Fix the client idle disconnect audit event for desktops

We were attempting to use the desktop name as the server ID,
but in order to publish audit events we must use the HostUUID
of the windows_desktop_service.

Updates #8665

lib/srv/desktop/windows_server.go

@@ -582,13 +582,13 @@ func (s *WindowsService) handleConnection(con net.Conn) {
 		return
 	}
 
-	// Fetch the target desktop info. UUID of the desktop is passed via SNI.
-	desktopUUID := strings.TrimSuffix(tlsConn.ConnectionState().ServerName, SNISuffix)
-	log = log.WithField("desktop-uuid", desktopUUID)
+	// Fetch the target desktop info. Name of the desktop is passed via SNI.
+	desktopName := strings.TrimSuffix(tlsConn.ConnectionState().ServerName, SNISuffix)
+	log = log.WithField("desktop-name", desktopName)
 
-	desktop, err := s.cfg.AccessPoint.GetWindowsDesktop(ctx, desktopUUID)
+	desktop, err := s.cfg.AccessPoint.GetWindowsDesktop(ctx, desktopName)
 	if err != nil {
-		log.WithError(err).Warning("Failed to fetch desktop by UUID")
+		log.WithError(err).Warning("Failed to fetch desktop by name")
 		return
 	}
 
@@ -653,7 +653,7 @@ func (s *WindowsService) connectRDP(ctx context.Context, log logrus.FieldLogger,
 		LockTargets:       services.LockTargetsFromTLSIdentity(identity),
 		Tracker:           rdpc,
 		TeleportUser:      identity.Username,
-		ServerID:          desktop.GetName(),
+		ServerID:          s.cfg.Heartbeat.HostUUID,
 	}
 	shouldDisconnectExpiredCert := authCtx.Checker.AdjustDisconnectExpiredCert(authPref.GetDisconnectExpiredCert())
 	if shouldDisconnectExpiredCert && !identity.Expires.IsZero() {