+      - name: nginx
+        image: nginx

pkg/commands/testdata/testcase-base-only/in/kustomization.yaml

@@ -0,0 +1,10 @@
+namePrefix: team-foo-
+commonLabels:
+  app: mynginx
+  org: example.com
+  team: foo
+commonAnnotations:
+  note: This is a test annotation
+resources:
+  - deployment.yaml
+  - service.yaml

pkg/commands/testdata/testcase-base-only/in/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  ports:
+    - port: 80
+  selector:
+    app: nginx

pkg/commands/testdata/testcase-base-only/test.yaml

@@ -0,0 +1,5 @@
+description: base only
+args: []
+filename: testdata/testcase-base-only/in
+expectedStdout: testdata/testcase-base-only/expected.yaml
+expectedDiff: testdata/testcase-base-only/expected.diff

pkg/commands/testdata/testcase-multiple-patches-conflict/in/overlay/deployment-patch1.yaml

@@ -0,0 +1,20 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+spec:
+  template:
+    spec:
+      containers:
+      - name: nginx
+        env:
+        - name: ENABLE_FEATURE_FOO
+          value: TRUE
+      volumes:
+      - name: nginx-persistent-storage
+        emptyDir: null
+        gcePersistentDisk:
+          pdName: nginx-persistent-storage
+      - configMap:
+          name: configmap-in-overlay
+        name: configmap-in-overlay

pkg/commands/testdata/testcase-multiple-patches-conflict/in/overlay/deployment-patch2.yaml

@@ -0,0 +1,12 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+spec:
+  template:
+    spec:
+      containers:
+      - name: nginx
+        env:
+        - name: ENABLE_FEATURE_FOO
+          value: FALSE

pkg/commands/testdata/testcase-multiple-patches-conflict/in/overlay/kustomization.yaml

@@ -0,0 +1,12 @@
+namePrefix: staging-
+commonLabels:
+  env: staging
+patches:
+  - deployment-patch2.yaml
+  - deployment-patch1.yaml
+bases:
+  - ../package/
+configMapGenerator:
+  - name: configmap-in-overlay
+    literals:
+      - hello=world

pkg/commands/testdata/testcase-multiple-patches-conflict/in/package/deployment.yaml

@@ -0,0 +1,24 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  template:
+    metadata:
+      labels:
+        app: nginx
+    spec:
+      containers:
+      - name: nginx
+        image: nginx
+        volumeMounts:
+        - name: nginx-persistent-storage
+          mountPath: /tmp/ps
+      volumes:
+      - name: nginx-persistent-storage
+        emptyDir: {}
+      - configMap:
+          name: configmap-in-base
+        name: configmap-in-base

pkg/commands/testdata/testcase-multiple-patches-conflict/in/package/kustomization.yaml

@@ -0,0 +1,14 @@
+namePrefix: team-foo-
+commonLabels:
+  app: mynginx
+  org: example.com
+  team: foo
+commonAnnotations:
+  note: This is a test annotation
+resources:
+  - deployment.yaml
+  - service.yaml
+configMapGenerator:
+  - name: configmap-in-base
+    literals:
+      - foo=bar

pkg/commands/testdata/testcase-multiple-patches-conflict/in/package/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  ports:
+    - port: 80
+  selector:
+    app: nginx

pkg/commands/testdata/testcase-multiple-patches-conflict/test.yaml

@@ -0,0 +1,4 @@
+description: conflict between multiple patches
+args: []
+filename: testdata/testcase-multiple-patches-conflict/in/overlay/
+expectedError: conflict

