Break Service interface into smaller chunks. Add Start and Stop methods.

example/main.go

@@ -6,11 +6,15 @@ import (
 	"os"
 )
 
+var localLog service.Logger
+
 func main() {
 	var name = "GoServiceTest"
 	var displayName = "Go Service Test"
 	var desc = "This is a test Go service.  It is designed to run well."
-	var ws, err = service.NewService(name, displayName, desc)
+
+	var s, err = service.NewService(name, displayName, desc)
+	localLog = s
 
 	if err != nil {
 		fmt.Printf("%s unable to start: %s", displayName, err)
@@ -22,41 +26,56 @@ func main() {
 		verb := os.Args[1]
 		switch verb {
 		case "install":
-			err = ws.Install()
+			err = s.Install()
 			if err != nil {
 				fmt.Printf("Failed to install: %s\n", err)
 				return
 			}
 			fmt.Printf("Service \"%s\" installed.\n", displayName)
 		case "remove":
-			err = ws.Remove()
+			err = s.Remove()
 			if err != nil {
 				fmt.Printf("Failed to remove: %s\n", err)
 				return
 			}
 			fmt.Printf("Service \"%s\" removed.\n", displayName)
+		case "run":
+			doWork()
+		case "start":
+			err = s.Start()
+			if err != nil {
+				fmt.Printf("Failed to start: %s\n", err)
+				return
+			}
+			fmt.Printf("Service \"%s\" started.\n", displayName)
+		case "stop":
+			err = s.Stop()
+			if err != nil {
+				fmt.Printf("Failed to stop: %s\n", err)
+				return
+			}
+			fmt.Printf("Service \"%s\" stopped.\n", displayName)
 		}
 		return
 	}
-	err = ws.Run(func() error {
+	err = s.Run(func() error {
 		// start
 		go doWork()
-		ws.LogInfo("I'm Running!")
 		return nil
 	}, func() error {
 		// stop
 		stopWork()
-		ws.LogInfo("I'm Stopping!")
 		return nil
 	})
 	if err != nil {
-		ws.LogError(err.Error())
+		s.LogError(err.Error())
 	}
 }
 
 func doWork() {
-
+	localLog.LogInfo("I'm Running!")
+	select {}
 }
 func stopWork() {
-
+	localLog.LogInfo("I'm Stopping!")
 }

service.go

@@ -1,5 +1,5 @@
 // Package service provides a simple way to create a system service.
-// Currently supports Windows and Linux/Upstart.
+// Currently supports Windows, Linux/Upstart, OSX/Launchd.
 package service
 
 // Creates a new service. name is the internal name
@@ -12,14 +12,14 @@ func NewService(name, displayName, description string) (Service, error) {
 
 // Represents a generic way to interact with the system's service.
 type Service interface {
-	// Installs this service on the system.  May return an
+	Installer
-	// error if this service is already installed.
+	Controller
-	Install() error
+	Runner
-
+	Logger
-	// Removes this service from the system.  May return an
+}
-	// error if this service is not already installed.
-	Remove() error
 
+// A Generic way to stop and start a service.
+type Runner interface {
 	// Call quickly after initial entry point.  Does not return until
 	// service is ready to stop.  onStart is called when the service is
 	// starting, returning an error will fail to start the service.
@@ -28,7 +28,31 @@ type Service interface {
 	// an error from Run.
 	// Both callbacks should return quickly and not block.
 	Run(onStart, onStop func() error) error
+}
 
+// Simple install and remove commands.
+type Installer interface {
+	// Installs this service on the system.  May return an
+	// error if this service is already installed.
+	Install() error
+
+	// Removes this service from the system.  May return an
+	// error if this service is not already installed.
+	Remove() error
+}
+
+// A service that implements ServiceController is able to
+// start and stop itself.
+type Controller interface {
+	// Starts this service on the system.
+	Start() error
+
+	// Stops this service on the system.
+	Stop() error
+}
+
+// A service that implements ServiceLogger can perform simple system logging.
+type Logger interface {
 	// Basic log functions in the context of the service.
 	LogError(format string, a ...interface{}) error
 	LogWarning(format string, a ...interface{}) error

service_darwin.go

@@ -5,8 +5,8 @@ package service
 #include <string.h>
 
 int
-GetExecPath(char* path) {
+GetExecPath(char* path, int bufferSize) {
-	uint32_t size = 32*1024;
+	uint32_t size = bufferSize;
 	if (_NSGetExecutablePath(path, &size) == 0) {
 		// Despite Apple docs, size does NOT get set in call.
 		return strlen(path);
@@ -28,7 +28,8 @@ import (
 	"text/template"
 )
 
