Add event subscribers.

- Add exit event for exec processes.

Signed-off-by: David Calavera <david.calavera@gmail.com>

exit.go

@@ -6,17 +6,23 @@ type ExitEvent struct {
 	s *Supervisor
 }
 
+type ExecExitEvent struct {
+	s *Supervisor
+}
+
 func (h *ExitEvent) Handle(e *Event) error {
 	logrus.WithFields(logrus.Fields{"pid": e.Pid, "status": e.Status}).
 		Debug("containerd: process exited")
 	// is it the child process of a container
 	if container, ok := h.s.processes[e.Pid]; ok {
-		if err := container.RemoveProcess(e.Pid); err != nil {
-			logrus.WithField("error", err).Error("containerd: find container for pid")
-		}
-		delete(h.s.processes, e.Pid)
+		ne := NewEvent(ExecExitEventType)
+		ne.ID = container.ID()
+		ne.Pid = e.Pid
+		ne.Status = e.Status
+		h.s.SendEvent(ne)
 		return nil
 	}
+
 	// is it the main container's process
 	container, err := h.s.getContainerForPid(e.Pid)
 	if err != nil {
@@ -31,3 +37,14 @@ func (h *ExitEvent) Handle(e *Event) error {
 	h.s.SendEvent(ne)
 	return nil
 }
+
+func (h *ExecExitEvent) Handle(e *Event) error {
+	// exec process: we remove this process without notifying the main event loop
+	container := h.s.processes[e.Pid]
+	if err := container.RemoveProcess(e.Pid); err != nil {
+		logrus.WithField("error", err).Error("containerd: find container for pid")
+	}
+	delete(h.s.processes, e.Pid)
+	h.s.NotifySubscribers(e)
+	return nil
+}