Move supervisor to it's own package

It allows to keep main namespace cleaner

Signed-off-by: Alexander Morozov <lk4d4@docker.com>

supervisor/exit.go

@@ -0,0 +1,58 @@
+package supervisor
+
+import "github.com/Sirupsen/logrus"
+
+type ExitEvent 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 info, ok := h.s.processes[e.Pid]; ok {
+		ne := NewEvent(ExecExitEventType)
+		ne.ID = info.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 {
+		if err != errNoContainerForPid {
+			logrus.WithField("error", err).Error("containerd: find containers main pid")
+		}
+		return nil
+	}
+	container.SetExited(e.Status)
+	ne := NewEvent(DeleteEventType)
+	ne.ID = container.ID()
+	ne.Pid = e.Pid
+	ne.Status = e.Status
+	h.s.SendEvent(ne)
+
+	stopCollect := NewEvent(StopStatsEventType)
+	stopCollect.ID = container.ID()
+	h.s.SendEvent(stopCollect)
+	return nil
+}
+
+type ExecExitEvent struct {
+	s *Supervisor
+}
+
+func (h *ExecExitEvent) Handle(e *Event) error {
+	// exec process: we remove this process without notifying the main event loop
+	info := h.s.processes[e.Pid]
+	if err := info.container.RemoveProcess(e.Pid); err != nil {
+		logrus.WithField("error", err).Error("containerd: find container for pid")
+	}
+	if err := info.copier.Close(); err != nil {
+		logrus.WithField("error", err).Error("containerd: close process IO")
+	}
+	delete(h.s.processes, e.Pid)
+	h.s.notifySubscribers(e)
+	return nil
+}