pkg/commands/testdata/testcase-multiple-patches-noconflict/expected.diff

@@ -0,0 +1,99 @@
+diff -u -N /tmp/noop/apps_v1beta2_Deployment_nginx.yaml /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml
+--- /tmp/noop/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
+@@ -5,13 +5,15 @@
+     note: This is a test annotation
+   labels:
+     app: mynginx
++    env: staging
+     org: example.com
+     team: foo
+-  name: team-foo-nginx
++  name: staging-team-foo-nginx
+ spec:
+   selector:
+     matchLabels:
+       app: mynginx
++      env: staging
+       org: example.com
+       team: foo
+   template:
+@@ -20,18 +22,30 @@
+         note: This is a test annotation
+       labels:
+         app: mynginx
++        env: staging
+         org: example.com
+         team: foo
+     spec:
+       containers:
+-      - image: nginx
++      - env:
++        - name: ANOTHERENV
++          value: FOO
++        - name: ENVKEY
++          value: ENVVALUE
++        image: nginx:latest
+         name: nginx
+         volumeMounts:
+         - mountPath: /tmp/ps
+           name: nginx-persistent-storage
++      - image: sidecar
++        name: sidecar
+       volumes:
+-      - emptyDir: {}
++      - gcePersistentDisk:
++          pdName: nginx-persistent-storage
+         name: nginx-persistent-storage
+       - configMap:
+-          name: team-foo-configmap-in-base-bbdmdh7m8t
++          name: staging-configmap-in-overlay-k7cbc75tg8
++        name: configmap-in-overlay
++      - configMap:
++          name: staging-team-foo-configmap-in-base-g7k6gt2889
+         name: configmap-in-base
+diff -u -N /tmp/noop/v1_ConfigMap_configmap-in-base.yaml /tmp/transformed/v1_ConfigMap_configmap-in-base.yaml
+--- /tmp/noop/v1_ConfigMap_configmap-in-base.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_ConfigMap_configmap-in-base.yaml	YYYY-MM-DD HH:MM:SS
+@@ -8,6 +8,7 @@
+   creationTimestamp: null
+   labels:
+     app: mynginx
++    env: staging
+     org: example.com
+     team: foo
+-  name: team-foo-configmap-in-base-bbdmdh7m8t
++  name: staging-team-foo-configmap-in-base-g7k6gt2889
+diff -u -N /tmp/noop/v1_ConfigMap_configmap-in-overlay.yaml /tmp/transformed/v1_ConfigMap_configmap-in-overlay.yaml
+--- /tmp/noop/v1_ConfigMap_configmap-in-overlay.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_ConfigMap_configmap-in-overlay.yaml	YYYY-MM-DD HH:MM:SS
+@@ -0,0 +1,9 @@
++apiVersion: v1
++data:
++  hello: world
++kind: ConfigMap
++metadata:
++  creationTimestamp: null
++  labels:
++    env: staging
++  name: staging-configmap-in-overlay-k7cbc75tg8
+diff -u -N /tmp/noop/v1_Service_nginx.yaml /tmp/transformed/v1_Service_nginx.yaml
+--- /tmp/noop/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
+@@ -5,13 +5,15 @@
+     note: This is a test annotation
+   labels:
+     app: mynginx
++    env: staging
+     org: example.com
+     team: foo
+-  name: team-foo-nginx
++  name: staging-team-foo-nginx
+ spec:
+   ports:
+   - port: 80
+   selector:
+     app: mynginx
++    env: staging
+     org: example.com
+     team: foo

pkg/commands/testdata/testcase-multiple-patches-noconflict/expected.yaml

@@ -0,0 +1,96 @@
+apiVersion: v1
+data:
+  foo: bar
+kind: ConfigMap
+metadata:
+  annotations:
+    note: This is a test annotation
+  creationTimestamp: null
+  labels:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: foo
+  name: staging-team-foo-configmap-in-base-g7k6gt2889
+---
+apiVersion: v1
+data:
+  hello: world
+kind: ConfigMap
+metadata:
+  creationTimestamp: null
+  labels:
+    env: staging
+  name: staging-configmap-in-overlay-k7cbc75tg8
+---
+apiVersion: v1
+kind: Service
+metadata:
+  annotations:
+    note: This is a test annotation
+  labels:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: foo
+  name: staging-team-foo-nginx
+spec:
+  ports:
+  - port: 80
+  selector:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: foo
+---
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  annotations:
+    note: This is a test annotation
+  labels:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: foo
+  name: staging-team-foo-nginx
+spec:
+  selector:
+    matchLabels:
+      app: mynginx
+      env: staging
+      org: example.com
+      team: foo
+  template:
+    metadata:
+      annotations:
+        note: This is a test annotation
+      labels:
+        app: mynginx
+        env: staging
+        org: example.com
+        team: foo
+    spec:
+      containers:
+      - env:
+        - name: ANOTHERENV
+          value: FOO
+        - name: ENVKEY
+          value: ENVVALUE
+        image: nginx:latest
+        name: nginx
+        volumeMounts:
+        - mountPath: /tmp/ps
+          name: nginx-persistent-storage
+      - image: sidecar
+        name: sidecar
+      volumes:
+      - gcePersistentDisk:
+          pdName: nginx-persistent-storage
+        name: nginx-persistent-storage
+      - configMap:
+          name: staging-configmap-in-overlay-k7cbc75tg8
+        name: configmap-in-overlay
+      - configMap:
+          name: staging-team-foo-configmap-in-base-g7k6gt2889
+        name: configmap-in-base

pkg/commands/testdata/testcase-multiple-patches-noconflict/in/overlay/deployment-patch1.yaml

