Merge pull request #25457 from saad-ali/expectedStateOfWorldDataStructure

Automatic merge from submit-queue

Attach Detach Controller Business Logic

This PR adds the meat of the attach/detach controller proposed in #20262.

The PR splits the in-memory cache into a desired and actual state of the world.

cmd/kube-controller-manager/app/controllermanager.go

@@ -197,9 +197,13 @@ func Run(s *options.CMServer) error {
 func StartControllers(s *options.CMServer, kubeClient *client.Client, kubeconfig *restclient.Config, stop <-chan struct{}) error {
 	podInformer := informers.CreateSharedPodIndexInformer(clientset.NewForConfigOrDie(restclient.AddUserAgent(kubeconfig, "pod-informer")), ResyncPeriod(s)())
 	nodeInformer := informers.CreateSharedNodeIndexInformer(clientset.NewForConfigOrDie(restclient.AddUserAgent(kubeconfig, "node-informer")), ResyncPeriod(s)())
+	pvcInformer := informers.CreateSharedPVCIndexInformer(clientset.NewForConfigOrDie(restclient.AddUserAgent(kubeconfig, "pvc-informer")), ResyncPeriod(s)())
+	pvInformer := informers.CreateSharedPVIndexInformer(clientset.NewForConfigOrDie(restclient.AddUserAgent(kubeconfig, "pv-informer")), ResyncPeriod(s)())
 	informers := map[reflect.Type]framework.SharedIndexInformer{}
 	informers[reflect.TypeOf(&api.Pod{})] = podInformer
 	informers[reflect.TypeOf(&api.Node{})] = nodeInformer
+	informers[reflect.TypeOf(&api.PersistentVolumeClaim{})] = pvcInformer
+	informers[reflect.TypeOf(&api.PersistentVolume{})] = pvInformer
 
 	go endpointcontroller.NewEndpointController(podInformer, clientset.NewForConfigOrDie(restclient.AddUserAgent(kubeconfig, "endpoint-controller"))).
 		Run(int(s.ConcurrentEndpointSyncs), wait.NeverStop)
@@ -391,9 +395,21 @@ func StartControllers(s *options.CMServer, kubeClient *client.Client, kubeconfig
 	volumeController.Run()
 	time.Sleep(wait.Jitter(s.ControllerStartInterval.Duration, ControllerStartJitter))
 
-	go volume.NewAttachDetachController(clientset.NewForConfigOrDie(restclient.AddUserAgent(kubeconfig, "attachdetach-controller")), podInformer, nodeInformer, ResyncPeriod(s)()).
+	attachDetachController, attachDetachControllerErr :=
-		Run(wait.NeverStop)
+		volume.NewAttachDetachController(
-	time.Sleep(wait.Jitter(s.ControllerStartInterval.Duration, ControllerStartJitter))
+			clientset.NewForConfigOrDie(restclient.AddUserAgent(kubeconfig, "attachdetach-controller")),
+			podInformer,
+			nodeInformer,
+			pvcInformer,
+			pvInformer,
+			cloud,
+			ProbeAttachableVolumePlugins(s.VolumeConfiguration))
+	if attachDetachControllerErr != nil {
+		glog.Fatalf("Failed to start attach/detach controller: %v", attachDetachControllerErr)
+	} else {
+		go attachDetachController.Run(wait.NeverStop)
+		time.Sleep(wait.Jitter(s.ControllerStartInterval.Duration, ControllerStartJitter))
+	}
 
 	var rootCA []byte
 

cmd/kube-controller-manager/app/options/options.go

@@ -81,6 +81,7 @@ func NewCMServer() *CMServer {
 					MinimumTimeoutHostPath:   60,
 					IncrementTimeoutHostPath: 30,
 				},
+				FlexVolumePluginDir: "/usr/libexec/kubernetes/kubelet-plugins/volume/exec/",
 			},
 			ContentType:             "application/vnd.kubernetes.protobuf",
 			KubeAPIQPS:              20.0,
@@ -122,6 +123,7 @@ func (s *CMServer) AddFlags(fs *pflag.FlagSet) {
 	fs.Int32Var(&s.VolumeConfiguration.PersistentVolumeRecyclerConfiguration.MinimumTimeoutHostPath, "pv-recycler-minimum-timeout-hostpath", s.VolumeConfiguration.PersistentVolumeRecyclerConfiguration.MinimumTimeoutHostPath, "The minimum ActiveDeadlineSeconds to use for a HostPath Recycler pod.  This is for development and testing only and will not work in a multi-node cluster.")
 	fs.Int32Var(&s.VolumeConfiguration.PersistentVolumeRecyclerConfiguration.IncrementTimeoutHostPath, "pv-recycler-timeout-increment-hostpath", s.VolumeConfiguration.PersistentVolumeRecyclerConfiguration.IncrementTimeoutHostPath, "the increment of time added per Gi to ActiveDeadlineSeconds for a HostPath scrubber pod.  This is for development and testing only and will not work in a multi-node cluster.")
 	fs.BoolVar(&s.VolumeConfiguration.EnableHostPathProvisioning, "enable-hostpath-provisioner", s.VolumeConfiguration.EnableHostPathProvisioning, "Enable HostPath PV provisioning when running without a cloud provider. This allows testing and development of provisioning features.  HostPath provisioning is not supported in any way, won't work in a multi-node cluster, and should not be used for anything other than testing or development.")
+	fs.StringVar(&s.VolumeConfiguration.FlexVolumePluginDir, "flex-volume-plugin-dir", s.VolumeConfiguration.FlexVolumePluginDir, "Full path of the directory in which the flex volume plugin should search for additional third party volume plugins.")
 	fs.Int32Var(&s.TerminatedPodGCThreshold, "terminated-pod-gc-threshold", s.TerminatedPodGCThreshold, "Number of terminated pods that can exist before the terminated pod garbage collector starts deleting terminated pods. If <= 0, the terminated pod garbage collector is disabled.")
 	fs.DurationVar(&s.HorizontalPodAutoscalerSyncPeriod.Duration, "horizontal-pod-autoscaler-sync-period", s.HorizontalPodAutoscalerSyncPeriod.Duration, "The period for syncing the number of pods in horizontal pod autoscaler.")
 	fs.DurationVar(&s.DeploymentControllerSyncPeriod.Duration, "deployment-controller-sync-period", s.DeploymentControllerSyncPeriod.Duration, "Period for syncing the deployments.")

cmd/kube-controller-manager/app/plugins.go

@@ -37,6 +37,7 @@ import (
 	"k8s.io/kubernetes/pkg/volume"
 	"k8s.io/kubernetes/pkg/volume/aws_ebs"
 	"k8s.io/kubernetes/pkg/volume/cinder"
+	"k8s.io/kubernetes/pkg/volume/flexvolume"
 	"k8s.io/kubernetes/pkg/volume/gce_pd"
 	"k8s.io/kubernetes/pkg/volume/host_path"
 	"k8s.io/kubernetes/pkg/volume/nfs"
@@ -45,6 +46,22 @@ import (
 	"github.com/golang/glog"
 )
 
+// ProbeAttachableVolumePlugins collects all volume plugins for the attach/
+// detach controller. VolumeConfiguration is used ot get FlexVolumePluginDir
+// which specifies the directory to search for additional third party volume
+// plugins.
+// The list of plugins is manually compiled. This code and the plugin
+// initialization code for kubelet really, really need a through refactor.
+func ProbeAttachableVolumePlugins(config componentconfig.VolumeConfiguration) []volume.VolumePlugin {
+	allPlugins := []volume.VolumePlugin{}
+
+	allPlugins = append(allPlugins, aws_ebs.ProbeVolumePlugins()...)
+	allPlugins = append(allPlugins, gce_pd.ProbeVolumePlugins()...)
+	allPlugins = append(allPlugins, cinder.ProbeVolumePlugins()...)
+	allPlugins = append(allPlugins, flexvolume.ProbeVolumePlugins(config.FlexVolumePluginDir)...)
+	return allPlugins
+}
+
 // ProbeRecyclableVolumePlugins collects all persistent volume plugins into an easy to use list.
 func ProbeRecyclableVolumePlugins(config componentconfig.VolumeConfiguration) []volume.VolumePlugin {
 	allPlugins := []volume.VolumePlugin{}

docs/admin/kube-controller-manager.md

@@ -73,6 +73,7 @@ kube-controller-manager
       --deleting-pods-qps=0.1: Number of nodes per second on which pods are deleted in case of node failure.
       --deployment-controller-sync-period=30s: Period for syncing the deployments.
       --enable-hostpath-provisioner[=false]: Enable HostPath PV provisioning when running without a cloud provider. This allows testing and development of provisioning features.  HostPath provisioning is not supported in any way, won't work in a multi-node cluster, and should not be used for anything other than testing or development.
+      --flex-volume-plugin-dir="/usr/libexec/kubernetes/kubelet-plugins/volume/exec/": Full path of the directory in which the flex volume plugin should search for additional third party volume plugins.
       --google-json-key="": The Google Cloud Platform Service Account JSON Key to use for authentication.
       --horizontal-pod-autoscaler-sync-period=30s: The period for syncing the number of pods in horizontal pod autoscaler.
       --kube-api-burst=30: Burst to use while talking with kubernetes apiserver

hack/verify-flags/known-flags.txt

@@ -146,6 +146,7 @@ federated-api-qps
 file-check-frequency
 file-suffix
 file_content_in_loop
+flex-volume-plugin-dir
 forward-services
 framework-name
 framework-store-uri

pkg/apis/componentconfig/deep_copy_generated.go

@@ -359,5 +359,6 @@ func DeepCopy_componentconfig_VolumeConfiguration(in VolumeConfiguration, out *V
 	if err := DeepCopy_componentconfig_PersistentVolumeRecyclerConfiguration(in.PersistentVolumeRecyclerConfiguration, &out.PersistentVolumeRecyclerConfiguration, c); err != nil {
 		return err
 	}
+	out.FlexVolumePluginDir = in.FlexVolumePluginDir
 	return nil
 }

pkg/apis/componentconfig/types.generated.go

@@ -8709,14 +8709,14 @@ func (x *VolumeConfiguration) CodecEncodeSelf(e *codec1978.Encoder) {
 		} else {
 			yysep2 := !z.EncBinary()
 			yy2arr2 := z.EncBasicHandle().StructToArray
-			var yyq2 [2]bool
+			var yyq2 [3]bool
 			_, _, _ = yysep2, yyq2, yy2arr2
 			const yyr2 bool = false
 			var yynn2 int
 			if yyr2 || yy2arr2 {
-				r.EncodeArrayStart(2)
+				r.EncodeArrayStart(3)
 			} else {
-				yynn2 = 2
+				yynn2 = 3
 				for _, b := range yyq2 {
 					if b {
 						yynn2++
@@ -8755,6 +8755,25 @@ func (x *VolumeConfiguration) CodecEncodeSelf(e *codec1978.Encoder) {
 				yy9 := &x.PersistentVolumeRecyclerConfiguration
 				yy9.CodecEncodeSelf(e)
 			}
+			if yyr2 || yy2arr2 {
+				z.EncSendContainerState(codecSelfer_containerArrayElem1234)
+				yym12 := z.EncBinary()
+				_ = yym12
+				if false {
+				} else {
+					r.EncodeString(codecSelferC_UTF81234, string(x.FlexVolumePluginDir))
+				}
+			} else {
+				z.EncSendContainerState(codecSelfer_containerMapKey1234)
+				r.EncodeString(codecSelferC_UTF81234, string("flexVolumePluginDir"))
+				z.EncSendContainerState(codecSelfer_containerMapValue1234)
+				yym13 := z.EncBinary()
+				_ = yym13
+				if false {
+				} else {
+					r.EncodeString(codecSelferC_UTF81234, string(x.FlexVolumePluginDir))
+				}
+			}
 			if yyr2 || yy2arr2 {
 				z.EncSendContainerState(codecSelfer_containerArrayEnd1234)
 			} else {
@@ -8829,6 +8848,12 @@ func (x *VolumeConfiguration) codecDecodeSelfFromMap(l int, d *codec1978.Decoder
 				yyv5 := &x.PersistentVolumeRecyclerConfiguration
 				yyv5.CodecDecodeSelf(d)
 			}
+		case "flexVolumePluginDir":
+			if r.TryDecodeAsNil() {
+				x.FlexVolumePluginDir = ""
+			} else {
+				x.FlexVolumePluginDir = string(r.DecodeString())
+			}
 		default:
 			z.DecStructFieldNotFound(-1, yys3)
 		} // end switch yys3
@@ -8840,16 +8865,16 @@ func (x *VolumeConfiguration) codecDecodeSelfFromArray(l int, d *codec1978.Decod
 	var h codecSelfer1234
 	z, r := codec1978.GenHelperDecoder(d)
 	_, _, _ = h, z, r
-	var yyj6 int
+	var yyj7 int
-	var yyb6 bool
+	var yyb7 bool
-	var yyhl6 bool = l >= 0
+	var yyhl7 bool = l >= 0
-	yyj6++
+	yyj7++
-	if yyhl6 {
+	if yyhl7 {
-		yyb6 = yyj6 > l
+		yyb7 = yyj7 > l
 	} else {
-		yyb6 = r.CheckBreak()
+		yyb7 = r.CheckBreak()
 	}
-	if yyb6 {
+	if yyb7 {
 		z.DecSendContainerState(codecSelfer_containerArrayEnd1234)
 		return
 	}
@@ -8859,13 +8884,13 @@ func (x *VolumeConfiguration) codecDecodeSelfFromArray(l int, d *codec1978.Decod
 	} else {
 		x.EnableHostPathProvisioning = bool(r.DecodeBool())
 	}
-	yyj6++
+	yyj7++
-	if yyhl6 {
+	if yyhl7 {
-		yyb6 = yyj6 > l
+		yyb7 = yyj7 > l
 	} else {
-		yyb6 = r.CheckBreak()
+		yyb7 = r.CheckBreak()
 	}
-	if yyb6 {
+	if yyb7 {
 		z.DecSendContainerState(codecSelfer_containerArrayEnd1234)
 		return
 	}
@@ -8873,21 +8898,37 @@ func (x *VolumeConfiguration) codecDecodeSelfFromArray(l int, d *codec1978.Decod
 	if r.TryDecodeAsNil() {
 		x.PersistentVolumeRecyclerConfiguration = PersistentVolumeRecyclerConfiguration{}
 	} else {
-		yyv8 := &x.PersistentVolumeRecyclerConfiguration
+		yyv9 := &x.PersistentVolumeRecyclerConfiguration
-		yyv8.CodecDecodeSelf(d)
+		yyv9.CodecDecodeSelf(d)
+	}
+	yyj7++
+	if yyhl7 {
+		yyb7 = yyj7 > l
+	} else {
+		yyb7 = r.CheckBreak()
+	}
+	if yyb7 {
+		z.DecSendContainerState(codecSelfer_containerArrayEnd1234)
+		return
+	}
+	z.DecSendContainerState(codecSelfer_containerArrayElem1234)
+	if r.TryDecodeAsNil() {
+		x.FlexVolumePluginDir = ""
+	} else {
+		x.FlexVolumePluginDir = string(r.DecodeString())
 	}
 	for {
-		yyj6++
+		yyj7++
-		if yyhl6 {
+		if yyhl7 {
-			yyb6 = yyj6 > l
+			yyb7 = yyj7 > l
 		} else {
-			yyb6 = r.CheckBreak()
+			yyb7 = r.CheckBreak()
 		}
-		if yyb6 {
+		if yyb7 {
 			break
 		}
 		z.DecSendContainerState(codecSelfer_containerArrayElem1234)
-		z.DecStructFieldNotFound(yyj6-1, "")
+		z.DecStructFieldNotFound(yyj7-1, "")
 	}
 	z.DecSendContainerState(codecSelfer_containerArrayEnd1234)
 }

pkg/apis/componentconfig/types.go

@@ -564,6 +564,9 @@ type VolumeConfiguration struct {
 	EnableHostPathProvisioning bool `json:"enableHostPathProvisioning"`
 	// persistentVolumeRecyclerConfiguration holds configuration for persistent volume plugins.
 	PersistentVolumeRecyclerConfiguration PersistentVolumeRecyclerConfiguration `json:"persitentVolumeRecyclerConfiguration"`
+	// volumePluginDir is the full path of the directory in which the flex
+	// volume plugin should search for additional third party volume plugins
+	FlexVolumePluginDir string `json:"flexVolumePluginDir"`
 }
 
 type PersistentVolumeRecyclerConfiguration struct {

pkg/controller/framework/informers/factory.go

@@ -82,3 +82,39 @@ func CreateSharedNodeIndexInformer(client clientset.Interface, resyncPeriod time
 
 	return sharedIndexInformer
 }
+
+// CreateSharedPVCIndexInformer returns a SharedIndexInformer that lists and watches all PVCs
+func CreateSharedPVCIndexInformer(client clientset.Interface, resyncPeriod time.Duration) framework.SharedIndexInformer {
+	sharedIndexInformer := framework.NewSharedIndexInformer(
+		&cache.ListWatch{
+			ListFunc: func(options api.ListOptions) (runtime.Object, error) {
+				return client.Core().PersistentVolumeClaims(api.NamespaceAll).List(options)
+			},
+			WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
+				return client.Core().PersistentVolumeClaims(api.NamespaceAll).Watch(options)
+			},
+		},
+		&api.PersistentVolumeClaim{},
+		resyncPeriod,
+		cache.Indexers{})
+
+	return sharedIndexInformer
+}
+
+// CreateSharedPVIndexInformer returns a SharedIndexInformer that lists and watches all PVs
+func CreateSharedPVIndexInformer(client clientset.Interface, resyncPeriod time.Duration) framework.SharedIndexInformer {
+	sharedIndexInformer := framework.NewSharedIndexInformer(
+		&cache.ListWatch{
+			ListFunc: func(options api.ListOptions) (runtime.Object, error) {
+				return client.Core().PersistentVolumes().List(options)
+			},
+			WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
+				return client.Core().PersistentVolumes().Watch(options)
+			},
+		},
+		&api.PersistentVolume{},
+		resyncPeriod,
+		cache.Indexers{})
+
+	return sharedIndexInformer
+}

pkg/controller/volume/attach_detach_controller.go

@@ -19,13 +19,45 @@ limitations under the License.
 package volume
 
 import (
+	"fmt"
+	"strings"
 	"time"
 
 	"github.com/golang/glog"
+	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
+	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/controller/framework"
-	"k8s.io/kubernetes/pkg/controller/framework/informers"
+	"k8s.io/kubernetes/pkg/controller/volume/attacherdetacher"
+	"k8s.io/kubernetes/pkg/controller/volume/cache"
+	"k8s.io/kubernetes/pkg/controller/volume/reconciler"
+	"k8s.io/kubernetes/pkg/types"
+	"k8s.io/kubernetes/pkg/util/io"
+	"k8s.io/kubernetes/pkg/util/mount"
 	"k8s.io/kubernetes/pkg/util/runtime"
+	"k8s.io/kubernetes/pkg/volume"
+)
+
+const (
+	// ControllerManagedAnnotation is the key of the annotation on Node objects
+	// that indicates attach/detach operations for the node should be managed
+	// by the attach/detach controller
+	ControllerManagedAnnotation string = "volumes.kubernetes.io/controller-managed-attach"
+
+	// SafeToDetachAnnotation is the annotation added to the Node object by
+	// kubelet in the format "volumes.kubernetes.io/safetodetach/{volumename}"
+	// to indicate the volume has been unmounted and is safe to detach.
+	SafeToDetachAnnotation string = "volumes.kubernetes.io/safetodetach-"
+
+	// loopPeriod is the ammount of time the reconciler loop waits between
+	// successive executions
+	reconcilerLoopPeriod time.Duration = 100 * time.Millisecond
+
+	// reconcilerMaxSafeToDetachDuration is the maximum amount of time the
+	// attach detach controller will wait for a volume to be safely detached
+	// from its node. Once this time has expired, the controller will assume the
+	// node or kubelet are unresponsive and will detach the volume anyway.
+	reconcilerMaxSafeToDetachDuration time.Duration = 10 * time.Minute
 )
 
 // AttachDetachController defines the operations supported by this controller.
@@ -33,49 +65,34 @@ type AttachDetachController interface {
 	Run(stopCh <-chan struct{})
 }
 
