Merge pull request #67 from pohly/inline-and-persistent-volumes

Inline and persistent volumes

README.md

@@ -346,7 +346,7 @@ Follow the following example to create a volume from a volume snapshot:
 As of version 1.15 of Kubernetes, the CSI Hostpath driver (starting with version 1.0.1) now includes support for inline ephemeral volume.  This means that a volume can be specified directly inside a pod spec without the need to use a persistent volume object.
 Find out how to enable or create a CSI inline driver [here](https://kubernetes-csi.github.io/docs/ephemeral-local-volumes.html)
 
-To test this feature, redeploy the CSI Hostpath plugin YAML by updating the `hostpath` container to use  the inline ephemeral mode by setting the `ephemeral` flag, of the driver binary, to true as shown in the following setup:
+To test this feature on Kubernetes 1.15, redeploy the CSI Hostpath plugin YAML by updating the `hostpath` container to use  the inline ephemeral mode by setting the `ephemeral` flag, of the driver binary, to true as shown in the following setup:
 
 ```yaml
 kind: DaemonSet
@@ -369,6 +369,9 @@ spec:
 
 ```
 Notice the addition of the `ephemeral=true` flag used in the `args:` block in the previous snippet.
+This is an intermediate solution for Kubernetes 1.15. Kubernetes 1.16 will provide [additional
+information to the driver](https://github.com/kubernetes/kubernetes/pull/79983) which makes it
+possible to use the normal deployment for both inline ephemeral volumes and persistent volumes.
 
 Once the driver plugin has been deployed, it can be tested by deploying a simple pod which has an inline volume specified in the spec:
 

cmd/hostpathplugin/main.go

@@ -33,7 +33,7 @@ var (
 	endpoint    = flag.String("endpoint", "unix://tmp/csi.sock", "CSI endpoint")
 	driverName  = flag.String("drivername", "hostpath.csi.k8s.io", "name of the driver")
 	nodeID      = flag.String("nodeid", "", "node id")
-	ephemeral   = flag.Bool("ephemeral", false, "deploy in ephemeral mode")
+	ephemeral   = flag.Bool("ephemeral", false, "publish volumes in ephemeral mode even if kubelet did not ask for it (only needed for Kubernetes 1.15)")
 	showVersion = flag.Bool("version", false, "Show version.")
 	// Set by the build process
 	version = ""
@@ -48,6 +48,10 @@ func main() {
 		return
 	}
 
+	if *ephemeral {
+		fmt.Fprintln(os.Stderr, "Deprecation warning: The ephemeral flag is deprecated and should only be used when deploying on Kubernetes 1.15. It will be removed in the future.")
+	}
+
 	handle()
 	os.Exit(0)
 }

pkg/hostpath/controllerserver.go

@@ -167,7 +167,7 @@ func (cs *controllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 		}
 	}
 
-	vol, err := createHostpathVolume(volumeID, req.GetName(), capacity, requestedAccessType)
+	vol, err := createHostpathVolume(volumeID, req.GetName(), capacity, requestedAccessType, false /* ephemeral */)
 	if err != nil {
 		return nil, status.Error(codes.Internal, fmt.Sprintf("failed to create volume: %s", err))
 	}

pkg/hostpath/hostpath.go

@@ -53,6 +53,7 @@ type hostPathVolume struct {
 	VolSize       int64      `json:"volSize"`
 	VolPath       string     `json:"volPath"`
 	VolAccessType accessType `json:"volAccessType"`
+	Ephemeral     bool       `json:"ephemeral"`
 }
 
 type hostPathSnapshot struct {
@@ -148,7 +149,7 @@ func getVolumePath(volID string) string {
 
 // createVolume create the directory for the hostpath volume.
 // It returns the volume path or err if one occurs.
-func createHostpathVolume(volID, name string, cap int64, volAccessType accessType) (*hostPathVolume, error) {
+func createHostpathVolume(volID, name string, cap int64, volAccessType accessType, ephemeral bool) (*hostPathVolume, error) {
 	path := getVolumePath(volID)
 	if volAccessType == mountAccess {
 		err := os.MkdirAll(path, 0777)
@@ -163,6 +164,7 @@ func createHostpathVolume(volID, name string, cap int64, volAccessType accessTyp
 		VolSize:       cap,
 		VolPath:       path,
 		VolAccessType: volAccessType,
+		Ephemeral:     ephemeral,
 	}
 	hostPathVolumes[volID] = hostpathVol
 	return &hostpathVol, nil

pkg/hostpath/nodeserver.go

@@ -57,17 +57,19 @@ func (ns *nodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 	}
 
 	targetPath := req.GetTargetPath()
+	ephemeralVolume := req.GetVolumeContext()["csi.storage.k8s.io/ephemeral"] == "true" ||
+		req.GetVolumeContext()["csi.storage.k8s.io/ephemeral"] == "" && ns.ephemeral // Kubernetes 1.15 doesn't have csi.storage.k8s.io/ephemeral.
 
 	if req.GetVolumeCapability().GetBlock() != nil &&
 		req.GetVolumeCapability().GetMount() != nil {
 		return nil, status.Error(codes.InvalidArgument, "cannot have both block and mount access type")
 	}
 
 	// if ephemeral is specified, create volume here to avoid errors
-	if ns.ephemeral {
+	if ephemeralVolume {
 		volID := req.GetVolumeId()
 		volName := fmt.Sprintf("ephemeral-%s", volID)
-		vol, err := createHostpathVolume(req.GetVolumeId(), volName, maxStorageCapacity, mountAccess)
+		vol, err := createHostpathVolume(req.GetVolumeId(), volName, maxStorageCapacity, mountAccess, ephemeralVolume)
 		if err != nil && !os.IsExist(err) {
 			glog.Error("ephemeral mode failed to create volume: ", err)
 			return nil, status.Error(codes.Internal, err.Error())
@@ -170,7 +172,7 @@ func (ns *nodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 		if err := mounter.Mount(path, targetPath, "", options); err != nil {
 			var errList strings.Builder
 			errList.WriteString(err.Error())
-			if ns.ephemeral {
+			if vol.Ephemeral {
 				if rmErr := os.RemoveAll(path); rmErr != nil && !os.IsNotExist(rmErr) {
 					errList.WriteString(fmt.Sprintf(" :%s", rmErr.Error()))
 				}
@@ -218,7 +220,7 @@ func (ns *nodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpu
 		glog.V(4).Infof("hostpath: volume %s/%s has been unmounted.", targetPath, volumeID)
 	}
 
-	if ns.ephemeral {
+	if vol.Ephemeral {
 		glog.V(4).Infof("deleting volume %s", volumeID)
 		if err := deleteHostpathVolume(volumeID); err != nil && !os.IsNotExist(err) {
 			return nil, status.Error(codes.Internal, fmt.Sprintf("failed to delete volume: %s", err))