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Add Finalizer for VolumeSnapshot/VolumeSnapshotContent
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This PR adds a Finalizer for VolumeSnapshotContent.
If the VolumeSnapshotContent is bound to a VolumeSnapshot,
the VolumeSnapshotContent is being used and cannot be
deleted.
This PR also adds a Finalizer for VolumeSnapshot.
If a volume is being created from the snapshot,
the VolumeSnapshot is being used and cannot be deleted.
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@xing-yang
xing-yang committed Nov 1, 2018
1 parent e36d31f commit 70877b5
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161 changes: 161 additions & 0 deletions pkg/controller/snapshot_controller.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@ import (
ref "k8s.io/client-go/tools/reference"
"k8s.io/kubernetes/pkg/util/goroutinemap"
"k8s.io/kubernetes/pkg/util/goroutinemap/exponentialbackoff"
"k8s.io/kubernetes/pkg/util/slice"
)

// ==================================================================
Expand Down Expand Up @@ -78,6 +79,9 @@ import (

const pvcKind = "PersistentVolumeClaim"
const apiGroup = ""
const snapshotKind = "VolumeSnapshot"
const snapshotAPIGroup = crdv1.GroupName

const controllerUpdateFailMsg = "snapshot controller failed to update"

const IsDefaultSnapshotClassAnnotation = "snapshot.storage.kubernetes.io/is-default-class"
Expand All @@ -86,6 +90,26 @@ const IsDefaultSnapshotClassAnnotation = "snapshot.storage.kubernetes.io/is-defa
func (ctrl *csiSnapshotController) syncContent(content *crdv1.VolumeSnapshotContent) error {
glog.V(5).Infof("synchronizing VolumeSnapshotContent[%s]", content.Name)

if isContentDeletionCandidate(content) {
// Volume snapshot content should be deleted. Check if it's used
// and remove finalizer if it's not.
// Check if snapshot content is still bound to a snapshot.
isUsed := ctrl.isSnapshotContentBeingUsed(content)
if !isUsed {
glog.V(5).Infof("syncContent: Remove Finalizer for VolumeSnapshotContent[%s]", content.Name)
return ctrl.removeContentFinalizer(content)
}
}

if needToAddContentFinalizer(content) {
// Content is not being deleted -> it should have the finalizer. The
// finalizer should be added by admission plugin, this is just to add
// the finalizer to old volume snapshot contents that were created before
// the admission plugin was enabled.
glog.V(5).Infof("syncContent: Add Finalizer for VolumeSnapshotContent[%s]", content.Name)
return ctrl.addContentFinalizer(content)
}

// VolumeSnapshotContent is not bound to any VolumeSnapshot, in this case we just return err
if content.Spec.VolumeSnapshotRef == nil {
// content is not bound
Expand Down Expand Up @@ -140,6 +164,26 @@ func (ctrl *csiSnapshotController) syncContent(content *crdv1.VolumeSnapshotCont
func (ctrl *csiSnapshotController) syncSnapshot(snapshot *crdv1.VolumeSnapshot) error {
glog.V(5).Infof("synchonizing VolumeSnapshot[%s]: %s", snapshotKey(snapshot), getSnapshotStatusForLogging(snapshot))

if isSnapshotDeletionCandidate(snapshot) {
// Volume snapshot should be deleted. Check if it's used
// and remove finalizer if it's not.
// Check if a volume is being created from snapshot.
isUsed := ctrl.isVolumeBeingCreatedFromSnapshot(snapshot)
if !isUsed {
glog.V(5).Infof("syncSnapshot: Remove Finalizer for VolumeSnapshot[%s]", snapshot.Name)
return ctrl.removeSnapshotFinalizer(snapshot)
}
}

if needToAddSnapshotFinalizer(snapshot) {
// Snapshot is not being deleted -> it should have the finalizer. The
// finalizer should be added by admission plugin, this is just to add
// the finalizer to old volume snapshots that were created before
// the admission plugin was enabled.
glog.V(5).Infof("syncSnapshot: Add Finalizer for VolumeSnapshot[%s]", snapshot.Name)
return ctrl.addSnapshotFinalizer(snapshot)
}

if !snapshot.Status.Ready {
return ctrl.syncUnreadySnapshot(snapshot)
} else {
Expand Down Expand Up @@ -396,6 +440,48 @@ func IsSnapshotBound(snapshot *crdv1.VolumeSnapshot, content *crdv1.VolumeSnapsh
return false
}