-type attachDetachController struct {
-	// internalPodInformer is the shared pod informer used to fetch and store
-	// pod objects from the API server. It is shared with other controllers and
-	// therefore the pod objects in its store should be treated as immutable.
-	internalPodInformer framework.SharedInformer
-
-	// selfCreatedPodInformer is true if the internalPodInformer was created
-	// during initialization, not passed in.
-	selfCreatedPodInformer bool
-
-	// internalNodeInformer is the shared node informer used to fetch and store
-	// node objects from the API server. It is shared with other controllers
-	// and therefore the node objects in its store should be treated as
-	// immutable.
-	internalNodeInformer framework.SharedInformer
-
-	// selfCreatedNodeInformer is true if the internalNodeInformer was created
-	// during initialization, not passed in.
-	selfCreatedNodeInformer bool
-}
-
 // NewAttachDetachController returns a new instance of AttachDetachController.
 func NewAttachDetachController(
 	kubeClient internalclientset.Interface,
 	podInformer framework.SharedInformer,
 	nodeInformer framework.SharedInformer,
-	resyncPeriod time.Duration) AttachDetachController {
+	pvcInformer framework.SharedInformer,
-	selfCreatedPodInformer := false
+	pvInformer framework.SharedInformer,
-	selfCreatedNodeInformer := false
+	cloud cloudprovider.Interface,
-	if podInformer == nil {
+	plugins []volume.VolumePlugin) (AttachDetachController, error) {
-		podInformer = informers.CreateSharedPodInformer(kubeClient, resyncPeriod)
+	// TODO: The default resyncPeriod for shared informers is 12 hours, this is
-		selfCreatedPodInformer = true
+	// unacceptable for the attach/detach controller. For example, if a pod is
-	}
+	// skipped because the node it is scheduled to didn't set its annotation in
-	if nodeInformer == nil {
+	// time, we don't want to have to wait 12hrs before processing the pod
-		nodeInformer = informers.CreateSharedNodeIndexInformer(kubeClient, resyncPeriod)
+	// again.
-		selfCreatedNodeInformer = true
+	// Luckily https://github.com/kubernetes/kubernetes/issues/23394 is being
-	}
+	// worked on and will split resync in to resync and relist. Once that
-
+	// happens the resync period can be set to something much faster (30
+	// seconds).
+	// If that issue is not resolved in time, then this controller will have to
+	// consider some unappealing alternate options: use a non-shared informer
+	// and set a faster resync period even if it causes relist, or requeue
+	// dropped pods so they are continuously processed until it is accepted or
+	// deleted (probably can't do this with sharedInformer), etc.
 	adc := &attachDetachController{
-		internalPodInformer:     podInformer,
+		kubeClient:  kubeClient,
-		selfCreatedPodInformer:  selfCreatedPodInformer,
+		pvcInformer: pvcInformer,
-		internalNodeInformer:    nodeInformer,
+		pvInformer:  pvInformer,
-		selfCreatedNodeInformer: selfCreatedNodeInformer,
+		cloud:       cloud,
 	}
 
 	podInformer.AddEventHandler(framework.ResourceEventHandlerFuncs{
@@ -90,46 +107,426 @@ func NewAttachDetachController(
 		DeleteFunc: adc.nodeDelete,
 	})
 
-	return adc
+	if err := adc.volumePluginMgr.InitPlugins(plugins, adc); err != nil {
+		return nil, fmt.Errorf("Could not initialize volume plugins for Attach/Detach Controller: %+v", err)
+	}
+
+	adc.desiredStateOfWorld = cache.NewDesiredStateOfWorld(&adc.volumePluginMgr)
+	adc.actualStateOfWorld = cache.NewActualStateOfWorld(&adc.volumePluginMgr)
+	adc.attacherDetacher = attacherdetacher.NewAttacherDetacher(&adc.volumePluginMgr)
+	adc.reconciler = reconciler.NewReconciler(
+		reconcilerLoopPeriod,
+		reconcilerMaxSafeToDetachDuration,
+		adc.desiredStateOfWorld,
+		adc.actualStateOfWorld,
+		adc.attacherDetacher)
+
+	return adc, nil
+}
+
+type attachDetachController struct {
+	// kubeClient is the kube API client used by volumehost to communicate with
+	// the API server.
+	kubeClient internalclientset.Interface
+
+	// pvcInformer is the shared PVC informer used to fetch and store PVC
+	// objects from the API server. It is shared with other controllers and
+	// therefore the PVC objects in its store should be treated as immutable.
+	pvcInformer framework.SharedInformer
+
+	// pvInformer is the shared PV informer used to fetch and store PV objects
+	// from the API server. It is shared with other controllers and therefore
+	// the PV objects in its store should be treated as immutable.
+	pvInformer framework.SharedInformer
+
+	// cloud provider used by volume host
+	cloud cloudprovider.Interface
+
+	// volumePluginMgr used to initialize and fetch volume plugins
+	volumePluginMgr volume.VolumePluginMgr
+
+	// desiredStateOfWorld is a data structure containing the desired state of
+	// the world according to this controller: i.e. what nodes the controller
+	// is managing, what volumes it wants be attached to these nodes, and which
+	// pods are scheduled to those nodes referencing the volumes.
+	// The data structure is populated by the controller using a stream of node
+	// and pod API server objects fetched by the informers.
+	desiredStateOfWorld cache.DesiredStateOfWorld
+
+	// actualStateOfWorld is a data structure containing the actual state of
+	// the world according to this controller: i.e. which volumes are attached
+	// to which nodes.
+	// The data structure is populated upon successful completion of attach and
+	// detach actions triggered by the controller and a periodic sync with
+	// storage providers for the "true" state of the world.
+	actualStateOfWorld cache.ActualStateOfWorld
+
+	// attacherDetacher is used to start asynchronous attach and operations
+	attacherDetacher attacherdetacher.AttacherDetacher
+
+	// reconciler is used to run an asynchronous periodic loop to reconcile the
+	// desiredStateOfWorld with the actualStateOfWorld by triggering attach
+	// detach operations using the attacherDetacher.
+	reconciler reconciler.Reconciler
 }
 
 func (adc *attachDetachController) Run(stopCh <-chan struct{}) {
 	defer runtime.HandleCrash()
 	glog.Infof("Starting Attach Detach Controller")
 
-	// Start self-created shared informers
+	go adc.reconciler.Run(stopCh)
-	if adc.selfCreatedPodInformer {
-		go adc.internalPodInformer.Run(stopCh)
-	}
-
-	if adc.selfCreatedNodeInformer {
-		go adc.internalNodeInformer.Run(stopCh)
-	}
 
 	<-stopCh
 	glog.Infof("Shutting down Attach Detach Controller")
 }
 
 func (adc *attachDetachController) podAdd(obj interface{}) {
-	// No op for now
+	pod, ok := obj.(*api.Pod)
+	if pod == nil || !ok {
+		return
+	}
+
+	if pod.Spec.NodeName == "" {
+		// Ignore pods without NodeName, indicating they are not scheduled.
+		return
+	}
+
+	adc.processPodVolumes(pod, true /* addVolumes */)
 }
 
 func (adc *attachDetachController) podUpdate(oldObj, newObj interface{}) {
-	// No op for now
+	// The flow for update is the same as add.
+	adc.podAdd(newObj)
 }
 
 func (adc *attachDetachController) podDelete(obj interface{}) {
-	// No op for now
+	pod, ok := obj.(*api.Pod)
+	if pod == nil || !ok {
+		return
+	}
+
+	adc.processPodVolumes(pod, false /* addVolumes */)
 }
 
 func (adc *attachDetachController) nodeAdd(obj interface{}) {
-	// No op for now
+	node, ok := obj.(*api.Node)
+	if node == nil || !ok {
+		return
+	}
+
+	nodeName := node.Name
+	if _, exists := node.Annotations[ControllerManagedAnnotation]; exists {
+		// Node specifies annotation indicating it should be managed by attach
+		// detach controller. Add it to desired state of world.
+		adc.desiredStateOfWorld.AddNode(nodeName)
+	}
+
+	adc.processSafeToDetachAnnotations(nodeName, node.Annotations)
 }
 
 func (adc *attachDetachController) nodeUpdate(oldObj, newObj interface{}) {
-	// No op for now
+	// The flow for update is the same as add.
+	adc.nodeAdd(newObj)
 }
 
 func (adc *attachDetachController) nodeDelete(obj interface{}) {
-	// No op for now
+	node, ok := obj.(*api.Node)
+	if node == nil || !ok {
+		return
+	}
+
+	nodeName := node.Name
+	if err := adc.desiredStateOfWorld.DeleteNode(nodeName); err != nil {
+		glog.V(10).Infof("%v", err)
+	}
+
+	adc.processSafeToDetachAnnotations(nodeName, node.Annotations)
+}
+
+// processPodVolumes processes the volumes in the given pod and adds them to the
+// desired state of the world if addVolumes is true, otherwise it removes them.
+func (adc *attachDetachController) processPodVolumes(
+	pod *api.Pod, addVolumes bool) {
+	if pod == nil {
+		return
+	}
+
+	if len(pod.Spec.Volumes) <= 0 {
+		return
+	}
+
+	if !adc.desiredStateOfWorld.NodeExists(pod.Spec.NodeName) {
+		// If the node the pod is scheduled to does not exist in the desired
+		// state of the world data structure, that indicates the node is not
+		// yet managed by the controller. Therefore, ignore the pod.
+		// If the node is added to the list of managed nodes in the future,
+		// future adds and updates to the pod will be processed.
+		glog.V(10).Infof(
+			"Skipping processing of pod %q/%q: it is scheduled to node %q which is not managed by the controller.",
+			pod.Namespace,
+			pod.Name,
+			pod.Spec.NodeName)
+		return
+	}
+
+	// Process volume spec for each volume defined in pod
+	for _, podVolume := range pod.Spec.Volumes {
+		volumeSpec, err := adc.createVolumeSpec(podVolume, pod.Namespace)
+		if err != nil {
+			glog.V(10).Infof(
+				"Error processing volume %q for pod %q/%q: %v",
+				podVolume.Name,
+				pod.Namespace,
+				pod.Name,
+				err)
+			continue
+		}
+
+		attachableVolumePlugin, err :=
+			adc.volumePluginMgr.FindAttachablePluginBySpec(volumeSpec)
+		if err != nil || attachableVolumePlugin == nil {
+			glog.V(10).Infof(
+				"Skipping volume %q for pod %q/%q: it does not implement attacher interface. err=%v",
+				podVolume.Name,
+				pod.Namespace,
+				pod.Name,
+				err)
+			continue
+		}
+
+		if addVolumes {
+			// Add volume to desired state of world
+			_, err := adc.desiredStateOfWorld.AddPod(
+				getUniquePodName(pod), volumeSpec, pod.Spec.NodeName)
+			if err != nil {
+				glog.V(10).Infof(
+					"Failed to add volume %q for pod %q/%q to desiredStateOfWorld. %v",
+					podVolume.Name,
+					pod.Namespace,
+					pod.Name,
+					err)
+			}
+
+		} else {
+			// Remove volume from desired state of world
+			uniqueVolumeName, err := attachableVolumePlugin.GetUniqueVolumeName(volumeSpec)
+			if err != nil {
+				glog.V(10).Infof(
+					"Failed to delete volume %q for pod %q/%q from desiredStateOfWorld. GetUniqueVolumeName failed with %v",
+					podVolume.Name,
+					pod.Namespace,
+					pod.Name,
+					err)
+				continue
+			}
+			adc.desiredStateOfWorld.DeletePod(
+				getUniquePodName(pod), uniqueVolumeName, pod.Spec.NodeName)
+		}
+	}
+
+	return
+}
+
+// createVolumeSpec creates and returns a mutatable volume.Spec object for the
+// specified volume. It dereference any PVC to get PV objects, if needed.
+func (adc *attachDetachController) createVolumeSpec(
+	podVolume api.Volume, podNamespace string) (*volume.Spec, error) {
+	if pvcSource := podVolume.VolumeSource.PersistentVolumeClaim; pvcSource != nil {
+		// If podVolume is a PVC, fetch the real PV behind the claim
+		pvName, pvcUID, err := adc.getPVCFromCacheExtractPV(
+			podNamespace, pvcSource.ClaimName)
+		if err != nil {
+			return nil, fmt.Errorf("error processing PVC %q: %v", pvcSource.ClaimName, err)
+		}
+
+		// Fetch actual PV object
+		volumeSpec, err := adc.getPVSpecFromCache(
+			pvName, pvcSource.ReadOnly, pvcUID)
+		if err != nil {
+			return nil, fmt.Errorf("error processing PVC %q: %v", pvcSource.ClaimName, err)
+		}
+
+		return volumeSpec, nil
+	}
+
+	// Do not return the original volume object, since it's from the shared
+	// informer it may be mutated by another consumer.
+	clonedPodVolumeObj, err := api.Scheme.DeepCopy(podVolume)
+	if err != nil || clonedPodVolumeObj == nil {
+		return nil, fmt.Errorf("failed to deep copy %q volume object", podVolume.Name)
+	}
+
+	clonedPodVolume, ok := clonedPodVolumeObj.(api.Volume)
+	if !ok {
+		return nil, fmt.Errorf("failed to cast clonedPodVolume %#v to api.Volume", clonedPodVolumeObj)
+	}
+
+	return volume.NewSpecFromVolume(&clonedPodVolume), nil
+}
+
+// getPVCFromCacheExtractPV fetches the PVC object with the given namespace and
+// name from the shared internal PVC store extracts the name of the PV it is
+// pointing to and returns it.
+// This method returns an error if a PVC object does not exist in the cache
+// with the given namespace/name.
+// This method returns an error if the PVC object's phase is not "Bound".
+func (adc *attachDetachController) getPVCFromCacheExtractPV(
+	namespace string, name string) (string, types.UID, error) {
+	key := name
+	if len(namespace) > 0 {
+		key = namespace + "/" + name
+	}
+
+	pvcObj, exists, err := adc.pvcInformer.GetStore().Get(key)
+	if pvcObj == nil || !exists || err != nil {
+		return "", "", fmt.Errorf(
+			"failed to find PVC %q in PVCInformer cache. %v",
+			key,
+			err)
+	}
+
+	pvc, ok := pvcObj.(*api.PersistentVolumeClaim)
+	if ok || pvc == nil {
+		return "", "", fmt.Errorf(
+			"failed to cast %q object %#v to PersistentVolumeClaim",
+			key,
+			pvcObj)
+	}
+
+	if pvc.Status.Phase != api.ClaimBound || pvc.Spec.VolumeName == "" {
+		return "", "", fmt.Errorf(
+			"PVC %q has non-bound phase (%q) or empty pvc.Spec.VolumeName (%q)",
+			key,
+			pvc.Status.Phase,
+			pvc.Spec.VolumeName)
+	}
+
+	return pvc.Spec.VolumeName, pvc.UID, nil
+}
+
+// getPVSpecFromCache fetches the PV object with the given name from the shared
+// internal PV store and returns a volume.Spec representing it.
+// This method returns an error if a PV object does not exist in the cache with
+// the given name.
+// This method deep copies the PV object so the caller may use the returned
+// volume.Spec object without worrying about it mutating unexpectedly.
+func (adc *attachDetachController) getPVSpecFromCache(
+	name string,
+	pvcReadOnly bool,
+	expectedClaimUID types.UID) (*volume.Spec, error) {
+	pvObj, exists, err := adc.pvInformer.GetStore().Get(name)
+	if pvObj == nil || !exists || err != nil {
+		return nil, fmt.Errorf(
+			"failed to find PV %q in PVInformer cache. %v", name, err)
+	}
+
+	pv, ok := pvObj.(*api.PersistentVolume)
+	if ok || pv == nil {
+		return nil, fmt.Errorf(
+			"failed to cast %q object %#v to PersistentVolume", name, pvObj)
+	}
+
+	if pv.Spec.ClaimRef == nil {
+		return nil, fmt.Errorf(
+			"found PV object %q but it has a nil pv.Spec.ClaimRef indicating it is not yet bound to the claim",
+			name)
+	}
+
+	if pv.Spec.ClaimRef.UID != expectedClaimUID {
+		return nil, fmt.Errorf(
+			"found PV object %q but its pv.Spec.ClaimRef.UID (%q) does not point to claim.UID (%q)",
+			name,
+			pv.Spec.ClaimRef.UID,
+			expectedClaimUID)
+	}
+
+	// Do not return the object from the informer, since the store is shared it
+	// may be mutated by another consumer.
+	clonedPVObj, err := api.Scheme.DeepCopy(pv)
+	if err != nil || clonedPVObj == nil {
+		return nil, fmt.Errorf("failed to deep copy %q PV object", name)
+	}
+
+	clonedPV, ok := clonedPVObj.(api.PersistentVolume)
+	if !ok {
+		return nil, fmt.Errorf(
+			"failed to cast %q clonedPV %#v to PersistentVolume", name, pvObj)
+	}
+
+	return volume.NewSpecFromPersistentVolume(&clonedPV, pvcReadOnly), nil
+}
+
+// processSafeToDetachAnnotations processes the "safe to detach" annotations for
+// the given node. It makes calls to delete any annotations referring to volumes
+// it is not aware of. For volumes it is aware of, it marks them safe to detach
+// in the "actual state of world" data structure.
+func (adc *attachDetachController) processSafeToDetachAnnotations(
+	nodeName string, annotations map[string]string) {
+	var annotationsToRemove []string
+	for annotation := range annotations {
+		// Check annotations for "safe to detach" volumes
+		annotation = strings.ToLower(annotation)
+		if strings.HasPrefix(annotation, SafeToDetachAnnotation) {
+			// If volume exists in "actual state of world" mark it as safe to detach
+			safeToAttachVolume := strings.TrimPrefix(annotation, SafeToDetachAnnotation)
+			if err := adc.actualStateOfWorld.MarkVolumeNodeSafeToDetach(safeToAttachVolume, nodeName); err != nil {
+				// If volume doesn't exist in "actual state of world" remove
+				// the "safe to detach" annotation from the node
+				annotationsToRemove = append(annotationsToRemove, annotation)
+			}
+		}
+	}
+
+	// TODO: Call out to API server to delete annotationsToRemove from Node
+}
+
+// getUniquePodName returns a unique name to reference pod by in memory caches
+func getUniquePodName(pod *api.Pod) string {
+	return types.NamespacedName{Namespace: pod.Namespace, Name: pod.Name}.String()
+}
+
+// VolumeHost implementation
+// This is an unfortunate requirement of the current factoring of volume plugin
+// initializing code. It requires kubelet specific methods used by the mounting
+// code to be implemented by all initializers even if the initializer does not
+// do mounting (like this attach/detach controller).
+// Issue kubernetes/kubernetes/issues/14217 to fix this.
+func (adc *attachDetachController) GetPluginDir(podUID string) string {
+	return ""
+}
+
+func (adc *attachDetachController) GetPodVolumeDir(podUID types.UID, pluginName, volumeName string) string {
+	return ""
+}
+
+func (adc *attachDetachController) GetPodPluginDir(podUID types.UID, pluginName string) string {
+	return ""
+}
+
+func (adc *attachDetachController) GetKubeClient() internalclientset.Interface {
+	return adc.kubeClient
+}
+
+func (adc *attachDetachController) NewWrapperMounter(volName string, spec volume.Spec, pod *api.Pod, opts volume.VolumeOptions) (volume.Mounter, error) {
+	return nil, fmt.Errorf("NewWrapperMounter not supported by Attach/Detach controller's VolumeHost implementation")
+}
+
+func (adc *attachDetachController) NewWrapperUnmounter(volName string, spec volume.Spec, podUID types.UID) (volume.Unmounter, error) {
+	return nil, fmt.Errorf("NewWrapperUnmounter not supported by Attach/Detach controller's VolumeHost implementation")
+}
+
+func (adc *attachDetachController) GetCloudProvider() cloudprovider.Interface {
+	return adc.cloud
+}
+
+func (adc *attachDetachController) GetMounter() mount.Interface {
+	return nil
+}
+
+func (adc *attachDetachController) GetWriter() io.Writer {
+	return nil
+}
+
+func (adc *attachDetachController) GetHostName() string {
+	return ""
 }

pkg/controller/volume/attach_detach_controller_test.go

@@ -0,0 +1,114 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package volume
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset/fake"
+	"k8s.io/kubernetes/pkg/client/testing/core"
+	"k8s.io/kubernetes/pkg/controller/framework/informers"
+	"k8s.io/kubernetes/pkg/runtime"
+	"k8s.io/kubernetes/pkg/watch"
+)
+
+func Test_NewAttachDetachController_Positive(t *testing.T) {
+	// Arrange
+	fakeKubeClient := createTestClient()
+	resyncPeriod := 5 * time.Minute
+	podInformer := informers.CreateSharedPodIndexInformer(fakeKubeClient, resyncPeriod)
+	nodeInformer := informers.CreateSharedNodeIndexInformer(fakeKubeClient, resyncPeriod)
+	pvcInformer := informers.CreateSharedPVCIndexInformer(fakeKubeClient, resyncPeriod)
+	pvInformer := informers.CreateSharedPVIndexInformer(fakeKubeClient, resyncPeriod)
+
+	// Act
+	_, err := NewAttachDetachController(
+		fakeKubeClient,
+		podInformer,
+		nodeInformer,
+		pvcInformer,
+		pvInformer,
+		nil, /* cloud */
+		nil /* plugins */)
+
+	// Assert
+	if err != nil {
+		t.Fatalf("Run failed with error. Expected: <no error> Actual: <%v>", err)
+	}
+}
+
+func createTestClient() *fake.Clientset {
+	fakeClient := &fake.Clientset{}
+
+	fakeClient.AddReactor("list", "pods", func(action core.Action) (handled bool, ret runtime.Object, err error) {
+		obj := &api.PodList{}
+		podNamePrefix := "mypod"
+		namespace := "mynamespace"
+		for i := 0; i < 5; i++ {
+			podName := fmt.Sprintf("%s-%d", podNamePrefix, i)
+			pod := api.Pod{
+				Status: api.PodStatus{
+					Phase: api.PodRunning,
+				},
+				ObjectMeta: api.ObjectMeta{
+					Name:      podName,
+					Namespace: namespace,
+					Labels: map[string]string{
+						"name": podName,
+					},
+				},
+				Spec: api.PodSpec{
+					Containers: []api.Container{
+						{
+							Name:  "containerName",
+							Image: "containerImage",
+							VolumeMounts: []api.VolumeMount{
+								{
+									Name:      "volumeMountName",
+									ReadOnly:  false,
+									MountPath: "/mnt",
+								},
+							},
+						},
+					},
+					Volumes: []api.Volume{
+						{
+							Name: "volumeName",
+							VolumeSource: api.VolumeSource{
+								GCEPersistentDisk: &api.GCEPersistentDiskVolumeSource{
+									PDName:   "pdName",
+									FSType:   "ext4",
+									ReadOnly: false,
+								},
+							},
+						},
+					},
+				},
+			}
+			obj.Items = append(obj.Items, pod)
+		}
+		return true, obj, nil
+	})
+
+	fakeWatch := watch.NewFake()
+	fakeClient.AddWatchReactor("*", core.DefaultWatchReactor(fakeWatch, nil))
+
+	return fakeClient
+}

