use Symfony\Component\HttpFoundation\Request;
//...
        // 独自コントローラー
        //...
        $front->match('/abc', function(Request $request) use ($app) {
                $subRequest = Request::create(
                        '/',
                        $request->getMethod(),
                        $request->request->all(),
                        $request->cookies->all(),
                        $request->files->all(),
                        $request->server->all()
                );
                $response = $app->handle($subRequest, HttpKernelInterface::SUB_REQUEST, false);
                return $response;
        })->bind('abc_alias');