// isSnapshotConentBeingUsed checks if snapshot content is bound to snapshot.
func (ctrl *csiSnapshotController) isSnapshotContentBeingUsed(content *crdv1.VolumeSnapshotContent) bool {
if content.Spec.VolumeSnapshotRef != nil {
snapshotObj, err := ctrl.clientset.VolumesnapshotV1alpha1().VolumeSnapshots(content.Spec.VolumeSnapshotRef.Namespace).Get(content.Spec.VolumeSnapshotRef.Name, metav1.GetOptions{})
if err != nil {
glog.Infof("isSnapshotContentBeingUsed: Cannot get snapshot %s from api server: [%v]. VolumeSnapshot object may be deleted already.", content.Spec.VolumeSnapshotRef.Name, err)
return false
}

// Check if the snapshot content is bound to the snapshot
if IsSnapshotBound(snapshotObj, content) && snapshotObj.Spec.SnapshotContentName == content.Name {
glog.Infof("isSnapshotContentBeingUsed: VolumeSnapshot %s is bound to volumeSnapshotContent [%s]", snapshotObj.Name, content.Name)
return true
}
}

glog.V(5).Infof("isSnapshotContentBeingUsed: Snapshot content %s is not being used", content.Name)
return false
}

// isVolumeBeingCreatedFromSnapshot checks if an volume is being created from the snapshot.
func (ctrl *csiSnapshotController) isVolumeBeingCreatedFromSnapshot(snapshot *crdv1.VolumeSnapshot) bool {
pvcList, err := ctrl.client.CoreV1().PersistentVolumeClaims(snapshot.Namespace).List(metav1.ListOptions{})
if err != nil {
glog.Errorf("Failed to retrieve PVCs from the API server to check if volume snapshot %s is being used by a volume: %q", snapshot.Name, err)
return false
}
for _, pvc := range pvcList.Items {
if pvc.Spec.DataSource != nil && len(pvc.Spec.DataSource.Name) > 0 && pvc.Spec.DataSource.Name == snapshot.Name {
if pvc.Spec.DataSource.Kind == snapshotKind && *(pvc.Spec.DataSource.APIGroup) == snapshotAPIGroup {
if pvc.Status.Phase == v1.ClaimPending {
// A volume is being created from the snapshot
glog.Infof("isVolumeBeingCreatedFromSnapshot: volume %s is being created from snapshot %s", pvc.Name, pvc.Spec.DataSource.Name)
return true
}
}
}
}
glog.V(5).Infof("isVolumeBeingCreatedFromSnapshot: no volume is being created from snapshot %s", snapshot.Name)
return false
}

// The function checks whether the volumeSnapshotRef in snapshot content matches the given snapshot. If match, it binds the content with the snapshot
func (ctrl *csiSnapshotController) checkandBindSnapshotContent(snapshot *crdv1.VolumeSnapshot, content *crdv1.VolumeSnapshotContent) error {
if content.Spec.VolumeSnapshotRef == nil || content.Spec.VolumeSnapshotRef.Name != snapshot.Name {
Expand Down Expand Up @@ -871,3 +957,78 @@ func isControllerUpdateFailError(err *storage.VolumeError) bool {
}
return false
}

// addContentFinalizer adds a Finalizer for VolumeSnapshotContent.
func (ctrl *csiSnapshotController) addContentFinalizer(content *crdv1.VolumeSnapshotContent) error {
contentClone := content.DeepCopy()
contentClone.ObjectMeta.Finalizers = append(contentClone.ObjectMeta.Finalizers, VolumeSnapshotContentFinalizer)

_, err := ctrl.clientset.VolumesnapshotV1alpha1().VolumeSnapshotContents().Update(contentClone)
if err != nil {
return newControllerUpdateError(content.Name, err.Error())
}

_, err = ctrl.storeContentUpdate(contentClone)
if err != nil {
glog.Errorf("failed to update content store %v", err)
}

glog.V(5).Infof("Added protection finalizer to volume snapshot content %s", content.Name)
return nil
}

// removeContentFinalizer removes a Finalizer for VolumeSnapshotContent.
func (ctrl *csiSnapshotController) removeContentFinalizer(content *crdv1.VolumeSnapshotContent) error {
contentClone := content.DeepCopy()
contentClone.ObjectMeta.Finalizers = slice.RemoveString(contentClone.ObjectMeta.Finalizers, VolumeSnapshotContentFinalizer, nil)

_, err := ctrl.clientset.VolumesnapshotV1alpha1().VolumeSnapshotContents().Update(contentClone)
if err != nil {
return newControllerUpdateError(content.Name, err.Error())
}

