Add method comments

Signed-off-by: Madhu Rajanna <mrajanna@redhat.com>

cmd/rbd/main.go

@@ -56,7 +56,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	driver := rbd.GetDriver()
+	driver := rbd.NewDriver()
 	driver.Run(*driverName, *nodeID, *endpoint, *containerized, cp)
 
 	os.Exit(0)

pkg/cephfs/controllerserver.go

@@ -28,6 +28,8 @@ import (
 	"github.com/ceph/ceph-csi/pkg/util"
 )
 
+// ControllerServer struct of CEPH CSI driver with supported methods of CSI
+// controller server spec.
 type ControllerServer struct {
 	*csicommon.DefaultControllerServer
 	MetadataStore util.CachePersister
@@ -38,6 +40,7 @@ type controllerCacheEntry struct {
 	VolumeID   volumeID
 }
 
+// CreateVolume creates the volume in backend and store the volume metadata
 func (cs *ControllerServer) CreateVolume(ctx context.Context, req *csi.CreateVolumeRequest) (*csi.CreateVolumeResponse, error) {
 	if err := cs.validateCreateVolumeRequest(req); err != nil {
 		glog.Errorf("CreateVolumeRequest validation failed: %v", err)
@@ -102,6 +105,8 @@ func (cs *ControllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 	}, nil
 }
 
+// DeleteVolume deletes the volume in backend and removes the volume metadata
+// from store
 func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVolumeRequest) (*csi.DeleteVolumeResponse, error) {
 	if err := cs.validateDeleteVolumeRequest(); err != nil {
 		glog.Errorf("DeleteVolumeRequest validation failed: %v", err)
@@ -159,6 +164,8 @@ func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVol
 	return &csi.DeleteVolumeResponse{}, nil
 }
 
+// ValidateVolumeCapabilities checks whether the volume capabilities requested
+// are supported.
 func (cs *ControllerServer) ValidateVolumeCapabilities(
 	ctx context.Context,
 	req *csi.ValidateVolumeCapabilitiesRequest) (*csi.ValidateVolumeCapabilitiesResponse, error) {

pkg/cephfs/driver.go

@@ -26,10 +26,13 @@ import (
 )
 
 const (
+	// PluginFolder defines the location of ceph plugin
 	PluginFolder = "/var/lib/kubelet/plugins/csi-cephfsplugin"
-	Version      = "1.0.0"
+	// version of ceph driver
+	version = "1.0.0"
 )
 
+// Driver contains the default identity,node and controller struct
 type Driver struct {
 	cd *csicommon.CSIDriver
 
@@ -39,19 +42,23 @@ type Driver struct {
 }
 
 var (
+	// DefaultVolumeMounter for mounting volumes
 	DefaultVolumeMounter string
 )
 
+// NewDriver returns new ceph driver
 func NewDriver() *Driver {
 	return &Driver{}
 }
 
+// NewIdentityServer initialize a identity server for ceph CSI driver
 func NewIdentityServer(d *csicommon.CSIDriver) *IdentityServer {
 	return &IdentityServer{
 		DefaultIdentityServer: csicommon.NewDefaultIdentityServer(d),
 	}
 }
 
+// NewControllerServer initialize a controller server for ceph CSI driver
 func NewControllerServer(d *csicommon.CSIDriver, cachePersister util.CachePersister) *ControllerServer {
 	return &ControllerServer{
 		DefaultControllerServer: csicommon.NewDefaultControllerServer(d),
@@ -59,14 +66,17 @@ func NewControllerServer(d *csicommon.CSIDriver, cachePersister util.CachePersis
 	}
 }
 
+// NewNodeServer initialize a node server for ceph CSI driver.
 func NewNodeServer(d *csicommon.CSIDriver) *NodeServer {
 	return &NodeServer{
 		DefaultNodeServer: csicommon.NewDefaultNodeServer(d),
 	}
 }
 