@@ -0,0 +1,21 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+spec:
+  template:
+    spec:
+      containers:
+      - name: nginx
+        image: nginx:latest
+        env:
+        - name: ENVKEY
+          value: ENVVALUE
+      volumes:
+      - name: nginx-persistent-storage
+        emptyDir: null
+        gcePersistentDisk:
+          pdName: nginx-persistent-storage
+      - configMap:
+          name: configmap-in-overlay
+        name: configmap-in-overlay

pkg/commands/testdata/testcase-multiple-patches-noconflict/in/overlay/deployment-patch2.yaml

@@ -0,0 +1,16 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+spec:
+  template:
+    spec:
+      containers:
+      - name: nginx
+        env:
+        - name: ANOTHERENV
+          value: FOO
+      - name: sidecar
+        image: sidecar
+      volumes:
+      - name: nginx-persistent-storage

pkg/commands/testdata/testcase-multiple-patches-noconflict/in/overlay/kustomization.yaml

@@ -0,0 +1,12 @@
+namePrefix: staging-
+commonLabels:
+  env: staging
+patches:
+  - deployment-patch1.yaml
+  - deployment-patch2.yaml
+bases:
+  - ../package/
+configMapGenerator:
+  - name: configmap-in-overlay
+    literals:
+      - hello=world

pkg/commands/testdata/testcase-multiple-patches-noconflict/in/package/deployment.yaml

@@ -0,0 +1,24 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  template:
+    metadata:
+      labels:
+        app: nginx
+    spec:
+      containers:
+      - name: nginx
+        image: nginx
+        volumeMounts:
+        - name: nginx-persistent-storage
+          mountPath: /tmp/ps
+      volumes:
+      - name: nginx-persistent-storage
+        emptyDir: {}
+      - configMap:
+          name: configmap-in-base
+        name: configmap-in-base

pkg/commands/testdata/testcase-multiple-patches-noconflict/in/package/kustomization.yaml

@@ -0,0 +1,14 @@
+namePrefix: team-foo-
+commonLabels:
+  app: mynginx
+  org: example.com
+  team: foo
+commonAnnotations:
+  note: This is a test annotation
+resources:
+  - deployment.yaml
+  - service.yaml
+configMapGenerator:
+  - name: configmap-in-base
+    literals:
+      - foo=bar

pkg/commands/testdata/testcase-multiple-patches-noconflict/in/package/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  ports:
+    - port: 80
+  selector:
+    app: nginx

pkg/commands/testdata/testcase-multiple-patches-noconflict/test.yaml

@@ -0,0 +1,5 @@
+description: multiple patches no conflict
+args: []
+filename: testdata/testcase-multiple-patches-noconflict/in/overlay/
+expectedStdout: testdata/testcase-multiple-patches-noconflict/expected.yaml
+expectedDiff: testdata/testcase-multiple-patches-noconflict/expected.diff

