class MyEventSubscriber implements EventSubscriberInterface {

​

  public static function getSubscribedEvents() {

    $events['kernel.request'] = ['someEvent', 28];

    return $events;

  }

​

  private function someEvent(KernelEvent $event) {

    if (/* some condition */) {

      $url = Url::fromRoute('entity.node.canonical', ['node' => 1]);

      $response = new RedirectResponse($url->toString());

      $event->setResponse($response);

    }

  }

}