+// Run start a non-blocking grpc controller,node and identityserver for
+// ceph CSI driver which can serve multiple parallel requests
 func (fs *Driver) Run(driverName, nodeID, endpoint, volumeMounter string, cachePersister util.CachePersister) {
-	glog.Infof("Driver: %v version: %v", driverName, Version)
+	glog.Infof("Driver: %v version: %v", driverName, version)
 
 	// Configuration
 
@@ -91,7 +101,7 @@ func (fs *Driver) Run(driverName, nodeID, endpoint, volumeMounter string, cacheP
 
 	// Initialize default library driver
 
-	fs.cd = csicommon.NewCSIDriver(driverName, Version, nodeID)
+	fs.cd = csicommon.NewCSIDriver(driverName, version, nodeID)
 	if fs.cd == nil {
 		glog.Fatalln("Failed to initialize CSI driver")
 	}

pkg/cephfs/identityserver.go

@@ -23,10 +23,13 @@ import (
 	"github.com/kubernetes-csi/drivers/pkg/csi-common"
 )
 
+// IdentityServer struct of ceph CSI driver with supported methods of CSI
+// identity server spec.
 type IdentityServer struct {
 	*csicommon.DefaultIdentityServer
 }
 
+// GetPluginCapabilities returns available capabilities of the ceph driver
 func (is *IdentityServer) GetPluginCapabilities(ctx context.Context, req *csi.GetPluginCapabilitiesRequest) (*csi.GetPluginCapabilitiesResponse, error) {
 	return &csi.GetPluginCapabilitiesResponse{
 		Capabilities: []*csi.PluginCapability{

pkg/cephfs/nodeserver.go

@@ -29,6 +29,8 @@ import (
 	"github.com/kubernetes-csi/drivers/pkg/csi-common"
 )
 
+// NodeServer struct of ceph CSI driver with supported methods of CSI
+// node server spec.
 type NodeServer struct {
 	*csicommon.DefaultNodeServer
 }
@@ -77,6 +79,7 @@ func getCredentialsForVolume(volOptions *volumeOptions, volID volumeID, req *csi
 	return userCr, nil
 }
 
+// NodeStageVolume mounts the volume to a staging path on the node.
 func (ns *NodeServer) NodeStageVolume(ctx context.Context, req *csi.NodeStageVolumeRequest) (*csi.NodeStageVolumeResponse, error) {
 	if err := validateNodeStageVolumeRequest(req); err != nil {
 		return nil, status.Error(codes.InvalidArgument, err.Error())
@@ -149,6 +152,8 @@ func (ns *NodeServer) NodeStageVolume(ctx context.Context, req *csi.NodeStageVol
 	return &csi.NodeStageVolumeResponse{}, nil
 }
 
+// NodePublishVolume mounts the volume mounted to the staging path to the target
+// path
 func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
 	if err := validateNodePublishVolumeRequest(req); err != nil {
 		return nil, status.Error(codes.InvalidArgument, err.Error())
@@ -190,6 +195,7 @@ func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 	return &csi.NodePublishVolumeResponse{}, nil
 }
 
+// NodeUnpublishVolume unmounts the volume from the target path
 func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error) {
 	if err := validateNodeUnpublishVolumeRequest(req); err != nil {
 		return nil, status.Error(codes.InvalidArgument, err.Error())
@@ -209,6 +215,7 @@ func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpu
 	return &csi.NodeUnpublishVolumeResponse{}, nil
 }
 
+// NodeUnstageVolume unstages the volume from the staging path
 func (ns *NodeServer) NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstageVolumeRequest) (*csi.NodeUnstageVolumeResponse, error) {
 	if err := validateNodeUnstageVolumeRequest(req); err != nil {
 		return nil, status.Error(codes.InvalidArgument, err.Error())
@@ -228,6 +235,7 @@ func (ns *NodeServer) NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstag
 	return &csi.NodeUnstageVolumeResponse{}, nil
 }
 
