Merge pull request #480 from pohly/release-2-optional-volume-attachments

2.0.x: optional volume attachments

cmd/csi-provisioner/csi-provisioner.go

@@ -202,7 +202,13 @@ func main() {
 	claimLister := factory.Core().V1().PersistentVolumeClaims().Lister()
 
 	var csiNodeLister storagelistersv1.CSINodeLister
-	vaLister := factory.Storage().V1().VolumeAttachments().Lister()
+	var vaLister storagelistersv1.VolumeAttachmentLister
+	if controllerCapabilities[csi.ControllerServiceCapability_RPC_PUBLISH_UNPUBLISH_VOLUME] {
+		klog.Info("CSI driver supports PUBLISH_UNPUBLISH_VOLUME, watching VolumeAttachments")
+		vaLister = factory.Storage().V1().VolumeAttachments().Lister()
+	} else {
+		klog.Info("CSI driver does not support PUBLISH_UNPUBLISH_VOLUME, not watching VolumeAttachments")
+	}
 	var nodeLister v1.NodeLister
 	if ctrl.SupportsTopology(pluginCapabilities) {
 		csiNodeLister = factory.Storage().V1().CSINodes().Lister()

deploy/kubernetes/rbac.yaml

@@ -50,6 +50,10 @@ rules:
   - apiGroups: [""]
     resources: ["nodes"]
     verbs: ["get", "list", "watch"]
+  # Access to volumeattachments is only needed when the CSI driver
+  # has the PUBLISH_UNPUBLISH_VOLUME controller capability.
+  # In that case, external-provisioner will watch volumeattachments
+  # to determine when it is safe to delete a volume.
   - apiGroups: ["storage.k8s.io"]
     resources: ["volumeattachments"]
     verbs: ["get", "list", "watch"]

pkg/controller/controller.go

@@ -271,7 +271,10 @@ func GetDriverCapabilities(conn *grpc.ClientConn, timeout time.Duration) (rpc.Pl
 	return pluginCapabilities, controllerCapabilities, nil
 }
 
-// NewCSIProvisioner creates new CSI provisioner
+// NewCSIProvisioner creates new CSI provisioner.
+//
+// vaLister is optional and only needed when VolumeAttachments are
+// meant to be checked before deleting a volume.
 func NewCSIProvisioner(client kubernetes.Interface,
 	connectionTimeout time.Duration,
 	identity string,
@@ -1046,6 +1049,21 @@ func (p *csiProvisioner) Delete(ctx context.Context, volume *v1.PersistentVolume
 	deleteCtx, cancel := context.WithTimeout(ctx, p.timeout)
 	defer cancel()
 
+	if err := p.canDeleteVolume(volume); err != nil {
+		return err
+	}
+
+	_, err = p.csiClient.DeleteVolume(deleteCtx, &req)
+
+	return err
+}
+
+func (p *csiProvisioner) canDeleteVolume(volume *v1.PersistentVolume) error {
+	if p.vaLister == nil {
+		// Nothing to check.
+		return nil
+	}
+
 	// Verify if volume is attached to a node before proceeding with deletion
 	vaList, err := p.vaLister.List(labels.Everything())
 	if err != nil {
@@ -1058,9 +1076,7 @@ func (p *csiProvisioner) Delete(ctx context.Context, volume *v1.PersistentVolume
 		}
 	}
 
-	_, err = p.csiClient.DeleteVolume(deleteCtx, &req)
-
-	return err
+	return nil
 }
 
 func (p *csiProvisioner) SupportsBlock(ctx context.Context) bool {