Don't recycle PVs that are used by a pod

pkg/controller/volume/persistentvolume/BUILD

@@ -31,6 +31,7 @@ go_library(
         "//pkg/util/mount:go_default_library",
         "//pkg/volume:go_default_library",
         "//pkg/volume/util:go_default_library",
+        "//pkg/volume/util/volumehelper:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/api/storage/v1:go_default_library",
@@ -41,6 +42,7 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/labels:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//vendor/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//vendor/k8s.io/client-go/informers/core/v1:go_default_library",
@@ -95,6 +97,7 @@ go_test(
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/fake:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/scheme:go_default_library",
+        "//vendor/k8s.io/client-go/listers/core/v1:go_default_library",
         "//vendor/k8s.io/client-go/listers/storage/v1:go_default_library",
         "//vendor/k8s.io/client-go/testing:go_default_library",
         "//vendor/k8s.io/client-go/tools/cache:go_default_library",

pkg/controller/volume/persistentvolume/pv_controller.go

@@ -26,6 +26,8 @@ import (
 	storage "k8s.io/api/storage/v1"
 	apierrs "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/util/sets"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
@@ -43,6 +45,7 @@ import (
 	"k8s.io/kubernetes/pkg/util/goroutinemap/exponentialbackoff"
 	vol "k8s.io/kubernetes/pkg/volume"
 	"k8s.io/kubernetes/pkg/volume/util"
+	"k8s.io/kubernetes/pkg/volume/util/volumehelper"
 
 	"github.com/golang/glog"
 )
@@ -1067,6 +1070,17 @@ func (ctrl *PersistentVolumeController) recycleVolumeOperation(arg interface{})
 		glog.V(3).Infof("volume %q no longer needs recycling, skipping", volume.Name)
 		return
 	}
+	pods, used, err := ctrl.isVolumeUsed(newVolume)
+	if err != nil {
+		glog.V(3).Infof("can't recycle volume %q: %v", volume.Name, err)
+		return
+	}
+	if used {
+		msg := fmt.Sprintf("Volume is used by pods: %s", strings.Join(pods, ","))
+		glog.V(3).Infof("can't recycle volume %q: %s", volume.Name, msg)
+		ctrl.eventRecorder.Event(volume, v1.EventTypeNormal, events.VolumeFailedRecycle, msg)
+		return
+	}
 
 	// Use the newest volume copy, this will save us from version conflicts on
 	// saving.
@@ -1235,6 +1249,32 @@ func (ctrl *PersistentVolumeController) isVolumeReleased(volume *v1.PersistentVo
 	return true, nil
 }
 
+// isVolumeUsed returns list of pods that use given PV.
+func (ctrl *PersistentVolumeController) isVolumeUsed(pv *v1.PersistentVolume) ([]string, bool, error) {
+	if pv.Spec.ClaimRef == nil {
+		return nil, false, nil
+	}
+	claimName := pv.Spec.ClaimRef.Name
+
+	podNames := sets.NewString()
+	pods, err := ctrl.podLister.Pods(pv.Spec.ClaimRef.Namespace).List(labels.Everything())
+	if err != nil {
+		return nil, false, fmt.Errorf("error listing pods: %s", err)
+	}
+	for _, pod := range pods {
+		if volumehelper.IsPodTerminated(pod, pod.Status) {
+			continue
+		}
+		for i := range pod.Spec.Volumes {
+			usedPV := &pod.Spec.Volumes[i]
+			if usedPV.PersistentVolumeClaim != nil && usedPV.PersistentVolumeClaim.ClaimName == claimName {
+				podNames.Insert(pod.Namespace + "/" + pod.Name)
+			}
+		}
+	}
+	return podNames.List(), podNames.Len() != 0, nil
+}
+
 // doDeleteVolume finds appropriate delete plugin and deletes given volume. It
 // returns 'true', when the volume was deleted and 'false' when the volume
 // cannot be deleted because of the deleter is external. No error should be

