feedback, check for AllocConsole error

Author: dpaasman00

cmd/opampsupervisor/main_windows.go

@@ -25,7 +25,13 @@ var (
 func run() error {
 	// always allocate a console in case we're running as service
 	if err := allocConsole(); err != nil {
-		return fmt.Errorf("alloc console: %w", err)
+		if !errors.Is(err, windows.ERROR_ACCESS_DENIED) {
+			// Per https://learn.microsoft.com/en-us/windows/console/allocconsole#remarks
+			// AllocConsole fails with this error when there's already a console attached, such as not being ran as service
+			// ignore this error and only return other errors
+			return fmt.Errorf("alloc console: %w", err)
+		}
+
 	}
 	defer func() {
 		_ = freeConsole()
@@ -38,10 +44,6 @@ func run() error {
 			// Per https://learn.microsoft.com/en-us/windows/win32/api/winsvc/nf-winsvc-startservicectrldispatchera#return-value
 			// this means that the process is not running as a service, so run interactively.
 
-			// manually free console before running interactively
-			if err = freeConsole(); err != nil {
-				return fmt.Errorf("free console: %w", err)
-			}
 			return runInteractive()
 		}
 		return fmt.Errorf("failed to start supervisor: %w", err)

cmd/opampsupervisor/supervisor/supervisor_windows.go

@@ -28,18 +28,18 @@ func (ws *windowsService) Execute(args []string, requests <-chan svc.ChangeReque
 	// The first argument supplied to service.Execute is the service name. If this is
 	// not provided for some reason, raise a relevant error to the system event log
 	if len(args) == 0 {
-		return false, uint32(windows.ERROR_INVALID_SERVICENAME) // 1213: ERROR_INVALID_SERVICENAME
+		return false, uint32(windows.ERROR_INVALID_SERVICENAME)
 	}
 
 	elog, err := openEventLog(args[0])
 	if err != nil {
-		return false, uint32(windows.ERROR_EVENTLOG_CANT_START) // 1501: ERROR_EVENTLOG_CANT_START
+		return false, uint32(windows.ERROR_EVENTLOG_CANT_START)
 	}
 
 	changes <- svc.Status{State: svc.StartPending}
 	if err = ws.start(elog); err != nil {
 		_ = elog.Error(3, fmt.Sprintf("failed to start service: %v", err))
-		return false, uint32(windows.ERROR_EXCEPTION_IN_SERVICE) // 1064: ERROR_EXCEPTION_IN_SERVICE
+		return false, uint32(windows.ERROR_EXCEPTION_IN_SERVICE)
 	}
 	changes <- svc.Status{State: svc.Running, Accepts: svc.AcceptStop | svc.AcceptShutdown}
 
@@ -56,7 +56,7 @@ func (ws *windowsService) Execute(args []string, requests <-chan svc.ChangeReque
 
 		default:
 			_ = elog.Error(3, fmt.Sprintf("unexpected service control request #%d", req.Cmd))
-			return false, uint32(windows.ERROR_INVALID_SERVICE_CONTROL) // 1052: ERROR_INVALID_SERVICE_CONTROL
+			return false, uint32(windows.ERROR_INVALID_SERVICE_CONTROL)
 		}
 	}
 

cmd/opampsupervisor/supervisor/supervisor_windows_service_test.go

@@ -28,7 +28,7 @@ const (
 //
 // To test locally:
 // * Build the supervisor and collector binaries:
-//   - go build
+//   - cd cmd/opampsupervisor; go build
 //   - make otelcontribcol
 //
 // * Install the Windows service
@@ -70,7 +70,7 @@ func TestSupervisorAsService(t *testing.T) {
 	}, 10*time.Second, 500*time.Millisecond)
 
 	// verify supervisor service started & healthy
-	// Read the events from the otelcorecol source and check that they were emitted after the service
+	// Read the events from the opampsupervisor source and check that they were emitted after the service
 	// command started. This is a simple validation that the messages are being logged on the
 	// Windows event log.
 	cmd := exec.Command("wevtutil.exe", "qe", "Application", "/c:1", "/rd:true", "/f:RenderedXml", "/q:*[System[Provider[@Name='opampsupervisor']]]")