Beispiel #1
0
func run() int {
	flag.Parse()

	runtime := flag.Args()[1] // e.g. runc
	dir := flag.Args()[2]     // bundlePath for run, processPath for exec
	containerId := flag.Args()[3]

	signals := make(chan os.Signal, 100)
	signal.Notify(signals, syscall.SIGCHLD)

	fd3 := os.NewFile(3, "/proc/self/fd/3")
	logFile := fmt.Sprintf("/proc/%d/fd/4", os.Getpid())
	logFD := os.NewFile(4, "/proc/self/fd/4")
	syncPipe := os.NewFile(5, "/proc/self/fd/5")
	pidFilePath := filepath.Join(dir, "pidfile")

	stdin, stdout, stderr, winsz := openPipes(dir)

	syncPipe.Write([]byte{0})

	var runcStartCmd *exec.Cmd
	if *tty {
		ttySlave := setupTty(stdin, stdout, pidFilePath, winsz, garden.WindowSize{Rows: *rows, Columns: *cols})
		runcStartCmd = exec.Command(runtime, "-debug", "-log", logFile, "exec", "-d", "-tty", "-console", ttySlave.Name(), "-p", fmt.Sprintf("/proc/%d/fd/0", os.Getpid()), "-pid-file", pidFilePath, containerId)
	} else {
		runcStartCmd = exec.Command(runtime, "-debug", "-log", logFile, "exec", "-p", fmt.Sprintf("/proc/%d/fd/0", os.Getpid()), "-d", "-pid-file", pidFilePath, containerId)
		runcStartCmd.Stdin = stdin
		runcStartCmd.Stdout = stdout
		runcStartCmd.Stderr = stderr
	}

	// we need to be the subreaper so we can wait on the detached container process
	system.SetSubreaper(os.Getpid())

	if err := runcStartCmd.Start(); err != nil {
		fd3.Write([]byte{2})
		return 2
	}

	var status syscall.WaitStatus
	var rusage syscall.Rusage
	_, err := syscall.Wait4(runcStartCmd.Process.Pid, &status, 0, &rusage)
	check(err)    // Start succeeded but Wait4 failed, this can only be a programmer error
	logFD.Close() // No more logs from runc so close fd

	fd3.Write([]byte{byte(status.ExitStatus())})
	if status.ExitStatus() != 0 {
		return 3 // nothing to wait for, container didn't launch
	}

	containerPid, err := parsePid(pidFilePath)
	check(err)

	return waitForContainerToExit(dir, containerPid, signals)
}
Beispiel #2
0
// newSignalHandler returns a signal handler for processing SIGCHLD and SIGWINCH signals
// while still forwarding all other signals to the process.
func newSignalHandler(tty *tty, enableSubreaper bool) *signalHandler {
	if enableSubreaper {
		// set us as the subreaper before registering the signal handler for the container
		if err := system.SetSubreaper(1); err != nil {
			logrus.Warn(err)
		}
	}
	// ensure that we have a large buffer size so that we do not miss any signals
	// incase we are not processing them fast enough.
	s := make(chan os.Signal, signalBufferSize)
	// handle all signals for the process.
	signal.Notify(s)
	return &signalHandler{
		tty:     tty,
		signals: s,
	}
}