start mulit-containers with `runc start` command

With this patch, `runc start` command can start mulit-containers
at one command this patch also checks the argument of the `start`
command.

root@ubuntu:# runc list
ID          PID         STATUS      BUNDLE         CREATED
a           0           stopped     /mycontainer   2016-09-23T08:56:42.754026567Z
b           62979       created     /mycontainer   2016-09-23T09:01:36.421976458Z
c           62993       running     /mycontainer   2016-09-23T09:01:38.105940389Z
d           63006       created     /mycontainer   2016-09-23T09:01:39.65441942Z
e           63020       created     /mycontainer   2016-09-23T09:01:40.989995515Z
root@ubuntu:# runc start
runc: "start" requires a minimum of 1 argument
root@ubuntu:# runc start a b c d e f
cannot start a container that has run and stopped
cannot start an already running container
container f is not exist
all or part of the containers start failed
root@ubuntu:# runc list
ID          PID         STATUS      BUNDLE         CREATED
a           0           stopped     /mycontainer   2016-09-23T08:56:42.754026567Z
b           62979       running     /mycontainer   2016-09-23T09:01:36.421976458Z
c           62993       running     /mycontainer   2016-09-23T09:01:38.105940389Z
d           63006       running     /mycontainer   2016-09-23T09:01:39.65441942Z
e           63020       running     /mycontainer   2016-09-23T09:01:40.989995515Z

Signed-off-by: Wang Long <long.wanglong@huawei.com>

man/runc-start.8.md

@@ -2,7 +2,7 @@
    runc start - start signals a created container to execute the user defined process
 
 # SYNOPSIS
-   runc start <container-id>
+   runc start <container-id> [container-id...]
 
 Where "<container-id>" is your name for the instance of the container that you
 are starting. The name you provide for the container instance must be unique on

start.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/opencontainers/runc/libcontainer"
 	"github.com/urfave/cli"
@@ -10,30 +11,57 @@ import (
 var startCommand = cli.Command{
 	Name:  "start",
 	Usage: "executes the user defined process in a created container",
-	ArgsUsage: `<container-id>
+	ArgsUsage: `<container-id> [container-id...]
 
 Where "<container-id>" is your name for the instance of the container that you
 are starting. The name you provide for the container instance must be unique on
 your host.`,
-	Description: `The start command executes the user defined process in a created container.`,
+	Description: `The start command executes the user defined process in a created container .`,
 	Action: func(context *cli.Context) error {
-		container, err := getContainer(context)
+		hasError := false
+		if !context.Args().Present() {
+			return fmt.Errorf("runc: \"start\" requires a minimum of 1 argument")
+		}
+
+		factory, err := loadFactory(context)
 		if err != nil {
 			return err
 		}
-		status, err := container.Status()
-		if err != nil {
-			return err
+
+		for _, id := range context.Args() {
+			container, err := factory.Load(id)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "container %s is not exist\n", id)
+				hasError = true
+				continue
+			}
+			status, err := container.Status()
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "status for %s: %v\n", id, err)
+				hasError = true
+				continue
+			}
+			switch status {
+			case libcontainer.Created:
+				if err := container.Exec(); err != nil {
+					fmt.Fprintf(os.Stderr, "start for %s failed: %v\n", id, err)
+					hasError = true
+				}
+			case libcontainer.Stopped:
+				fmt.Fprintln(os.Stderr, "cannot start a container that has run and stopped")
+				hasError = true
+			case libcontainer.Running:
+				fmt.Fprintln(os.Stderr, "cannot start an already running container")
+				hasError = true
+			default:
+				fmt.Fprintf(os.Stderr, "cannot start a container in the %s state\n", status)
+				hasError = true
+			}
 		}
-		switch status {
-		case libcontainer.Created:
-			return container.Exec()
-		case libcontainer.Stopped:
-			return fmt.Errorf("cannot start a container that has run and stopped")
-		case libcontainer.Running:
-			return fmt.Errorf("cannot start an already running container")
-		default:
-			return fmt.Errorf("cannot start a container in the %s state", status)
+
+		if hasError {
+			return fmt.Errorf("one or more of container start failed")
 		}
+		return nil
 	},
 }

tests/integration/start.bats

@@ -0,0 +1,41 @@
+#!/usr/bin/env bats
+
+load helpers
+
+function setup() {
+  teardown_busybox
+  setup_busybox
+}
+
+function teardown() {
+  teardown_busybox
+}
+
+@test "runc start" {
+  runc create --console /dev/pts/ptmx test_busybox1
+  [ "$status" -eq 0 ]
+
+  testcontainer test_busybox1 created
+
+  runc create --console /dev/pts/ptmx test_busybox2
+  [ "$status" -eq 0 ]
+
+  testcontainer test_busybox2 created
+
+
+  # start conatiner test_busybox1 and test_busybox2
+  runc start test_busybox1 test_busybox2
+  [ "$status" -eq 0 ]
+
+  testcontainer test_busybox1 running
+  testcontainer test_busybox2 running
+
+  # delete test_busybox1 and test_busybox2
+  runc delete --force test_busybox1 test_busybox2
+
+  runc state test_busybox1
+  [ "$status" -ne 0 ]
+
+  runc state test_busybox2
+  [ "$status" -ne 0 ]
+}