Re-think integration vendoring

- remove docker/docker from  Traefik vendor (unused)
- use `ignore` for all Traefik vendor in integration glide.
- defined only integration specific version of the dependencies.

integration/vendor/github.com/opencontainers/runc/signals.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/opencontainers/runc/libcontainer"
+	"github.com/opencontainers/runc/libcontainer/system"
 	"github.com/opencontainers/runc/libcontainer/utils"
 )
 
@@ -16,15 +17,23 @@ const signalBufferSize = 2048
 
 // newSignalHandler returns a signal handler for processing SIGCHLD and SIGWINCH signals
 // while still forwarding all other signals to the process.
-func newSignalHandler(tty *tty) *signalHandler {
+// If notifySocket is present, use it to read systemd notifications from the container and
+// forward them to notifySocketHost.
+func newSignalHandler(enableSubreaper bool, notifySocket *notifySocket) *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,
+		signals:      s,
+		notifySocket: notifySocket,
 	}
 }
 
@@ -36,25 +45,39 @@ type exit struct {
 }
 
 type signalHandler struct {
-	signals chan os.Signal
-	tty     *tty
+	signals      chan os.Signal
+	notifySocket *notifySocket
 }
 
 // forward handles the main signal event loop forwarding, resizing, or reaping depending
 // on the signal received.
-func (h *signalHandler) forward(process *libcontainer.Process) (int, error) {
+func (h *signalHandler) forward(process *libcontainer.Process, tty *tty, detach bool) (int, error) {
 	// make sure we know the pid of our main process so that we can return
 	// after it dies.
+	if detach && h.notifySocket == nil {
+		return 0, nil
+	}
+
 	pid1, err := process.Pid()
 	if err != nil {
 		return -1, err
 	}
+
+	if h.notifySocket != nil {
+		if detach {
+			h.notifySocket.run(pid1)
+			return 0, nil
+		} else {
+			go h.notifySocket.run(0)
+		}
+	}
+
 	// perform the initial tty resize.
-	h.tty.resize()
+	tty.resize()
 	for s := range h.signals {
 		switch s {
 		case syscall.SIGWINCH:
-			h.tty.resize()
+			tty.resize()
 		case syscall.SIGCHLD:
 			exits, err := h.reap()
 			if err != nil {
@@ -70,6 +93,9 @@ func (h *signalHandler) forward(process *libcontainer.Process) (int, error) {
 					// status because we must ensure that any of the go specific process
 					// fun such as flushing pipes are complete before we return.
 					process.Wait()
+					if h.notifySocket != nil {
+						h.notifySocket.Close()
+					}
 					return e.status, nil
 				}
 			}
@@ -107,7 +133,3 @@ func (h *signalHandler) reap() (exits []exit, err error) {
 		})
 	}
 }
-
-func (h *signalHandler) Close() error {
-	return h.tty.Close()
-}