maintenanceMode = $maintenance_mode; $this->config = $config_factory; } /** * {@inheritdoc} */ public static function getSubscribedEvents(): array { $events = []; $events[MaintenanceModeEvents::MAINTENANCE_MODE_REQUEST][] = [ 'onMaintenanceModeRequest', -800, ]; return $events; } /** * Returns response when site is in maintenance mode and user is not exempt. * * @param \Symfony\Component\HttpKernel\Event\RequestEvent $event * The event to process. */ public function onMaintenanceModeRequest(RequestEvent $event) { $request = $event->getRequest(); if ($request->getRequestFormat() !== 'api_json') { return; } // Retry-After will be random within a range defined in jsonapi settings. // The goals are to keep it short and to reduce the thundering herd problem. $header_settings = $this->config->get('jsonapi.settings')->get('maintenance_header_retry_seconds'); $retry_after_time = rand($header_settings['min'], $header_settings['max']); $http_exception = new HttpException(503, $this->maintenanceMode->getSiteMaintenanceMessage()); $document = new JsonApiDocumentTopLevel(new ErrorCollection([$http_exception]), new NullIncludedData(), new LinkCollection([])); $response = new ResourceResponse($document, $http_exception->getStatusCode(), [ 'Content-Type' => 'application/vnd.api+json', 'Retry-After' => $retry_after_time, ]); // Calling RequestEvent::setResponse() also stops propagation of event. $event->setResponse($response); } }