From c232a0165ab7835e9b29509889ab8b1ac7d109c5 Mon Sep 17 00:00:00 2001
From: Jan Safranek <jsafrane@redhat.com>
Date: Wed, 14 Feb 2018 16:54:25 +0100
Subject: [PATCH] Fix DownwardAPI refresh race.

WaitForAttachAndMount should mark only pod in DesiredStateOfWorldPopulator (DSWP)
and DSWP should mark the volume to be remounted only when the new pod has been
processed.

Otherwise DSWP and reconciler race who gets the new pod first. If it's reconciler,
then DownwardAPI and Projected volumes of the pod are not refreshed with new
content and they are updated after the next periodic sync (60-90 seconds).
---
 .../populator/desired_state_of_world_populator.go           | 6 ++++++
 .../populator/desired_state_of_world_populator_test.go      | 2 ++
 pkg/kubelet/volumemanager/volume_manager.go                 | 2 +-
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator.go b/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator.go
index 6f86e43c3dc..f0a2a5c9f82 100644
--- a/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator.go
+++ b/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator.go
@@ -83,6 +83,7 @@ func NewDesiredStateOfWorldPopulator(
 	podManager pod.Manager,
 	podStatusProvider status.PodStatusProvider,
 	desiredStateOfWorld cache.DesiredStateOfWorld,
+	actualStateOfWorld cache.ActualStateOfWorld,
 	kubeContainerRuntime kubecontainer.Runtime,
 	keepTerminatedPodVolumes bool) DesiredStateOfWorldPopulator {
 	return &desiredStateOfWorldPopulator{
@@ -92,6 +93,7 @@ func NewDesiredStateOfWorldPopulator(
 		podManager:                podManager,
 		podStatusProvider:         podStatusProvider,
 		desiredStateOfWorld:       desiredStateOfWorld,
+		actualStateOfWorld:        actualStateOfWorld,
 		pods: processedPods{
 			processedPods: make(map[volumetypes.UniquePodName]bool)},
 		kubeContainerRuntime:     kubeContainerRuntime,
@@ -108,6 +110,7 @@ type desiredStateOfWorldPopulator struct {
 	podManager                pod.Manager
 	podStatusProvider         status.PodStatusProvider
 	desiredStateOfWorld       cache.DesiredStateOfWorld
+	actualStateOfWorld        cache.ActualStateOfWorld
 	pods                      processedPods
 	kubeContainerRuntime      kubecontainer.Runtime
 	timeOfLastGetPodStatus    time.Time
@@ -302,6 +305,9 @@ func (dswp *desiredStateOfWorldPopulator) processPodVolumes(pod *v1.Pod) {
 	// some of the volume additions may have failed, should not mark this pod as fully processed
 	if allVolumesAdded {
 		dswp.markPodProcessed(uniquePodName)
+		// New pod has been synced. Re-mount all volumes that need it
+		// (e.g. DownwardAPI)
+		dswp.actualStateOfWorld.MarkRemountRequired(uniquePodName)
 	}
 
 }
diff --git a/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator_test.go b/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator_test.go
index e9f27af810b..992116c4ad9 100644
--- a/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator_test.go
+++ b/pkg/kubelet/volumemanager/populator/desired_state_of_world_populator_test.go
@@ -525,6 +525,7 @@ func createDswpWithVolume(t *testing.T, pv *v1.PersistentVolume, pvc *v1.Persist
 		podtest.NewFakeMirrorClient(), fakeSecretManager, fakeConfigMapManager)
 
 	fakesDSW := cache.NewDesiredStateOfWorld(fakeVolumePluginMgr)
+	fakeASW := cache.NewActualStateOfWorld("fake", fakeVolumePluginMgr)
 	fakeRuntime := &containertest.FakeRuntime{}
 
 	fakeStatusManager := status.NewManager(fakeClient, fakePodManager, &statustest.FakePodDeletionSafetyProvider{})
@@ -536,6 +537,7 @@ func createDswpWithVolume(t *testing.T, pv *v1.PersistentVolume, pvc *v1.Persist
 		podManager:                fakePodManager,
 		podStatusProvider:         fakeStatusManager,
 		desiredStateOfWorld:       fakesDSW,
+		actualStateOfWorld:        fakeASW,
 		pods: processedPods{
 			processedPods: make(map[types.UniquePodName]bool)},
 		kubeContainerRuntime:     fakeRuntime,
diff --git a/pkg/kubelet/volumemanager/volume_manager.go b/pkg/kubelet/volumemanager/volume_manager.go
index 418a598085d..d8a1079858e 100644
--- a/pkg/kubelet/volumemanager/volume_manager.go
+++ b/pkg/kubelet/volumemanager/volume_manager.go
@@ -179,6 +179,7 @@ func NewVolumeManager(
 		podManager,
 		podStatusProvider,
 		vm.desiredStateOfWorld,
+		vm.actualStateOfWorld,
 		kubeContainerRuntime,
 		keepTerminatedPodVolumes)
 	vm.reconciler = reconciler.NewReconciler(
@@ -345,7 +346,6 @@ func (vm *volumeManager) WaitForAttachAndMount(pod *v1.Pod) error {
 	// Remount plugins for which this is true. (Atomically updating volumes,
 	// like Downward API, depend on this to update the contents of the volume).
 	vm.desiredStateOfWorldPopulator.ReprocessPod(uniquePodName)
-	vm.actualStateOfWorld.MarkRemountRequired(uniquePodName)
 
 	err := wait.Poll(
 		podAttachAndMountRetryInterval,