pkg/controller/volume/persistentvolume/recycle_test.go

@@ -22,6 +22,7 @@ import (
 
 	"k8s.io/api/core/v1"
 	storage "k8s.io/api/storage/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 // Test single call to syncVolume, expecting recycling to happen.
@@ -29,6 +30,44 @@ import (
 // 2. Call the syncVolume *once*.
 // 3. Compare resulting volumes with expected volumes.
 func TestRecycleSync(t *testing.T) {
+	runningPod := &v1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "runningPod",
+			Namespace: testNamespace,
+		},
+		Spec: v1.PodSpec{
+			Volumes: []v1.Volume{
+				{
+					Name: "vol1",
+					VolumeSource: v1.VolumeSource{
+						PersistentVolumeClaim: &v1.PersistentVolumeClaimVolumeSource{
+							ClaimName: "runningClaim",
+						},
+					},
+				},
+			},
+		},
+		Status: v1.PodStatus{
+			Phase: v1.PodRunning,
+		},
+	}
+
+	pendingPod := runningPod.DeepCopy()
+	pendingPod.Name = "pendingPod"
+	pendingPod.Status.Phase = v1.PodPending
+	pendingPod.Spec.Volumes[0].PersistentVolumeClaim.ClaimName = "pendingClaim"
+
+	completedPod := runningPod.DeepCopy()
+	completedPod.Name = "completedPod"
+	completedPod.Status.Phase = v1.PodSucceeded
+	completedPod.Spec.Volumes[0].PersistentVolumeClaim.ClaimName = "completedClaim"
+
+	pods := []*v1.Pod{
+		runningPod,
+		pendingPod,
+		completedPod,
+	}
+
 	tests := []controllerTest{
 		{
 			// recycle volume bound by controller
@@ -160,8 +199,38 @@ func TestRecycleSync(t *testing.T) {
 			noclaims,
 			[]string{"Warning VolumeUnknownReclaimPolicy"}, noerrors, testSyncVolume,
 		},
+		{
+			// volume is used by a running pod - failure expected
+			"6-11 - used by running pod",
+			newVolumeArray("volume6-11", "1Gi", "uid6-11", "runningClaim", v1.VolumeBound, v1.PersistentVolumeReclaimRecycle, classEmpty, annBoundByController),
+			newVolumeArray("volume6-11", "1Gi", "uid6-11", "runningClaim", v1.VolumeReleased, v1.PersistentVolumeReclaimRecycle, classEmpty, annBoundByController),
+			noclaims,
+			noclaims,
+			[]string{"Normal VolumeFailedRecycle"}, noerrors, testSyncVolume,
+		},
+		{
+			// volume is used by a pending pod - failure expected
+			"6-12 - used by pending pod",
+			newVolumeArray("volume6-12", "1Gi", "uid6-12", "pendingClaim", v1.VolumeBound, v1.PersistentVolumeReclaimRecycle, classEmpty, annBoundByController),
+			newVolumeArray("volume6-12", "1Gi", "uid6-12", "pendingClaim", v1.VolumeReleased, v1.PersistentVolumeReclaimRecycle, classEmpty, annBoundByController),
+			noclaims,
+			noclaims,
+			[]string{"Normal VolumeFailedRecycle"}, noerrors, testSyncVolume,
+		},
+		{
+			// volume is used by a completed pod - recycle succeeds
+			"6-13 - used by completed pod",
+			newVolumeArray("volume6-13", "1Gi", "uid6-13", "completedClaim", v1.VolumeBound, v1.PersistentVolumeReclaimRecycle, classEmpty, annBoundByController),
+			newVolumeArray("volume6-13", "1Gi", "", "", v1.VolumeAvailable, v1.PersistentVolumeReclaimRecycle, classEmpty),
+			noclaims,
+			noclaims,
+			noevents, noerrors,
+			// Inject recycler into the controller and call syncVolume. The
+			// recycler simulates one recycle() call that succeeds.
+			wrapTestWithReclaimCalls(operationRecycle, []error{nil}, testSyncVolume),
+		},
 	}
-	runSyncTests(t, tests, []*storage.StorageClass{}, []*v1.Pod{})
+	runSyncTests(t, tests, []*storage.StorageClass{}, pods)
 }
 
 // Test multiple calls to syncClaim/syncVolume and periodic sync of all