Add TestServiceRestart to verify service restarts upon failure on Windows

This test monitors the service's process ID (PID) to confirm that the Windows Service Control Manager (SCM) restarts the service when it fails. It starts the service, records its initial PID, and then waits for the service to fail and restart.

Author: n0owud

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)
+	}
+}