pkg/controller/volume/attacherdetacher/attacher_detacher.go

@@ -0,0 +1,183 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package attacherdetacher implements interfaces that enable triggering attach
+// and detach operations on volumes.
+package attacherdetacher
+
+import (
+	"fmt"
+
+	"github.com/golang/glog"
+
+	"k8s.io/kubernetes/pkg/controller/volume/cache"
+	"k8s.io/kubernetes/pkg/util/goroutinemap"
+	"k8s.io/kubernetes/pkg/volume"
+)
+
+// AttacherDetacher defines a set of operations for attaching or detaching a
+// volume from a node.
+type AttacherDetacher interface {
+	// Spawns a new goroutine to execute volume-specific logic to attach the
+	// volume to the node specified in the volumeToAttach.
+	// Once attachment completes successfully, the actualStateOfWorld is updated
+	// to indicate the volume is attached to the node.
+	// If there is an error indicating the volume is already attached to the
+	// specified node, attachment is assumed to be successful (plugins are
+	// responsible for implmenting this behavior).
+	// All other errors are logged and the goroutine terminates without updating
+	// actualStateOfWorld (caller is responsible for retrying as needed).
+	AttachVolume(volumeToAttach *cache.VolumeToAttach, actualStateOfWorld cache.ActualStateOfWorld) error
+
+	// Spawns a new goroutine to execute volume-specific logic to detach the
+	// volume from the node specified in volumeToDetach.
+	// Once detachment completes successfully, the actualStateOfWorld is updated
+	// to remove the volume/node combo.
+	// If there is an error indicating the volume is already detached from the
+	// specified node, detachment is assumed to be successful (plugins are
+	// responsible for implmenting this behavior).
+	// All other errors are logged and the goroutine terminates without updating
+	// actualStateOfWorld (caller is responsible for retrying as needed).
+	DetachVolume(volumeToDetach *cache.AttachedVolume, actualStateOfWorld cache.ActualStateOfWorld) error
+}
+
+// NewAttacherDetacher returns a new instance of AttacherDetacher.
+func NewAttacherDetacher(volumePluginMgr *volume.VolumePluginMgr) AttacherDetacher {
+	return &attacherDetacher{
+		volumePluginMgr:   volumePluginMgr,
+		pendingOperations: goroutinemap.NewGoRoutineMap(),
+	}
+}
+
+type attacherDetacher struct {
+	// volumePluginMgr is the volume plugin manager used to create volume
+	// plugin objects.
+	volumePluginMgr *volume.VolumePluginMgr
+	// pendingOperations keeps track of pending attach and detach operations so
+	// multiple operations are not started on the same volume
+	pendingOperations goroutinemap.GoRoutineMap
+}
+
+func (ad *attacherDetacher) AttachVolume(
+	volumeToAttach *cache.VolumeToAttach,
+	actualStateOfWorld cache.ActualStateOfWorld) error {
+	attachFunc, err := ad.generateAttachVolumeFunc(volumeToAttach, actualStateOfWorld)
+	if err != nil {
+		return err
+	}
+
+	return ad.pendingOperations.Run(volumeToAttach.VolumeName, attachFunc)
+}
+
+func (ad *attacherDetacher) DetachVolume(
+	volumeToDetach *cache.AttachedVolume,
+	actualStateOfWorld cache.ActualStateOfWorld) error {
+	detachFunc, err := ad.generateDetachVolumeFunc(volumeToDetach, actualStateOfWorld)
+	if err != nil {
+		return err
+	}
+
+	return ad.pendingOperations.Run(volumeToDetach.VolumeName, detachFunc)
+}
+
+func (ad *attacherDetacher) generateAttachVolumeFunc(
+	volumeToAttach *cache.VolumeToAttach,
+	actualStateOfWorld cache.ActualStateOfWorld) (func() error, error) {
+	// Get attacher plugin
+	attachableVolumePlugin, err := ad.volumePluginMgr.FindAttachablePluginBySpec(volumeToAttach.VolumeSpec)
+	if err != nil || attachableVolumePlugin == nil {
+		return nil, fmt.Errorf(
+			"failed to get AttachablePlugin from volumeSpec for volume %q err=%v",
+			volumeToAttach.VolumeSpec.Name(),
+			err)
+	}
+
+	volumeAttacher, newAttacherErr := attachableVolumePlugin.NewAttacher()
+	if newAttacherErr != nil {
+		return nil, fmt.Errorf(
+			"failed to get NewAttacher from volumeSpec for volume %q err=%v",
+			volumeToAttach.VolumeSpec.Name(),
+			newAttacherErr)
+	}
+
+	return func() error {
+		// Execute attach
+		attachErr := volumeAttacher.Attach(volumeToAttach.VolumeSpec, volumeToAttach.NodeName)
+
+		if attachErr != nil {
+			// On failure, just log and exit. The controller will retry
+			glog.Errorf("Attach operation for %q failed with: %v", volumeToAttach.VolumeName, attachErr)
+			return attachErr
+		}
+
+		// Update actual state of world
+		_, addVolumeNodeErr := actualStateOfWorld.AddVolumeNode(volumeToAttach.VolumeSpec, volumeToAttach.NodeName)
+		if addVolumeNodeErr != nil {
+			// On failure, just log and exit. The controller will retry
+			glog.Errorf("Attach operation for %q succeeded but updating actualStateOfWorld failed with: %v", volumeToAttach.VolumeName, addVolumeNodeErr)
+			return addVolumeNodeErr
+		}
+
+		return nil
+	}, nil
+}
+
+func (ad *attacherDetacher) generateDetachVolumeFunc(
+	volumeToDetach *cache.AttachedVolume,
+	actualStateOfWorld cache.ActualStateOfWorld) (func() error, error) {
+	// Get attacher plugin
+	attachableVolumePlugin, err := ad.volumePluginMgr.FindAttachablePluginBySpec(volumeToDetach.VolumeSpec)
+	if err != nil || attachableVolumePlugin == nil {
+		return nil, fmt.Errorf(
+			"failed to get AttachablePlugin from volumeSpec for volume %q err=%v",
+			volumeToDetach.VolumeSpec.Name(),
+			err)
+	}
+
+	deviceName, err := attachableVolumePlugin.GetDeviceName(volumeToDetach.VolumeSpec)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"failed to GetUniqueVolumeName from AttachablePlugin for volumeSpec %q err=%v",
+			volumeToDetach.VolumeSpec.Name(),
+			err)
+	}
+
+	volumeDetacher, err := attachableVolumePlugin.NewDetacher()
+	if err != nil {
+		return nil, fmt.Errorf(
+			"failed to get NewDetacher from volumeSpec for volume %q err=%v",
+			volumeToDetach.VolumeSpec.Name(),
+			err)
+	}
+
+	return func() error {
+		// Execute detach
+		detachErr := volumeDetacher.Detach(deviceName, volumeToDetach.NodeName)
+
+		if detachErr != nil {
+			// On failure, just log and exit. The controller will retry
+			glog.Errorf("Detach operation for %q failed with: %v", volumeToDetach.VolumeName, detachErr)
+			return detachErr
+		}
+
+		// TODO: Reset "safe to detach" annotation on Node
+
+		// Update actual state of world
+		actualStateOfWorld.DeleteVolumeNode(volumeToDetach.VolumeName, volumeToDetach.NodeName)
+
+		return nil
+	}, nil
+}

pkg/controller/volume/cache/actual_state_of_world.go

@@ -0,0 +1,314 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/*
+Package cache implements data structures used by the attach/detach controller
+to keep track of volumes, the nodes they are attached to, and the pods that
+reference them.
+*/
+package cache
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"k8s.io/kubernetes/pkg/volume"
+)
+
+// ActualStateOfWorld defines a set of thread-safe operations supported on
+// the attach/detach controller's actual state of the world cache.
+// This cache contains volumes->nodes i.e. a set of all volumes and the nodes
+// the attach/detach controller believes are successfully attached.
+type ActualStateOfWorld interface {
+	// AddVolumeNode adds the given volume and node to the underlying store
+	// indicating the specified volume is attached to the specified node.
+	// A unique volumeName is generated from the volumeSpec and returned on
+	// success.
+	// If the volume/node combo already exists, this is a no-op.
+	// If volumeSpec is not an attachable volume plugin, an error is returned.
+	// If no volume with the name volumeName exists in the store, the volume is
+	// added.
+	// If no node with the name nodeName exists in list of attached nodes for
+	// the specified volume, the node is added.
+	AddVolumeNode(volumeSpec *volume.Spec, nodeName string) (string, error)
+
+	// MarkVolumeNodeSafeToDetach marks the given volume as safe to detach from
+	// the given node.
+	// If no volume with the name volumeName exists in the store, an error is
+	// returned.
+	// If no node with the name nodeName exists in list of attached nodes for
+	// the specified volume, an error is returned.
+	MarkVolumeNodeSafeToDetach(volumeName, nodeName string) error
+
+	// MarkDesireToDetach returns the difference between the current time  and
+	// the DetachRequestedTime for the given volume/node combo. If the
+	// DetachRequestedTime is zero, it is set to the current time.
+	// If no volume with the name volumeName exists in the store, an error is
+	// returned.
+	// If no node with the name nodeName exists in list of attached nodes for
+	// the specified volume, an error is returned.
+	MarkDesireToDetach(volumeName, nodeName string) (time.Duration, error)
+
+	// DeleteVolumeNode removes the given volume and node from the underlying
+	// store indicating the specified volume is no longer attached to the
+	// specified node.
+	// If the volume/node combo does not exist, this is a no-op.
+	// If after deleting the node, the specified volume contains no other child
+	// nodes, the volume is also deleted.
+	DeleteVolumeNode(volumeName, nodeName string)
+
+	// VolumeNodeExists returns true if the specified volume/node combo exists
+	// in the underlying store indicating the specified volume is attached to
+	// the specified node.
+	VolumeNodeExists(volumeName, nodeName string) bool
+
+	// GetAttachedVolumes generates and returns a list of volumes/node pairs
+	// reflecting which volumes are attached to which nodes based on the
+	// current actual state of the world.
+	GetAttachedVolumes() []AttachedVolume
+}
+
+// AttachedVolume represents a volume that is attached to a node.
+type AttachedVolume struct {
+	// VolumeName is the unique identifier for the volume that is attached.
+	VolumeName string
+
+	// VolumeSpec is the volume spec containing the specification for the
+	// volume that is attached.
+	VolumeSpec *volume.Spec
+
+	// NodeName is the identifier for the node that the volume is attached to.
+	NodeName string
+
+	// SafeToDetach indicates that this volume has been been unmounted from the
+	// node and is safe to detach.
+	// The value is set by MarkVolumeNodeSafeToDetach(...) and  reset on
+	// AddVolumeNode(...) calls.
+	SafeToDetach bool
+
+	// DetachRequestedTime is used to capture the desire to detach this volume.
+	// When the volume is newly created this value is set to time zero.
+	// It is set to current time, when MarkDesireToDetach(...) is called, if it
+	// was previously set to zero (other wise its value remains the same).
+	// It is reset to zero on AddVolumeNode(...) calls.
+	DetachRequestedTime time.Time
+}
+
+// NewActualStateOfWorld returns a new instance of ActualStateOfWorld.
+func NewActualStateOfWorld(volumePluginMgr *volume.VolumePluginMgr) ActualStateOfWorld {
+	return &actualStateOfWorld{
+		attachedVolumes: make(map[string]attachedVolume),
+		volumePluginMgr: volumePluginMgr,
+	}
+}
+
+type actualStateOfWorld struct {
+	// attachedVolumes is a map containing the set of volumes the attach/detach
+	// controller believes to be successfully attached to the nodes it is
+	// managing. The key in this map is the name of the volume and the value is
+	// an object containing more information about the attached volume.
+	attachedVolumes map[string]attachedVolume
+	// volumePluginMgr is the volume plugin manager used to create volume
+	// plugin objects.
+	volumePluginMgr *volume.VolumePluginMgr
+	sync.RWMutex
+}
+
+// The volume object represents a volume the the attach/detach controller
+// believes to be succesfully attached to a node it is managing.
+type attachedVolume struct {
+	// volumeName contains the unique identifier for this volume.
+	volumeName string
+
+	// spec is the volume spec containing the specification for this volume.
+	// Used to generate the volume plugin object, and passed to attach/detach
+	// methods.
+	spec *volume.Spec
+
+	// nodesAttachedTo is a map containing the set of nodes this volume has
+	// successfully been attached to. The key in this map is the name of the
+	// node and the value is a node object containing more information about
+	// the node.
+	nodesAttachedTo map[string]nodeAttachedTo
+}
+
+// The nodeAttachedTo object represents a node that .
+type nodeAttachedTo struct {
+	// nodeName contains the name of this node.
+	nodeName string
+
+	// safeToDetach indicates that this node/volume combo has been unmounted
+	// by the node and is safe to detach
+	safeToDetach bool
+
+	// detachRequestedTime used to capture the desire to detach this volume
+	detachRequestedTime time.Time
+}
+
+func (asw *actualStateOfWorld) AddVolumeNode(volumeSpec *volume.Spec, nodeName string) (string, error) {
+	asw.Lock()
+	defer asw.Unlock()
+
+	attachableVolumePlugin, err := asw.volumePluginMgr.FindAttachablePluginBySpec(volumeSpec)
+	if err != nil || attachableVolumePlugin == nil {
+		return "", fmt.Errorf(
+			"failed to get AttachablePlugin from volumeSpec for volume %q err=%v",
+			volumeSpec.Name(),
+			err)
+	}
+
+	volumeName, err := attachableVolumePlugin.GetUniqueVolumeName(volumeSpec)
+	if err != nil {
+		return "", fmt.Errorf(
+			"failed to GetUniqueVolumeName from AttachablePlugin for volumeSpec %q err=%v",
+			volumeSpec.Name(),
+			err)
+	}
+
+	volumeObj, volumeExists := asw.attachedVolumes[volumeName]
+	if !volumeExists {
+		volumeObj = attachedVolume{
+			volumeName:      volumeName,
+			spec:            volumeSpec,
+			nodesAttachedTo: make(map[string]nodeAttachedTo),
+		}
+		asw.attachedVolumes[volumeName] = volumeObj
+	}
+
+	nodeObj, nodeExists := volumeObj.nodesAttachedTo[nodeName]
+	if !nodeExists || nodeObj.safeToDetach || !nodeObj.detachRequestedTime.IsZero() {
+		// Create object if it doesn't exist.
+		// Reset safeToDeatch and detachRequestedTime values if it does.
+		volumeObj.nodesAttachedTo[nodeName] = nodeAttachedTo{
+			nodeName:            nodeName,
+			safeToDetach:        false,
+			detachRequestedTime: time.Time{},
+		}
+	}
+
+	return volumeName, nil
+}
+
+func (asw *actualStateOfWorld) MarkVolumeNodeSafeToDetach(
+	volumeName, nodeName string) error {
+	asw.Lock()
+	defer asw.Unlock()
+	volumeObj, volumeExists := asw.attachedVolumes[volumeName]
+	if !volumeExists {
+		return fmt.Errorf(
+			"failed to MarkVolumeNodeSafeToDetach(volumeName=%q, nodeName=%q) volumeName does not exist",
+			volumeName,
+			nodeName)
+	}
+
+	nodeObj, nodeExists := volumeObj.nodesAttachedTo[nodeName]
+	if !nodeExists {
+		return fmt.Errorf(
+			"failed to MarkVolumeNodeSafeToDetach(volumeName=%q, nodeName=%q) nodeName does not exist",
+			volumeName,
+			nodeName)
+	}
+
+	// Reset safe to detach
+	nodeObj.safeToDetach = true
+	volumeObj.nodesAttachedTo[nodeName] = nodeObj
+
+	return nil
+}
+
+func (asw *actualStateOfWorld) MarkDesireToDetach(
+	volumeName, nodeName string) (time.Duration, error) {
+	asw.Lock()
+	defer asw.Unlock()
+
+	volumeObj, volumeExists := asw.attachedVolumes[volumeName]
+	if !volumeExists {
+		return time.Millisecond * 0, fmt.Errorf(
+			"failed to MarkVolumeNodeSafeToDetach(volumeName=%q, nodeName=%q) volumeName does not exist",
+			volumeName,
+			nodeName)
+	}
+
+	nodeObj, nodeExists := volumeObj.nodesAttachedTo[nodeName]
+	if !nodeExists {
+		return time.Millisecond * 0, fmt.Errorf(
+			"failed to MarkVolumeNodeSafeToDetach(volumeName=%q, nodeName=%q) nodeName does not exist",
+			volumeName,
+			nodeName)
+	}
+
+	if nodeObj.detachRequestedTime.IsZero() {
+		nodeObj.detachRequestedTime = time.Now()
+		volumeObj.nodesAttachedTo[nodeName] = nodeObj
+	}
+
+	return time.Since(volumeObj.nodesAttachedTo[nodeName].detachRequestedTime), nil
+}
+
+func (asw *actualStateOfWorld) DeleteVolumeNode(volumeName, nodeName string) {
+	asw.Lock()
+	defer asw.Unlock()
+
+	volumeObj, volumeExists := asw.attachedVolumes[volumeName]
+	if !volumeExists {
+		return
+	}
+
+	_, nodeExists := volumeObj.nodesAttachedTo[nodeName]
+	if nodeExists {
+		delete(asw.attachedVolumes[volumeName].nodesAttachedTo, nodeName)
+	}
+
+	if len(volumeObj.nodesAttachedTo) == 0 {
+		delete(asw.attachedVolumes, volumeName)
+	}
+}
+
+func (asw *actualStateOfWorld) VolumeNodeExists(volumeName, nodeName string) bool {
+	asw.RLock()
+	defer asw.RUnlock()
+
+	volumeObj, volumeExists := asw.attachedVolumes[volumeName]
+	if volumeExists {
+		if _, nodeExists := volumeObj.nodesAttachedTo[nodeName]; nodeExists {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (asw *actualStateOfWorld) GetAttachedVolumes() []AttachedVolume {
+	asw.RLock()
+	defer asw.RUnlock()
+
+	attachedVolumes := make([]AttachedVolume, 0 /* len */, len(asw.attachedVolumes) /* cap */)
+	for volumeName, volumeObj := range asw.attachedVolumes {
+		for nodeName, nodeObj := range volumeObj.nodesAttachedTo {
+			attachedVolumes = append(
+				attachedVolumes,
+				AttachedVolume{
+					NodeName:            nodeName,
+					VolumeName:          volumeName,
+					VolumeSpec:          volumeObj.spec,
+					SafeToDetach:        nodeObj.safeToDetach,
+					DetachRequestedTime: nodeObj.detachRequestedTime})
+		}
+	}
+
+	return attachedVolumes
+}