-// BUG(kardia): I have not confirmed this service works as intended on launchd.
+const maxPathSize = 32 * 1024
+
 func newService(name, displayName, description string) (s *darwinLaunchdService, err error) {
 	s = &darwinLaunchdService{
 		name:        name,
@@ -83,30 +84,26 @@ func (s *darwinLaunchdService) Install() error {
 		path,
 	}
 
-	t := template.Must(template.New("upstartScript").Parse(upstartScript))
+	t := template.Must(template.New("launchdConfig").Parse(launchdConfig))
-	err = t.Execute(f, to)
+	return t.Execute(f, to)
-
-	if err != nil {
-		return err
-	}
-
-	cmd := exec.Command("launchctl", "load", confPath)
-	err = cmd.Run()
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 func (s *darwinLaunchdService) Remove() error {
+	s.Stop()
+
+	confPath := s.getServiceFilePath()
+	return os.Remove(confPath)
+}
+
+func (s *darwinLaunchdService) Start() error {
+	confPath := s.getServiceFilePath()
+	cmd := exec.Command("launchctl", "load", confPath)
+	return cmd.Run()
+}
+func (s *darwinLaunchdService) Stop() error {
 	confPath := s.getServiceFilePath()
 	cmd := exec.Command("launchctl", "unload", confPath)
-	err := cmd.Run()
+	return cmd.Run()
-
-	// Don't worry about his error if not found.
-	os.Remove(confPath)
-	return err
 }
 
 func (s *darwinLaunchdService) Run(onStart, onStop func() error) error {
@@ -137,8 +134,8 @@ func (s *darwinLaunchdService) LogInfo(format string, a ...interface{}) error {
 }
 
 func getExePath() (exePath string, err error) {
-	buffer := make([]byte, 32*1024)
+	buffer := make([]byte, maxPathSize)
-	size := C.GetExecPath((*C.char)(unsafe.Pointer(&buffer[0])))
+	size := C.GetExecPath((*C.char)(unsafe.Pointer(&buffer[0])), maxPathSize)
 	if size == 0 {
 		return "", errors.New("Unable to get exec path.")
 	}
@@ -147,7 +144,7 @@ func getExePath() (exePath string, err error) {
 	return ret, nil
 }
 
-var upstartScript = `<?xml version='1.0' encoding='UTF-8'?>
+var launchdConfig = `<?xml version='1.0' encoding='UTF-8'?>
 <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN"
 "http://www.apple.com/DTDs/PropertyList-1.0.dtd" >
 <plist version='1.0'>

service_linux.go

@@ -4,8 +4,10 @@ import (
 	"fmt"
 	"log/syslog"
 	"os"
+	"os/exec"
 	"os/signal"
 	"text/template"
+	"path/filepath"
 )
 
 func newService(name, displayName, description string) (s *linuxUpstartService, err error) {
@@ -87,6 +89,16 @@ func (s *linuxUpstartService) Run(onStart, onStop func() error) error {
 	return onStop()
 }
 
+func (s *linuxUpstartService) Start() error {
+	cmd := exec.Command("start", s.name)
+	return cmd.Run()
+}
+
+func (s *linuxUpstartService) Stop() error {
+	cmd := exec.Command("stop", s.name)
+	return cmd.Run()
+}
+
 func (s *linuxUpstartService) LogError(format string, a ...interface{}) error {
 	return s.logger.Err(fmt.Sprintf(format, a...))
 }
@@ -98,7 +110,9 @@ func (s *linuxUpstartService) LogInfo(format string, a ...interface{}) error {
 }
 
 func getExePath() (exePath string, err error) {
-	return os.Readlink(`/proc/self/exe`)
+	exePath, err = os.Readlink(`/proc/self/exe`)
+	exePath = filepath.Clean(exePath)
+	return
 }
 
 var upstartScript = `# {{.Description}}

service_windows.go

@@ -124,6 +124,37 @@ func (ws *windowsService) Run(onStart, onStop func() error) error {
 	return svc.Run(ws.name, ws)
 }
 
+func (ws *windowsService) Start() error {
+	m, err := mgr.Connect()
+	if err != nil {
+		return err
+	}
+	defer m.Disconnect()
+
+	s, err := m.OpenService(ws.name)
+	if err != nil {
+		return err
+	}
+	defer s.Close()
+	return s.Start([]string{})
+}
+
+func (ws *windowsService) Stop() error {
+	m, err := mgr.Connect()
+	if err != nil {
+		return err
+	}
+	defer m.Disconnect()
+
+	s, err := m.OpenService(ws.name)
+	if err != nil {
+		return err
+	}
+	defer s.Close()
+	_, err = s.Control(svc.Stop)
+	return err
+}
+
 func (ws *windowsService) LogError(format string, a ...interface{}) error {
 	if ws.logger == nil {
 		return nil