Fix runin code for nsinit

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)

nsinit/exec.go

@@ -23,30 +23,45 @@ var execCommand = cli.Command{
 }
 
 func execAction(context *cli.Context) {
+	var exitCode int
+
+	container, err := loadContainer()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	state, err := libcontainer.GetState(dataPath)
+	if err != nil && !os.IsNotExist(err) {
+		log.Fatalf("unable to read state.json: %s", err)
+	}
+
+	if state != nil {
+		exitCode, err = runIn(container, state, []string(context.Args()))
+	} else {
+		exitCode, err = startContainer(container, dataPath, []string(context.Args()))
+	}
+
+	if err != nil {
+		log.Fatalf("failed to exec: %s", err)
+	}
+
+	os.Exit(exitCode)
+}
+
+func runIn(container *libcontainer.Config, state *libcontainer.State, args []string) (int, error) {
 	var (
-		exitCode int
 		master  *os.File
 		console string
 		err     error
 
 		stdin  = os.Stdin
 		stdout = os.Stdout
 		stderr = os.Stderr
-		sigc = make(chan os.Signal, 10)
+		sigc   = make(chan os.Signal, 10)
 	)
 
 	signal.Notify(sigc)
 
-	container, err := loadContainer()
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	state, err := libcontainer.GetState(dataPath)
-	if err != nil && !os.IsNotExist(err) {
-		log.Fatalf("unable to read state.json: %s", err)
-	}
-
 	if container.Tty {
 		stdin = nil
 		stdout = nil
@@ -83,17 +98,7 @@ func execAction(context *cli.Context) {
 		}()
 	}
 
-	if state != nil {
-		exitCode, err = namespaces.RunIn(container, state, []string(context.Args()), os.Args[0], stdin, stdout, stderr, console, startCallback)
-	} else {
-		exitCode, err = startContainer(container, dataPath, []string(context.Args()))
-	}
-
-	if err != nil {
-		log.Fatalf("failed to exec: %s", err)
-	}
-
-	os.Exit(exitCode)
+	return namespaces.RunIn(container, state, args, os.Args[0], stdin, stdout, stderr, console, startCallback)
 }
 
 // startContainer starts the container. Returns the exit status or -1 and an