pkg/controller/volume/cache/actual_state_of_world_test.go

@@ -0,0 +1,682 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cache
+
+import (
+	"testing"
+
+	controllervolumetesting "k8s.io/kubernetes/pkg/controller/volume/testing"
+)
+
+func Test_AddVolumeNode_Positive_NewVolumeNewNode(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+
+	nodeName := "node-name"
+
+	// Act
+	generatedVolumeName, err := asw.AddVolumeNode(volumeSpec, nodeName)
+
+	// Assert
+	if err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", err)
+	}
+
+	volumeNodeComboExists := asw.VolumeNodeExists(generatedVolumeName, nodeName)
+	if !volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo does not exist, it should.", generatedVolumeName, nodeName)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_AddVolumeNode_Positive_ExistingVolumeNewNode(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	node1Name := "node1-name"
+	node2Name := "node2-name"
+
+	// Act
+	generatedVolumeName1, add1Err := asw.AddVolumeNode(volumeSpec, node1Name)
+	generatedVolumeName2, add2Err := asw.AddVolumeNode(volumeSpec, node2Name)
+
+	// Assert
+	if add1Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add1Err)
+	}
+	if add2Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add2Err)
+	}
+
+	if generatedVolumeName1 != generatedVolumeName2 {
+		t.Fatalf(
+			"Generated volume names for the same volume should be the same but they are not: %q and %q",
+			generatedVolumeName1,
+			generatedVolumeName2)
+	}
+
+	volumeNode1ComboExists := asw.VolumeNodeExists(generatedVolumeName1, node1Name)
+	if !volumeNode1ComboExists {
+		t.Fatalf("%q/%q volume/node combo does not exist, it should.", generatedVolumeName1, node1Name)
+	}
+
+	volumeNode2ComboExists := asw.VolumeNodeExists(generatedVolumeName1, node2Name)
+	if !volumeNode2ComboExists {
+		t.Fatalf("%q/%q volume/node combo does not exist, it should.", generatedVolumeName1, node2Name)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 2 {
+		t.Fatalf("len(attachedVolumes) Expected: <2> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName1, volumeName, node1Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName1, volumeName, node2Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_AddVolumeNode_Positive_ExistingVolumeExistingNode(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+
+	// Act
+	generatedVolumeName1, add1Err := asw.AddVolumeNode(volumeSpec, nodeName)
+	generatedVolumeName2, add2Err := asw.AddVolumeNode(volumeSpec, nodeName)
+
+	// Assert
+	if add1Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add1Err)
+	}
+	if add2Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add2Err)
+	}
+
+	if generatedVolumeName1 != generatedVolumeName2 {
+		t.Fatalf(
+			"Generated volume names for the same volume should be the same but they are not: %q and %q",
+			generatedVolumeName1,
+			generatedVolumeName2)
+	}
+
+	volumeNodeComboExists := asw.VolumeNodeExists(generatedVolumeName1, nodeName)
+	if !volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo does not exist, it should.", generatedVolumeName1, nodeName)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName1, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_DeleteVolumeNode_Positive_VolumeExistsNodeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	asw.DeleteVolumeNode(generatedVolumeName, nodeName)
+
+	// Assert
+	volumeNodeComboExists := asw.VolumeNodeExists(generatedVolumeName, nodeName)
+	if volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo exists, it should not.", generatedVolumeName, nodeName)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 0 {
+		t.Fatalf("len(attachedVolumes) Expected: <0> Actual: <%v>", len(attachedVolumes))
+	}
+}
+
+func Test_DeleteVolumeNode_Positive_VolumeDoesntExistNodeDoesntExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	nodeName := "node-name"
+
+	// Act
+	asw.DeleteVolumeNode(volumeName, nodeName)
+
+	// Assert
+	volumeNodeComboExists := asw.VolumeNodeExists(volumeName, nodeName)
+	if volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo exists, it should not.", volumeName, nodeName)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 0 {
+		t.Fatalf("len(attachedVolumes) Expected: <0> Actual: <%v>", len(attachedVolumes))
+	}
+}
+
+func Test_DeleteVolumeNode_Positive_TwoNodesOneDeleted(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	node1Name := "node1-name"
+	node2Name := "node2-name"
+	generatedVolumeName1, add1Err := asw.AddVolumeNode(volumeSpec, node1Name)
+	if add1Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add1Err)
+	}
+	generatedVolumeName2, add2Err := asw.AddVolumeNode(volumeSpec, node2Name)
+	if add2Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add2Err)
+	}
+	if generatedVolumeName1 != generatedVolumeName2 {
+		t.Fatalf(
+			"Generated volume names for the same volume should be the same but they are not: %q and %q",
+			generatedVolumeName1,
+			generatedVolumeName2)
+	}
+
+	// Act
+	asw.DeleteVolumeNode(generatedVolumeName1, node1Name)
+
+	// Assert
+	volumeNodeComboExists := asw.VolumeNodeExists(generatedVolumeName1, node1Name)
+	if volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo exists, it should not.", generatedVolumeName1, node1Name)
+	}
+
+	volumeNodeComboExists = asw.VolumeNodeExists(generatedVolumeName1, node2Name)
+	if !volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo does not exist, it should.", generatedVolumeName1, node2Name)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName1, volumeName, node2Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_VolumeNodeExists_Positive_VolumeExistsNodeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	volumeNodeComboExists := asw.VolumeNodeExists(generatedVolumeName, nodeName)
+
+	// Assert
+	if !volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo does not exist, it should.", generatedVolumeName, nodeName)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_VolumeNodeExists_Positive_VolumeExistsNodeDoesntExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	node1Name := "node1-name"
+	node2Name := "node2-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, node1Name)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	volumeNodeComboExists := asw.VolumeNodeExists(generatedVolumeName, node2Name)
+
+	// Assert
+	if volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo exists, it should not.", generatedVolumeName, node2Name)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, node1Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_VolumeNodeExists_Positive_VolumeAndNodeDontExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	nodeName := "node-name"
+
+	// Act
+	volumeNodeComboExists := asw.VolumeNodeExists(volumeName, nodeName)
+
+	// Assert
+	if volumeNodeComboExists {
+		t.Fatalf("%q/%q volume/node combo exists, it should not.", volumeName, nodeName)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 0 {
+		t.Fatalf("len(attachedVolumes) Expected: <0> Actual: <%v>", len(attachedVolumes))
+	}
+}
+
+func Test_GetAttachedVolumes_Positive_NoVolumesOrNodes(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+
+	// Act
+	attachedVolumes := asw.GetAttachedVolumes()
+
+	// Assert
+	if len(attachedVolumes) != 0 {
+		t.Fatalf("len(attachedVolumes) Expected: <0> Actual: <%v>", len(attachedVolumes))
+	}
+}
+
+func Test_GetAttachedVolumes_Positive_OneVolumeOneNode(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	attachedVolumes := asw.GetAttachedVolumes()
+
+	// Assert
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_GetAttachedVolumes_Positive_TwoVolumeTwoNodes(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volume1Name := "volume1-name"
+	volume1Spec := controllervolumetesting.GetTestVolumeSpec(volume1Name, volume1Name)
+	node1Name := "node1-name"
+	generatedVolumeName1, add1Err := asw.AddVolumeNode(volume1Spec, node1Name)
+	if add1Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add1Err)
+	}
+	volume2Name := "volume2-name"
+	volume2Spec := controllervolumetesting.GetTestVolumeSpec(volume2Name, volume2Name)
+	node2Name := "node2-name"
+	generatedVolumeName2, add2Err := asw.AddVolumeNode(volume2Spec, node2Name)
+	if add2Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add2Err)
+	}
+
+	// Act
+	attachedVolumes := asw.GetAttachedVolumes()
+
+	// Assert
+	if len(attachedVolumes) != 2 {
+		t.Fatalf("len(attachedVolumes) Expected: <2> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName1, volume1Name, node1Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName2, volume2Name, node2Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_GetAttachedVolumes_Positive_OneVolumeTwoNodes(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	node1Name := "node1-name"
+	generatedVolumeName1, add1Err := asw.AddVolumeNode(volumeSpec, node1Name)
+	if add1Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add1Err)
+	}
+	node2Name := "node2-name"
+	generatedVolumeName2, add2Err := asw.AddVolumeNode(volumeSpec, node2Name)
+	if add2Err != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", add2Err)
+	}
+
+	if generatedVolumeName1 != generatedVolumeName2 {
+		t.Fatalf(
+			"Generated volume names for the same volume should be the same but they are not: %q and %q",
+			generatedVolumeName1,
+			generatedVolumeName2)
+	}
+
+	// Act
+	attachedVolumes := asw.GetAttachedVolumes()
+
+	// Assert
+	if len(attachedVolumes) != 2 {
+		t.Fatalf("len(attachedVolumes) Expected: <2> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName1, volumeName, node1Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName1, volumeName, node2Name, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_MarkVolumeNodeSafeToDetach_Positive_NotMarked(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act: do not mark -- test default value
+
+	// Assert
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_MarkVolumeNodeSafeToDetach_Positive_Marked(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	markSafeToDetachErr := asw.MarkVolumeNodeSafeToDetach(generatedVolumeName, nodeName)
+
+	// Assert
+	if markSafeToDetachErr != nil {
+		t.Fatalf("MarkVolumeNodeSafeToDetach failed. Expected <no error> Actual: <%v>", markSafeToDetachErr)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, true /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_MarkVolumeNodeSafeToDetach_Positive_MarkedAddVolumeNodeReset(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	markSafeToDetachErr := asw.MarkVolumeNodeSafeToDetach(generatedVolumeName, nodeName)
+	generatedVolumeName, addErr = asw.AddVolumeNode(volumeSpec, nodeName)
+
+	// Assert
+	if markSafeToDetachErr != nil {
+		t.Fatalf("MarkVolumeNodeSafeToDetach failed. Expected <no error> Actual: <%v>", markSafeToDetachErr)
+	}
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_MarkVolumeNodeSafeToDetach_Positive_MarkedVerifyDetachRequestedTimePerserved(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+	_, err := asw.MarkDesireToDetach(generatedVolumeName, nodeName)
+	if err != nil {
+		t.Fatalf("MarkDesireToDetach failed. Expected: <no error> Actual: <%v>", err)
+	}
+	expectedDetachRequestedTime := asw.GetAttachedVolumes()[0].DetachRequestedTime
+
+	// Act
+	markSafeToDetachErr := asw.MarkVolumeNodeSafeToDetach(generatedVolumeName, nodeName)
+
+	// Assert
+	if markSafeToDetachErr != nil {
+		t.Fatalf("MarkVolumeNodeSafeToDetach failed. Expected <no error> Actual: <%v>", markSafeToDetachErr)
+	}
+
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, true /* expectedSafeToDetach */, true /* expectNonZeroDetachRequestedTime */)
+	if !expectedDetachRequestedTime.Equal(attachedVolumes[0].DetachRequestedTime) {
+		t.Fatalf("DetachRequestedTime changed. Expected: <%v> Actual: <%v>", expectedDetachRequestedTime, attachedVolumes[0].DetachRequestedTime)
+	}
+}
+
+func Test_MarkDesireToDetach_Positive_NotMarked(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act: do not mark -- test default value
+
+	// Assert
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_MarkDesireToDetach_Positive_Marked(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	_, markDesireToDetachErr := asw.MarkDesireToDetach(generatedVolumeName, nodeName)
+
+	// Assert
+	if markDesireToDetachErr != nil {
+		t.Fatalf("MarkDesireToDetach failed. Expected: <no error> Actual: <%v>", markDesireToDetachErr)
+	}
+
+	// Assert
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, true /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_MarkDesireToDetach_Positive_MarkedAddVolumeNodeReset(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Act
+	_, markDesireToDetachErr := asw.MarkDesireToDetach(generatedVolumeName, nodeName)
+	generatedVolumeName, addErr = asw.AddVolumeNode(volumeSpec, nodeName)
+
+	// Assert
+	if markDesireToDetachErr != nil {
+		t.Fatalf("MarkDesireToDetach failed. Expected: <no error> Actual: <%v>", markDesireToDetachErr)
+	}
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+
+	// Assert
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, false /* expectedSafeToDetach */, false /* expectNonZeroDetachRequestedTime */)
+}
+
+func Test_MarkDesireToDetach_Positive_MarkedVerifySafeToDetachPreserved(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	asw := NewActualStateOfWorld(volumePluginMgr)
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	generatedVolumeName, addErr := asw.AddVolumeNode(volumeSpec, nodeName)
+	if addErr != nil {
+		t.Fatalf("AddVolumeNode failed. Expected: <no error> Actual: <%v>", addErr)
+	}
+	markSafeToDetachErr := asw.MarkVolumeNodeSafeToDetach(generatedVolumeName, nodeName)
+	if markSafeToDetachErr != nil {
+		t.Fatalf("MarkVolumeNodeSafeToDetach failed. Expected <no error> Actual: <%v>", markSafeToDetachErr)
+	}
+
+	// Act
+	_, markDesireToDetachErr := asw.MarkDesireToDetach(generatedVolumeName, nodeName)
+
+	// Assert
+	if markDesireToDetachErr != nil {
+		t.Fatalf("MarkDesireToDetach failed. Expected: <no error> Actual: <%v>", markDesireToDetachErr)
+	}
+
+	// Assert
+	attachedVolumes := asw.GetAttachedVolumes()
+	if len(attachedVolumes) != 1 {
+		t.Fatalf("len(attachedVolumes) Expected: <1> Actual: <%v>", len(attachedVolumes))
+	}
+
+	verifyAttachedVolume(t, attachedVolumes, generatedVolumeName, volumeName, nodeName, true /* expectedSafeToDetach */, true /* expectNonZeroDetachRequestedTime */)
+}
+
+func verifyAttachedVolume(
+	t *testing.T,
+	attachedVolumes []AttachedVolume,
+	expectedVolumeName,
+	expectedVolumeSpecName,
+	expectedNodeName string,
+	expectedSafeToDetach,
+	expectNonZeroDetachRequestedTime bool) {
+	for _, attachedVolume := range attachedVolumes {
+		if attachedVolume.VolumeName == expectedVolumeName &&
+			attachedVolume.VolumeSpec.Name() == expectedVolumeSpecName &&
+			attachedVolume.NodeName == expectedNodeName &&
+			attachedVolume.SafeToDetach == expectedSafeToDetach &&
+			attachedVolume.DetachRequestedTime.IsZero() == !expectNonZeroDetachRequestedTime {
+			return
+		}
+	}
+
+	t.Fatalf(
+		"attachedVolumes (%v) should contain the volume/node combo %q/%q with SafeToDetach=%v and NonZeroDetachRequestedTime=%v. It does not.",
+		attachedVolumes,
+		expectedVolumeName,
+		expectedNodeName,
+		expectedSafeToDetach,
+		expectNonZeroDetachRequestedTime)
+}
+
+// t.Logf("attachedVolumes: %v", asw.GetAttachedVolumes()) // TEMP

pkg/controller/volume/cache/attach_detach_volume_cache.go

@@ -1,412 +0,0 @@
-/*
-Copyright 2016 The Kubernetes Authors All rights reserved.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-/*
-Package cache implements a data structure used by the attach/detach controller
-to keep track of volumes, the nodes they are attached to, and the pods that
-reference them. It is thread-safe.
-*/
-package cache
-
-import (
-	"fmt"
-	"sync"
-)
-
-// AttachDetachVolumeCache defines the set of operations the volume cache
-// supports.
-type AttachDetachVolumeCache interface {
-	// AddVolume adds the given volume to the list of volumes managed by the
-	// attach detach controller.
-	// If the volume already exists, this is a no-op.
-	AddVolume(volumeName string)
-
-	// AddNode adds the given node to the list of nodes the specified volume is
-	// attached to.
-	// If no volume with the name volumeName exists in the list of managed
-	// volumes, an error is returned.
-	// If the node already exists for the specified volume, this is a no-op.
-	AddNode(nodeName, volumeName string) error
-
-	// AddPod adds the given pod to the list of pods that are scheduled to
-	// the specified node and referencing the specified volume.
-	// If no node with the name nodeName exists in the list of attached nodes,
-	// an error is returned.
-	// If no volume with the name volumeName exists in the list of managed
-	// volumes, an error is returned.
-	// If the pod already exists for the specified volume, this is a no-op.
-	AddPod(podName, nodeName, volumeName string) error
-
-	// DeleteVolume removes the given volume from the list of volumes managed
-	// by the attach detach controller.
-	// If no volume with the name volumeName exists in the list of managed
-	// volumes, an error is returned.
-	// All attachedNodes must be deleted from the volume before it is deleted.
-	// If the specified volume contains 1 or more attachedNodes, an error is
-	// returned.
-	DeleteVolume(volumeName string) error
-
-	// DeleteNode removes the given node from the list of nodes the specified
-	// volume is attached to.
-	// If no node with the name nodeName exists in the list of attached nodes,
-	// an error is returned.
-	// If no volume with the name volumeName exists in the list of managed
-	// volumes, an error is returned.
-	// All scheduledPods must be deleted from the node before it is deleted.
-	// If the specified node contains 1 or more scheduledPods, an error is
-	// returned.
-	DeleteNode(nodeName, volumeName string) error
-
-	// DeletePod removes the given pod from the list of pods that are scheduled
-	// to the specified node and referencing the specified volume.
-	// If no pod with the name podName exists for the specified volume/node, an
-	// error is returned.
-	// If no node with the name nodeName exists in the list of attached nodes,
-	// an error is returned.
-	// If no volume with the name volumeName exists in the list of managed
-	// volumes, an error is returned.
-	DeletePod(podName, nodeName, volumeName string) error
-
-	// VolumeExists returns true if the volume with the specified name exists
-	// in the list of volumes managed by the attach detach controller.
-	VolumeExists(volumeName string) bool
-
-	// NodeExists returns true if the node with the specified name exists in
-	// the list of nodes the specified volume is attached to.
-	// If no volume with the name volumeName exists in the list of managed
-	// volumes, an error is returned.
-	NodeExists(nodeName, volumeName string) (bool, error)
-
-	// PodExists returns true if the pod with the specified name exists in the
-	// list of pods that are scheduled to the specified node and referencing
-	// the specified volume.
-	// If no node with the name nodeName exists in the list of attached nodes,
-	// an error is returned.
-	// If no volume with the name volumeName exists in the list of managed
-	// volumes, an error is returned.
-	PodExists(podName, nodeName, volumeName string) (bool, error)
-}
-
-// NewAttachDetachVolumeCache returns a new instance of the
-// AttachDetachVolumeCache.
-func NewAttachDetachVolumeCache() AttachDetachVolumeCache {
-	return &attachDetachVolumeCache{
-		volumesManaged: make(map[string]volume),
-	}
-}
-
-type attachDetachVolumeCache struct {
-	// volumesManaged is a map containing the set of volumes managed by the
-	// attach/detach controller. The key in this map is the name of the unique
-	// volume identifier and the value is a volume object containing more
-	// information about the volume.
-	volumesManaged map[string]volume
-	sync.RWMutex
-}
-
-// The volume object represents a volume that is being tracked by the attach
-// detach controller.
-type volume struct {
-	// name contains the unique identifer for this volume.
-	name string
-
-	// attachedNodes is a map containing the set of nodes this volume has
-	// successfully been attached to. The key in this map is the name of the
-	// node and the value is a node object containing more information about
-	// the node.
-	attachedNodes map[string]node
-}
-
-// The node object represents a node that a volume is attached to.
-type node struct {
-	// name contains the name of this node.
-	name string
-
-	// scheduledPods is a map containing the set of pods that are scheduled to
-	// this node and referencing the underlying volume. The key in the map is
-	// the name of the pod and the value is a pod object containing more
-	// information about the pod.
-	scheduledPods map[string]pod
-}
-
-// The pod object represents a pod that is scheduled to a node and referncing
-// the underlying volume.
-type pod struct {
-	// name contains the name of this pod.
-	name string
-}
-
-// AddVolume adds the given volume to the list of volumes managed by the attach
-// detach controller.
-// If the volume already exists, this is a no-op.
-func (vc *attachDetachVolumeCache) AddVolume(volumeName string) {
-	vc.Lock()
-	defer vc.Unlock()
-	if _, exists := vc.volumesManaged[volumeName]; !exists {
-		vc.volumesManaged[volumeName] = volume{
-			name:          volumeName,
-			attachedNodes: make(map[string]node),
-		}
-	}
-}
-
-// AddNode adds the given node to the list of nodes the specified volume is
-// attached to.
-// If no volume with the name volumeName exists in the list of managed volumes,
-// an error is returned.
-// If the node already exists for the specified volume, this is a no-op.
-func (vc *attachDetachVolumeCache) AddNode(nodeName, volumeName string) error {
-	vc.Lock()
-	defer vc.Unlock()
-
-	vol, volExists := vc.volumesManaged[volumeName]
-	if !volExists {
-		return fmt.Errorf(
-			"failed to add node %q to volume %q--no volume with that name exists in the list of managed volumes",
-			nodeName,
-			volumeName)
-	}
-
-	if _, nodeExists := vol.attachedNodes[nodeName]; !nodeExists {
-		vc.volumesManaged[volumeName].attachedNodes[nodeName] = node{
-			name:          nodeName,
-			scheduledPods: make(map[string]pod),
-		}
-	}
-
-	return nil
-}
-
-// AddPod adds the given pod to the list of pods that are scheduled to the
-// specified node and referencing the specified volume.
-// If no node with the name nodeName exists in the list of attached nodes,
-// an error is returned.
-// If no volume with the name volumeName exists in the list of managed
-// volumes, an error is returned.
-// If the pod already exists for the specified volume, this is a no-op.
-func (vc *attachDetachVolumeCache) AddPod(podName, nodeName, volumeName string) error {
-	vc.Lock()
-	defer vc.Unlock()
-
-	volObj, volExists := vc.volumesManaged[volumeName]
-	if !volExists {
-		return fmt.Errorf(
-			"failed to add pod %q to node %q volume %q--no volume with that name exists in the list of managed volumes",
-			podName,
-			nodeName,
-			volumeName)
-	}
-
-	nodeObj, nodeExists := volObj.attachedNodes[nodeName]
-	if !nodeExists {
-		return fmt.Errorf(
-			"failed to add pod %q to node %q volume %q--no node with that name exists in the list of attached nodes for that volume",
-			podName,
-			nodeName,
-			volumeName)
-	}
-
-	if _, podExists := nodeObj.scheduledPods[podName]; !podExists {
-		vc.volumesManaged[volumeName].attachedNodes[nodeName].scheduledPods[podName] =
-			pod{
-				name: podName,
-			}
-	}
-
-	return nil
-}
-
-// DeleteVolume removes the given volume from the list of volumes managed by
-// the attach detach controller.
-// If no volume with the name volumeName exists in the list of managed volumes,
-// an error is returned.
-// All attachedNodes must be deleted from the volume before it is deleted.
-// If the specified volume contains 1 or more attachedNodes, an error is
-// returned.
-func (vc *attachDetachVolumeCache) DeleteVolume(volumeName string) error {
-	vc.Lock()
-	defer vc.Unlock()
-
-	volObj, volExists := vc.volumesManaged[volumeName]
-	if !volExists {
-		return fmt.Errorf(
-			"failed to delete volume %q--no volume with that name exists in the list of managed volumes",
-			volumeName)
-	}
-
-	if len(volObj.attachedNodes) > 0 {
-		return fmt.Errorf(
-			"failed to remove volume %q from list of managed volumes--the volume still contains %v nodes in its list of attached nodes",
-			volumeName,
-			len(volObj.attachedNodes))
-	}
-
-	delete(
-		vc.volumesManaged,
-		volumeName)
-	return nil
-}
-
-// DeleteNode removes the given node from the list of nodes the specified
-// volume is attached to.
-// If no node with the name nodeName exists in the list of attached nodes, an
-// error is returned.
-// If no volume with the name volumeName exists in the list of managed
-// volumes, an error is returned.
-// All scheduledPods must be deleted from the node before it is deleted.
-// If the specified node contains 1 or more scheduledPods, an error is
-// returned.
-func (vc *attachDetachVolumeCache) DeleteNode(nodeName, volumeName string) error {
-	vc.Lock()
-	defer vc.Unlock()
-
-	volObj, volExists := vc.volumesManaged[volumeName]
-	if !volExists {
-		return fmt.Errorf(
-			"failed to delete node %q from volume %q--no volume with that name exists in the list of managed volumes",
-			nodeName,
-			volumeName)
-	}
-
-	nodeObj, nodeExists := volObj.attachedNodes[nodeName]
-	if !nodeExists {
-		return fmt.Errorf(
-			"failed to delete node %q from volume %q--no node with the that name exists in the list of attached nodes for that volume",
-			nodeName,
-			volumeName)
-	}
-
-	if len(nodeObj.scheduledPods) > 0 {
-		return fmt.Errorf(
-			"failed to remove node %q from volume %q--the node still contains %v pods in its list of scheduled pods",
-			nodeName,
-			volumeName,
-			len(nodeObj.scheduledPods))
-	}
-
-	delete(
-		vc.volumesManaged[volumeName].attachedNodes,
-		nodeName)
-	return nil
-}
-
-// DeletePod removes the given pod from the list of pods that are scheduled
-// to the specified node and referencing the specified volume.
-// If no pod with the name podName exists for the specified volume/node, an
-// error is returned.
-// If no node with the name nodeName exists in the list of attached nodes,
-// an error is returned.
-// If no volume with the name volumeName exists in the list of managed
-// volumes, an error is returned.
-func (vc *attachDetachVolumeCache) DeletePod(podName, nodeName, volumeName string) error {
-	vc.Lock()
-	defer vc.Unlock()
-
-	volObj, volExists := vc.volumesManaged[volumeName]
-	if !volExists {
-		return fmt.Errorf(
-			"failed to delete pod %q from node %q volume %q--no volume with that name exists in the list of managed volumes",
-			podName,
-			nodeName,
-			volumeName)
-	}
-
-	nodeObj, nodeExists := volObj.attachedNodes[nodeName]
-	if !nodeExists {
-		return fmt.Errorf(
-			"failed to delete pod %q from node %q volume %q--no node with that name exists in the list of attached nodes for that volume",
-			podName,
-			nodeName,
-			volumeName)
-	}
-
-	if _, podExists := nodeObj.scheduledPods[podName]; !podExists {
-		return fmt.Errorf(
-			"failed to delete pod %q from node %q volume %q--no pod with that name exists in the list of scheduled pods under that node/volume",
-			podName,
-			nodeName,
-			volumeName)
-	}
-
-	delete(
-		vc.volumesManaged[volumeName].attachedNodes[nodeName].scheduledPods,
-		podName)
-	return nil
-}
-
-// VolumeExists returns true if the volume with the specified name exists in
-// the list of volumes managed by the attach detach controller.
-func (vc *attachDetachVolumeCache) VolumeExists(volumeName string) bool {
-	vc.RLock()
-	defer vc.RUnlock()
-
-	_, volExists := vc.volumesManaged[volumeName]
-	return volExists
-}
-
-// NodeExists returns true if the node with the specified name exists in the
-// list of nodes the specified volume is attached to.
-// If no volume with the name volumeName exists in the list of managed
-// volumes, an error is returned.
-func (vc *attachDetachVolumeCache) NodeExists(nodeName, volumeName string) (bool, error) {
-	vc.RLock()
-	defer vc.RUnlock()
-
-	volObj, volExists := vc.volumesManaged[volumeName]
-	if !volExists {
-		return false,
-			fmt.Errorf(
-				"failed to check if node %q exists under volume %q--no volume with that name exists in the list of managed volumes",
-				nodeName,
-				volumeName)
-	}
-
-	_, nodeExists := volObj.attachedNodes[nodeName]
-	return nodeExists, nil
-}
-
-// PodExists returns true if the pod with the specified name exists in the list
-// of pods that are scheduled to the specified node and referencing the
-// specified volume.
-// If no node with the name nodeName exists in the list of attached nodes, an
-// error is returned.
-// If no volume with the name volumeName exists in the list of managed volumes,
-// an error is returned.
-func (vc *attachDetachVolumeCache) PodExists(podName, nodeName, volumeName string) (bool, error) {
-	vc.RLock()
-	defer vc.RUnlock()
-
-	volObj, volExists := vc.volumesManaged[volumeName]
-	if !volExists {
-		return false,
-			fmt.Errorf(
-				"failed to check if node %q exists under volume %q--no volume with that name exists in the list of managed volumes",
-				nodeName,
-				volumeName)
-	}
-
-	nodeObj, nodeExists := volObj.attachedNodes[nodeName]
-	if !nodeExists {
-		return false, fmt.Errorf(
-			"failed to check if pod %q exists under node %q volume %q--no node with that name exists in the list of attached nodes for that volume",
-			podName,
-			nodeName,
-			volumeName)
-	}
-
-	_, podExists := nodeObj.scheduledPods[podName]
-	return podExists, nil
-}

