From 59720469aca1be6e7dc17b8f980e6b6ba6b1809a Mon Sep 17 00:00:00 2001
From: Zhang Wei <zhangwei555@huawei.com>
Date: Wed, 13 Apr 2016 15:03:53 +0800
Subject: [PATCH] Provide more useful help information for ctr

`ctr containers/checkpoints` contains lots of important subcommands,
but now help command can't show subcommands. Adding subcommands to
help information will avoid user from digging into the code for
getting necessary command list.

Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
---
 README.md         |  2 +-
 ctr/checkpoint.go | 24 +++++++++++++++++-------
 ctr/container.go  | 41 ++++++++++++++++++++++++++---------------
 3 files changed, 44 insertions(+), 23 deletions(-)

diff --git a/README.md b/README.md
index 1991725..6413bdc 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ The included `ctr` command-line tool allows you interact with the containerd dae
 $ sudo ctr containers start redis /containers/redis
 $ sudo ctr containers list
 ID                  PATH                STATUS              PROCESSES
-1                   /containers/redis   running             14063
+redis               /containers/redis   running             14063
 ```
 
 `/containers/redis` is the path to an OCI bundle. [See the docs for more information.](docs/bundle.md)
diff --git a/ctr/checkpoint.go b/ctr/checkpoint.go
index 5332a84..bc02097 100644
--- a/ctr/checkpoint.go
+++ b/ctr/checkpoint.go
@@ -10,14 +10,24 @@ import (
 	netcontext "golang.org/x/net/context"
 )
 
+var checkpointSubCmds = []cli.Command{
+	listCheckpointCommand,
+	createCheckpointCommand,
+	deleteCheckpointCommand,
+}
+
 var checkpointCommand = cli.Command{
-	Name:  "checkpoints",
-	Usage: "list all checkpoints",
-	Subcommands: []cli.Command{
-		listCheckpointCommand,
-		createCheckpointCommand,
-		deleteCheckpointCommand,
-	},
+	Name:        "checkpoints",
+	Usage:       "list all checkpoints",
+	ArgsUsage:   "COMMAND [arguments...]",
+	Subcommands: checkpointSubCmds,
+	Description: func() string {
+		desc := "\n    COMMAND:\n"
+		for _, command := range checkpointSubCmds {
+			desc += fmt.Sprintf("    %-10.10s%s\n", command.Name, command.Usage)
+		}
+		return desc
+	}(),
 	Action: listCheckpoints,
 }
 
diff --git a/ctr/container.go b/ctr/container.go
index 7989384..ab44606 100644
--- a/ctr/container.go
+++ b/ctr/container.go
@@ -41,20 +41,30 @@ func getClient(ctx *cli.Context) types.APIClient {
 	return types.NewAPIClient(conn)
 }
 
+var contSubCmds = []cli.Command{
+	execCommand,
+	killCommand,
+	listCommand,
+	pauseCommand,
+	resumeCommand,
+	startCommand,
+	statsCommand,
+	watchCommand,
+	updateCommand,
+}
+
 var containersCommand = cli.Command{
-	Name:  "containers",
-	Usage: "interact with running containers",
-	Subcommands: []cli.Command{
-		execCommand,
-		killCommand,
-		listCommand,
-		pauseCommand,
-		resumeCommand,
-		startCommand,
-		statsCommand,
-		watchCommand,
-		updateCommand,
-	},
+	Name:        "containers",
+	Usage:       "interact with running containers",
+	ArgsUsage:   "COMMAND [arguments...]",
+	Subcommands: contSubCmds,
+	Description: func() string {
+		desc := "\n    COMMAND:\n"
+		for _, command := range contSubCmds {
+			desc += fmt.Sprintf("    %-10.10s%s\n", command.Name, command.Usage)
+		}
+		return desc
+	}(),
 	Action: listContainers,
 }
 
@@ -107,8 +117,9 @@ func listContainers(context *cli.Context) {
 }
 
 var startCommand = cli.Command{
-	Name:  "start",
-	Usage: "start a container",
+	Name:      "start",
+	Usage:     "start a container",
+	ArgsUsage: "ID BundlePath",
 	Flags: []cli.Flag{
 		cli.StringFlag{
 			Name:  "checkpoint,c",