Add volume expansion support

pkg/hostpath/controllerserver.go

@@ -63,6 +63,7 @@ func NewControllerServer(ephemeral bool) *controllerServer {
 				csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT,
 				csi.ControllerServiceCapability_RPC_LIST_SNAPSHOTS,
 				csi.ControllerServiceCapability_RPC_CLONE_VOLUME,
+				csi.ControllerServiceCapability_RPC_EXPAND_VOLUME,
 			}),
 	}
 }
@@ -457,6 +458,42 @@ func (cs *controllerServer) ListSnapshots(ctx context.Context, req *csi.ListSnap
 	}, nil
 }
 
+func (cs *controllerServer) ControllerExpandVolume(ctx context.Context, req *csi.ControllerExpandVolumeRequest) (*csi.ControllerExpandVolumeResponse, error) {
+
+	volID := req.GetVolumeId()
+	if len(volID) == 0 {
+		return nil, status.Error(codes.InvalidArgument, "Volume ID missing in request")
+	}
+
+	capRange := req.GetCapacityRange()
+	if capRange == nil {
+		return nil, status.Error(codes.InvalidArgument, "Capacity range not provided")
+	}
+
+	capacity := int64(capRange.GetRequiredBytes())
+	if capacity >= maxStorageCapacity {
+		return nil, status.Errorf(codes.OutOfRange, "Requested capacity %d exceeds maximum allowed %d", capacity, maxStorageCapacity)
+	}
+
+	exVol, err := getVolumeByID(volID)
+	if err != nil {
+		// Assume not found error
+		return nil, status.Errorf(codes.NotFound, "Could not get volume %s: %v", volID, err)
+	}
+
+	if exVol.VolSize < capacity {
+		exVol.VolSize = capacity
+		if err := updateHostpathVolume(volID, exVol); err != nil {
+			return nil, status.Errorf(codes.Internal, "Could not update volume %s: %v", volID, err)
+		}
+	}
+
+	return &csi.ControllerExpandVolumeResponse{
+		CapacityBytes:         exVol.VolSize,
+		NodeExpansionRequired: false,
+	}, nil
+}
+
 func convertSnapshot(snap hostPathSnapshot) *csi.ListSnapshotsResponse {
 	entries := []*csi.ListSnapshotsResponse_Entry{
 		{

pkg/hostpath/hostpath.go

@@ -209,6 +209,18 @@ func createHostpathVolume(volID, name string, cap int64, volAccessType accessTyp
 	return &hostpathVol, nil
 }
 
+// updateVolume updates the existing hostpath volume.
+func updateHostpathVolume(volID string, volume hostPathVolume) error {
+	glog.V(4).Infof("updating hostpath volume: %s", volID)
+
+	if _, err := getVolumeByID(volID); err != nil {
+		return err
+	}
+
+	hostPathVolumes[volID] = volume
+	return nil
+}
+
 // deleteVolume deletes the directory for the hostpath volume.
 func deleteHostpathVolume(volID string) error {
 	glog.V(4).Infof("deleting hostpath volume: %s", volID)

pkg/hostpath/nodeserver.go

@@ -284,3 +284,7 @@ func (ns *nodeServer) NodeGetCapabilities(ctx context.Context, req *csi.NodeGetC
 func (ns *nodeServer) NodeGetVolumeStats(ctx context.Context, in *csi.NodeGetVolumeStatsRequest) (*csi.NodeGetVolumeStatsResponse, error) {
 	return nil, status.Error(codes.Unimplemented, "")
 }
+
+func (ns *nodeServer) NodeExpandVolume(ctx context.Context, req *csi.NodeExpandVolumeRequest) (*csi.NodeExpandVolumeResponse, error) {
+	return nil, status.Error(codes.Unimplemented, "")
+}