pkg/controller/volume/cache/attach_detach_volume_cache_test.go

@@ -1,579 +0,0 @@
-/*
-Copyright 2016 The Kubernetes Authors All rights reserved.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package cache
-
-import "testing"
-
-func Test_AddVolume_Positive_NewVolume(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-
-	// Act
-	vc.AddVolume(volumeName)
-
-	// Assert
-	volumeExists := vc.VolumeExists(volumeName)
-	if !volumeExists {
-		t.Fatalf("Added volume %q does not exist, it should.", volumeName)
-	}
-}
-
-func Test_AddVolume_Positive_ExistingVolume(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	vc.AddVolume(volumeName)
-
-	// Assert
-	volumeExists := vc.VolumeExists(volumeName)
-	if !volumeExists {
-		t.Fatalf("Added volume %q does not exist, it should.", volumeName)
-	}
-}
-
-func Test_AddNode_Positive_NewNodeVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	nodeErr := vc.AddNode(nodeName, volumeName)
-
-	// Assert
-	if nodeErr != nil {
-		t.Fatalf("AddNode failed. Expected: <no error> Actual: <%v>", nodeErr)
-	}
-
-	nodeExists, nodeExistsErr := vc.NodeExists(nodeName, volumeName)
-	if nodeExistsErr != nil {
-		t.Fatalf("NodeExists failed. Expected: <no error> Actual: <%v>", nodeExistsErr)
-	}
-	if !nodeExists {
-		t.Fatalf("Added node %q does not exist, it should.", nodeName)
-	}
-}
-
-func Test_AddNode_Positive_NodeExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	vc.AddVolume(volumeName)
-	nodeErr1 := vc.AddNode(nodeName, volumeName)
-	if nodeErr1 != nil {
-		t.Fatalf("First call to AddNode failed. Expected: <no error> Actual: <%v>", nodeErr1)
-	}
-
-	// Act
-	nodeErr2 := vc.AddNode(nodeName, volumeName)
-
-	// Assert
-	if nodeErr2 != nil {
-		t.Fatalf("Second call to AddNode failed. Expected: <no error> Actual: <%v>", nodeErr2)
-	}
-
-	nodeExists, nodeExistsErr := vc.NodeExists(nodeName, volumeName)
-	if nodeExistsErr != nil {
-		t.Fatalf("NodeExists failed. Expected: <no error> Actual: <%v>", nodeExistsErr)
-	}
-	if !nodeExists {
-		t.Fatalf("Added node %q does not exist, it should.", nodeName)
-	}
-}
-
-func Test_AddNode_Negative_NewNodeVolumeDoesntExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-
-	// Act
-	nodeErr := vc.AddNode(nodeName, volumeName)
-
-	// Assert
-	if nodeErr == nil {
-		t.Fatalf("AddNode did not fail. Expected: <\"failed to add node...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-
-	nodeExists, nodeExistsErr := vc.NodeExists(nodeName, volumeName)
-	if nodeExistsErr == nil {
-		t.Fatalf("NodeExists did not fail. Expected: <failed to check if node...no volume with that name exists in the list of managed volumes> Actual: <no error>")
-	}
-	if nodeExists {
-		t.Fatalf("Added node %q exists, it should not.", nodeName)
-	}
-}
-
-func Test_AddPod_Positive_NewPodNodeExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-	vc.AddVolume(volumeName)
-	nodeErr := vc.AddNode(nodeName, volumeName)
-	if nodeErr != nil {
-		t.Fatalf("AddNode failed. Expected: <no error> Actual: <%v>", nodeErr)
-	}
-
-	// Act
-	podErr := vc.AddPod(podName, nodeName, volumeName)
-
-	// Assert
-	if podErr != nil {
-		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podErr)
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr != nil {
-		t.Fatalf("PodExists failed. Expected: <no error> Actual: <%v>", podExistsErr)
-	}
-	if !podExists {
-		t.Fatalf("Added pod %q does not exist, it should.", podName)
-	}
-}
-
-func Test_AddPod_Positive_PodExistsNodeExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-	vc.AddVolume(volumeName)
-	nodeErr := vc.AddNode(nodeName, volumeName)
-	if nodeErr != nil {
-		t.Fatalf("AddNode failed. Expected: <no error> Actual: <%v>", nodeErr)
-	}
-	podErr1 := vc.AddPod(podName, nodeName, volumeName)
-	if podErr1 != nil {
-		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podErr1)
-	}
-
-	// Act
-	podErr2 := vc.AddPod(podName, nodeName, volumeName)
-
-	// Assert
-	if podErr2 != nil {
-		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podErr2)
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr != nil {
-		t.Fatalf("PodExists failed. Expected: <no error> Actual: <%v>", podExistsErr)
-	}
-	if !podExists {
-		t.Fatalf("Added pod %q does not exist, it should.", podName)
-	}
-}
-
-func Test_AddPod_Negative_NewPodNodeDoesntExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	podErr := vc.AddPod(podName, nodeName, volumeName)
-
-	// Assert
-	if podErr == nil {
-		t.Fatalf("AddPod did not fail. Expected: <\"failed to add pod...no node with that name exists in the list of attached nodes for that volume\"> Actual: <no error>")
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr == nil {
-		t.Fatalf("PodExists did not fail. Expected: <\"failed to check if pod exists...no node with that name exists in the list of attached nodes for that volume\"> Actual: <no error>")
-	}
-	if podExists {
-		t.Fatalf("Added pod %q exists, it should not.", podName)
-	}
-}
-
-func Test_AddPod_Negative_NewPodNodeDoesntExistsVolumeDoesntExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-
-	// Act
-	podErr := vc.AddPod(podName, nodeName, volumeName)
-
-	// Assert
-	if podErr == nil {
-		t.Fatalf("AddPod did not fail. Expected: <\"failed to add pod...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr == nil {
-		t.Fatalf("PodExists did not fail. Expected: <\"failed to check if node...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-	if podExists {
-		t.Fatalf("Added pod %q exists, it should not.", podName)
-	}
-}
-
-func Test_VolumeExists_Positive_NonExistantVolume(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	notAddedVolumeName := "volume-not-added-name"
-
-	// Act
-	notAddedVolumeExists := vc.VolumeExists(notAddedVolumeName)
-
-	// Assert
-	if notAddedVolumeExists {
-		t.Fatalf("Not added volume %q exists, it should not.", notAddedVolumeName)
-	}
-}
-
-func Test_NodeExists_Positive_NonExistantNodeVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	notAddedNodeName := "node-not-added-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	notAddedNodeExists, notAddedNodeExistsErr := vc.NodeExists(notAddedNodeName, volumeName)
-
-	// Assert
-	if notAddedNodeExistsErr != nil {
-		t.Fatalf("NodeExists failed. Expected: <no error> Actual: <%v>", notAddedNodeExistsErr)
-	}
-	if notAddedNodeExists {
-		t.Fatalf("Not added node %q exists, it should not.", notAddedNodeName)
-	}
-}
-
-func Test_NodeExists_Negative_NonExistantNodeVolumeDoesntExist(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	notAddedNodeName := "node-not-added-name"
-
-	// Act
-	notAddedNodeExists, notAddedNodeExistsErr := vc.NodeExists(notAddedNodeName, volumeName)
-
-	// Assert
-	if notAddedNodeExistsErr == nil {
-		t.Fatalf("NodeExists did not fail. Expected: <failed to check if node...no volume with that name exists in the list of managed volumes> Actual: <no error>")
-	}
-	if notAddedNodeExists {
-		t.Fatalf("Added node %q exists, it should not.", notAddedNodeName)
-	}
-}
-
-func Test_PodExists_Positive_NonExistantPodNodeExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	notAddedPodName := "pod-not-added-name"
-	vc.AddVolume(volumeName)
-	addNodeErr := vc.AddNode(nodeName, volumeName)
-	if addNodeErr != nil {
-		t.Fatalf("AddNode for node %q failed. Expected: <no error> Actual: <%v>", nodeName, addNodeErr)
-	}
-
-	// Act
-	notAddedPodExists, notAddedPodExistsErr := vc.PodExists(notAddedPodName, nodeName, volumeName)
-
-	// Assert
-	if notAddedPodExistsErr != nil {
-		t.Fatalf("PodExists failed. Expected: <no error> Actual: <%v>", notAddedPodExistsErr)
-	}
-	if notAddedPodExists {
-		t.Fatalf("Not added pod %q exists, it should not.", notAddedPodName)
-	}
-}
-
-func Test_PodExists_Negative_NonExistantPodNodeDoesntExistVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	notAddedPodName := "pod-not-added-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	notAddedPodExists, notAddedPodExistsErr := vc.PodExists(notAddedPodName, nodeName, volumeName)
-
-	// Assert
-	if notAddedPodExistsErr == nil {
-		t.Fatalf("PodExists did not fail. Expected: <\"failed to check if pod exists...no node with that name exists in the list of attached nodes for that volume\"> Actual: <no error>")
-	}
-	if notAddedPodExists {
-		t.Fatalf("Added pod %q exists, it should not.", notAddedPodName)
-	}
-}
-
-func Test_PodExists_Negative_NonExistantPodNodeDoesntExistVolumeDoesntExist(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	notAddedPodName := "pod-not-added-name"
-
-	// Act
-	notAddedPodExists, notAddedPodExistsErr := vc.PodExists(notAddedPodName, nodeName, volumeName)
-
-	// Assert
-	if notAddedPodExistsErr == nil {
-		t.Fatalf("PodExists did not fail. Expected: <\"failed to check if node...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-	if notAddedPodExists {
-		t.Fatalf("Added pod %q exists, it should not.", notAddedPodName)
-	}
-}
-
-func Test_DeleteVolume_Positive_VolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	deleteVolumeErr := vc.DeleteVolume(volumeName)
-
-	// Assert
-	if deleteVolumeErr != nil {
-		t.Fatalf("DeleteVolume failed. Expected: <no error> Actual: <%v>", deleteVolumeErr)
-	}
-
-	volumeExists := vc.VolumeExists(volumeName)
-	if volumeExists {
-		t.Fatalf("Deleted volume %q still exists, it should not.", volumeName)
-	}
-}
-
-func Test_DeleteVolume_Negative_VolumeDoesntExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	notAddedVolumeName := "volume-not-added-name"
-
-	// Act
-	deleteVolumeErr := vc.DeleteVolume(notAddedVolumeName)
-
-	// Assert
-	if deleteVolumeErr == nil {
-		t.Fatalf("DeleteVolume did not fail. Expected: <\"failed to delete volume...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-
-	notAddedVolumeExists := vc.VolumeExists(notAddedVolumeName)
-	if notAddedVolumeExists {
-		t.Fatalf("Not added volume %q exists, it should not.", notAddedVolumeName)
-	}
-}
-
-func Test_DeleteNode_Positive_NodeExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	vc.AddVolume(volumeName)
-	nodeErr := vc.AddNode(nodeName, volumeName)
-	if nodeErr != nil {
-		t.Fatalf("AddNode failed. Expected: <no error> Actual: <%v>", nodeErr)
-	}
-
-	// Act
-	deleteNodeErr := vc.DeleteNode(nodeName, volumeName)
-
-	// Assert
-	if deleteNodeErr != nil {
-		t.Fatalf("DeleteNode failed. Expected: <no error> Actual: <%v>", deleteNodeErr)
-	}
-
-	nodeExists, nodeExistsErr := vc.NodeExists(nodeName, volumeName)
-	if nodeExistsErr != nil {
-		t.Fatalf("NodeExists failed. Expected: <no error> Actual: <%v>", nodeExistsErr)
-	}
-	if nodeExists {
-		t.Fatalf("Deleted node %q still exists, it should not.", nodeName)
-	}
-}
-
-func Test_DeleteNode_Negative_NodeDoesntExistVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	notAddedNodeName := "node-not-added-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	deleteNodeErr := vc.DeleteNode(notAddedNodeName, volumeName)
-
-	// Assert
-	if deleteNodeErr == nil {
-		t.Fatalf("DeleteNode did not fail. Expected: <\"failed to delete node...no node with the that name exists in the list of attached nodes for that volume\"> Actual: <no error>")
-	}
-
-	notAddedNodeExists, notAddedNodeExistsErr := vc.NodeExists(notAddedNodeName, volumeName)
-	if notAddedNodeExistsErr != nil {
-		t.Fatalf("NodeExists failed. Expected: <no error> Actual: <%v>", notAddedNodeExistsErr)
-	}
-	if notAddedNodeExists {
-		t.Fatalf("Not added node %q exists, it should not.", notAddedNodeName)
-	}
-}
-
-func Test_DeleteNode_Negative_NodeDoesntExistVolumeDoesntExist(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	notAddedNodeName := "node-not-added-name"
-
-	// Act
-	deleteNodeErr := vc.DeleteNode(notAddedNodeName, volumeName)
-
-	// Assert
-	if deleteNodeErr == nil {
-		t.Fatalf("DeleteNode did not fail. Expected: <\"failed to delete node...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-
-	notAddedNodeExists, notAddedNodeExistsErr := vc.NodeExists(notAddedNodeName, volumeName)
-	if notAddedNodeExistsErr == nil {
-		t.Fatalf("NodeExists did not fail. Expected: <\failed to check if node...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-	if notAddedNodeExists {
-		t.Fatalf("Not added node %q exists, it should not.", notAddedNodeName)
-	}
-}
-
-func Test_DeletePod_Positive_PodExistsNodeExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-	vc.AddVolume(volumeName)
-	nodeErr := vc.AddNode(nodeName, volumeName)
-	if nodeErr != nil {
-		t.Fatalf("AddNode failed. Expected: <no error> Actual: <%v>", nodeErr)
-	}
-	podErr := vc.AddPod(podName, nodeName, volumeName)
-	if podErr != nil {
-		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podErr)
-	}
-
-	// Act
-	deletePodErr := vc.DeletePod(podName, nodeName, volumeName)
-
-	// Assert
-	if deletePodErr != nil {
-		t.Fatalf("DeletePod failed. Expected: <no error> Actual: <%v>", podName)
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr != nil {
-		t.Fatalf("PodExists failed. Expected: <no error> Actual: <%v>", podExistsErr)
-	}
-	if podExists {
-		t.Fatalf("Deleted pod %q still exists, it should not.", podName)
-	}
-}
-
-func Test_DeletePod_Positive_PodDoesntExistNodeExistsVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-	vc.AddVolume(volumeName)
-	nodeErr := vc.AddNode(nodeName, volumeName)
-	if nodeErr != nil {
-		t.Fatalf("AddNode failed. Expected: <no error> Actual: <%v>", nodeErr)
-	}
-
-	// Act
-	deletePodErr := vc.DeletePod(podName, nodeName, volumeName)
-
-	// Assert
-	if deletePodErr == nil {
-		t.Fatalf("DeletePod did not fail. Expected: <\"failed to delete pod...no pod with that name exists in the list of scheduled pods under that node/volume\"> Actual: <no error>")
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr != nil {
-		t.Fatalf("PodExists failed. Expected: <no error> Actual: <%v>", podExistsErr)
-	}
-	if podExists {
-		t.Fatalf("Deleted pod %q still exists, it should not.", podName)
-	}
-}
-
-func Test_DeletePod_Positive_PodDoesntExistNodeDoesntExistVolumeExists(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-	vc.AddVolume(volumeName)
-
-	// Act
-	deletePodErr := vc.DeletePod(podName, nodeName, volumeName)
-
-	// Assert
-	if deletePodErr == nil {
-		t.Fatalf("DeletePod did not fail. Expected: <\"failed to delete pod...no node with that name exists in the list of attached nodes for that volume\"> Actual: <no error>")
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr == nil {
-		t.Fatalf("PodExists did not fail. Expected: <\failed to check if pod...no node with that name exists in the list of attached nodes for that volume\"> Actual: <no error>")
-	}
-	if podExists {
-		t.Fatalf("Deleted pod %q still exists, it should not.", podName)
-	}
-}
-
-func Test_DeletePod_Positive_PodDoesntExistNodeDoesntExistVolumeDoesntExist(t *testing.T) {
-	// Arrange
-	vc := NewAttachDetachVolumeCache()
-	volumeName := "volume-name"
-	nodeName := "node-name"
-	podName := "pod-name"
-
-	// Act
-	deletePodErr := vc.DeletePod(podName, nodeName, volumeName)
-
-	// Assert
-	if deletePodErr == nil {
-		t.Fatalf("DeletePod did not fail. Expected: <\"failed to delete pod...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-
-	podExists, podExistsErr := vc.PodExists(podName, nodeName, volumeName)
-	if podExistsErr == nil {
-		t.Fatalf("PodExists did not fail. Expected: <\failed to check if pod...no volume with that name exists in the list of managed volumes\"> Actual: <no error>")
-	}
-	if podExists {
-		t.Fatalf("Deleted pod %q still exists, it should not.", podName)
-	}
-}
-
-/*
-	t.Fatalf("%q", notAddedNodeExistsErr)
-*/

