feat(helm): Merges helm-template plugin into cli.

Sets up the template command using cobra, and adds tests to ensure
the command is working properly.

Closes #1887

cmd/helm/helm.go

@@ -106,6 +106,7 @@ func newRootCmd(args []string) *cobra.Command {
 		newSearchCmd(out),
 		newServeCmd(out),
 		newVerifyCmd(out),
+		newTemplateCmd(out),
 
 		// release commands
 		addFlagsTLS(newDeleteCmd(nil, out)),

cmd/helm/template.go

@@ -0,0 +1,199 @@
+/*
+Copyright 2017 The Kubernetes Authors All rights reserved.
+
+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 main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/ghodss/yaml"
+	"github.com/spf13/cobra"
+
+	"k8s.io/helm/pkg/chartutil"
+	"k8s.io/helm/pkg/engine"
+	"k8s.io/helm/pkg/proto/hapi/chart"
+	"k8s.io/helm/pkg/strvals"
+	"k8s.io/helm/pkg/timeconv"
+)
+
+const templateDesc = `
+Render chart templates locally and display the output.
+
+This does not require Tiller. However, any values that would normally be
+looked up or retrieved in-cluster will be faked locally. Additionally, none
+of the server-side testing of chart validity (e.g. whether an API is supported)
+is done.
+
+To render just one template in a chart, use '-x':
+	$ helm template mychart -x mychart/templates/deployment.yaml
+`
+
+type templateCmd struct {
+	setVals     []string
+	valsFiles   valueFiles
+	flagVerbose bool
+	showNotes   bool
+	releaseName string
+	namespace   string
+	renderFiles []string
+
+	out io.Writer
+}
+
+func newTemplateCmd(out io.Writer) *cobra.Command {
+	tem := &templateCmd{
+		out: out,
+	}
+
+	cmd := &cobra.Command{
+		Use:   "template [flags] CHART",
+		Short: "locally render templates",
+		Long:  templateDesc,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) < 1 {
+				return errors.New("chart is required")
+			}
+			return tem.run(args)
+		},
+	}
+
+	f := cmd.Flags()
+	f.StringArrayVar(&tem.setVals, "set", []string{}, "set values on the command line. See 'helm install -h'")
+	f.VarP(&tem.valsFiles, "values", "f", "specify one or more YAML files of values")
+	f.BoolVarP(&tem.flagVerbose, "verbose", "v", false, "show the computed YAML values as well.")
+	f.BoolVar(&tem.showNotes, "notes", false, "show the computed NOTES.txt file as well.")
+	f.StringVarP(&tem.releaseName, "release", "r", "RELEASE-NAME", "release name")
+	f.StringVarP(&tem.namespace, "namespace", "n", "NAMESPACE", "namespace")
+	f.StringArrayVarP(&tem.renderFiles, "execute", "x", []string{}, "only execute the given templates.")
+
+	return cmd
+}
+
+func (tc *templateCmd) run(args []string) error {
+	c, err := chartutil.Load(args[0])
+	if err != nil {
+		return err
+	}
+
+	vv, err := tc.vals()
+	if err != nil {
+		return err
+	}
+
+	config := &chart.Config{Raw: string(vv), Values: map[string]*chart.Value{}}
+
+	if tc.flagVerbose {
+		fmt.Fprintf(tc.out, "---\n# merged values")
+		fmt.Fprintf(tc.out, "%s\n", string(vv))
+
+	}
+
+	options := chartutil.ReleaseOptions{
+		Name:      tc.releaseName,
+		Time:      timeconv.Now(),
+		Namespace: tc.namespace,
+		//Revision:  1,
+		//IsInstall: true,
+	}
+
+	// Set up engine.
+	renderer := engine.New()
+
+	vals, err := chartutil.ToRenderValues(c, config, options)
+	if err != nil {
+		return err
+	}
+
+	out, err := renderer.Render(c, vals)
+	if err != nil {
+		return err
+	}
+
+	in := func(needle string, haystack []string) bool {
+		for _, h := range haystack {
+			if h == needle {
+				return true
+			}
+		}
+		return false
+	}
+
+	sortedKeys := make([]string, 0, len(out))
+	for key := range out {
+		sortedKeys = append(sortedKeys, key)
+	}
+	sort.Strings(sortedKeys)
+
+	// If renderFiles is set, we ONLY print those.
+	if len(tc.renderFiles) > 0 {
+		for _, name := range sortedKeys {
+			data := out[name]
+			if in(name, tc.renderFiles) {
+				fmt.Fprintf(tc.out, "---\n# Source: %s\n", name)
+				fmt.Fprintf(tc.out, "%s\n", data)
+			}
+		}
+		return nil
+	}
+
+	for _, name := range sortedKeys {
+		data := out[name]
+		b := filepath.Base(name)
+		if !tc.showNotes && b == "NOTES.txt" {
+			continue
+		}
+		if strings.HasPrefix(b, "_") {
+			continue
+		}
+		fmt.Fprintf(tc.out, "---\n# Source: %s\n", name)
+		fmt.Fprintf(tc.out, "%s\n", data)
+	}
+	return nil
+}
+
+func (tc *templateCmd) vals() ([]byte, error) {
+	base := map[string]interface{}{}
+
+	// User specified a values files via -f/--values
+	for _, filePath := range tc.valsFiles {
+		currentMap := map[string]interface{}{}
+		bytes, err := ioutil.ReadFile(filePath)
+		if err != nil {
+			return []byte{}, err
+		}
+
+		if err := yaml.Unmarshal(bytes, &currentMap); err != nil {
+			return []byte{}, fmt.Errorf("failed to parse %s: %s", filePath, err)
+		}
+		// Merge with the previous map
+		base = mergeValues(base, currentMap)
+	}
+
+	// User specified a value via --set
+	for _, value := range tc.setVals {
+		if err := strvals.ParseInto(value, base); err != nil {
+			return []byte{}, fmt.Errorf("failed parsing --set data: %s", err)
+		}
+	}
+
+	return yaml.Marshal(base)
+}