pkg/commands/testdata/testcase-simple/expected.diff

@@ -0,0 +1,154 @@
+diff -u -N /tmp/noop/extensions_v1beta1_Deployment_mungebot.yaml /tmp/transformed/extensions_v1beta1_Deployment_mungebot.yaml
+--- /tmp/noop/extensions_v1beta1_Deployment_mungebot.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/extensions_v1beta1_Deployment_mungebot.yaml	YYYY-MM-DD HH:MM:SS
+@@ -3,28 +3,68 @@
+ metadata:
+   annotations:
+     baseAnno: This is an base annotation
++    note: This is a test annotation
+   labels:
+     app: mungebot
+     foo: bar
+-  name: baseprefix-mungebot
++    org: kubernetes
++    repo: test-infra
++  name: test-infra-baseprefix-mungebot
+ spec:
+-  replicas: 1
++  replicas: 2
+   selector:
+     matchLabels:
++      app: mungebot
+       foo: bar
++      org: kubernetes
++      repo: test-infra
+   template:
+     metadata:
+       annotations:
+         baseAnno: This is an base annotation
++        note: This is a test annotation
+       labels:
+         app: mungebot
+         foo: bar
++        org: kubernetes
++        repo: test-infra
+     spec:
+       containers:
+       - env:
++        - name: FOO
++          valueFrom:
++            configMapKeyRef:
++              key: somekey
++              name: test-infra-app-env-bh449c299k
++        - name: BAR
++          valueFrom:
++            secretKeyRef:
++              key: somekey
++              name: test-infra-app-tls-6hkmhf2224
+         - name: foo
+           value: bar
+-        image: nginx
++        image: nginx:1.7.9
+         name: nginx
+         ports:
+         - containerPort: 80
++      - envFrom:
++        - configMapRef:
++            name: someConfigMap
++        - configMapRef:
++            name: test-infra-app-env-bh449c299k
++        - secretRef:
++            name: test-infra-app-tls-6hkmhf2224
++        image: busybox
++        name: busybox
++        volumeMounts:
++        - mountPath: /tmp/env
++          name: app-env
++        - mountPath: /tmp/tls
++          name: app-tls
++      volumes:
++      - configMap:
++          name: test-infra-app-env-bh449c299k
++        name: app-env
++      - name: app-tls
++        secret:
++          secretName: test-infra-app-tls-6hkmhf2224
+diff -u -N /tmp/noop/v1_ConfigMap_app-config.yaml /tmp/transformed/v1_ConfigMap_app-config.yaml
+--- /tmp/noop/v1_ConfigMap_app-config.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_ConfigMap_app-config.yaml	YYYY-MM-DD HH:MM:SS
+@@ -0,0 +1,15 @@
++apiVersion: v1
++data:
++  app-init.ini: |
++    FOO=bar
++    BAR=baz
++kind: ConfigMap
++metadata:
++  annotations:
++    note: This is a test annotation
++  creationTimestamp: null
++  labels:
++    app: mungebot
++    org: kubernetes
++    repo: test-infra
++  name: test-infra-app-config-hf5424hg8g
+diff -u -N /tmp/noop/v1_ConfigMap_app-env.yaml /tmp/transformed/v1_ConfigMap_app-env.yaml
+--- /tmp/noop/v1_ConfigMap_app-env.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_ConfigMap_app-env.yaml	YYYY-MM-DD HH:MM:SS
+@@ -0,0 +1,14 @@
++apiVersion: v1
++data:
++  DB_PASSWORD: somepw
++  DB_USERNAME: admin
++kind: ConfigMap
++metadata:
++  annotations:
++    note: This is a test annotation
++  creationTimestamp: null
++  labels:
++    app: mungebot
++    org: kubernetes
++    repo: test-infra
++  name: test-infra-app-env-bh449c299k
+diff -u -N /tmp/noop/v1_Secret_app-tls.yaml /tmp/transformed/v1_Secret_app-tls.yaml
+--- /tmp/noop/v1_Secret_app-tls.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_Secret_app-tls.yaml	YYYY-MM-DD HH:MM:SS
+@@ -0,0 +1,15 @@
++apiVersion: v1
++data:
++  tls.crt: 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
++  tls.key: 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
++kind: Secret
++metadata:
++  annotations:
++    note: This is a test annotation
++  creationTimestamp: null
++  labels:
++    app: mungebot
++    org: kubernetes
++    repo: test-infra
++  name: test-infra-app-tls-6hkmhf2224
++type: kubernetes.io/tls
+diff -u -N /tmp/noop/v1_Service_mungebot-service.yaml /tmp/transformed/v1_Service_mungebot-service.yaml
+--- /tmp/noop/v1_Service_mungebot-service.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_Service_mungebot-service.yaml	YYYY-MM-DD HH:MM:SS
+@@ -3,13 +3,18 @@
+ metadata:
+   annotations:
+     baseAnno: This is an base annotation
++    note: This is a test annotation
+   labels:
+     app: mungebot
+     foo: bar
+-  name: baseprefix-mungebot-service
++    org: kubernetes
++    repo: test-infra
++  name: test-infra-baseprefix-mungebot-service
+ spec:
+   ports:
+   - port: 7002
+   selector:
+     app: mungebot
+     foo: bar
++    org: kubernetes
++    repo: test-infra