pkg/controller/volume/cache/desired_state_of_world.go

@@ -0,0 +1,301 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/*
+Package cache implements data structures used by the attach/detach controller
+to keep track of volumes, the nodes they are attached to, and the pods that
+reference them.
+*/
+package cache
+
+import (
+	"fmt"
+	"sync"
+
+	"k8s.io/kubernetes/pkg/volume"
+)
+
+// DesiredStateOfWorld defines a set of thread-safe operations supported on
+// the attach/detach controller's desired state of the world cache.
+// This cache contains nodes->volumes->pods where nodes are all the nodes
+// managed by the attach/detach controller, volumes are all the volumes that
+// should be attached to the specified node, and pods are the pods that
+// reference the volume and are scheduled to that node.
+type DesiredStateOfWorld interface {
+	// AddNode adds the given node to the list of nodes managed by the attach/
+	// detach controller.
+	// If the node already exists this is a no-op.
+	AddNode(nodeName string)
+
+	// AddPod adds the given pod to the list of pods that reference the
+	// specified volume and is scheduled to the specified node.
+	// A unique volumeName is generated from the volumeSpec and returned on
+	// success.
+	// If the pod already exists under the specified volume, this is a no-op.
+	// If volumeSpec is not an attachable volume plugin, an error is returned.
+	// If no volume with the name volumeName exists in the list of volumes that
+	// should be attached to the specified node, the volume is implicitly added.
+	// If no node with the name nodeName exists in list of nodes managed by the
+	// attach/detach attached controller, an error is returned.
+	AddPod(podName string, volumeSpec *volume.Spec, nodeName string) (string, error)
+
+	// DeleteNode removes the given node from the list of nodes managed by the
+	// attach/detach controller.
+	// If the node does not exist this is a no-op.
+	// If the node exists but has 1 or more child volumes, an error is returned.
+	DeleteNode(nodeName string) error
+
+	// DeletePod removes the given pod from the list of pods that reference the
+	// specified volume and are scheduled to the specified node.
+	// If no pod exists in the list of pods that reference the specified volume
+	// and are scheduled to the specified node, this is a no-op.
+	// If a node with the name nodeName does not exist in the list of nodes
+	// managed by the attach/detach attached controller, this is a no-op.
+	// If no volume with the name volumeName exists in the list of managed
+	// volumes under the specified node, this is a no-op.
+	// If after deleting the pod, the specified volume contains no other child
+	// pods, the volume is also deleted.
+	DeletePod(podName, volumeName, nodeName string)
+
+	// NodeExists returns true if the node with the specified name exists in
+	// the list of nodes managed by the attach/detach controller.
+	NodeExists(nodeName string) bool
+
+	// VolumeExists returns true if the volume with the specified name exists
+	// in the list of volumes that should be attached to the specified node by
+	// the attach detach controller.
+	VolumeExists(volumeName, nodeName string) bool
+
+	// GetVolumesToAttach generates and returns a list of volumes to attach
+	// and the nodes they should be attached to based on the current desired
+	// state of the world.
+	GetVolumesToAttach() []VolumeToAttach
+}
+
+// VolumeToAttach represents a volume that should be attached to a node.
+type VolumeToAttach struct {
+	// VolumeName is the unique identifier for the volume that should be
+	// attached.
+	VolumeName string
+
+	// VolumeSpec is a volume spec containing the specification for the volume
+	// that should be attached.
+	VolumeSpec *volume.Spec
+
+	// NodeName is the identifier for the node that the volume should be
+	// attached to.
+	NodeName string
+}
+
+// NewDesiredStateOfWorld returns a new instance of DesiredStateOfWorld.
+func NewDesiredStateOfWorld(volumePluginMgr *volume.VolumePluginMgr) DesiredStateOfWorld {
+	return &desiredStateOfWorld{
+		nodesManaged:    make(map[string]nodeManaged),
+		volumePluginMgr: volumePluginMgr,
+	}
+}
+
+type desiredStateOfWorld struct {
+	// nodesManaged is a map containing the set of nodes managed by the attach/
+	// detach controller. The key in this map is the name of the node and the
+	// value is a node object containing more information about the node.
+	nodesManaged map[string]nodeManaged
+	// volumePluginMgr is the volume plugin manager used to create volume
+	// plugin objects.
+	volumePluginMgr *volume.VolumePluginMgr
+	sync.RWMutex
+}
+
+// nodeManaged represents a node that is being managed by the attach/detach
+// controller.
+type nodeManaged struct {
+	// nodName contains the name of this node.
+	nodeName string
+
+	// volumesToAttach is a map containing the set of volumes that should be
+	// attached to this node. The key in the map is the name of the volume and
+	// the value is a pod object containing more information about the volume.
+	volumesToAttach map[string]volumeToAttach
+}
+
+// The volume object represents a volume that should be attached to a node.
+type volumeToAttach struct {
+	// volumeName contains the unique identifier for this volume.
+	volumeName string
+
+	// spec is the volume spec containing the specification for this volume.
+	// Used to generate the volume plugin object, and passed to attach/detach
+	// methods.
+	spec *volume.Spec
+
+	// scheduledPods is a map containing the set of pods that reference this
+	// volume and are scheduled to the underlying node. The key in the map is
+	// the name of the pod and the value is a pod object containing more
+	// information about the pod.
+	scheduledPods map[string]pod
+}
+
+// The pod object represents a pod that references the underlying volume and is
+// scheduled to the underlying node.
+type pod struct {
+	// podName contains the name of this pod.
+	podName string
+}
+
+func (dsw *desiredStateOfWorld) AddNode(nodeName string) {
+	dsw.Lock()
+	defer dsw.Unlock()
+
+	if _, nodeExists := dsw.nodesManaged[nodeName]; !nodeExists {
+		dsw.nodesManaged[nodeName] = nodeManaged{
+			nodeName:        nodeName,
+			volumesToAttach: make(map[string]volumeToAttach),
+		}
+	}
+}
+
+func (dsw *desiredStateOfWorld) AddPod(podName string, volumeSpec *volume.Spec, nodeName string) (string, error) {
+	dsw.Lock()
+	defer dsw.Unlock()
+
+	nodeObj, nodeExists := dsw.nodesManaged[nodeName]
+	if !nodeExists {
+		return "", fmt.Errorf(
+			"no node with the name %q exists in the list of managed nodes",
+			nodeName)
+	}
+
+	attachableVolumePlugin, err := dsw.volumePluginMgr.FindAttachablePluginBySpec(volumeSpec)
+	if err != nil || attachableVolumePlugin == nil {
+		return "", fmt.Errorf(
+			"failed to get AttachablePlugin from volumeSpec for volume %q err=%v",
+			volumeSpec.Name(),
+			err)
+	}
+
+	volumeName, err := attachableVolumePlugin.GetUniqueVolumeName(volumeSpec)
+	if err != nil {
+		return "", fmt.Errorf(
+			"failed to GetUniqueVolumeName from AttachablePlugin for volumeSpec %q err=%v",
+			volumeSpec.Name(),
+			err)
+	}
+
+	volumeObj, volumeExists := nodeObj.volumesToAttach[volumeName]
+	if !volumeExists {
+		volumeObj = volumeToAttach{
+			volumeName:    volumeName,
+			spec:          volumeSpec,
+			scheduledPods: make(map[string]pod),
+		}
+		dsw.nodesManaged[nodeName].volumesToAttach[volumeName] = volumeObj
+	}
+
+	if _, podExists := volumeObj.scheduledPods[podName]; !podExists {
+		dsw.nodesManaged[nodeName].volumesToAttach[volumeName].scheduledPods[podName] =
+			pod{
+				podName: podName,
+			}
+	}
+
+	return volumeName, nil
+}
+
+func (dsw *desiredStateOfWorld) DeleteNode(nodeName string) error {
+	dsw.Lock()
+	defer dsw.Unlock()
+
+	nodeObj, nodeExists := dsw.nodesManaged[nodeName]
+	if !nodeExists {
+		return nil
+	}
+
+	if len(nodeObj.volumesToAttach) > 0 {
+		return fmt.Errorf(
+			"failed to delete node %q from list of nodes managed by attach/detach controller--the node still contains %v volumes in its list of volumes to attach",
+			nodeName,
+			len(nodeObj.volumesToAttach))
+	}
+
+	delete(
+		dsw.nodesManaged,
+		nodeName)
+	return nil
+}
+
+func (dsw *desiredStateOfWorld) DeletePod(podName, volumeName, nodeName string) {
+	dsw.Lock()
+	defer dsw.Unlock()
+
+	nodeObj, nodeExists := dsw.nodesManaged[nodeName]
+	if !nodeExists {
+		return
+	}
+
+	volumeObj, volumeExists := nodeObj.volumesToAttach[volumeName]
+	if !volumeExists {
+		return
+	}
+	if _, podExists := volumeObj.scheduledPods[podName]; !podExists {
+		return
+	}
+
+	delete(
+		dsw.nodesManaged[nodeName].volumesToAttach[volumeName].scheduledPods,
+		podName)
+
+	if len(volumeObj.scheduledPods) == 0 {
+		delete(
+			dsw.nodesManaged[nodeName].volumesToAttach,
+			volumeName)
+	}
+}
+
+func (dsw *desiredStateOfWorld) NodeExists(nodeName string) bool {
+	dsw.RLock()
+	defer dsw.RUnlock()
+
+	_, nodeExists := dsw.nodesManaged[nodeName]
+	return nodeExists
+}
+
+func (dsw *desiredStateOfWorld) VolumeExists(volumeName, nodeName string) bool {
+	dsw.RLock()
+	defer dsw.RUnlock()
+
+	nodeObj, nodeExists := dsw.nodesManaged[nodeName]
+	if nodeExists {
+		if _, volumeExists := nodeObj.volumesToAttach[volumeName]; volumeExists {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (dsw *desiredStateOfWorld) GetVolumesToAttach() []VolumeToAttach {
+	dsw.RLock()
+	defer dsw.RUnlock()
+
+	volumesToAttach := make([]VolumeToAttach, 0 /* len */, len(dsw.nodesManaged) /* cap */)
+	for nodeName, nodeObj := range dsw.nodesManaged {
+		for volumeName, volumeObj := range nodeObj.volumesToAttach {
+			volumesToAttach = append(volumesToAttach, VolumeToAttach{NodeName: nodeName, VolumeName: volumeName, VolumeSpec: volumeObj.spec})
+		}
+	}
+
+	return volumesToAttach
+}

pkg/controller/volume/cache/desired_state_of_world_test.go

@@ -0,0 +1,974 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cache
+
+import (
+	"testing"
+
+	controllervolumetesting "k8s.io/kubernetes/pkg/controller/volume/testing"
+)
+
+func Test_AddNode_Positive_NewNode(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+
+	// Act
+	dsw.AddNode(nodeName)
+
+	// Assert
+	nodeExists := dsw.NodeExists(nodeName)
+	if !nodeExists {
+		t.Fatalf("Added node %q does not exist, it should.", nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_AddNode_Positive_ExistingVolume(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+
+	// Act
+	dsw.AddNode(nodeName)
+
+	// Assert
+	nodeExists := dsw.NodeExists(nodeName)
+	if !nodeExists {
+		t.Fatalf("Added node %q does not exist, it should.", nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+func Test_AddNode_Positive_ExistingNode(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+
+	// Act
+	dsw.AddNode(nodeName)
+
+	// Assert
+	nodeExists := dsw.NodeExists(nodeName)
+	if !nodeExists {
+		t.Fatalf("Added node %q does not exist, it should.", nodeName)
+	}
+
+	// Act
+	dsw.AddNode(nodeName)
+
+	// Assert
+	nodeExists = dsw.NodeExists(nodeName)
+	if !nodeExists {
+		t.Fatalf("Added node %q does not exist, it should.", nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_AddPod_Positive_NewPodNodeExistsVolumeDoesntExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	// Act
+	generatedVolumeName, podErr := dsw.AddPod(podName, volumeSpec, nodeName)
+
+	// Assert
+	if podErr != nil {
+		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podErr)
+	}
+
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			podName,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolumeName, volumeName)
+}
+
+func Test_AddPod_Positive_NewPodNodeExistsVolumeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	pod1Name := "pod1-name"
+	pod2Name := "pod2-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	// Act
+	generatedVolumeName, podErr := dsw.AddPod(pod1Name, volumeSpec, nodeName)
+
+	// Assert
+	if podErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod1Name,
+			podErr)
+	}
+
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			pod1Name,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	// Act
+	generatedVolumeName, podErr = dsw.AddPod(pod2Name, volumeSpec, nodeName)
+
+	// Assert
+	if podErr != nil {
+		t.Fatalf("AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod2Name,
+			podErr)
+	}
+
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			pod1Name,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolumeName, volumeName)
+}
+
+func Test_AddPod_Positive_PodExistsNodeExistsVolumeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	// Act
+	generatedVolumeName, podErr := dsw.AddPod(podName, volumeSpec, nodeName)
+
+	// Assert
+	if podErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			podName,
+			podErr)
+	}
+
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			podName,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	// Act
+	generatedVolumeName, podErr = dsw.AddPod(podName, volumeSpec, nodeName)
+
+	// Assert
+	if podErr != nil {
+		t.Fatalf("AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			podName,
+			podErr)
+	}
+
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			podName,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolumeName, volumeName)
+}
+
+func Test_AddPod_Negative_NewPodNodeDoesntExistVolumeDoesntExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	// Act
+	_, podErr := dsw.AddPod(podName, volumeSpec, nodeName)
+
+	// Assert
+	if podErr == nil {
+		t.Fatalf("AddPod did not fail. Expected: <\"failed to add pod...no node with that name exists in the list of managed nodes\"> Actual: <no error>")
+	}
+
+	volumeExists = dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_DeleteNode_Positive_NodeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+
+	// Act
+	err := dsw.DeleteNode(nodeName)
+
+	// Assert
+	if err != nil {
+		t.Fatalf("DeleteNode failed. Expected: <no error> Actual: <%v>", err)
+	}
+
+	nodeExists := dsw.NodeExists(nodeName)
+	if nodeExists {
+		t.Fatalf("Deleted node %q still exists, it should not.", nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_DeleteNode_Positive_NodeDoesntExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	notAddedNodeName := "node-not-added-name"
+
+	// Act
+	err := dsw.DeleteNode(notAddedNodeName)
+
+	// Assert
+	if err != nil {
+		t.Fatalf("DeleteNode failed. Expected: <no error> Actual: <%v>", err)
+	}
+
+	nodeExists := dsw.NodeExists(notAddedNodeName)
+	if nodeExists {
+		t.Fatalf("Deleted node %q still exists, it should not.", notAddedNodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_DeleteNode_Negative_NodeExistsHasChildVolumes(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	generatedVolumeName, podAddErr := dsw.AddPod(podName, volumeSpec, nodeName)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			podName,
+			podAddErr)
+	}
+
+	// Act
+	err := dsw.DeleteNode(nodeName)
+
+	// Assert
+	if err == nil {
+		t.Fatalf("DeleteNode did not fail. Expected: <\"\"> Actual: <no error>")
+	}
+
+	nodeExists := dsw.NodeExists(nodeName)
+	if !nodeExists {
+		t.Fatalf("Node %q no longer exists, it should.", nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolumeName, volumeName)
+}
+
+func Test_DeletePod_Positive_PodExistsNodeExistsVolumeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	generatedVolumeName, podAddErr := dsw.AddPod(podName, volumeSpec, nodeName)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			podName,
+			podAddErr)
+	}
+	volumeExists := dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			podName,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	// Act
+	dsw.DeletePod(podName, generatedVolumeName, nodeName)
+
+	// Assert
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Deleted pod %q from volume %q/node %q. Volume should also be deleted but it still exists.",
+			podName,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_DeletePod_Positive_2PodsExistNodeExistsVolumesExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	pod1Name := "pod1-name"
+	pod2Name := "pod2-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	generatedVolumeName1, pod1AddErr := dsw.AddPod(pod1Name, volumeSpec, nodeName)
+	if pod1AddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod1Name,
+			pod1AddErr)
+	}
+	generatedVolumeName2, pod2AddErr := dsw.AddPod(pod2Name, volumeSpec, nodeName)
+	if pod2AddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod2Name,
+			pod2AddErr)
+	}
+	if generatedVolumeName1 != generatedVolumeName2 {
+		t.Fatalf(
+			"Generated volume names for the same volume should be the same but they are not: %q and %q",
+			generatedVolumeName1,
+			generatedVolumeName2)
+	}
+	volumeExists := dsw.VolumeExists(generatedVolumeName1, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Volume %q does not exist under node %q, it should.",
+			generatedVolumeName1,
+			nodeName)
+	}
+
+	// Act
+	dsw.DeletePod(pod1Name, generatedVolumeName1, nodeName)
+
+	// Assert
+	volumeExists = dsw.VolumeExists(generatedVolumeName1, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Volume %q under node %q should still exist, but it does not.",
+			generatedVolumeName1,
+			nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolumeName1, volumeName)
+}
+
+func Test_DeletePod_Positive_PodDoesNotExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	pod1Name := "pod1-name"
+	pod2Name := "pod2-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	generatedVolumeName, pod1AddErr := dsw.AddPod(pod1Name, volumeSpec, nodeName)
+	if pod1AddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod1Name,
+			pod1AddErr)
+	}
+	volumeExists := dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			pod1Name,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	// Act
+	dsw.DeletePod(pod2Name, generatedVolumeName, nodeName)
+
+	// Assert
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q does not exist, it should.",
+			generatedVolumeName,
+			nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolumeName, volumeName)
+}
+
+func Test_DeletePod_Positive_NodeDoesNotExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	node1Name := "node1-name"
+	dsw.AddNode(node1Name)
+	generatedVolumeName, podAddErr := dsw.AddPod(podName, volumeSpec, node1Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			podName,
+			podAddErr)
+	}
+	volumeExists := dsw.VolumeExists(generatedVolumeName, node1Name)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			podName,
+			generatedVolumeName,
+			node1Name)
+	}
+	node2Name := "node2-name"
+
+	// Act
+	dsw.DeletePod(podName, generatedVolumeName, node2Name)
+
+	// Assert
+	volumeExists = dsw.VolumeExists(generatedVolumeName, node1Name)
+	if !volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q does not exist, it should.",
+			generatedVolumeName,
+			node1Name)
+	}
+	volumeExists = dsw.VolumeExists(generatedVolumeName, node2Name)
+	if volumeExists {
+		t.Fatalf(
+			"node %q exists, it should not.",
+			node2Name)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, node1Name, generatedVolumeName, volumeName)
+}
+
+func Test_DeletePod_Positive_VolumeDoesNotExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	podName := "pod-name"
+	volume1Name := "volume1-name"
+	volume1Spec := controllervolumetesting.GetTestVolumeSpec(volume1Name, volume1Name)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	generatedVolume1Name, podAddErr := dsw.AddPod(podName, volume1Spec, nodeName)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			podName,
+			podAddErr)
+	}
+	volumeExists := dsw.VolumeExists(generatedVolume1Name, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Added pod %q to volume %q/node %q. Volume does not exist, it should.",
+			podName,
+			generatedVolume1Name,
+			nodeName)
+	}
+	volume2Name := "volume2-name"
+
+	// Act
+	dsw.DeletePod(podName, volume2Name, nodeName)
+
+	// Assert
+	volumeExists = dsw.VolumeExists(generatedVolume1Name, nodeName)
+	if !volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q does not exist, it should.",
+			generatedVolume1Name,
+			nodeName)
+	}
+	volumeExists = dsw.VolumeExists(volume2Name, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"volume %q exists, it should not.",
+			volume2Name)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolume1Name, volume1Name)
+}
+
+func Test_NodeExists_Positive_NodeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	notAddedNodeName := "node-not-added-name"
+
+	// Act
+	notAddedNodeExists := dsw.NodeExists(notAddedNodeName)
+
+	// Assert
+	if notAddedNodeExists {
+		t.Fatalf("Node %q exists, it should not.", notAddedNodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_NodeExists_Positive_NodeDoesntExist(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+
+	// Act
+	nodeExists := dsw.NodeExists(nodeName)
+
+	// Assert
+	if !nodeExists {
+		t.Fatalf("Node %q does not exist, it should.", nodeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_VolumeExists_Positive_VolumeExistsNodeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	generatedVolumeName, _ := dsw.AddPod(podName, volumeSpec, nodeName)
+
+	// Act
+	volumeExists := dsw.VolumeExists(generatedVolumeName, nodeName)
+
+	// Assert
+	if !volumeExists {
+		t.Fatalf("Volume %q does not exist, it should.", generatedVolumeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolumeName, volumeName)
+}
+
+func Test_VolumeExists_Positive_VolumeDoesntExistNodeExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	podName := "pod-name"
+	volume1Name := "volume1-name"
+	volume1Spec := controllervolumetesting.GetTestVolumeSpec(volume1Name, volume1Name)
+	generatedVolume1Name, podAddErr := dsw.AddPod(podName, volume1Spec, nodeName)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			podName,
+			podAddErr)
+	}
+	volume2Name := "volume2-name"
+
+	// Act
+	volumeExists := dsw.VolumeExists(volume2Name, nodeName)
+
+	// Assert
+	if volumeExists {
+		t.Fatalf("Volume %q exists, it should not.", volume2Name)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 1 {
+		t.Fatalf("len(volumesToAttach) Expected: <1> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, nodeName, generatedVolume1Name, volume1Name)
+}
+
+func Test_VolumeExists_Positive_VolumeDoesntExistNodeDoesntExists(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	nodeName := "node-name"
+	volumeName := "volume-name"
+
+	// Act
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+
+	// Assert
+	if volumeExists {
+		t.Fatalf("Volume %q exists, it should not.", volumeName)
+	}
+
+	volumesToAttach := dsw.GetVolumesToAttach()
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_GetVolumesToAttach_Positive_NoNodes(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+
+	// Act
+	volumesToAttach := dsw.GetVolumesToAttach()
+
+	// Assert
+	if len(volumesToAttach) > 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_GetVolumesToAttach_Positive_TwoNodes(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	node1Name := "node1-name"
+	node2Name := "node2-name"
+	dsw.AddNode(node1Name)
+	dsw.AddNode(node2Name)
+
+	// Act
+	volumesToAttach := dsw.GetVolumesToAttach()
+
+	// Assert
+	if len(volumesToAttach) != 0 {
+		t.Fatalf("len(volumesToAttach) Expected: <0> Actual: <%v>", len(volumesToAttach))
+	}
+}
+
+func Test_GetVolumesToAttach_Positive_TwoNodesOneVolumeEach(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	node1Name := "node1-name"
+	pod1Name := "pod1-name"
+	volume1Name := "volume1-name"
+	volume1Spec := controllervolumetesting.GetTestVolumeSpec(volume1Name, volume1Name)
+	dsw.AddNode(node1Name)
+	generatedVolume1Name, podAddErr := dsw.AddPod(pod1Name, volume1Spec, node1Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod1Name,
+			podAddErr)
+	}
+	node2Name := "node2-name"
+	pod2Name := "pod2-name"
+	volume2Name := "volume2-name"
+	volume2Spec := controllervolumetesting.GetTestVolumeSpec(volume2Name, volume2Name)
+	dsw.AddNode(node2Name)
+	generatedVolume2Name, podAddErr := dsw.AddPod(pod2Name, volume2Spec, node2Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod2Name,
+			podAddErr)
+	}
+
+	// Act
+	volumesToAttach := dsw.GetVolumesToAttach()
+
+	// Assert
+	if len(volumesToAttach) != 2 {
+		t.Fatalf("len(volumesToAttach) Expected: <2> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, node1Name, generatedVolume1Name, volume1Name)
+	verifyVolumeToAttach(t, volumesToAttach, node2Name, generatedVolume2Name, volume2Name)
+}
+
+func Test_GetVolumesToAttach_Positive_TwoNodesOneVolumeEachExtraPod(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	node1Name := "node1-name"
+	pod1Name := "pod1-name"
+	volume1Name := "volume1-name"
+	volume1Spec := controllervolumetesting.GetTestVolumeSpec(volume1Name, volume1Name)
+	dsw.AddNode(node1Name)
+	generatedVolume1Name, podAddErr := dsw.AddPod(pod1Name, volume1Spec, node1Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod1Name,
+			podAddErr)
+	}
+	node2Name := "node2-name"
+	pod2Name := "pod2-name"
+	volume2Name := "volume2-name"
+	volume2Spec := controllervolumetesting.GetTestVolumeSpec(volume2Name, volume2Name)
+	dsw.AddNode(node2Name)
+	generatedVolume2Name, podAddErr := dsw.AddPod(pod2Name, volume2Spec, node2Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod2Name,
+			podAddErr)
+	}
+	pod3Name := "pod3-name"
+	dsw.AddPod(pod3Name, volume2Spec, node2Name)
+	_, podAddErr = dsw.AddPod(pod3Name, volume2Spec, node2Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod3Name,
+			podAddErr)
+	}
+
+	// Act
+	volumesToAttach := dsw.GetVolumesToAttach()
+
+	// Assert
+	if len(volumesToAttach) != 2 {
+		t.Fatalf("len(volumesToAttach) Expected: <2> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, node1Name, generatedVolume1Name, volume1Name)
+	verifyVolumeToAttach(t, volumesToAttach, node2Name, generatedVolume2Name, volume2Name)
+}
+
+func Test_GetVolumesToAttach_Positive_TwoNodesThreeVolumes(t *testing.T) {
+	// Arrange
+	volumePluginMgr, _ := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := NewDesiredStateOfWorld(volumePluginMgr)
+	node1Name := "node1-name"
+	pod1Name := "pod1-name"
+	volume1Name := "volume1-name"
+	volume1Spec := controllervolumetesting.GetTestVolumeSpec(volume1Name, volume1Name)
+	dsw.AddNode(node1Name)
+	generatedVolume1Name, podAddErr := dsw.AddPod(pod1Name, volume1Spec, node1Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod1Name,
+			podAddErr)
+	}
+	node2Name := "node2-name"
+	pod2aName := "pod2a-name"
+	volume2Name := "volume2-name"
+	volume2Spec := controllervolumetesting.GetTestVolumeSpec(volume2Name, volume2Name)
+	dsw.AddNode(node2Name)
+	generatedVolume2Name1, podAddErr := dsw.AddPod(pod2aName, volume2Spec, node2Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod2aName,
+			podAddErr)
+	}
+	pod2bName := "pod2b-name"
+	generatedVolume2Name2, podAddErr := dsw.AddPod(pod2bName, volume2Spec, node2Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod2bName,
+			podAddErr)
+	}
+	if generatedVolume2Name1 != generatedVolume2Name2 {
+		t.Fatalf(
+			"Generated volume names for the same volume should be the same but they are not: %q and %q",
+			generatedVolume2Name1,
+			generatedVolume2Name2)
+	}
+	pod3Name := "pod3-name"
+	volume3Name := "volume3-name"
+	volume3Spec := controllervolumetesting.GetTestVolumeSpec(volume3Name, volume3Name)
+	generatedVolume3Name, podAddErr := dsw.AddPod(pod3Name, volume3Spec, node1Name)
+	if podAddErr != nil {
+		t.Fatalf(
+			"AddPod failed for pod %q. Expected: <no error> Actual: <%v>",
+			pod3Name,
+			podAddErr)
+	}
+
+	// Act
+	volumesToAttach := dsw.GetVolumesToAttach()
+
+	// Assert
+	if len(volumesToAttach) != 3 {
+		t.Fatalf("len(volumesToAttach) Expected: <3> Actual: <%v>", len(volumesToAttach))
+	}
+
+	verifyVolumeToAttach(t, volumesToAttach, node1Name, generatedVolume1Name, volume1Name)
+	verifyVolumeToAttach(t, volumesToAttach, node2Name, generatedVolume2Name1, volume2Name)
+	verifyVolumeToAttach(t, volumesToAttach, node1Name, generatedVolume3Name, volume3Name)
+}
+
+func verifyVolumeToAttach(
+	t *testing.T,
+	volumesToAttach []VolumeToAttach,
+	expectedNodeName,
+	expectedVolumeName,
+	expectedVolumeSpecName string) {
+	for _, volumeToAttach := range volumesToAttach {
+		if volumeToAttach.NodeName == expectedNodeName &&
+			volumeToAttach.VolumeName == expectedVolumeName &&
+			volumeToAttach.VolumeSpec.Name() == expectedVolumeSpecName {
+			return
+		}
+	}
+
+	t.Fatalf("volumesToAttach (%v) should contain %q/%q. It does not.", volumesToAttach, expectedVolumeName, expectedNodeName)
+}