cmd/helm/template_test.go

@@ -0,0 +1,130 @@
+/*
+Copyright 2017 The Kubernetes Authors All rights reserved.
+
+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 main
+
+import (
+	"bytes"
+	"regexp"
+	"testing"
+)
+
+type templateCase struct {
+	name  string
+	args  []string
+	flags []string
+	// expected and notExpected are strings to be matched. This supports regular expressions.
+	expected    []string
+	notExpected []string
+	err         bool
+}
+
+func TestTemplate(t *testing.T) {
+	testCases := []templateCase{
+		{
+			name: "template basic",
+			args: []string{"testdata/testcharts/templatetest"},
+			expected: []string{
+				"name: defaultname",
+				"Source: templatetest/templates/deployment.yaml",
+				"Source: templatetest/templates/service.yaml",
+			},
+			notExpected: []string{
+				"1. These are the notes",
+				"merged values",
+			},
+		},
+		{
+			name: "template missing chart",
+			args: []string{""},
+			err:  true,
+		},
+		{
+			name:     "template with valid value file",
+			args:     []string{"testdata/testcharts/templatetest"},
+			flags:    []string{"--values", "testdata/testcharts/templatetest/other_values.yaml"},
+			expected: []string{"name: othername"},
+		},
+		{
+			name:  "template with invalid value file",
+			args:  []string{"testdata/testcharts/templatetest"},
+			flags: []string{"--values", ""},
+			err:   true,
+		},
+		{
+			name:     "template set existing key",
+			args:     []string{"testdata/testcharts/templatetest"},
+			flags:    []string{"--set", "name=customname"},
+			expected: []string{"name: customname"},
+		},
+		{
+			name:        "template set non-existing key",
+			args:        []string{"testdata/testcharts/templatetest"},
+			flags:       []string{"--set", "invalid=customvalue"},
+			notExpected: []string{"customvalue"},
+		},
+		{
+			name:     "template include notes",
+			args:     []string{"testdata/testcharts/templatetest"},
+			flags:    []string{"--notes"},
+			expected: []string{"1. These are the notes"},
+		},
+		{
+			name:     "template verbose output",
+			args:     []string{"testdata/testcharts/templatetest"},
+			flags:    []string{"--verbose"},
+			expected: []string{"merged values"},
+		},
+		{
+			name:        "template render specific existing file",
+			args:        []string{"testdata/testcharts/templatetest"},
+			flags:       []string{"--execute", "templatetest/templates/deployment.yaml"},
+			expected:    []string{"Source: templatetest/templates/deployment.yaml"},
+			notExpected: []string{"Source: templatetest/templates/service.yaml"},
+		},
+		{
+			name:        "template render specific non-existing file",
+			args:        []string{"testdata/testcharts/templatetest"},
+			flags:       []string{"--execute", "templatetest/templates/ingress.yaml"},
+			notExpected: []string{"Source: templatetest/templates/ingress.yaml"},
+		},
+	}
+
+	var buf bytes.Buffer
+	for _, tc := range testCases {
+		cmd := newTemplateCmd(&buf)
+		cmd.ParseFlags(tc.flags)
+		err := cmd.RunE(cmd, tc.args)
+		if (err != nil) != tc.err {
+			t.Errorf("%q. expected error, got '%v'", tc.name, err)
+		}
+
+		by := buf.Bytes()
+		for _, exp := range tc.expected {
+			re := regexp.MustCompile(exp)
+			if !re.Match(by) {
+				t.Errorf("%q. expected\n%q\ngot\n%q", tc.name, exp, buf.String())
+			}
+		}
+		for _, exp := range tc.notExpected {
+			re := regexp.MustCompile(exp)
+			if re.Match(by) {
+				t.Errorf("%q. not expected\n%q\nin\n%q", tc.name, exp, buf.String())
+			}
+		}
+		buf.Reset()
+	}
+}

cmd/helm/testdata/testcharts/templatetest/Chart.yaml

@@ -0,0 +1,3 @@
+description: A Helm chart for Kubernetes 
+name: templatetest
+version: 0.1.0

cmd/helm/testdata/testcharts/templatetest/other_values.yaml

@@ -0,0 +1 @@
+name: othername 

cmd/helm/testdata/testcharts/templatetest/templates/NOTES.txt

@@ -0,0 +1 @@
+1. These are the notes 

cmd/helm/testdata/testcharts/templatetest/templates/deployment.yaml

@@ -0,0 +1,4 @@
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: {{ .Values.name }}

cmd/helm/testdata/testcharts/templatetest/templates/service.yaml

@@ -0,0 +1,4 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ .Values.name }}

cmd/helm/testdata/testcharts/templatetest/values.yaml

@@ -0,0 +1 @@
+name: defaultname