pkg/commands/testdata/testcase-simple/expected.yaml

@@ -0,0 +1,138 @@
+apiVersion: v1
+data:
+  app-init.ini: |
+    FOO=bar
+    BAR=baz
+kind: ConfigMap
+metadata:
+  annotations:
+    note: This is a test annotation
+  creationTimestamp: null
+  labels:
+    app: mungebot
+    org: kubernetes
+    repo: test-infra
+  name: test-infra-app-config-hf5424hg8g
+---
+apiVersion: v1
+data:
+  DB_PASSWORD: somepw
+  DB_USERNAME: admin
+kind: ConfigMap
+metadata:
+  annotations:
+    note: This is a test annotation
+  creationTimestamp: null
+  labels:
+    app: mungebot
+    org: kubernetes
+    repo: test-infra
+  name: test-infra-app-env-bh449c299k
+---
+apiVersion: v1
+data:
+  tls.crt: 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
+  tls.key: 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
+kind: Secret
+metadata:
+  annotations:
+    note: This is a test annotation
+  creationTimestamp: null
+  labels:
+    app: mungebot
+    org: kubernetes
+    repo: test-infra
+  name: test-infra-app-tls-6hkmhf2224
+type: kubernetes.io/tls
+---
+apiVersion: v1
+kind: Service
+metadata:
+  annotations:
+    baseAnno: This is an base annotation
+    note: This is a test annotation
+  labels:
+    app: mungebot
+    foo: bar
+    org: kubernetes
+    repo: test-infra
+  name: test-infra-baseprefix-mungebot-service
+spec:
+  ports:
+  - port: 7002
+  selector:
+    app: mungebot
+    foo: bar
+    org: kubernetes
+    repo: test-infra
+---
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  annotations:
+    baseAnno: This is an base annotation
+    note: This is a test annotation
+  labels:
+    app: mungebot
+    foo: bar
+    org: kubernetes
+    repo: test-infra
+  name: test-infra-baseprefix-mungebot
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: mungebot
+      foo: bar
+      org: kubernetes
+      repo: test-infra
+  template:
+    metadata:
+      annotations:
+        baseAnno: This is an base annotation
+        note: This is a test annotation
+      labels:
+        app: mungebot
+        foo: bar
+        org: kubernetes
+        repo: test-infra
+    spec:
+      containers:
+      - env:
+        - name: FOO
+          valueFrom:
+            configMapKeyRef:
+              key: somekey
+              name: test-infra-app-env-bh449c299k
+        - name: BAR
+          valueFrom:
+            secretKeyRef:
+              key: somekey
+              name: test-infra-app-tls-6hkmhf2224
+        - name: foo
+          value: bar
+        image: nginx:1.7.9
+        name: nginx
+        ports:
+        - containerPort: 80
+      - envFrom:
+        - configMapRef:
+            name: someConfigMap
+        - configMapRef:
+            name: test-infra-app-env-bh449c299k
+        - secretRef:
+            name: test-infra-app-tls-6hkmhf2224
+        image: busybox
+        name: busybox
+        volumeMounts:
+        - mountPath: /tmp/env
+          name: app-env
+        - mountPath: /tmp/tls
+          name: app-tls
+      volumes:
+      - configMap:
+          name: test-infra-app-env-bh449c299k
+        name: app-env
+      - name: app-tls
+        secret:
+          secretName: test-infra-app-tls-6hkmhf2224

pkg/commands/testdata/testcase-simple/test.yaml

@@ -0,0 +1,5 @@
+description: simple
+args: []
+filename: ../examples/simple/instances/exampleinstance/
+expectedStdout: testdata/testcase-simple/expected.yaml
+expectedDiff: testdata/testcase-simple/expected.diff