+// NodeGetCapabilities returns the supported capabilities of the node server
 func (ns *NodeServer) NodeGetCapabilities(ctx context.Context, req *csi.NodeGetCapabilitiesRequest) (*csi.NodeGetCapabilitiesResponse, error) {
 	return &csi.NodeGetCapabilitiesResponse{
 		Capabilities: []*csi.NodeServiceCapability{
@@ -241,7 +249,3 @@ func (ns *NodeServer) NodeGetCapabilities(ctx context.Context, req *csi.NodeGetC
 		},
 	}, nil
 }
-
-func (ns *NodeServer) NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoRequest) (*csi.NodeGetInfoResponse, error) {
-	return ns.DefaultNodeServer.NodeGetInfo(ctx, req)
-}

pkg/rbd/controllerserver.go

@@ -39,6 +39,8 @@ const (
 	oneGB = 1073741824
 )
 
+// ControllerServer struct of rbd CSI driver with supported methods of CSI
+// controller server spec.
 type ControllerServer struct {
 	*csicommon.DefaultControllerServer
 	MetadataStore util.CachePersister
@@ -49,6 +51,8 @@ var (
 	rbdSnapshots = map[string]*rbdSnapshot{}
 )
 
+// LoadExDataFromMetadataStore loads the rbd volume and snapshot
+// info from metadata store
 func (cs *ControllerServer) LoadExDataFromMetadataStore() error {
 	vol := &rbdVolume{}
 	cs.MetadataStore.ForAll("csi-rbd-vol-", vol, func(identifier string) error {
@@ -80,6 +84,7 @@ func (cs *ControllerServer) validateVolumeReq(req *csi.CreateVolumeRequest) erro
 	return nil
 }
 
+// CreateVolume creates the volume in backend and store the volume metadata
 func (cs *ControllerServer) CreateVolume(ctx context.Context, req *csi.CreateVolumeRequest) (*csi.CreateVolumeResponse, error) {
 
 	if err := cs.validateVolumeReq(req); err != nil {
@@ -193,6 +198,8 @@ func (cs *ControllerServer) checkSnapshot(req *csi.CreateVolumeRequest, rbdVol *
 	return nil
 }
 
+// DeleteVolume deletes the volume in backend and removes the volume metadata
+// from store
 func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVolumeRequest) (*csi.DeleteVolumeResponse, error) {
 	if err := cs.Driver.ValidateControllerServiceRequest(csi.ControllerServiceCapability_RPC_CREATE_DELETE_VOLUME); err != nil {
 		glog.Warningf("invalid delete volume req: %v", req)
@@ -227,6 +234,8 @@ func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVol
 	return &csi.DeleteVolumeResponse{}, nil
 }
 
+// ValidateVolumeCapabilities checks whether the volume capabilities requested
+// are supported.
 func (cs *ControllerServer) ValidateVolumeCapabilities(ctx context.Context, req *csi.ValidateVolumeCapabilitiesRequest) (*csi.ValidateVolumeCapabilitiesResponse, error) {
 	for _, cap := range req.VolumeCapabilities {
 		if cap.GetAccessMode().GetMode() != csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER {
@@ -240,14 +249,18 @@ func (cs *ControllerServer) ValidateVolumeCapabilities(ctx context.Context, req
 	}, nil
 }
 
+// ControllerUnpublishVolume returns success response
 func (cs *ControllerServer) ControllerUnpublishVolume(ctx context.Context, req *csi.ControllerUnpublishVolumeRequest) (*csi.ControllerUnpublishVolumeResponse, error) {
 	return &csi.ControllerUnpublishVolumeResponse{}, nil
 }
 
+// ControllerPublishVolume returns success response
 func (cs *ControllerServer) ControllerPublishVolume(ctx context.Context, req *csi.ControllerPublishVolumeRequest) (*csi.ControllerPublishVolumeResponse, error) {
 	return &csi.ControllerPublishVolumeResponse{}, nil
 }
 
+// CreateSnapshot creates the snapshot in backend and stores metadata
+// in store
 func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateSnapshotRequest) (*csi.CreateSnapshotResponse, error) {
 	if err := cs.Driver.ValidateControllerServiceRequest(csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT); err != nil {
 		glog.Warningf("invalid create snapshot req: %v", req)
@@ -371,6 +384,8 @@ func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateS
 	}, nil
 }
 
