fix golint issues in core/service (#512)

core/service/serviceconf.go

@@ -10,12 +10,17 @@ import (
 )
 
 const (
-	DevMode  = "dev"
+	// DevMode means development mode.
+	DevMode = "dev"
+	// TestMode means test mode.
 	TestMode = "test"
-	PreMode  = "pre"
-	ProMode  = "pro"
+	// PreMode means pre-release mode.
+	PreMode = "pre"
+	// ProMode means production mode.
+	ProMode = "pro"
 )
 
+// A ServiceConf is a service config.
 type ServiceConf struct {
 	Name       string
 	Log        logx.LogConf
@@ -24,12 +29,14 @@ type ServiceConf struct {
 	Prometheus prometheus.Config `json:",optional"`
 }
 
+// MustSetUp sets up the service, exits on error.
 func (sc ServiceConf) MustSetUp() {
 	if err := sc.SetUp(); err != nil {
 		log.Fatal(err)
 	}
 }
 
+// SetUp sets up the service.
 func (sc ServiceConf) SetUp() error {
 	if len(sc.Log.ServiceName) == 0 {
 		sc.Log.ServiceName = sc.Name

core/service/servicegroup.go

@@ -9,39 +9,45 @@ import (
 )
 
 type (
+	// Starter is the interface wraps the Start method.
 	Starter interface {
 		Start()
 	}
 
+	// Stopper is the interface wraps the Stop method.
 	Stopper interface {
 		Stop()
 	}
 
+	// Service is the interface that groups Start and Stop methods.
 	Service interface {
 		Starter
 		Stopper
 	}
 
-	ServiceGroup struct {
+	// A Group is a group of services.
+	Group struct {
 		services []Service
 		stopOnce func()
 	}
 )
 
-func NewServiceGroup() *ServiceGroup {
-	sg := new(ServiceGroup)
+// NewGroup returns a Group.
+func NewGroup() *Group {
+	sg := new(Group)
 	sg.stopOnce = syncx.Once(sg.doStop)
 	return sg
 }
 
-func (sg *ServiceGroup) Add(service Service) {
+// Add adds service into sg.
+func (sg *Group) Add(service Service) {
 	sg.services = append(sg.services, service)
 }
 
-// Start starts the ServiceGroup.
+// Start starts the Group.
 // There should not be any logic code after calling this method, because this method is a blocking one.
 // Also, quitting this method will close the logx output.
-func (sg *ServiceGroup) Start() {
+func (sg *Group) Start() {
 	proc.AddShutdownListener(func() {
 		log.Println("Shutting down...")
 		sg.stopOnce()
@@ -50,11 +56,12 @@ func (sg *ServiceGroup) Start() {
 	sg.doStart()
 }
 
-func (sg *ServiceGroup) Stop() {
+// Stop stops the Group.
+func (sg *Group) Stop() {
 	sg.stopOnce()
 }
 
-func (sg *ServiceGroup) doStart() {
+func (sg *Group) doStart() {
 	routineGroup := threading.NewRoutineGroup()
 
 	for i := range sg.services {
@@ -67,18 +74,20 @@ func (sg *ServiceGroup) doStart() {
 	routineGroup.Wait()
 }
 
-func (sg *ServiceGroup) doStop() {
+func (sg *Group) doStop() {
 	for _, service := range sg.services {
 		service.Stop()
 	}
 }
 
+// WithStart wraps a start func as a Service.
 func WithStart(start func()) Service {
 	return startOnlyService{
 		start: start,
 	}
 }
 
+// WithStarter wraps a Starter as a Service.
 func WithStarter(start Starter) Service {
 	return starterOnlyService{
 		Starter: start,

core/service/servicegroup_test.go

@@ -41,7 +41,7 @@ func TestServiceGroup(t *testing.T) {
 	multipliers := []int{2, 3, 5, 7}
 	want := 1
 
-	group := NewServiceGroup()
+	group := NewGroup()
 	for _, multiplier := range multipliers {
 		want *= multiplier
 		service := newMockedService(multiplier)
@@ -68,7 +68,7 @@ func TestServiceGroup_WithStart(t *testing.T) {
 	var wait sync.WaitGroup
 	var lock sync.Mutex
 	wait.Add(len(multipliers))
-	group := NewServiceGroup()
+	group := NewGroup()
 	for _, multiplier := range multipliers {
 		var mul = multiplier
 		group.Add(WithStart(func() {
@@ -95,7 +95,7 @@ func TestServiceGroup_WithStarter(t *testing.T) {
 	var wait sync.WaitGroup
 	var lock sync.Mutex
 	wait.Add(len(multipliers))
-	group := NewServiceGroup()
+	group := NewGroup()
 	for _, multiplier := range multipliers {
 		var mul = multiplier
 		group.Add(WithStarter(mockedStarter{