pkg/commands/testdata/testcase-single-overlay/expected.diff

@@ -0,0 +1,128 @@
+diff -u -N /tmp/noop/apps_v1beta2_Deployment_nginx.yaml /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml
+--- /tmp/noop/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
+@@ -5,23 +5,26 @@
+     note: This is a test annotation
+   labels:
+     app: mynginx
++    env: staging
+     org: example.com
+-    team: foo
+-  name: team-foo-nginx
++    team: override-foo
++  name: staging-team-foo-nginx
+ spec:
+   selector:
+     matchLabels:
+       app: mynginx
++      env: staging
+       org: example.com
+-      team: foo
++      team: override-foo
+   template:
+     metadata:
+       annotations:
+         note: This is a test annotation
+       labels:
+         app: mynginx
++        env: staging
+         org: example.com
+-        team: foo
++        team: override-foo
+     spec:
+       containers:
+       - image: nginx
+@@ -30,8 +33,12 @@
+         - mountPath: /tmp/ps
+           name: nginx-persistent-storage
+       volumes:
+-      - emptyDir: {}
++      - gcePersistentDisk:
++          pdName: nginx-persistent-storage
+         name: nginx-persistent-storage
+       - configMap:
+-          name: team-foo-configmap-in-base-bbdmdh7m8t
++          name: staging-configmap-in-overlay-k7cbc75tg8
++        name: configmap-in-overlay
++      - configMap:
++          name: staging-team-foo-configmap-in-base-gh9d7t85gb
+         name: configmap-in-base
+diff -u -N /tmp/noop/v1_ConfigMap_configmap-in-base.yaml /tmp/transformed/v1_ConfigMap_configmap-in-base.yaml
+--- /tmp/noop/v1_ConfigMap_configmap-in-base.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_ConfigMap_configmap-in-base.yaml	YYYY-MM-DD HH:MM:SS
+@@ -1,6 +1,6 @@
+ apiVersion: v1
+ data:
+-  foo: bar
++  foo: override-bar
+ kind: ConfigMap
+ metadata:
+   annotations:
+@@ -8,6 +8,7 @@
+   creationTimestamp: null
+   labels:
+     app: mynginx
++    env: staging
+     org: example.com
+-    team: foo
+-  name: team-foo-configmap-in-base-bbdmdh7m8t
++    team: override-foo
++  name: staging-team-foo-configmap-in-base-gh9d7t85gb
+diff -u -N /tmp/noop/v1_ConfigMap_configmap-in-overlay.yaml /tmp/transformed/v1_ConfigMap_configmap-in-overlay.yaml
+--- /tmp/noop/v1_ConfigMap_configmap-in-overlay.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_ConfigMap_configmap-in-overlay.yaml	YYYY-MM-DD HH:MM:SS
+@@ -0,0 +1,10 @@
++apiVersion: v1
++data:
++  hello: world
++kind: ConfigMap
++metadata:
++  creationTimestamp: null
++  labels:
++    env: staging
++    team: override-foo
++  name: staging-configmap-in-overlay-k7cbc75tg8
+diff -u -N /tmp/noop/v1_Secret_secret-in-base.yaml /tmp/transformed/v1_Secret_secret-in-base.yaml
+--- /tmp/noop/v1_Secret_secret-in-base.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_Secret_secret-in-base.yaml	YYYY-MM-DD HH:MM:SS
+@@ -1,6 +1,7 @@
+ apiVersion: v1
+ data:
+   password: c29tZXB3
++  proxy: aGFwcm94eQ==
+   username: YWRtaW4=
+ kind: Secret
+ metadata:
+@@ -9,7 +10,8 @@
+   creationTimestamp: null
+   labels:
+     app: mynginx
++    env: staging
+     org: example.com
+-    team: foo
+-  name: team-foo-secret-in-base-tkm7hhtf8d
++    team: override-foo
++  name: staging-team-foo-secret-in-base-c8db7gk2m2
+ type: Opaque
+diff -u -N /tmp/noop/v1_Service_nginx.yaml /tmp/transformed/v1_Service_nginx.yaml
+--- /tmp/noop/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
++++ /tmp/transformed/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
+@@ -5,13 +5,15 @@
+     note: This is a test annotation
+   labels:
+     app: mynginx
++    env: staging
+     org: example.com
+-    team: foo
+-  name: team-foo-nginx
++    team: override-foo
++  name: staging-team-foo-nginx
+ spec:
+   ports:
+   - port: 80
+   selector:
+     app: mynginx
++    env: staging
+     org: example.com
+-    team: foo
++    team: override-foo

pkg/commands/testdata/testcase-single-overlay/expected.yaml

@@ -0,0 +1,108 @@
+apiVersion: v1
+data:
+  foo: override-bar
+kind: ConfigMap
+metadata:
+  annotations:
+    note: This is a test annotation
+  creationTimestamp: null
+  labels:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: override-foo
+  name: staging-team-foo-configmap-in-base-gh9d7t85gb
+---
+apiVersion: v1
+data:
+  hello: world
+kind: ConfigMap
+metadata:
+  creationTimestamp: null
+  labels:
+    env: staging
+    team: override-foo
+  name: staging-configmap-in-overlay-k7cbc75tg8
+---
+apiVersion: v1
+data:
+  password: c29tZXB3
+  proxy: aGFwcm94eQ==
+  username: YWRtaW4=
+kind: Secret
+metadata:
+  annotations:
+    note: This is a test annotation
+  creationTimestamp: null
+  labels:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: override-foo
+  name: staging-team-foo-secret-in-base-c8db7gk2m2
+type: Opaque
+---
+apiVersion: v1
+kind: Service
+metadata:
+  annotations:
+    note: This is a test annotation
+  labels:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: override-foo
+  name: staging-team-foo-nginx
+spec:
+  ports:
+  - port: 80
+  selector:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: override-foo
+---
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  annotations:
+    note: This is a test annotation
+  labels:
+    app: mynginx
+    env: staging
+    org: example.com
+    team: override-foo
+  name: staging-team-foo-nginx
+spec:
+  selector:
+    matchLabels:
+      app: mynginx
+      env: staging
+      org: example.com
+      team: override-foo
+  template:
+    metadata:
+      annotations:
+        note: This is a test annotation
+      labels:
+        app: mynginx
+        env: staging
+        org: example.com
+        team: override-foo
+    spec:
+      containers:
+      - image: nginx
+        name: nginx
+        volumeMounts:
+        - mountPath: /tmp/ps
+          name: nginx-persistent-storage
+      volumes:
+      - gcePersistentDisk:
+          pdName: nginx-persistent-storage
+        name: nginx-persistent-storage
+      - configMap:
+          name: staging-configmap-in-overlay-k7cbc75tg8
+        name: configmap-in-overlay
+      - configMap:
+          name: staging-team-foo-configmap-in-base-gh9d7t85gb
+        name: configmap-in-base

