From 388689238b7dfe5c8ac55b66c1288a02a42729af Mon Sep 17 00:00:00 2001
From: Yu-Ju Hong <yjhong@google.com>
Date: Fri, 26 Feb 2016 18:41:38 -0800
Subject: [PATCH] pleg: ensure the cache is updated whenever container are
 removed

Even though we don't rely on the cache for garbage collection yet, we should
keep it up-to-date.
---
 pkg/kubelet/pleg/generic.go | 14 +++++++++-----
 pkg/kubelet/pleg/pleg.go    |  9 +++++----
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/pkg/kubelet/pleg/generic.go b/pkg/kubelet/pleg/generic.go
index 2d89157d17d..51e795a9913 100644
--- a/pkg/kubelet/pleg/generic.go
+++ b/pkg/kubelet/pleg/generic.go
@@ -124,17 +124,17 @@ func generateEvent(podID types.UID, cid string, oldState, newState plegContainer
 	case plegContainerExited:
 		return &PodLifecycleEvent{ID: podID, Type: ContainerDied, Data: cid}
 	case plegContainerUnknown:
-		// Don't generate any event if the status is unknown.
-		return nil
+		return &PodLifecycleEvent{ID: podID, Type: ContainerChanged, Data: cid}
 	case plegContainerNonExistent:
 		// We report "ContainerDied" when container was stopped OR removed. We
 		// may want to distinguish the two cases in the future.
 		switch oldState {
 		case plegContainerExited:
-			// We already reported that the container died before. There is no
-			// need to do it again.
-			return nil
+			// We already reported that the container died before.
+			return &PodLifecycleEvent{ID: podID, Type: ContainerRemoved, Data: cid}
 		default:
+			// TODO: We may want to generate a ContainerRemoved event as well.
+			// It's ok now because no one relies on the ContainerRemoved event.
 			return &PodLifecycleEvent{ID: podID, Type: ContainerDied, Data: cid}
 		}
 	default:
@@ -204,6 +204,10 @@ func (g *GenericPLEG) relist() {
 		// Update the internal storage and send out the events.
 		g.podRecords.update(pid)
 		for i := range events {
+			// Filter out events that are not reliable and no other components use yet.
+			if events[i].Type == ContainerChanged || events[i].Type == ContainerRemoved {
+				continue
+			}
 			g.eventChannel <- events[i]
 		}
 	}
diff --git a/pkg/kubelet/pleg/pleg.go b/pkg/kubelet/pleg/pleg.go
index 57a80f4481a..c23472ca925 100644
--- a/pkg/kubelet/pleg/pleg.go
+++ b/pkg/kubelet/pleg/pleg.go
@@ -23,13 +23,14 @@ import (
 type PodLifeCycleEventType string
 
 const (
-	ContainerStarted      PodLifeCycleEventType = "ContainerStarted"
-	ContainerDied         PodLifeCycleEventType = "ContainerDied"
-	NetworkSetupCompleted PodLifeCycleEventType = "NetworkSetupCompleted"
-	NetworkFailed         PodLifeCycleEventType = "NetworkFailed"
+	ContainerStarted PodLifeCycleEventType = "ContainerStarted"
+	ContainerDied    PodLifeCycleEventType = "ContainerDied"
 	// PodSync is used to trigger syncing of a pod when the observed change of
 	// the state of the pod cannot be captured by any single event above.
 	PodSync PodLifeCycleEventType = "PodSync"
+	// Do not use the events below because they are disabled in GenericPLEG.
+	ContainerRemoved PodLifeCycleEventType = "ContainerRemoved"
+	ContainerChanged PodLifeCycleEventType = "ContainerChanged"
 )
 
 // PodLifecycleEvent is an event that reflects the change of the pod state.