Add pause command to ctr

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

ctr/container.go

@@ -48,6 +48,7 @@ var containersCommand = cli.Command{
 		execCommand,
 		killCommand,
 		listCommand,
+		pauseCommand,
 		startCommand,
 		statsCommand,
 	},
@@ -269,6 +270,26 @@ func attachStdio(s stdio) error {
 	return nil
 }
 
+var pauseCommand = cli.Command{
+	Name:  "pause",
+	Usage: "pause a container",
+	Action: func(context *cli.Context) {
+		id := context.Args().First()
+		if id == "" {
+			fatal("container id cannot be empty", 1)
+		}
+		c := getClient(context)
+		_, err := c.UpdateContainer(netcontext.Background(), &types.UpdateContainerRequest{
+			Id:     id,
+			Pid:    "init",
+			Status: "paused",
+		})
+		if err != nil {
+			fatal(err.Error(), 1)
+		}
+	},
+}
+
 var killCommand = cli.Command{
 	Name:  "kill",
 	Usage: "send a signal to a container or its processes",