service: update api.

example/main.go

@@ -10,30 +10,31 @@ import (
 
 var logger service.Logger
 
+// Program structures.
+//  Define Start and Stop methods.
 type program struct {
 	exit chan struct{}
 }
 
 func (p *program) Start(s service.Service) error {
-	if s.Interactive() {
+	if service.Local.Interactive() {
 		logger.Info("Running in terminal.")
 	} else {
 		logger.Info("Running under service manager.")
 	}
 	p.exit = make(chan struct{})
+
+	// Start should not block. Do the actual work async.
 	go p.run()
 	return nil
 }
 func (p *program) run() error {
-	logger.Infof("I'm running %v.", service.LocalSystem())
+	logger.Infof("I'm running %v.", service.Local)
 	ticker := time.NewTicker(2 * time.Second)
 	for {
 		select {
 		case tm := <-ticker.C:
-			err := logger.Infof("Still running at %v...", tm)
-			if err != nil {
-				panic(err)
-			}
+			logger.Infof("Still running at %v...", tm)
 		case <-p.exit:
 			ticker.Stop()
 			return nil
@@ -42,14 +43,18 @@ func (p *program) run() error {
 	return nil
 }
 func (p *program) Stop(s service.Service) error {
-	err := logger.Info("I'm Stopping!")
-	if err != nil {
-		panic(err)
-	}
+	// Any work in Stop should be quick, usually a few seconds at most.
+	logger.Info("I'm Stopping!")
 	close(p.exit)
 	return nil
 }
 
+// Service setup.
+//   Define service config.
+//   Create the service.
+//   Setup the logger.
+//   Handle service controls (optional).
+//   Run the service.
 func main() {
 	svcConfig := &service.Config{
 		Name:        "GoServiceTest",
@@ -60,16 +65,26 @@ func main() {
 	prg := &program{}
 	s, err := service.New(prg, svcConfig)
 	if err != nil {
-		panic(err)
+		log.Fatal(err)
 	}
-	logger, err = s.Logger()
+	errs := make(chan error, 5)
+	logger, err = s.Logger(errs)
 	if err != nil {
-		panic(err)
+		log.Fatal(err)
 	}
+	go func() {
+		for {
+			err := <-errs
+			if err != nil {
+				log.Print(err)
+			}
+		}
+	}()
 
 	if len(os.Args) > 1 {
 		err := service.Control(s, os.Args[1])
 		if err != nil {
+			log.Printf("Valid actions: %q\n", service.ControlAction)
 			log.Fatal(err)
 		}
 		return