pkg/controller/volume/reconciler/reconciler.go

@@ -0,0 +1,118 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package reconciler implements interfaces that attempt to reconcile the
+// desired state of the with the actual state of the world by triggering
+// actions.
+package reconciler
+
+import (
+	"time"
+
+	"github.com/golang/glog"
+	"k8s.io/kubernetes/pkg/controller/volume/attacherdetacher"
+	"k8s.io/kubernetes/pkg/controller/volume/cache"
+	"k8s.io/kubernetes/pkg/util/wait"
+)
+
+// Reconciler runs a periodic loop to reconcile the desired state of the with
+// the actual state of the world by triggering attach detach operations.
+type Reconciler interface {
+	// Starts running the reconcilation loop which executes periodically, checks
+	// if volumes that should be attached are attached and volumes that should
+	// be detached are detached. If not, it will trigger attach/detach
+	// operations to rectify.
+	Run(stopCh <-chan struct{})
+}
+
+// NewReconciler returns a new instance of Reconciler that waits loopPeriod
+// between successive executions.
+// loopPeriod is the ammount of time the reconciler loop waits between
+// successive executions.
+// maxSafeToDetachDuration is the max ammount of time the reconciler will wait
+// for the volume to deatch, after this it will detach the volume anyway
+// assuming the node is unavilable. If during this time the volume becomes used
+// by a new pod, the detach request will be aborted and the timer cleared.
+func NewReconciler(
+	loopPeriod time.Duration,
+	maxSafeToDetachDuration time.Duration,
+	desiredStateOfWorld cache.DesiredStateOfWorld,
+	actualStateOfWorld cache.ActualStateOfWorld,
+	attacherDetacher attacherdetacher.AttacherDetacher) Reconciler {
+	return &reconciler{
+		loopPeriod:              loopPeriod,
+		maxSafeToDetachDuration: maxSafeToDetachDuration,
+		desiredStateOfWorld:     desiredStateOfWorld,
+		actualStateOfWorld:      actualStateOfWorld,
+		attacherDetacher:        attacherDetacher,
+	}
+}
+
+type reconciler struct {
+	loopPeriod              time.Duration
+	maxSafeToDetachDuration time.Duration
+	desiredStateOfWorld     cache.DesiredStateOfWorld
+	actualStateOfWorld      cache.ActualStateOfWorld
+	attacherDetacher        attacherdetacher.AttacherDetacher
+}
+
+func (rc *reconciler) Run(stopCh <-chan struct{}) {
+	wait.Until(rc.reconciliationLoopFunc(), rc.loopPeriod, stopCh)
+}
+
+func (rc *reconciler) reconciliationLoopFunc() func() {
+	return func() {
+		// Ensure volumes that should be attached are attached.
+		for _, volumeToAttach := range rc.desiredStateOfWorld.GetVolumesToAttach() {
+			if rc.actualStateOfWorld.VolumeNodeExists(
+				volumeToAttach.VolumeName, volumeToAttach.NodeName) {
+				// Volume/Node exists, touch it to reset "safe to detach"
+				glog.V(12).Infof("Volume %q/Node %q is attached--touching.", volumeToAttach.VolumeName, volumeToAttach.NodeName)
+				_, err := rc.actualStateOfWorld.AddVolumeNode(
+					volumeToAttach.VolumeSpec, volumeToAttach.NodeName)
+				if err != nil {
+					glog.Errorf("Unexpected error on actualStateOfWorld.AddVolumeNode(): %v", err)
+				}
+			} else {
+				// Volume/Node doesn't exist, spawn a goroutine to attach it
+				glog.V(5).Infof("Triggering AttachVolume for volume %q to node %q", volumeToAttach.VolumeName, volumeToAttach.NodeName)
+				rc.attacherDetacher.AttachVolume(&volumeToAttach, rc.actualStateOfWorld)
+			}
+		}
+
+		// Ensure volumes that should be detached are detached.
+		for _, attachedVolume := range rc.actualStateOfWorld.GetAttachedVolumes() {
+			if !rc.desiredStateOfWorld.VolumeExists(
+				attachedVolume.VolumeName, attachedVolume.NodeName) {
+				// Volume exists in actual state of world but not desired
+				if attachedVolume.SafeToDetach {
+					glog.V(5).Infof("Triggering DetachVolume for volume %q to node %q", attachedVolume.VolumeName, attachedVolume.NodeName)
+					rc.attacherDetacher.DetachVolume(&attachedVolume, rc.actualStateOfWorld)
+				} else {
+					// If volume is not safe to detach wait a max amount of time before detaching any way.
+					timeElapsed, err := rc.actualStateOfWorld.MarkDesireToDetach(attachedVolume.VolumeName, attachedVolume.NodeName)
+					if err != nil {
+						glog.Errorf("Unexpected error actualStateOfWorld.MarkDesireToDetach(): %v", err)
+					}
+					if timeElapsed > rc.maxSafeToDetachDuration {
+						glog.V(5).Infof("Triggering DetachVolume for volume %q to node %q. Volume is not safe to detach, but max wait time expired.", attachedVolume.VolumeName, attachedVolume.NodeName)
+						rc.attacherDetacher.DetachVolume(&attachedVolume, rc.actualStateOfWorld)
+					}
+				}
+			}
+		}
+	}
+}

pkg/controller/volume/reconciler/reconciler_test.go

@@ -0,0 +1,365 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package reconciler
+
+import (
+	"testing"
+	"time"
+
+	"k8s.io/kubernetes/pkg/controller/volume/attacherdetacher"
+	"k8s.io/kubernetes/pkg/controller/volume/cache"
+	controllervolumetesting "k8s.io/kubernetes/pkg/controller/volume/testing"
+	"k8s.io/kubernetes/pkg/util/wait"
+	volumetesting "k8s.io/kubernetes/pkg/volume/testing"
+)
+
+const (
+	reconcilerLoopPeriod    time.Duration = 0 * time.Millisecond
+	maxSafeToDetachDuration time.Duration = 50 * time.Millisecond
+)
+
+func Test_Run_Positive_DoNothing(t *testing.T) {
+	// Arrange
+	volumePluginMgr, fakePlugin := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := cache.NewDesiredStateOfWorld(volumePluginMgr)
+	asw := cache.NewActualStateOfWorld(volumePluginMgr)
+	ad := attacherdetacher.NewAttacherDetacher(volumePluginMgr)
+	reconciler := NewReconciler(
+		reconcilerLoopPeriod, maxSafeToDetachDuration, dsw, asw, ad)
+
+	// Act
+	go reconciler.Run(wait.NeverStop)
+
+	// Assert
+	waitForNewAttacherCallCount(t, 0 /* expectedCallCount */, fakePlugin)
+	verifyNewAttacherCallCount(t, true /* expectZeroNewAttacherCallCount */, fakePlugin)
+	verifyNewDetacherCallCount(t, true /* expectZeroNewDetacherCallCount */, fakePlugin)
+	waitForAttachCallCount(t, 0 /* expectedAttachCallCount */, fakePlugin)
+	waitForDetachCallCount(t, 0 /* expectedDetachCallCount */, fakePlugin)
+}
+
+func Test_Run_Positive_OneDesiredVolumeAttach(t *testing.T) {
+	// Arrange
+	volumePluginMgr, fakePlugin := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := cache.NewDesiredStateOfWorld(volumePluginMgr)
+	asw := cache.NewActualStateOfWorld(volumePluginMgr)
+	ad := attacherdetacher.NewAttacherDetacher(volumePluginMgr)
+	reconciler := NewReconciler(
+		reconcilerLoopPeriod, maxSafeToDetachDuration, dsw, asw, ad)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	_, podErr := dsw.AddPod(podName, volumeSpec, nodeName)
+	if podErr != nil {
+		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podErr)
+	}
+
+	// Act
+	go reconciler.Run(wait.NeverStop)
+
+	// Assert
+	waitForNewAttacherCallCount(t, 1 /* expectedCallCount */, fakePlugin)
+	waitForAttachCallCount(t, 1 /* expectedAttachCallCount */, fakePlugin)
+	verifyNewDetacherCallCount(t, true /* expectZeroNewDetacherCallCount */, fakePlugin)
+}
+
+func Test_Run_Positive_OneDesiredVolumeAttachThenDetachWithMarkVolume(t *testing.T) {
+	// Arrange
+	volumePluginMgr, fakePlugin := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := cache.NewDesiredStateOfWorld(volumePluginMgr)
+	asw := cache.NewActualStateOfWorld(volumePluginMgr)
+	ad := attacherdetacher.NewAttacherDetacher(volumePluginMgr)
+	reconciler := NewReconciler(
+		reconcilerLoopPeriod, maxSafeToDetachDuration, dsw, asw, ad)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	generatedVolumeName, podAddErr := dsw.AddPod(podName, volumeSpec, nodeName)
+	if podAddErr != nil {
+		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podAddErr)
+	}
+
+	// Act
+	go reconciler.Run(wait.NeverStop)
+
+	// Assert
+	waitForNewAttacherCallCount(t, 1 /* expectedCallCount */, fakePlugin)
+	verifyNewAttacherCallCount(t, false /* expectZeroNewAttacherCallCount */, fakePlugin)
+	waitForAttachCallCount(t, 1 /* expectedAttachCallCount */, fakePlugin)
+	verifyNewDetacherCallCount(t, true /* expectZeroNewDetacherCallCount */, fakePlugin)
+	waitForDetachCallCount(t, 0 /* expectedDetachCallCount */, fakePlugin)
+
+	// Act
+	dsw.DeletePod(podName, generatedVolumeName, nodeName)
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Deleted pod %q from volume %q/node %q. Volume should also be deleted but it still exists.",
+			podName,
+			generatedVolumeName,
+			nodeName)
+	}
+	asw.MarkVolumeNodeSafeToDetach(generatedVolumeName, nodeName)
+
+	// Assert -- Marked SafeToDetach
+	waitForNewDetacherCallCount(t, 1 /* expectedCallCount */, fakePlugin)
+	verifyNewAttacherCallCount(t, false /* expectZeroNewAttacherCallCount */, fakePlugin)
+	waitForAttachCallCount(t, 1 /* expectedAttachCallCount */, fakePlugin)
+	verifyNewDetacherCallCount(t, false /* expectZeroNewDetacherCallCount */, fakePlugin)
+	waitForDetachCallCount(t, 1 /* expectedDetachCallCount */, fakePlugin)
+}
+
+func Test_Run_Positive_OneDesiredVolumeAttachThenDetachWithoutMarkVolume(t *testing.T) {
+	// Arrange
+	volumePluginMgr, fakePlugin := controllervolumetesting.GetTestVolumePluginMgr((t))
+	dsw := cache.NewDesiredStateOfWorld(volumePluginMgr)
+	asw := cache.NewActualStateOfWorld(volumePluginMgr)
+	ad := attacherdetacher.NewAttacherDetacher(volumePluginMgr)
+	reconciler := NewReconciler(
+		reconcilerLoopPeriod, maxSafeToDetachDuration, dsw, asw, ad)
+	podName := "pod-name"
+	volumeName := "volume-name"
+	volumeSpec := controllervolumetesting.GetTestVolumeSpec(volumeName, volumeName)
+	nodeName := "node-name"
+	dsw.AddNode(nodeName)
+	volumeExists := dsw.VolumeExists(volumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Volume %q/node %q should not exist, but it does.",
+			volumeName,
+			nodeName)
+	}
+
+	generatedVolumeName, podAddErr := dsw.AddPod(podName, volumeSpec, nodeName)
+	if podAddErr != nil {
+		t.Fatalf("AddPod failed. Expected: <no error> Actual: <%v>", podAddErr)
+	}
+
+	// Act
+	go reconciler.Run(wait.NeverStop)
+
+	// Assert
+	waitForNewAttacherCallCount(t, 1 /* expectedCallCount */, fakePlugin)
+	verifyNewAttacherCallCount(t, false /* expectZeroNewAttacherCallCount */, fakePlugin)
+	waitForAttachCallCount(t, 1 /* expectedAttachCallCount */, fakePlugin)
+	verifyNewDetacherCallCount(t, true /* expectZeroNewDetacherCallCount */, fakePlugin)
+	waitForDetachCallCount(t, 0 /* expectedDetachCallCount */, fakePlugin)
+
+	// Act
+	dsw.DeletePod(podName, generatedVolumeName, nodeName)
+	volumeExists = dsw.VolumeExists(generatedVolumeName, nodeName)
+	if volumeExists {
+		t.Fatalf(
+			"Deleted pod %q from volume %q/node %q. Volume should also be deleted but it still exists.",
+			podName,
+			generatedVolumeName,
+			nodeName)
+	}
+
+	// Assert -- Timer will triger detach
+	waitForNewDetacherCallCount(t, 1 /* expectedCallCount */, fakePlugin)
+	verifyNewAttacherCallCount(t, false /* expectZeroNewAttacherCallCount */, fakePlugin)
+	waitForAttachCallCount(t, 1 /* expectedAttachCallCount */, fakePlugin)
+	verifyNewDetacherCallCount(t, false /* expectZeroNewDetacherCallCount */, fakePlugin)
+	waitForDetachCallCount(t, 1 /* expectedDetachCallCount */, fakePlugin)
+}
+
+func waitForNewAttacherCallCount(
+	t *testing.T,
+	expectedCallCount int,
+	fakePlugin *volumetesting.FakeVolumePlugin) {
+	err := retryWithExponentialBackOff(
+		time.Duration(5*time.Millisecond),
+		func() (bool, error) {
+			actualCallCount := fakePlugin.GetNewAttacherCallCount()
+			if actualCallCount >= expectedCallCount {
+				return true, nil
+			}
+			t.Logf(
+				"Warning: Wrong NewAttacherCallCount. Expected: <%v> Actual: <%v>. Will retry.",
+				expectedCallCount,
+				actualCallCount)
+			return false, nil
+		},
+	)
+
+	if err != nil {
+		t.Fatalf(
+			"Timed out waiting for NewAttacherCallCount. Expected: <%v> Actual: <%v>",
+			expectedCallCount,
+			fakePlugin.GetNewAttacherCallCount())
+	}
+}
+
+func waitForNewDetacherCallCount(
+	t *testing.T,
+	expectedCallCount int,
+	fakePlugin *volumetesting.FakeVolumePlugin) {
+	err := retryWithExponentialBackOff(
+		time.Duration(5*time.Millisecond),
+		func() (bool, error) {
+			actualCallCount := fakePlugin.GetNewDetacherCallCount()
+			if actualCallCount >= expectedCallCount {
+				return true, nil
+			}
+			t.Logf(
+				"Warning: Wrong NewDetacherCallCount. Expected: <%v> Actual: <%v>. Will retry.",
+				expectedCallCount,
+				actualCallCount)
+			return false, nil
+		},
+	)
+
+	if err != nil {
+		t.Fatalf(
+			"Timed out waiting for NewDetacherCallCount. Expected: <%v> Actual: <%v>",
+			expectedCallCount,
+			fakePlugin.GetNewDetacherCallCount())
+	}
+}
+
+func waitForAttachCallCount(
+	t *testing.T,
+	expectedAttachCallCount int,
+	fakePlugin *volumetesting.FakeVolumePlugin) {
+	if len(fakePlugin.Attachers) == 0 && expectedAttachCallCount == 0 {
+		return
+	}
+
+	err := retryWithExponentialBackOff(
+		time.Duration(5*time.Millisecond),
+		func() (bool, error) {
+			for i, attacher := range fakePlugin.Attachers {
+				actualCallCount := attacher.GetAttachCallCount()
+				if actualCallCount == expectedAttachCallCount {
+					return true, nil
+				}
+				t.Logf(
+					"Warning: Wrong attacher[%v].GetAttachCallCount(). Expected: <%v> Actual: <%v>. Will try next attacher.",
+					i,
+					expectedAttachCallCount,
+					actualCallCount)
+			}
+
+			t.Logf(
+				"Warning: No attachers have expected AttachCallCount. Expected: <%v>. Will retry.",
+				expectedAttachCallCount)
+			return false, nil
+		},
+	)
+
+	if err != nil {
+		t.Fatalf(
+			"No attachers have expected AttachCallCount. Expected: <%v>",
+			expectedAttachCallCount)
+	}
+}
+
+func waitForDetachCallCount(
+	t *testing.T,
+	expectedDetachCallCount int,
+	fakePlugin *volumetesting.FakeVolumePlugin) {
+	if len(fakePlugin.Detachers) == 0 && expectedDetachCallCount == 0 {
+		return
+	}
+
+	err := retryWithExponentialBackOff(
+		time.Duration(5*time.Millisecond),
+		func() (bool, error) {
+			for i, detacher := range fakePlugin.Detachers {
+				actualCallCount := detacher.GetDetachCallCount()
+				if actualCallCount == expectedDetachCallCount {
+					return true, nil
+				}
+				t.Logf(
+					"Wrong detacher[%v].GetDetachCallCount(). Expected: <%v> Actual: <%v>. Will try next detacher.",
+					i,
+					expectedDetachCallCount,
+					actualCallCount)
+			}
+
+			t.Logf(
+				"Warning: No detachers have expected DetachCallCount. Expected: <%v>. Will retry.",
+				expectedDetachCallCount)
+			return false, nil
+		},
+	)
+
+	if err != nil {
+		t.Fatalf(
+			"No detachers have expected DetachCallCount. Expected: <%v>",
+			expectedDetachCallCount)
+	}
+}
+
+func verifyNewAttacherCallCount(
+	t *testing.T,
+	expectZeroNewAttacherCallCount bool,
+	fakePlugin *volumetesting.FakeVolumePlugin) {
+
+	if expectZeroNewAttacherCallCount &&
+		fakePlugin.GetNewAttacherCallCount() != 0 {
+		t.Fatalf(
+			"Wrong NewAttacherCallCount. Expected: <0> Actual: <%v>",
+			fakePlugin.GetNewAttacherCallCount())
+	}
+}
+
+func verifyNewDetacherCallCount(
+	t *testing.T,
+	expectZeroNewDetacherCallCount bool,
+	fakePlugin *volumetesting.FakeVolumePlugin) {
+
+	if expectZeroNewDetacherCallCount &&
+		fakePlugin.GetNewDetacherCallCount() != 0 {
+		t.Fatalf("Wrong NewDetacherCallCount. Expected: <0> Actual: <%v>",
+			fakePlugin.GetNewDetacherCallCount())
+	}
+}
+
+func retryWithExponentialBackOff(initialDuration time.Duration, fn wait.ConditionFunc) error {
+	backoff := wait.Backoff{
+		Duration: initialDuration,
+		Factor:   3,
+		Jitter:   0,
+		Steps:    6,
+	}
+	return wait.ExponentialBackoff(backoff, fn)
+}
+
+// t.Logf("asw: %v", asw.GetAttachedVolumes())
+// t.Logf("dsw: %v", dsw.GetVolumesToAttach())

