service: return better error messages from executed commands.

example/logging/main.go

@@ -65,9 +65,9 @@ func main() {
 	flag.Parse()
 
 	svcConfig := &service.Config{
-		Name:        "GoServiceTest",
+		Name:        "GoServiceExampleLogging",
-		DisplayName: "Go Service Test",
+		DisplayName: "Go Service Example for Logging",
-		Description: "This is a test Go service.",
+		Description: "This is an example Go service that outputs log messages.",
 	}
 
 	prg := &program{}

example/simple/main.go

@@ -30,9 +30,9 @@ func (p *program) Stop(s service.Service) error {
 
 func main() {
 	svcConfig := &service.Config{
-		Name:        "GoServiceTest",
+		Name:        "GoServiceExampleSimple",
-		DisplayName: "Go Service Test",
+		DisplayName: "Go Service Example",
-		Description: "This is a test Go service.",
+		Description: "This is an example Go service.",
 	}
 
 	prg := &program{}

service_darwin.go

@@ -7,7 +7,6 @@ package service
 import (
 	"fmt"
 	"os"
-	"os/exec"
 	"os/signal"
 	"os/user"
 	"syscall"
@@ -143,16 +142,14 @@ func (s *darwinLaunchdService) Start() error {
 	if err != nil {
 		return err
 	}
-	cmd := exec.Command("launchctl", "load", confPath)
+	return run("launchctl", "load", confPath)
-	return cmd.Run()
 }
 func (s *darwinLaunchdService) Stop() error {
 	confPath, err := s.getServiceFilePath()
 	if err != nil {
 		return err
 	}
-	cmd := exec.Command("launchctl", "unload", confPath)
+	return run("launchctl", "unload", confPath)
-	return cmd.Run()
 }
 func (s *darwinLaunchdService) Restart() error {
 	err := s.Stop()

service_systemd_linux.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"os/exec"
 	"os/signal"
 	"syscall"
 	"text/template"
@@ -94,15 +93,18 @@ func (s *systemd) Install() error {
 		return err
 	}
 
-	err = exec.Command("systemctl", "enable", s.Name+".service").Run()
+	err = run("systemctl", "enable", s.Name+".service")
 	if err != nil {
 		return err
 	}
-	return exec.Command("systemctl", "daemon-reload").Run()
+	return run("systemctl", "daemon-reload")
 }
 
 func (s *systemd) Uninstall() error {
-	exec.Command("systemctl", "disable", s.Name+".service").Run()
+	err := run("systemctl", "disable", s.Name+".service")
+	if err != nil {
+		return err
+	}
 	cp, err := s.configPath()
 	if err != nil {
 		return err
@@ -139,11 +141,11 @@ func (s *systemd) Run() (err error) {
 }
 
 func (s *systemd) Start() error {
-	return exec.Command("systemctl", "start", s.Name+".service").Run()
+	return run("systemctl", "start", s.Name+".service")
 }
 
 func (s *systemd) Stop() error {
-	return exec.Command("systemctl", "stop", s.Name+".service").Run()
+	return run("systemctl", "stop", s.Name+".service")
 }
 
 func (s *systemd) Restart() error {

service_sysv_linux.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"os/exec"
 	"os/signal"
 	"syscall"
 	"text/template"
@@ -140,11 +139,11 @@ func (s *sysv) Run() (err error) {
 }
 
 func (s *sysv) Start() error {
-	return exec.Command("service", s.Name, "start").Run()
+	return run("service", s.Name, "start")
 }
 
 func (s *sysv) Stop() error {
-	return exec.Command("service", s.Name, "stop").Run()
+	return run("service", s.Name, "stop")
 }
 
 func (s *sysv) Restart() error {

service_unix.go

@@ -9,6 +9,7 @@ package service
 import (
 	"fmt"
 	"log/syslog"
+	"os/exec"
 )
 
 func newSysLogger(name string, errs chan<- error) (Logger, error) {
@@ -49,3 +50,12 @@ func (s sysLogger) Warningf(format string, a ...interface{}) error {
 func (s sysLogger) Infof(format string, a ...interface{}) error {
 	return s.send(s.Writer.Info(fmt.Sprintf(format, a...)))
 }
+
+func run(command string, arguments ...string) error {
+	cmd := exec.Command(command, arguments...)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("%q failed: %v, %s", command, err, out)
+	}
+	return nil
+}

service_upstart_linux.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"os/exec"
 	"os/signal"
 	"syscall"
 	"text/template"
@@ -131,11 +130,11 @@ func (s *upstart) Run() (err error) {
 }
 
 func (s *upstart) Start() error {
-	return exec.Command("initctl", "start", s.Name).Run()
+	return run("initctl", "start", s.Name)
 }
 
 func (s *upstart) Stop() error {
-	return exec.Command("initctl", "stop", s.Name).Run()
+	return run("initctl", "stop", s.Name)
 }
 
 func (s *upstart) Restart() error {