_, err = ctrl.storeContentUpdate(contentClone)
if err != nil {
glog.Errorf("failed to update content store %v", err)
}

glog.V(5).Infof("Removed protection finalizer from volume snapshot content %s", content.Name)
return nil
}

// addSnapshotFinalizer adds a Finalizer for VolumeSnapshot.
func (ctrl *csiSnapshotController) addSnapshotFinalizer(snapshot *crdv1.VolumeSnapshot) error {
snapshotClone := snapshot.DeepCopy()
snapshotClone.ObjectMeta.Finalizers = append(snapshotClone.ObjectMeta.Finalizers, VolumeSnapshotFinalizer)
_, err := ctrl.clientset.VolumesnapshotV1alpha1().VolumeSnapshots(snapshotClone.Namespace).Update(snapshotClone)
if err != nil {
return newControllerUpdateError(snapshot.Name, err.Error())
}

_, err = ctrl.storeSnapshotUpdate(snapshotClone)
if err != nil {
glog.Errorf("failed to update snapshot store %v", err)
}

glog.V(5).Infof("Added protection finalizer to volume snapshot %s", snapshot.Name)
return nil
}

// removeContentFinalizer removes a Finalizer for VolumeSnapshot.
func (ctrl *csiSnapshotController) removeSnapshotFinalizer(snapshot *crdv1.VolumeSnapshot) error {
snapshotClone := snapshot.DeepCopy()
snapshotClone.ObjectMeta.Finalizers = slice.RemoveString(snapshotClone.ObjectMeta.Finalizers, VolumeSnapshotFinalizer, nil)

_, err := ctrl.clientset.VolumesnapshotV1alpha1().VolumeSnapshots(snapshotClone.Namespace).Update(snapshotClone)
if err != nil {
return newControllerUpdateError(snapshot.Name, err.Error())
}

_, err = ctrl.storeSnapshotUpdate(snapshotClone)
if err != nil {
glog.Errorf("failed to update snapshot store %v", err)
}

glog.V(5).Infof("Removed protection finalizer from volume snapshot %s", snapshot.Name)
return nil
}
25 changes: 25 additions & 0 deletions pkg/controller/util.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@ import (
"k8s.io/apimachinery/pkg/util/validation"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/cache"
"k8s.io/kubernetes/pkg/util/slice"
"os"
"strconv"
"time"
Expand All @@ -39,6 +40,10 @@ var (
const snapshotterSecretNameKey = "csiSnapshotterSecretName"
const snapshotterSecretNamespaceKey = "csiSnapshotterSecretNamespace"

// Name of finalizer on VolumeSnapshotContents that are bound by VolumeSnapshots
const VolumeSnapshotContentFinalizer = "snapshot.storage.kubernetes.io/volumesnapshotcontent-protection"
const VolumeSnapshotFinalizer = "snapshot.storage.kubernetes.io/volumesnapshot-protection"

func snapshotKey(vs *crdv1.VolumeSnapshot) string {
return fmt.Sprintf("%s/%s", vs.Namespace, vs.Name)
}
Expand Down Expand Up @@ -240,3 +245,23 @@ func GetCredentials(k8s kubernetes.Interface, ref *v1.SecretReference) (map[stri
func NoResyncPeriodFunc() time.Duration {
return 0
}

// isContentDeletionCandidate checks if a volume snapshot content is a deletion candidate.
func isContentDeletionCandidate(content *crdv1.VolumeSnapshotContent) bool {
return content.ObjectMeta.DeletionTimestamp != nil && slice.ContainsString(content.ObjectMeta.Finalizers, VolumeSnapshotContentFinalizer, nil)
}

// needToAddContentFinalizer checks if a Finalizer needs to be added for the volume snapshot content.
func needToAddContentFinalizer(content *crdv1.VolumeSnapshotContent) bool {
return content.ObjectMeta.DeletionTimestamp == nil && !slice.ContainsString(content.ObjectMeta.Finalizers, VolumeSnapshotContentFinalizer, nil)
}

// isSnapshotDeletionCandidate checks if a volume snapshot is a deletion candidate.
func isSnapshotDeletionCandidate(snapshot *crdv1.VolumeSnapshot) bool {
return snapshot.ObjectMeta.DeletionTimestamp != nil && slice.ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotFinalizer, nil)
}

// needToAddSnapshotFinalizer checks if a Finalizer needs to be added for the volume snapshot.
func needToAddSnapshotFinalizer(snapshot *crdv1.VolumeSnapshot) bool {
return snapshot.ObjectMeta.DeletionTimestamp == nil && !slice.ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotFinalizer, nil)
}

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