pkg/controller/volume/testing/testvolumepluginmgr.go

@@ -0,0 +1,102 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package testing
+
+import (
+	"fmt"
+	"testing"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
+	"k8s.io/kubernetes/pkg/cloudprovider"
+	"k8s.io/kubernetes/pkg/cloudprovider/providers/fake"
+	"k8s.io/kubernetes/pkg/types"
+	"k8s.io/kubernetes/pkg/util/io"
+	"k8s.io/kubernetes/pkg/util/mount"
+	"k8s.io/kubernetes/pkg/volume"
+	volumetesting "k8s.io/kubernetes/pkg/volume/testing"
+)
+
+// GetTestVolumePluginMgr creates, initializes, and returns a test volume
+// plugin manager.
+func GetTestVolumePluginMgr(t *testing.T) (*volume.VolumePluginMgr, *volumetesting.FakeVolumePlugin) {
+	plugins := []volume.VolumePlugin{}
+
+	// plugins = append(plugins, aws_ebs.ProbeVolumePlugins()...)
+	// plugins = append(plugins, gce_pd.ProbeVolumePlugins()...)
+	// plugins = append(plugins, cinder.ProbeVolumePlugins()...)
+	volumeTestingPlugins := volumetesting.ProbeVolumePlugins(volume.VolumeConfig{})
+	plugins = append(plugins, volumeTestingPlugins...)
+
+	volumePluginMgr := testVolumePluginMgr{}
+
+	if err := volumePluginMgr.InitPlugins(plugins, &volumePluginMgr); err != nil {
+		t.Fatalf("Could not initialize volume plugins for Attach/Detach Controller: %+v", err)
+	}
+
+	return &volumePluginMgr.VolumePluginMgr, volumeTestingPlugins[0].(*volumetesting.FakeVolumePlugin)
+}
+
+type testVolumePluginMgr struct {
+	volume.VolumePluginMgr
+}
+
+// VolumeHost implementation
+// This is an unfortunate requirement of the current factoring of volume plugin
+// initializing code. It requires kubelet specific methods used by the mounting
+// code to be implemented by all initializers even if the initializer does not
+// do mounting (like this attach/detach controller).
+// Issue kubernetes/kubernetes/issues/14217 to fix this.
+func (vpm *testVolumePluginMgr) GetPluginDir(podUID string) string {
+	return ""
+}
+
+func (vpm *testVolumePluginMgr) GetPodVolumeDir(podUID types.UID, pluginName, volumeName string) string {
+	return ""
+}
+
+func (vpm *testVolumePluginMgr) GetPodPluginDir(podUID types.UID, pluginName string) string {
+	return ""
+}
+
+func (vpm *testVolumePluginMgr) GetKubeClient() internalclientset.Interface {
+	return nil
+}
+
+func (vpm *testVolumePluginMgr) NewWrapperMounter(volName string, spec volume.Spec, pod *api.Pod, opts volume.VolumeOptions) (volume.Mounter, error) {
+	return nil, fmt.Errorf("NewWrapperMounter not supported by Attach/Detach controller's VolumeHost implementation")
+}
+
+func (vpm *testVolumePluginMgr) NewWrapperUnmounter(volName string, spec volume.Spec, podUID types.UID) (volume.Unmounter, error) {
+	return nil, fmt.Errorf("NewWrapperUnmounter not supported by Attach/Detach controller's VolumeHost implementation")
+}
+
+func (vpm *testVolumePluginMgr) GetCloudProvider() cloudprovider.Interface {
+	return &fake.FakeCloud{}
+}
+
+func (vpm *testVolumePluginMgr) GetMounter() mount.Interface {
+	return nil
+}
+
+func (vpm *testVolumePluginMgr) GetWriter() io.Writer {
+	return nil
+}
+
+func (vpm *testVolumePluginMgr) GetHostName() string {
+	return ""
+}

pkg/controller/volume/testing/testvolumespec.go

@@ -0,0 +1,38 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package testing
+
+import (
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/volume"
+)
+
+// GetTestVolumeSpec returns a test volume spec
+func GetTestVolumeSpec(volumeName, diskName string) *volume.Spec {
+	return &volume.Spec{
+		Volume: &api.Volume{
+			Name: volumeName,
+			VolumeSource: api.VolumeSource{
+				GCEPersistentDisk: &api.GCEPersistentDiskVolumeSource{
+					PDName:   diskName,
+					FSType:   "fake",
+					ReadOnly: false,
+				},
+			},
+		},
+	}
+}

pkg/volume/gce_pd/attacher.go

@@ -50,6 +50,24 @@ func (plugin *gcePersistentDiskPlugin) NewAttacher() (volume.Attacher, error) {
 	return &gcePersistentDiskAttacher{host: plugin.host}, nil
 }
 
+func (plugin *gcePersistentDiskPlugin) GetUniqueVolumeName(spec *volume.Spec) (string, error) {
+	volumeSource, _ := getVolumeSource(spec)
+	if volumeSource == nil {
+		return "", fmt.Errorf("Spec does not reference a GCE volume type")
+	}
+
+	return fmt.Sprintf("%s/%s:%v", gcePersistentDiskPluginName, volumeSource.PDName, volumeSource.ReadOnly), nil
+}
+
+func (plugin *gcePersistentDiskPlugin) GetDeviceName(spec *volume.Spec) (string, error) {
+	volumeSource, _ := getVolumeSource(spec)
+	if volumeSource == nil {
+		return "", fmt.Errorf("Spec does not reference a GCE volume type")
+	}
+
+	return volumeSource.PDName, nil
+}
+
 func (attacher *gcePersistentDiskAttacher) Attach(spec *volume.Spec, hostName string) error {
 	volumeSource, readOnly := getVolumeSource(spec)
 	pdName := volumeSource.PDName

pkg/volume/plugins.go

@@ -133,6 +133,18 @@ type AttachableVolumePlugin interface {
 	VolumePlugin
 	NewAttacher() (Attacher, error)
 	NewDetacher() (Detacher, error)
+
+	// GetUniqueVolumeName returns a unique name representing the volume
+	// defined in spec. e.g. pluginname-deviceName-readwrite
+	// This helps ensures that the same operation (attach/detach) is never
+	// started on the same volume.
+	// If the plugin does not support the given spec, this returns an error.
+	GetUniqueVolumeName(spec *Spec) (string, error)
+
+	// GetDeviceName returns the name or ID of the device referenced in the
+	// specified volume spec. This is passed by callers to the Deatch method.
+	// If the plugin does not support the given spec, this returns an error.
+	GetDeviceName(spec *Spec) (string, error)
 }
 
 // VolumeHost is an interface that plugins can use to access the kubelet.

pkg/volume/testing/testing.go

@@ -23,6 +23,7 @@ import (
 	"os/exec"
 	"path"
 	"strings"
+	"sync"
 	"time"
 
 	"k8s.io/kubernetes/pkg/api"
@@ -132,6 +133,7 @@ func ProbeVolumePlugins(config VolumeConfig) []VolumePlugin {
 // Use as:
 //   volume.RegisterPlugin(&FakePlugin{"fake-name"})
 type FakeVolumePlugin struct {
+	sync.RWMutex
 	PluginName             string
 	Host                   VolumeHost
 	Config                 VolumeConfig
@@ -158,11 +160,15 @@ func (plugin *FakeVolumePlugin) getFakeVolume(list *[]*FakeVolume) *FakeVolume {
 }
 
 func (plugin *FakeVolumePlugin) Init(host VolumeHost) error {
+	plugin.Lock()
+	defer plugin.Unlock()
 	plugin.Host = host
 	return nil
 }
 
 func (plugin *FakeVolumePlugin) Name() string {
+	plugin.RLock()
+	defer plugin.RUnlock()
 	return plugin.PluginName
 }
 
@@ -172,6 +178,8 @@ func (plugin *FakeVolumePlugin) CanSupport(spec *Spec) bool {
 }
 
 func (plugin *FakeVolumePlugin) NewMounter(spec *Spec, pod *api.Pod, opts VolumeOptions) (Mounter, error) {
+	plugin.Lock()
+	defer plugin.Unlock()
 	volume := plugin.getFakeVolume(&plugin.Mounters)
 	volume.PodUID = pod.UID
 	volume.VolName = spec.Name()
@@ -181,6 +189,8 @@ func (plugin *FakeVolumePlugin) NewMounter(spec *Spec, pod *api.Pod, opts Volume
 }
 
 func (plugin *FakeVolumePlugin) NewUnmounter(volName string, podUID types.UID) (Unmounter, error) {
+	plugin.Lock()
+	defer plugin.Unlock()
 	volume := plugin.getFakeVolume(&plugin.Unmounters)
 	volume.PodUID = podUID
 	volume.VolName = volName
@@ -190,15 +200,41 @@ func (plugin *FakeVolumePlugin) NewUnmounter(volName string, podUID types.UID) (
 }
 
 func (plugin *FakeVolumePlugin) NewAttacher() (Attacher, error) {
+	plugin.Lock()
+	defer plugin.Unlock()
 	plugin.NewAttacherCallCount = plugin.NewAttacherCallCount + 1
 	return plugin.getFakeVolume(&plugin.Attachers), nil
 }
 
+func (plugin *FakeVolumePlugin) GetNewAttacherCallCount() int {
+	plugin.RLock()
+	defer plugin.RUnlock()
+	return plugin.NewAttacherCallCount
+}
+
 func (plugin *FakeVolumePlugin) NewDetacher() (Detacher, error) {
+	plugin.Lock()
+	defer plugin.Unlock()
 	plugin.NewDetacherCallCount = plugin.NewDetacherCallCount + 1
 	return plugin.getFakeVolume(&plugin.Detachers), nil
 }
 
+func (plugin *FakeVolumePlugin) GetNewDetacherCallCount() int {
+	plugin.RLock()
+	defer plugin.RUnlock()
+	return plugin.NewDetacherCallCount
+}
+
+func (plugin *FakeVolumePlugin) GetUniqueVolumeName(spec *Spec) (string, error) {
+	plugin.RLock()
+	defer plugin.RUnlock()
+	return plugin.Name() + "/" + spec.Name(), nil
+}
+
+func (plugin *FakeVolumePlugin) GetDeviceName(spec *Spec) (string, error) {
+	return spec.Name(), nil
+}
+
 func (plugin *FakeVolumePlugin) NewRecycler(pvName string, spec *Spec) (Recycler, error) {
 	return &fakeRecycler{"/attributesTransferredFromSpec", MetricsNil{}}, nil
 }
@@ -208,6 +244,8 @@ func (plugin *FakeVolumePlugin) NewDeleter(spec *Spec) (Deleter, error) {
 }
 
 func (plugin *FakeVolumePlugin) NewProvisioner(options VolumeOptions) (Provisioner, error) {
+	plugin.Lock()
+	defer plugin.Unlock()
 	plugin.LastProvisionerOptions = options
 	return &FakeProvisioner{options, plugin.Host}, nil
 }
@@ -217,6 +255,7 @@ func (plugin *FakeVolumePlugin) GetAccessModes() []api.PersistentVolumeAccessMod
 }
 
 type FakeVolume struct {
+	sync.RWMutex
 	PodUID  types.UID
 	VolName string
 	Plugin  *FakeVolumePlugin
@@ -242,8 +281,10 @@ func (_ *FakeVolume) GetAttributes() Attributes {
 }
 
 func (fv *FakeVolume) SetUp(fsGroup *int64) error {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.SetUpCallCount++
-	return fv.SetUpAt(fv.GetPath(), fsGroup)
+	return fv.SetUpAt(fv.getPath(), fsGroup)
 }
 
 func (fv *FakeVolume) SetUpAt(dir string, fsGroup *int64) error {
@@ -251,12 +292,20 @@ func (fv *FakeVolume) SetUpAt(dir string, fsGroup *int64) error {
 }
 
 func (fv *FakeVolume) GetPath() string {
+	fv.RLock()
+	defer fv.RUnlock()
+	return fv.getPath()
+}
+
+func (fv *FakeVolume) getPath() string {
 	return path.Join(fv.Plugin.Host.GetPodVolumeDir(fv.PodUID, utilstrings.EscapeQualifiedNameForDisk(fv.Plugin.PluginName), fv.VolName))
 }
 
 func (fv *FakeVolume) TearDown() error {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.TearDownCallCount++
-	return fv.TearDownAt(fv.GetPath())
+	return fv.TearDownAt(fv.getPath())
 }
 
 func (fv *FakeVolume) TearDownAt(dir string) error {
@@ -264,36 +313,62 @@ func (fv *FakeVolume) TearDownAt(dir string) error {
 }
 
 func (fv *FakeVolume) Attach(spec *Spec, hostName string) error {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.AttachCallCount++
 	return nil
 }
 
+func (fv *FakeVolume) GetAttachCallCount() int {
+	fv.RLock()
+	defer fv.RUnlock()
+	return fv.AttachCallCount
+}
+
 func (fv *FakeVolume) WaitForAttach(spec *Spec, spectimeout time.Duration) (string, error) {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.WaitForAttachCallCount++
 	return "", nil
 }
 
 func (fv *FakeVolume) GetDeviceMountPath(spec *Spec) string {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.GetDeviceMountPathCallCount++
 	return ""
 }
 
 func (fv *FakeVolume) MountDevice(spec *Spec, devicePath string, deviceMountPath string, mounter mount.Interface) error {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.MountDeviceCallCount++
 	return nil
 }
 
 func (fv *FakeVolume) Detach(deviceMountPath string, hostName string) error {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.DetachCallCount++
 	return nil
 }
 
+func (fv *FakeVolume) GetDetachCallCount() int {
+	fv.RLock()
+	defer fv.RUnlock()
+	return fv.DetachCallCount
+}
+
 func (fv *FakeVolume) WaitForDetach(devicePath string, timeout time.Duration) error {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.WaitForDetachCallCount++
 	return nil
 }
 
 func (fv *FakeVolume) UnmountDevice(globalMountPath string, mounter mount.Interface) error {
+	fv.Lock()
+	defer fv.Unlock()
 	fv.UnmountDeviceCallCount++
 	return nil
 }

test/integration/persistent_volumes_test.go

@@ -291,7 +291,18 @@ func createClients(s *httptest.Server) (*clientset.Clientset, *persistentvolumec
 	// creates many claims and default values were too low.
 	testClient := clientset.NewForConfigOrDie(&restclient.Config{Host: s.URL, ContentConfig: restclient.ContentConfig{GroupVersion: testapi.Default.GroupVersion()}, QPS: 1000, Burst: 100000})
 	host := volumetest.NewFakeVolumeHost("/tmp/fake", nil, nil)
-	plugins := []volume.VolumePlugin{&volumetest.FakeVolumePlugin{"plugin-name", host, volume.VolumeConfig{}, volume.VolumeOptions{}, 0, 0, nil, nil, nil, nil}}
+	plugins := []volume.VolumePlugin{&volumetest.FakeVolumePlugin{
+		PluginName:             "plugin-name",
+		Host:                   host,
+		Config:                 volume.VolumeConfig{},
+		LastProvisionerOptions: volume.VolumeOptions{},
+		NewAttacherCallCount:   0,
+		NewDetacherCallCount:   0,
+		Mounters:               nil,
+		Unmounters:             nil,
+		Attachers:              nil,
+		Detachers:              nil,
+	}}
 	cloud := &fake_cloud.FakeCloud{}
 	ctrl := persistentvolumecontroller.NewPersistentVolumeController(testClient, 10*time.Second, nil, plugins, cloud, "", nil, nil, nil)
 	return testClient, ctrl