feat(helm) add command to generate bash autocompletions.

cmd/helm/completion.go

@@ -0,0 +1,61 @@
+/*
+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 (
+	"io"
+
+	"github.com/spf13/cobra"
+)
+
+const completionDesc = `
+Generate bash autocompletions script for Helm.
+
+This command can generate shell autocompletions.
+
+	$ helm completion
+
+Can be sourced as such
+
+	$ source <(helm completion)
+`
+
+type completionCmd struct {
+	out    io.Writer
+	topCmd *cobra.Command
+}
+
+func newCompletionCmd(out io.Writer, topCmd *cobra.Command) *cobra.Command {
+	cc := &completionCmd{out: out, topCmd: topCmd}
+
+	cmd := &cobra.Command{
+		Use:    "completion",
+		Short:  "Generate bash autocompletions script",
+		Long:   completionDesc,
+		Hidden: false,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cc.run()
+			return nil
+		},
+	}
+
+	return cmd
+}
+
+func (c *completionCmd) run() error {
+
+	return c.topCmd.GenBashCompletion(c.out)
+}

cmd/helm/helm.go

@@ -122,6 +122,7 @@ func newRootCmd(out io.Writer) *cobra.Command {
 		newUpgradeCmd(nil, out),
 		newVerifyCmd(out),
 		newVersionCmd(nil, out),
+		newCompletionCmd(out, cmd),
 
 		// Hidden documentation generator command: 'helm docs'
 		newDocsCmd(out, cmd),