feat(helm): add plugin management commands

Add plugin management subcommands for installing and removing plugins
to `$HELM_HOST/plugins`.

Install accepts a vcs url or a local directory.

```
$ helm plugin install http://github.com/adamreese/helm-env
Installed plugin: env

$ helm plugin list
NAME    	VERSION	DESCRIPTION
env     	0.1.0  	Print out the helm environment.

$ helm plugin remove env
Removed plugin: env
```

closes helm#1977

cmd/helm/helm.go

@@ -136,12 +136,16 @@ func newRootCmd(out io.Writer) *cobra.Command {
 		addFlagsTLS(newStatusCmd(nil, out)),
 		addFlagsTLS(newUpgradeCmd(nil, out)),
 
+		addFlagsTLS(newReleaseTestCmd(nil, out)),
+		addFlagsTLS(newResetCmd(nil, out)),
+		addFlagsTLS(newVersionCmd(nil, out)),
 		newCompletionCmd(out),
 		newHomeCmd(out),
 		newInitCmd(out),
-		addFlagsTLS(newResetCmd(nil, out)),
-		addFlagsTLS(newVersionCmd(nil, out)),
-		addFlagsTLS(newReleaseTestCmd(nil, out)),
+		newResetCmd(nil, out),
+		newVersionCmd(nil, out),
+		newReleaseTestCmd(nil, out),
+		newPluginCmd(out),
 
 		// Hidden documentation generator command: 'helm docs'
 		newDocsCmd(out),

cmd/helm/plugins.go → cmd/helm/load_plugins.go

@@ -31,6 +31,13 @@ import (
 
 const pluginEnvVar = "HELM_PLUGIN"
 
+func pluginDirs(home helmpath.Home) string {
+	if dirs := os.Getenv(pluginEnvVar); dirs != "" {
+		return dirs
+	}
+	return home.Plugins()
+}
+
 // loadPlugins loads plugins into the command list.
 //
 // This follows a different pattern than the other commands because it has
@@ -43,11 +50,7 @@ func loadPlugins(baseCmd *cobra.Command, home helmpath.Home, out io.Writer) {
 		return
 	}
 
-	plugdirs := os.Getenv(pluginEnvVar)
-	if plugdirs == "" {
-		plugdirs = home.Plugins()
-	}
-
+	plugdirs := pluginDirs(home)
 	found, err := findPlugins(plugdirs)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "failed to load plugins: %s", err)

cmd/helm/plugin.go

@@ -0,0 +1,72 @@
+/*
+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"
+	"os"
+	"os/exec"
+
+	"k8s.io/helm/pkg/helm/helmpath"
+	"k8s.io/helm/pkg/plugin"
+
+	"github.com/spf13/cobra"
+)
+
+const pluginHelp = `
+Manage client-side Helm plugins.
+`
+
+func newPluginCmd(out io.Writer) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "plugin",
+		Short: "add, list, or remove Helm plugins",
+		Long:  pluginHelp,
+	}
+	cmd.AddCommand(
+		newPluginInstallCmd(out),
+		newPluginListCmd(out),
+		newPluginRemoveCmd(out),
+	)
+	return cmd
+}
+
+// runHook will execute a plugin hook.
+func runHook(p *plugin.Plugin, event string, home helmpath.Home) error {
+	hook := p.Metadata.Hooks.Get(event)
+	if hook == "" {
+		return nil
+	}
+
+	prog := exec.Command("sh", "-c", hook)
+	// TODO make this work on windows
+	// I think its ... ¯\_(ツ)_/¯
+	// prog := exec.Command("cmd", "/C", p.Metadata.Hooks.Install())
+
+	debug("running %s hook: %s", event, prog)
+
+	setupEnv(p.Metadata.Name, p.Dir, home.Plugins(), home)
+	prog.Stdout, prog.Stderr = os.Stdout, os.Stderr
+	if err := prog.Run(); err != nil {
+		if eerr, ok := err.(*exec.ExitError); ok {
+			os.Stderr.Write(eerr.Stderr)
+			return fmt.Errorf("plugin %s hook for %q exited with error", event, p.Metadata.Name)
+		}
+		return err
+	}
+	return nil
+}