+// DeleteSnapshot deletes the snapshot in backend and removes the
+//snapshot metadata from store
 func (cs *ControllerServer) DeleteSnapshot(ctx context.Context, req *csi.DeleteSnapshotRequest) (*csi.DeleteSnapshotResponse, error) {
 	if err := cs.Driver.ValidateControllerServiceRequest(csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT); err != nil {
 		glog.Warningf("invalid delete snapshot req: %v", req)
@@ -410,6 +425,7 @@ func (cs *ControllerServer) DeleteSnapshot(ctx context.Context, req *csi.DeleteS
 	return &csi.DeleteSnapshotResponse{}, nil
 }
 
+// ListSnapshots lists the snapshots in the store
 func (cs *ControllerServer) ListSnapshots(ctx context.Context, req *csi.ListSnapshotsRequest) (*csi.ListSnapshotsResponse, error) {
 	if err := cs.Driver.ValidateControllerServiceRequest(csi.ControllerServiceCapability_RPC_LIST_SNAPSHOTS); err != nil {
 		glog.Warningf("invalid list snapshot req: %v", req)

pkg/rbd/identityserver.go

@@ -23,10 +23,13 @@ import (
 	"github.com/kubernetes-csi/drivers/pkg/csi-common"
 )
 
+// IdentityServer struct of rbd CSI driver with supported methods of CSI
+// identity server spec.
 type IdentityServer struct {
 	*csicommon.DefaultIdentityServer
 }
 
+// GetPluginCapabilities returns available capabilities of the rbd driver
 func (is *IdentityServer) GetPluginCapabilities(ctx context.Context, req *csi.GetPluginCapabilitiesRequest) (*csi.GetPluginCapabilitiesResponse, error) {
 	return &csi.GetPluginCapabilitiesResponse{
 		Capabilities: []*csi.PluginCapability{

pkg/rbd/nodeserver.go

@@ -35,11 +35,28 @@ import (
 	"github.com/kubernetes-csi/drivers/pkg/csi-common"
 )
 
+// NodeServer struct of ceph rbd driver with supported methods of CSI
+// node server spec
 type NodeServer struct {
 	*csicommon.DefaultNodeServer
 	mounter mount.Interface
 }
 
+//TODO remove both stage and unstage methods
+//once https://github.com/kubernetes-csi/drivers/pull/145 is merged
+
+// NodeStageVolume returns unimplemented response
+func (ns *NodeServer) NodeStageVolume(ctx context.Context, req *csi.NodeStageVolumeRequest) (*csi.NodeStageVolumeResponse, error) {
+	return nil, status.Error(codes.Unimplemented, "")
+}
+
+// NodeUnstageVolume returns unimplemented response
+func (ns *NodeServer) NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstageVolumeRequest) (*csi.NodeUnstageVolumeResponse, error) {
+	return nil, status.Error(codes.Unimplemented, "")
+}
+
+// NodePublishVolume mounts the volume mounted to the device path to the target
+// path
 func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
 	targetPath := req.GetTargetPath()
 	targetPathMutex.LockKey(targetPath)
@@ -132,6 +149,7 @@ func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 	return &csi.NodePublishVolumeResponse{}, nil
 }
 
+// NodeUnpublishVolume unmounts the volume from the target path
 func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error) {
 	targetPath := req.GetTargetPath()
 	targetPathMutex.LockKey(targetPath)
@@ -202,26 +220,6 @@ func (ns *NodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpu
 	return &csi.NodeUnpublishVolumeResponse{}, nil
 }
 