pkg/commands/testdata/testcase-single-overlay/in/overlay/deployment.yaml

@@ -0,0 +1,15 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+spec:
+  template:
+    spec:
+      volumes:
+      - name: nginx-persistent-storage
+        emptyDir: null
+        gcePersistentDisk:
+          pdName: nginx-persistent-storage
+      - configMap:
+          name: configmap-in-overlay
+        name: configmap-in-overlay

pkg/commands/testdata/testcase-single-overlay/in/overlay/kustomization.yaml

@@ -0,0 +1,21 @@
+namePrefix: staging-
+commonLabels:
+  env: staging
+  team: override-foo
+patches:
+  - deployment.yaml
+bases:
+  - ../package/
+configMapGenerator:
+  - name: configmap-in-overlay
+    literals:
+      - hello=world
+  - name: configmap-in-base
+    behavior: replace
+    literals:
+      - foo=override-bar
+secretGenerator:
+- name: secret-in-base
+  behavior: merge
+  commands:
+    proxy: "printf haproxy"

pkg/commands/testdata/testcase-single-overlay/in/package/deployment.yaml

@@ -0,0 +1,24 @@
+apiVersion: apps/v1beta2
+kind: Deployment
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  template:
+    metadata:
+      labels:
+        app: nginx
+    spec:
+      containers:
+      - name: nginx
+        image: nginx
+        volumeMounts:
+        - name: nginx-persistent-storage
+          mountPath: /tmp/ps
+      volumes:
+      - name: nginx-persistent-storage
+        emptyDir: {}
+      - configMap:
+          name: configmap-in-base
+        name: configmap-in-base

pkg/commands/testdata/testcase-single-overlay/in/package/kustomization.yaml

@@ -0,0 +1,19 @@
+namePrefix: team-foo-
+commonLabels:
+  app: mynginx
+  org: example.com
+  team: foo
+commonAnnotations:
+  note: This is a test annotation
+resources:
+  - deployment.yaml
+  - service.yaml
+configMapGenerator:
+  - name: configmap-in-base
+    literals:
+      - foo=bar
+secretGenerator:
+- name: secret-in-base
+  commands:
+    username: "printf admin"
+    password: "printf somepw"

pkg/commands/testdata/testcase-single-overlay/in/package/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: nginx
+  labels:
+    app: nginx
+spec:
+  ports:
+    - port: 80
+  selector:
+    app: nginx

pkg/commands/testdata/testcase-single-overlay/test.yaml

@@ -0,0 +1,5 @@
+description: single overlay
+args: []
+filename: testdata/testcase-single-overlay/in/overlay/
+expectedStdout: testdata/testcase-single-overlay/expected.yaml
+expectedDiff: testdata/testcase-single-overlay/expected.diff

