Restart service on failure (Windows)

windows/svc/example/service.go

@@ -8,9 +8,11 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"strings"
 	"time"
 
+	"golang.org/x/sys/windows"
 	"golang.org/x/sys/windows/svc"
 	"golang.org/x/sys/windows/svc/debug"
 	"golang.org/x/sys/windows/svc/eventlog"
@@ -27,9 +29,17 @@ func (m *exampleService) Execute(args []string, r <-chan svc.ChangeRequest, chan
 	slowtick := time.Tick(2 * time.Second)
 	tick := fasttick
 	changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
+
+	// Simulate failure after 5 seconds
+	failureTimer := time.NewTimer(5 * time.Second)
+	defer failureTimer.Stop()
+
 loop:
 	for {
 		select {
+		case <-failureTimer.C:
+			// Simulate failure by returning a non-zero exit code
+			return false, uint32(windows.ERROR_UNEXP_NET_ERR)
 		case <-tick:
 			beep()
 			elog.Info(1, "beep")
@@ -81,6 +91,11 @@ func runService(name string, isDebug bool) {
 	err = run(name, &exampleService{})
 	if err != nil {
 		elog.Error(1, fmt.Sprintf("%s service failed: %v", name, err))
+		if exitErr, ok := err.(*svc.ExitError); ok {
+			os.Exit(int(exitErr.Code))
+		} else {
+			os.Exit(1)
+		}
 		return
 	}
 	elog.Info(1, fmt.Sprintf("%s service stopped", name))

windows/svc/service.go

@@ -9,6 +9,7 @@ package svc
 
 import (
 	"errors"
+	"fmt"
 	"sync"
 	"unsafe"
 
@@ -132,17 +133,26 @@ type ctlEvent struct {
 
 // service provides access to windows service api.
 type service struct {
-	name    string
-	h       windows.Handle
-	c       chan ctlEvent
-	handler Handler
+	name     string
+	h        windows.Handle
+	c        chan ctlEvent
+	handler  Handler
+	exitCode uint32
 }
 
 type exitCode struct {
 	isSvcSpecific bool
 	errno         uint32
 }
 
+type ExitError struct {
+	Code uint32
+}
+
+func (e *ExitError) Error() string {
+	return fmt.Sprintf("service exited with error code %d", e.Code)
+}
+
 func (s *service) updateStatus(status *Status, ec *exitCode) error {
 	if s.h == 0 {
 		return errors.New("updateStatus with no service status handle")
@@ -274,6 +284,7 @@ loop:
 	}
 
 	theService.updateStatus(&Status{State: Stopped}, &ec)
+	theService.exitCode = ec.errno
 
 	return windows.NO_ERROR
 }

windows/svc/svc_test.go

@@ -239,3 +239,106 @@ func TestIsWindowsServiceWhenParentExits(t *testing.T) {
 		}
 	}
 }
+
+func TestServiceRestart(t *testing.T) {
+	if os.Getenv("GO_BUILDER_NAME") == "" {
+		// Don't install services on arbitrary users' machines.
+		t.Skip("Skipping test that modifies system services: GO_BUILDER_NAME not set")
+	}
+	if testing.Short() {
+		t.Skip("Skipping test in short mode that modifies system services")
+	}
+
+	const name = "svctestservice"
+
+	m, err := mgr.Connect()
+	if err != nil {
+		t.Fatalf("SCM connection failed: %v", err)
+	}
+	defer m.Disconnect()
+
+	// Build the service executable
+	exepath := filepath.Join(t.TempDir(), "a.exe")
+	o, err := exec.Command("go", "build", "-o", exepath, "golang.org/x/sys/windows/svc/example").CombinedOutput()
+	if err != nil {
+		t.Fatalf("Failed to build service program: %v\n%v", err, string(o))
+	}
+
+	// Ensure any existing service is stopped and deleted
+	stopAndDeleteIfInstalled(t, m, name)
+
+	// Create the service
+	s, err := m.CreateService(name, exepath, mgr.Config{DisplayName: "x-sys svc test service"})
+	if err != nil {
+		t.Fatalf("CreateService(%s) failed: %v", name, err)
+	}
+	defer s.Close()
+
+	// Set the service to restart on failure
+	actions := []mgr.RecoveryAction{
+		{Type: mgr.ServiceRestart, Delay: 1 * time.Second}, // Restart after 1 second
+	}
+	err = s.SetRecoveryActions(actions, 0)
+	if err != nil {
+		t.Fatalf("Failed to set service recovery actions: %v", err)
+	}
+
+	// Set the flag to perform recovery actions on non-crash failures
+	err = s.SetRecoveryActionsOnNonCrashFailures(true)
+	if err != nil {
+		t.Fatalf("Failed to set RecoveryActionsOnNonCrashFailures: %v", err)
+	}
+
+	// Start the service
+	testState(t, s, svc.Stopped)
+	err = s.Start()
+	if err != nil {
+		t.Fatalf("Start(%s) failed: %v", s.Name, err)
+	}
+
+	// Wait for the service to start
+	waitState(t, s, svc.Running)
+
+	// Get the initial process ID
+	status, err := s.Query()
+	if err != nil {
+		t.Fatalf("Query(%s) failed: %v", s.Name, err)
+	}
+	initialPID := status.ProcessId
+	t.Logf("Initial PID: %d", initialPID)
+
+	// Wait up to 30 seconds for the PID to change, indicating a restart
+	var newPID uint32
+	success := false
+	for i := 0; i < 30; i++ {
+		time.Sleep(1 * time.Second)
+
+		status, err = s.Query()
+		if err != nil {
+			t.Fatalf("Query(%s) failed: %v", s.Name, err)
+		}
+		newPID = status.ProcessId
+
+		if newPID != 0 && newPID != initialPID {
+			success = true
+			t.Logf("Service restarted successfully, new PID: %d", newPID)
+			break
+		}
+	}
+
+	if !success {
+		t.Fatalf("Service did not restart within the expected time")
+	}
+
+	// Cleanup: Stop and delete the service
+	_, err = s.Control(svc.Stop)
+	if err != nil {
+		t.Fatalf("Control(%s) failed: %v", s.Name, err)
+	}
+	waitState(t, s, svc.Stopped)
+
+	err = s.Delete()
+	if err != nil {
+		t.Fatalf("Delete failed: %v", err)
+	}
+}