-func (ns *NodeServer) NodeStageVolume(
-	ctx context.Context,
-	req *csi.NodeStageVolumeRequest) (
-	*csi.NodeStageVolumeResponse, error) {
-
-	return nil, status.Error(codes.Unimplemented, "")
-}
-
-func (ns *NodeServer) NodeUnstageVolume(
-	ctx context.Context,
-	req *csi.NodeUnstageVolumeRequest) (
-	*csi.NodeUnstageVolumeResponse, error) {
-
-	return nil, status.Error(codes.Unimplemented, "")
-}
-
-func (ns *NodeServer) NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoRequest) (*csi.NodeGetInfoResponse, error) {
-	return ns.DefaultNodeServer.NodeGetInfo(ctx, req)
-}
-
 func resolveBindMountedBlockDevice(mountPath string) (string, error) {
 	cmd := exec.Command("findmnt", "-n", "-o", "SOURCE", "--first-only", "--target", mountPath)
 	out, err := cmd.CombinedOutput()

pkg/rbd/rbd.go

@@ -35,6 +35,7 @@ const (
 	rbdDefaultUserID  = rbdDefaultAdminID
 )
 
+// Driver contains the default identity,node and controller struct
 type Driver struct {
 	cd *csicommon.CSIDriver
 
@@ -47,16 +48,19 @@ var (
 	version = "1.0.0"
 )
 
-func GetDriver() *Driver {
+// NewDriver returns new rbd driver
+func NewDriver() *Driver {
 	return &Driver{}
 }
 
+// NewIdentityServer initialize a identity server for rbd CSI driver
 func NewIdentityServer(d *csicommon.CSIDriver) *IdentityServer {
 	return &IdentityServer{
 		DefaultIdentityServer: csicommon.NewDefaultIdentityServer(d),
 	}
 }
 
+// NewControllerServer initialize a controller server for rbd CSI driver
 func NewControllerServer(d *csicommon.CSIDriver, cachePersister util.CachePersister) *ControllerServer {
 	return &ControllerServer{
 		DefaultControllerServer: csicommon.NewDefaultControllerServer(d),
@@ -64,6 +68,7 @@ func NewControllerServer(d *csicommon.CSIDriver, cachePersister util.CachePersis
 	}
 }
 
+// NewNodeServer initialize a node server for rbd CSI driver.
 func NewNodeServer(d *csicommon.CSIDriver, containerized bool) (*NodeServer, error) {
 	mounter := mount.New("")
 	if containerized {
@@ -79,6 +84,8 @@ func NewNodeServer(d *csicommon.CSIDriver, containerized bool) (*NodeServer, err
 	}, nil
 }
 
+// Run start a non-blocking grpc controller,node and identityserver for
+// rbd CSI driver which can serve multiple parallel requests
 func (r *Driver) Run(driverName, nodeID, endpoint string, containerized bool, cachePersister util.CachePersister) {
 	var err error
 	glog.Infof("Driver: %v version: %v", driverName, version)

pkg/util/cachepersister.go

@@ -23,11 +23,14 @@ import (
 )
 
 const (
+	//PluginFolder defines location of plugins
 	PluginFolder = "/var/lib/kubelet/plugins"
 )
 
+// ForAllFunc stores metdata with identifier
 type ForAllFunc func(identifier string) error
 
+// CachePersister interface implemented for store
 type CachePersister interface {
 	Create(identifier string, data interface{}) error
 	Get(identifier string, data interface{}) error
@@ -35,6 +38,7 @@ type CachePersister interface {
 	Delete(identifier string) error
 }
 
+// NewCachePersister returns CachePersister based on store
 func NewCachePersister(metadataStore, driverName string) (CachePersister, error) {
 	if metadataStore == "k8s_configmap" {
 		glog.Infof("cache-perister: using kubernetes configmap as metadata cache persister")

pkg/util/k8scmcache.go

@@ -33,6 +33,7 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 )
 
+// K8sCMCache to store metadata
 type K8sCMCache struct {
 	Client    *k8s.Clientset
 	Namespace string
@@ -47,6 +48,8 @@ const (
 	csiMetadataLabelAttr = "com.ceph.ceph-csi/metadata"
 )
 
+// GetK8sNamespace returns pod namespace. if pod namespace is empty
+// it returns default namespace
 func GetK8sNamespace() string {
 	namespace := os.Getenv("POD_NAMESPACE")
 	if namespace == "" {
@@ -55,6 +58,7 @@ func GetK8sNamespace() string {
 	return namespace
 }
 
