Merge pull request #43289 from tsmetana/adc-race-fix

Automatic merge from submit-queue Attach/detach controller: fix potential race in constructor **What this PR does / why we need it**: There is a potential race condition in the Attach/detach controller: The "constructor" first installs informer event handlers and then creates and initializes the other data structures. However there is no guarantee an event cannot arrive before the data structures required by the event handlers are ready. This may result in nil pointer derefernces and potential crashes (e.g. the nodeAdd method calls adc.actualStateOfWorld.SetNodeStatusUpdateNeeded even though the actualStateOfWorld might be still nil). It should be enough just to move the event handlers installation at the end of the constructor function. **Release note**: ```release-note NONE ```

Merge pull request #43289 from tsmetana/adc-race-fix
fff5fae0 · Kubernetes Submit Queue · GitHub · 682f68df · 6898bc60 · fff5fae0
Commit fff5fae0 authored Mar 31, 2017 by Kubernetes Submit Queue Committed by GitHub Mar 31, 2017
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Showing with 14 additions and 14 deletions

attach_detach_controller.go ...ontroller/volume/attachdetach/attach_detach_controller.go +14 -14

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--- a/pkg/controller/volume/attachdetach/attach_detach_controller.go
+++ b/pkg/controller/volume/attachdetach/attach_detach_controller.go
@@ -103,20 +103,6 @@ func NewAttachDetachController(
 		cloud:      cloud,
 	}

-	podInformer.Informer().AddEventHandler(kcache.ResourceEventHandlerFuncs{
-		AddFunc:    adc.podAdd,
-		UpdateFunc: adc.podUpdate,
-		DeleteFunc: adc.podDelete,
-	})
-	adc.podsSynced = podInformer.Informer().HasSynced
-
-	nodeInformer.Informer().AddEventHandler(kcache.ResourceEventHandlerFuncs{
-		AddFunc:    adc.nodeAdd,
-		UpdateFunc: adc.nodeUpdate,
-		DeleteFunc: adc.nodeDelete,
-	})
-	adc.nodesSynced = nodeInformer.Informer().HasSynced
-
 	if err := adc.volumePluginMgr.InitPlugins(plugins, adc); err != nil {
 		return nil, fmt.Errorf("Could not initialize volume plugins for Attach/Detach Controller: %+v", err)
 	}
@@ -153,6 +139,20 @@ func NewAttachDetachController(
 		podInformer.Lister(),
 		adc.desiredStateOfWorld)

+	podInformer.Informer().AddEventHandler(kcache.ResourceEventHandlerFuncs{
+		AddFunc:    adc.podAdd,
+		UpdateFunc: adc.podUpdate,
+		DeleteFunc: adc.podDelete,
+	})
+	adc.podsSynced = podInformer.Informer().HasSynced
+
+	nodeInformer.Informer().AddEventHandler(kcache.ResourceEventHandlerFuncs{
+		AddFunc:    adc.nodeAdd,
+		UpdateFunc: adc.nodeUpdate,
+		DeleteFunc: adc.nodeDelete,
+	})
+	adc.nodesSynced = nodeInformer.Informer().HasSynced
+
 	return adc, nil
 }