chore(go-lint): fix golint warning (#133)

Fixes several go lint cases reported by go report. 

Signed-off-by: wiwen <shenggxhz@gmail.com>

pkg/driver/agent.go

@@ -69,6 +69,7 @@ func NewNode(d *CSIDriver) csi.NodeServer {
 	}
 }
 
+// GetVolAndMountInfo get volume and mount info from node csi volume request
 func GetVolAndMountInfo(
 	req *csi.NodePublishVolumeRequest,
 ) (*apis.ZFSVolume, *apis.MountInfo, error) {

pkg/driver/controller.go

@@ -24,6 +24,10 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/container-storage-interface/spec/lib/go/csi"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
 	"github.com/openebs/zfs-localpv/pkg/builder/snapbuilder"
 	"github.com/openebs/zfs-localpv/pkg/builder/volbuilder"
 	errors "github.com/openebs/zfs-localpv/pkg/common/errors"
@@ -31,9 +35,6 @@ import (
 	csipayload "github.com/openebs/zfs-localpv/pkg/response"
 	analytics "github.com/openebs/zfs-localpv/pkg/usage"
 	zfs "github.com/openebs/zfs-localpv/pkg/zfs"
-	"golang.org/x/net/context"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
 )
 
 // controller is the server implementation
@@ -74,6 +75,7 @@ func sendEventOrIgnore(pvcName, pvName, capacity, stgType, method string) {
 	}
 }
 
+// CreateZFSVolume create new zfs volume from csi volume request
 func CreateZFSVolume(req *csi.CreateVolumeRequest) (string, error) {
 	volName := req.GetName()
 	size := req.GetCapacityRange().RequiredBytes
@@ -137,6 +139,7 @@ func CreateZFSVolume(req *csi.CreateVolumeRequest) (string, error) {
 	return selected, nil
 }
 
+// CreateZFSClone create a clone of zfs volume
 func CreateZFSClone(req *csi.CreateVolumeRequest, snapshot string) (string, error) {
 
 	volName := req.GetName()
@@ -260,6 +263,14 @@ func (cs *controller) DeleteVolume(
 		goto deleteResponse
 	}
 
+	if err != nil {
+		return nil, errors.Wrapf(
+			err,
+			"failed to get volume for {%s}",
+			volumeID,
+		)
+	}
+
 	// Delete the corresponding ZV CR
 	err = zfs.DeleteVolume(volumeID)
 	if err != nil {

pkg/driver/driver.go

@@ -29,10 +29,9 @@ var supportedAccessMode = &csi.VolumeCapability_AccessMode{
 	Mode: csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER,
 }
 
-// TODO check if this can be renamed to Base
-//
 // CSIDriver defines a common data structure
 // for drivers
+// TODO check if this can be renamed to Base
 type CSIDriver struct {
 	// TODO change the field names to make it
 	// readable

pkg/driver/grpc.go

@@ -75,22 +75,22 @@ type NonBlockingGRPCServer interface {
 // NewNonBlockingGRPCServer returns a new instance of NonBlockingGRPCServer
 func NewNonBlockingGRPCServer(ep string, ids csi.IdentityServer, cs csi.ControllerServer, ns csi.NodeServer) NonBlockingGRPCServer {
 	return &nonBlockingGRPCServer{
-		endpoint:     ep,
-		idnty_server: ids,
-		ctrl_server:  cs,
-		agent_server: ns}
+		endpoint:    ep,
+		idntyServer: ids,
+		ctrlServer:  cs,
+		agentServer: ns}
 }
 
 // NonBlocking server
 // dont block the execution for a task to complete.
 // use wait group to wait for all the tasks dispatched.
 type nonBlockingGRPCServer struct {
-	wg           sync.WaitGroup
-	server       *grpc.Server
-	endpoint     string
-	idnty_server csi.IdentityServer
-	ctrl_server  csi.ControllerServer
-	agent_server csi.NodeServer
+	wg          sync.WaitGroup
+	server      *grpc.Server
+	endpoint    string
+	idntyServer csi.IdentityServer
+	ctrlServer  csi.ControllerServer
+	agentServer csi.NodeServer
 }
 
 // Start grpc server for serving CSI endpoints
@@ -98,7 +98,7 @@ func (s *nonBlockingGRPCServer) Start() {
 
 	s.wg.Add(1)
 
-	go s.serve(s.endpoint, s.idnty_server, s.ctrl_server, s.agent_server)
+	go s.serve(s.endpoint, s.idntyServer, s.ctrlServer, s.agentServer)
 
 	return
 }