Revert "Revert "Gracefully delete pods from the Kubelet""

This reverts commit 98115facfd.

pkg/controller/replication/replication_controller.go

@@ -213,6 +213,12 @@ func (rm *ReplicationManager) getPodController(pod *api.Pod) *api.ReplicationCon
 // When a pod is created, enqueue the controller that manages it and update it's expectations.
 func (rm *ReplicationManager) addPod(obj interface{}) {
 	pod := obj.(*api.Pod)
+	if pod.DeletionTimestamp != nil {
+		// on a restart of the controller manager, it's possible a new pod shows up in a state that
+		// is already pending deletion. Prevent the pod from being a creation observation.
+		rm.deletePod(pod)
+		return
+	}
 	if rc := rm.getPodController(pod); rc != nil {
 		rcKey, err := controller.KeyFunc(rc)
 		if err != nil {
@@ -234,6 +240,15 @@ func (rm *ReplicationManager) updatePod(old, cur interface{}) {
 	}
 	// TODO: Write a unittest for this case
 	curPod := cur.(*api.Pod)
+	if curPod.DeletionTimestamp != nil {
+		// when a pod is deleted gracefully it's deletion timestamp is first modified to reflect a grace period,
+		// and after such time has passed, the kubelet actually deletes it from the store. We receive an update
+		// for modification of the deletion timestamp and expect an rc to create more replicas asap, not wait
+		// until the kubelet actually deletes the pod. This is different from the Phase of a pod changing, because
+		// an rc never initiates a phase change, and so is never asleep waiting for the same.
+		rm.deletePod(curPod)
+		return
+	}
 	if rc := rm.getPodController(curPod); rc != nil {
 		rm.enqueueController(rc)
 	}