[skip ci]Fix golint in indexnode/indexnode_mock.go (#9120)

Signed-off-by: Ncai.zhang <cai.zhang@zilliz.com>

internal/indexnode/indexnode_mock.go

@@ -31,6 +31,7 @@ import (
 	"github.com/milvus-io/milvus/internal/util/typeutil"
 )
 
+// Mock is an alternative to IndexNode, it will return specific results based on specific parameters.
 type Mock struct {
 	Build   bool
 	Failure bool
@@ -45,6 +46,7 @@ type Mock struct {
 	buildIndex chan *indexpb.CreateIndexRequest
 }
 
+// Init initializes the Mock of IndexNode. If the internal member `Err` is True, return an error.
 func (inm *Mock) Init() error {
 	if inm.Err {
 		return errors.New("IndexNode init failed")
@@ -146,6 +148,7 @@ func (inm *Mock) buildIndexTask() {
 	}
 }
 
+// Start starts the Mock of IndexNode. If the internal member `Err` is true, it will return an error.
 func (inm *Mock) Start() error {
 	if inm.Err {
 		return errors.New("IndexNode start failed")
@@ -155,6 +158,7 @@ func (inm *Mock) Start() error {
 	return nil
 }
 
+// Stop stops the Mock of IndexNode. If the internal member `Err` is true, it will return an error.
 func (inm *Mock) Stop() error {
 	if inm.Err {
 		return errors.New("IndexNode stop failed")
@@ -165,6 +169,7 @@ func (inm *Mock) Stop() error {
 	return nil
 }
 
+// Register registers an IndexNode role in ETCD, if the internal member `Err` is true, it will return an error.
 func (inm *Mock) Register() error {
 	if inm.Err {
 		return errors.New("IndexNode register failed")
@@ -177,6 +182,8 @@ func (inm *Mock) Register() error {
 	return nil
 }
 
+// GetComponentStates gets the component states of the mocked IndexNode, if the internal member `Err` is true, it will return an error,
+// and the state is `StateCode_Abnormal`. Under normal circumstances the state is `StateCode_Healthy`.
 func (inm *Mock) GetComponentStates(ctx context.Context) (*internalpb.ComponentStates, error) {
 	if inm.Err {
 		return &internalpb.ComponentStates{
@@ -198,6 +205,7 @@ func (inm *Mock) GetComponentStates(ctx context.Context) (*internalpb.ComponentS
 	}, nil
 }
 
+// GetStatisticsChannel gets the statistics channel of the mocked IndexNode, if the internal member `Err` is true, it will return an error.
 func (inm *Mock) GetStatisticsChannel(ctx context.Context) (*milvuspb.StringResponse, error) {
 	if inm.Err {
 		return &milvuspb.StringResponse{
@@ -214,6 +222,7 @@ func (inm *Mock) GetStatisticsChannel(ctx context.Context) (*milvuspb.StringResp
 	}, nil
 }
 
+// GetTimeTickChannel gets the time tick channel of the mocked IndexNode, if the internal member `Err` is true, it will return an error.
 func (inm *Mock) GetTimeTickChannel(ctx context.Context) (*milvuspb.StringResponse, error) {
 	if inm.Err {
 		return &milvuspb.StringResponse{
@@ -230,6 +239,9 @@ func (inm *Mock) GetTimeTickChannel(ctx context.Context) (*milvuspb.StringRespon
 	}, nil
 }
 
+// CreateIndex receives a building index request, and return success, if the internal member `Build` is true,
+// the indexing task will be executed. If the internal member `Err` is true, it will return an error.
+// If the internal member `Failure` is true, the indexing task will be executed and the index state is Failed.
 func (inm *Mock) CreateIndex(ctx context.Context, req *indexpb.CreateIndexRequest) (*commonpb.Status, error) {
 	if inm.Build {
 		inm.buildIndex <- req
@@ -246,6 +258,7 @@ func (inm *Mock) CreateIndex(ctx context.Context, req *indexpb.CreateIndexReques
 	}, nil
 }
 
+// GetMetrics gets the metrics of mocked IndexNode, if the internal member `Failure` is true, it will return an error.
 func (inm *Mock) GetMetrics(ctx context.Context, req *milvuspb.GetMetricsRequest) (*milvuspb.GetMetricsResponse, error) {
 	if inm.Err {
 		return &milvuspb.GetMetricsResponse{