cmd/helm/plugin_install.go

@@ -0,0 +1,84 @@
+/*
+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"
+
+	"k8s.io/helm/pkg/helm/helmpath"
+	"k8s.io/helm/pkg/plugin"
+	"k8s.io/helm/pkg/plugin/installer"
+
+	"github.com/spf13/cobra"
+)
+
+type pluginInstallCmd struct {
+	source  string
+	version string
+	home    helmpath.Home
+	out     io.Writer
+}
+
+func newPluginInstallCmd(out io.Writer) *cobra.Command {
+	pcmd := &pluginInstallCmd{out: out}
+	cmd := &cobra.Command{
+		Use:   "install [options] <path|url>...",
+		Short: "install one or more Helm plugins",
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			return pcmd.complete(args)
+		},
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return pcmd.run()
+		},
+	}
+	cmd.Flags().StringVar(&pcmd.version, "version", "", "specify a version constraint. If this is not specified, the latest version is installed")
+	return cmd
+}
+
+func (pcmd *pluginInstallCmd) complete(args []string) error {
+	if err := checkArgsLength(len(args), "plugin"); err != nil {
+		return err
+	}
+	pcmd.source = args[0]
+	pcmd.home = helmpath.Home(homePath())
+	return nil
+}
+
+func (pcmd *pluginInstallCmd) run() error {
+	installer.Debug = flagDebug
+
+	i, err := installer.NewForSource(pcmd.source, pcmd.version, pcmd.home)
+	if err != nil {
+		return err
+	}
+	if err := installer.Install(i); err != nil {
+		return err
+	}
+
+	debug("loading plugin from %s", i.Path())
+	p, err := plugin.LoadDir(i.Path())
+	if err != nil {
+		return err
+	}
+
+	if err := runHook(p, plugin.Install, pcmd.home); err != nil {
+		return err
+	}
+
+	fmt.Fprintf(pcmd.out, "Installed plugin: %s\n", p.Metadata.Name)
+	return nil
+}

cmd/helm/plugin_list.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 (
+	"fmt"
+	"io"
+
+	"k8s.io/helm/pkg/helm/helmpath"
+
+	"github.com/gosuri/uitable"
+	"github.com/spf13/cobra"
+)
+
+type pluginListCmd struct {
+	home helmpath.Home
+	out  io.Writer
+}
+
+func newPluginListCmd(out io.Writer) *cobra.Command {
+	pcmd := &pluginListCmd{out: out}
+	cmd := &cobra.Command{
+		Use:   "list",
+		Short: "list installed Helm plugins",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			pcmd.home = helmpath.Home(homePath())
+			return pcmd.run()
+		},
+	}
+	return cmd
+}
+
+func (pcmd *pluginListCmd) run() error {
+	plugdirs := pluginDirs(pcmd.home)
+
+	debug("pluginDirs: %s", plugdirs)
+
+	plugins, err := findPlugins(plugdirs)
+	if err != nil {
+		return err
+	}
+
+	table := uitable.New()
+	table.AddRow("NAME", "VERSION", "DESCRIPTION")
+	for _, p := range plugins {
+		table.AddRow(p.Metadata.Name, p.Metadata.Version, p.Metadata.Description)
+	}
+	fmt.Fprintln(pcmd.out, table)
+	return nil
+}

cmd/helm/plugin_remove.go

@@ -0,0 +1,92 @@
+/*
+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"
+	"os"
+
+	"k8s.io/helm/pkg/helm/helmpath"
+	"k8s.io/helm/pkg/plugin"
+
+	"github.com/spf13/cobra"
+)
+
+type pluginRemoveCmd struct {
+	names []string
+	home  helmpath.Home
+	out   io.Writer
+}
+
+func newPluginRemoveCmd(out io.Writer) *cobra.Command {
+	pcmd := &pluginRemoveCmd{out: out}
+	cmd := &cobra.Command{
+		Use:   "remove <plugin>...",
+		Short: "remove one or more Helm plugins",
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			return pcmd.complete(args)
+		},
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return pcmd.run()
+		},
+	}
+	return cmd
+}
+
+func (pcmd *pluginRemoveCmd) complete(args []string) error {
+	if err := checkArgsLength(len(args), "plugin"); err != nil {
+		return err
+	}
+	pcmd.names = args
+	pcmd.home = helmpath.Home(homePath())
+	return nil
+}
+
+func (pcmd *pluginRemoveCmd) run() error {
+	plugdirs := pluginDirs(pcmd.home)
+	debug("loading installed plugins from %s", plugdirs)
+	plugins, err := findPlugins(plugdirs)
+	if err != nil {
+		return err
+	}
+
+	for _, name := range pcmd.names {
+		if found := findPlugin(plugins, name); found != nil {
+			if err := removePlugin(found, pcmd.home); err != nil {
+				return err
+			}
+			fmt.Fprintf(pcmd.out, "Removed plugin: %s\n", name)
+		}
+	}
+	return nil
+}
+
+func removePlugin(p *plugin.Plugin, home helmpath.Home) error {
+	if err := os.Remove(p.Dir); err != nil {
+		return err
+	}
+	return runHook(p, plugin.Delete, home)
+}
+
+func findPlugin(plugins []*plugin.Plugin, name string) *plugin.Plugin {
+	for _, p := range plugins {
+		if p.Metadata.Name == name {
+			return p
+		}
+	}
+	return nil
+}

cmd/helm/printer.go

@@ -17,6 +17,7 @@ limitations under the License.
 package main
 
 import (
+	"fmt"
 	"io"
 	"text/template"
 	"time"
@@ -72,3 +73,10 @@ func tpl(t string, vals map[string]interface{}, out io.Writer) error {
 	}
 	return tt.Execute(out, vals)
 }
+
+func debug(format string, args ...interface{}) {
+	if flagDebug {
+		format = fmt.Sprintf("[debug] %s\n", format)
+		fmt.Printf(format, args...)
+	}
+}