+// NewK8sClient create kubernetes client
 func NewK8sClient() *k8s.Clientset {
 	var cfg *rest.Config
 	var err error
@@ -88,6 +92,7 @@ func (k8scm *K8sCMCache) getMetadataCM(resourceID string) (*v1.ConfigMap, error)
 	return cm, nil
 }
 
+//ForAll list the metadata in configmaps and filters outs based on the pattern
 func (k8scm *K8sCMCache) ForAll(pattern string, destObj interface{}, f ForAllFunc) error {
 	listOpts := metav1.ListOptions{LabelSelector: fmt.Sprintf("%s=%s", csiMetadataLabelAttr, cmLabel)}
 	cms, err := k8scm.Client.CoreV1().ConfigMaps(k8scm.Namespace).List(listOpts)
@@ -114,6 +119,7 @@ func (k8scm *K8sCMCache) ForAll(pattern string, destObj interface{}, f ForAllFun
 	return nil
 }
 
+// Create stores the metadata in configmaps with identifier name
 func (k8scm *K8sCMCache) Create(identifier string, data interface{}) error {
 	cm, err := k8scm.getMetadataCM(identifier)
 	if cm != nil && err == nil {
@@ -149,6 +155,7 @@ func (k8scm *K8sCMCache) Create(identifier string, data interface{}) error {
 	return nil
 }
 
+// Get retrieves the metadata in configmaps with identifier name
 func (k8scm *K8sCMCache) Get(identifier string, data interface{}) error {
 	cm, err := k8scm.getMetadataCM(identifier)
 	if err != nil {
@@ -161,6 +168,7 @@ func (k8scm *K8sCMCache) Get(identifier string, data interface{}) error {
 	return nil
 }
 
+// Delete deletes the metadata in configmaps with identifier name
 func (k8scm *K8sCMCache) Delete(identifier string) error {
 	err := k8scm.Client.CoreV1().ConfigMaps(k8scm.Namespace).Delete(identifier, nil)
 	if err != nil {

pkg/util/nodecache.go

@@ -29,12 +29,14 @@ import (
 	"github.com/pkg/errors"
 )
 
+// NodeCache to store metadata
 type NodeCache struct {
 	BasePath string
 }
 
 var cacheDir = "controller"
 
+// EnsureCacheDirectory creates cache directory if not present
 func (nc *NodeCache) EnsureCacheDirectory(cacheDir string) error {
 	fullPath := path.Join(nc.BasePath, cacheDir)
 	if _, err := os.Stat(fullPath); os.IsNotExist(err) {
@@ -45,6 +47,7 @@ func (nc *NodeCache) EnsureCacheDirectory(cacheDir string) error {
 	return nil
 }
 
+//ForAll list the metadata in Nodecache and filters outs based on the pattern
 func (nc *NodeCache) ForAll(pattern string, destObj interface{}, f ForAllFunc) error {
 	err := nc.EnsureCacheDirectory(cacheDir)
 	if err != nil {
@@ -80,6 +83,7 @@ func (nc *NodeCache) ForAll(pattern string, destObj interface{}, f ForAllFunc) e
 	return nil
 }
 
+// Create creates the metadata file in cache directory with identifier name
 func (nc *NodeCache) Create(identifier string, data interface{}) error {
 	file := path.Join(nc.BasePath, cacheDir, identifier+".json")
 	fp, err := os.Create(file)
@@ -95,6 +99,7 @@ func (nc *NodeCache) Create(identifier string, data interface{}) error {
 	return nil
 }
 
+// Get retrieves the metadata from cache directory with identifier name
 func (nc *NodeCache) Get(identifier string, data interface{}) error {
 	file := path.Join(nc.BasePath, cacheDir, identifier+".json")
 	fp, err := os.Open(file)
@@ -111,6 +116,7 @@ func (nc *NodeCache) Get(identifier string, data interface{}) error {
 	return nil
 }
 
+// Delete deletes the metadata file from cache directory with identifier name
 func (nc *NodeCache) Delete(identifier string) error {
 	file := path.Join(nc.BasePath, cacheDir, identifier+".json")
 	err := os.Remove(file)