pkg/commands/util.go

@@ -0,0 +1,104 @@
+/*
+Copyright 2018 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 commands
+
+import (
+	"errors"
+	"fmt"
+	"path"
+	"strings"
+
+	"github.com/ghodss/yaml"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	interror "k8s.io/kubectl/pkg/kustomize/internal/error"
+	"k8s.io/kubectl/pkg/kustomize/types"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+type kustomizationFile struct {
+	path string
+	fsys fs.FileSystem
+}
+
+func newKustomizationFile(mPath string, fsys fs.FileSystem) (*kustomizationFile, error) {
+	mf := &kustomizationFile{path: mPath, fsys: fsys}
+	err := mf.validate()
+	if err != nil {
+		return nil, err
+	}
+	return mf, nil
+}
+
+func (mf *kustomizationFile) validate() error {
+	f, err := mf.fsys.Stat(mf.path)
+	if err != nil {
+		errorMsg := fmt.Sprintf("Missing kustomization file '%s'.\n", mf.path)
+		merr := interror.KustomizationError{KustomizationPath: mf.path, ErrorMsg: errorMsg}
+		return merr
+	}
+	if f.IsDir() {
+		mf.path = path.Join(mf.path, constants.KustomizationFileName)
+		_, err = mf.fsys.Stat(mf.path)
+		if err != nil {
+			errorMsg := fmt.Sprintf("Missing kustomization file '%s'.\n", mf.path)
+			merr := interror.KustomizationError{KustomizationPath: mf.path, ErrorMsg: errorMsg}
+			return merr
+		}
+	} else {
+		if !strings.HasSuffix(mf.path, constants.KustomizationFileName) {
+			errorMsg := fmt.Sprintf("Kustomization file path (%s) should have %s suffix\n", mf.path, constants.KustomizationSuffix)
+			merr := interror.KustomizationError{KustomizationPath: mf.path, ErrorMsg: errorMsg}
+			return merr
+		}
+	}
+	return nil
+}
+
+func (mf *kustomizationFile) read() (*types.Kustomization, error) {
+	bytes, err := mf.fsys.ReadFile(mf.path)
+	if err != nil {
+		return nil, err
+	}
+	var kustomization types.Kustomization
+	err = yaml.Unmarshal(bytes, &kustomization)
+	if err != nil {
+		return nil, err
+	}
+	return &kustomization, err
+}
+
+func (mf *kustomizationFile) write(kustomization *types.Kustomization) error {
+	if kustomization == nil {
+		return errors.New("util: kustomization file arg is nil.")
+	}
+	bytes, err := yaml.Marshal(kustomization)
+	if err != nil {
+		return err
+	}
+
+	return mf.fsys.WriteFile(mf.path, bytes)
+}
+
+func stringInSlice(str string, list []string) bool {
+	for _, v := range list {
+		if v == str {
+			return true
+		}
+	}
+	return false
+}

pkg/commands/util_test.go

@@ -0,0 +1,90 @@
+/*
+Copyright 2018 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 commands
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+
+	"k8s.io/kubectl/pkg/kustomize/constants"
+	"k8s.io/kubectl/pkg/kustomize/types"
+	"k8s.io/kubectl/pkg/kustomize/util/fs"
+)
+
+func TestWriteAndRead(t *testing.T) {
+	kustomization := &types.Kustomization{
+		NamePrefix: "prefix",
+	}
+
+	fsys := fs.MakeFakeFS()
+	fsys.Create(constants.KustomizationFileName)
+	mf, err := newKustomizationFile(constants.KustomizationFileName, fsys)
+	if err != nil {
+		t.Fatalf("Unexpected Error: %v", err)
+	}
+
+	if err := mf.write(kustomization); err != nil {
+		t.Fatalf("Couldn't write kustomization file: %v\n", err)
+	}
+
+	content, err := mf.read()
+	if err != nil {
+		t.Fatalf("Couldn't read kustomization file: %v\n", err)
+	}
+	if !reflect.DeepEqual(kustomization, content) {
+		t.Fatal("Read kustomization is different from written kustomization")
+	}
+}
+
+func TestEmptyFile(t *testing.T) {
+	fsys := fs.MakeFakeFS()
+	_, err := newKustomizationFile("", fsys)
+	if err == nil {
+		t.Fatalf("Create kustomizationFile from empty filename should fail")
+	}
+}
+
+func TestNewNotExist(t *testing.T) {
+	badSuffix := "foo.bar"
+	fakeFS := fs.MakeFakeFS()
+	fakeFS.Mkdir(".", 0644)
+	fakeFS.Create(badSuffix)
+	_, err := newKustomizationFile(constants.KustomizationFileName, fakeFS)
+	if err == nil {
+		t.Fatalf("expect an error")
+	}
+	contained := "Missing kustomization file"
+	if !strings.Contains(err.Error(), contained) {
+		t.Fatalf("expect an error contains %q, but got %v", contained, err)
+	}
+	_, err = newKustomizationFile(constants.KustomizationFileName, fakeFS)
+	if err == nil {
+		t.Fatalf("expect an error")
+	}
+	if !strings.Contains(err.Error(), contained) {
+		t.Fatalf("expect an error contains %q, but got %v", contained, err)
+	}
+	_, err = newKustomizationFile(badSuffix, fakeFS)
+	if err == nil {
+		t.Fatalf("expect an error")
+	}
+	contained = "should have .yaml suffix"
+	if !strings.Contains(err.Error(), contained) {
+		t.Fatalf("expect an error contains %q, but got %v", contained, err)
+	}
+}