feat(helm): add 'helm inspect'

This basic version of helm inspect displays the Chart.yaml and
values.yaml files on STDOUT.

Closes #967

cmd/helm/helm.go

@@ -90,6 +90,7 @@ func newRootCmd(out io.Writer) *cobra.Command {
 		newStatusCmd(nil, out),
 		newInstallCmd(nil, out),
 		newDeleteCmd(nil, out),
+		newInspectCmd(nil, out),
 	)
 	return cmd
 }

cmd/helm/inspect.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2016 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 (
+	"fmt"
+	"io"
+
+	"github.com/ghodss/yaml"
+	"github.com/spf13/cobra"
+
+	"k8s.io/helm/pkg/chartutil"
+	"k8s.io/helm/pkg/helm"
+)
+
+const inspectDesc = `
+This command inspects a chart (directory, file, or URL) and displays information.
+
+Inspect prints the contents of the Chart.yaml file and the values.yaml file.
+`
+
+type inspectCmd struct {
+	chartpath string
+
+	out    io.Writer
+	client helm.Interface
+}
+
+func newInspectCmd(c helm.Interface, out io.Writer) *cobra.Command {
+	insp := &inspectCmd{
+		client: c,
+		out:    out,
+	}
+
+	cc := &cobra.Command{
+		Use:   "inspect [CHART]",
+		Short: "inspect a chart",
+		Long:  installDesc,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if err := checkArgsLength(1, len(args), "chart name"); err != nil {
+				return err
+			}
+			cp, err := locateChartPath(args[0])
+			if err != nil {
+				return err
+			}
+			insp.chartpath = cp
+			return insp.run()
+		},
+	}
+	return cc
+}
+
+func (i *inspectCmd) run() error {
+	chrt, err := chartutil.Load(i.chartpath)
+	if err != nil {
+		return err
+	}
+	cf, err := yaml.Marshal(chrt.Metadata)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintln(i.out, string(cf))
+	fmt.Fprintln(i.out, "---")
+	fmt.Fprintln(i.out, chrt.Values.Raw)
+	return nil
+}

cmd/helm/inspect_test.go

@@ -0,0 +1,63 @@
+/*
+Copyright 2016 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"
+	"io/ioutil"
+	"strings"
+	"testing"
+)
+
+func TestInspect(t *testing.T) {
+	b := bytes.NewBuffer(nil)
+
+	insp := &inspectCmd{
+		chartpath: "testdata/testcharts/alpine",
+		out:       b,
+	}
+	insp.run()
+
+	// Load the data from the textfixture directly.
+	cdata, err := ioutil.ReadFile("testdata/testcharts/alpine/Chart.yaml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	data, err := ioutil.ReadFile("testdata/testcharts/alpine/values.yaml")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	parts := strings.SplitN(b.String(), "---", 2)
+	if len(parts) != 2 {
+		t.Fatalf("Expected 2 parts, got %d", len(parts))
+	}
+
+	expect := []string{
+		strings.TrimSpace(string(cdata)),
+		strings.TrimSpace(string(data)),
+	}
+
+	// Problem: ghodss/yaml doesn't marshal into struct order. To solve, we
+	// have to carefully craft the Chart.yaml to match.
+	for i, got := range parts {
+		got = strings.TrimSpace(got)
+		if got != expect[i] {
+			t.Errorf("Expected\n%q\nGot\n%q\n", expect[i], got)
+		}
+	}
+}

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

@@ -1,6 +1,6 @@
-name: alpine
 description: Deploy a basic Alpine Linux pod
-version: 0.1.0
 home: https://k8s.io/helm
+name: alpine
 sources:
-  - https://github.com/kubernetes/helm
+- https://github.com/kubernetes/helm
+version: 0.1.0