gistfile1.txt

deci ar fi cam asa:

ai avea de adaugat o clasa intr-un modul custom numita <nume_modul>ServiceProvider 
care sa extinda ServiceProviderBase, asta ar trebui sa stea in folderul src.
e.g. daca numele modulului e xxx_yyy, atunci clasa ar trebui sa fie XxxYyyServiceProvider

=====================
namespace Drupal\xxx_yyy;

use Drupal\Core\DependencyInjection\ContainerBuilder;
use Drupal\Core\DependencyInjection\ServiceProviderBase;

class XxxYyyServiceProvider extends ServiceProviderBase {

  public function alter(ContainerBuilder $container) {

    $reverse_proxy_definition = $container->getDefinition('http_middleware.reverse_proxy');
    $reverse_proxy_definition->setClass('Drupal\xxx_yyy\StackMiddleware\MyReverseProxyMiddleware');
  }
}
===========================

Practic alterezi service-ul core sa foloseasca clasa ta.

Clasa ta trebuie sa extinda ReverseProxyMiddleware si ai de facut override la function setSettingsOnRequest
Aici core-ul altereaza putin requestul, pe baza unor setari, deci ar trebui doar sa adaugi la ce face el, inca 2 linii aprox:

namespace Drupal\xxx_yyy\StackMiddleware;

use Drupal\Core\Site\Settings;
use Drupal\Core\StackMiddleware\ReverseProxyMiddleware;
use Symfony\Component\HttpFoundation\Request;

class MyReverseProxymiddleware extends ReverseProxyMiddleware {
  /**
   * Sets reverse proxy settings on Request object.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   A Request instance.
   * @param \Drupal\Core\Site\Settings $settings
   *   The site settings.
   */
  public static function setSettingsOnRequest(Request $request, Settings $settings) {
    // Initialize proxy settings.
    if ($settings->get('reverse_proxy', FALSE)) {
      $ip_header = $settings->get('reverse_proxy_header', 'X_FORWARDED_FOR');
      $request::setTrustedHeaderName($request::HEADER_CLIENT_IP, $ip_header);

      $proto_header = $settings->get('reverse_proxy_proto_header', 'X_FORWARDED_PROTO');
      $request::setTrustedHeaderName($request::HEADER_CLIENT_PROTO, $proto_header);

      $host_header = $settings->get('reverse_proxy_host_header', 'X_FORWARDED_HOST');
      $request::setTrustedHeaderName($request::HEADER_CLIENT_HOST, $host_header);

      $port_header = $settings->get('reverse_proxy_port_header', 'X_FORWARDED_PORT');
      $request::setTrustedHeaderName($request::HEADER_CLIENT_PORT, $port_header);

      $forwarded_header = $settings->get('reverse_proxy_forwarded_header', 'FORWARDED');
      $request::setTrustedHeaderName($request::HEADER_FORWARDED, $forwarded_header);

      $proxies = $settings->get('reverse_proxy_addresses', []);
      if (count($proxies) > 0) {
        $request::setTrustedProxies($proxies);
      }
    }
    else {
      $request->server->set('REMOTE_ADDR', $_SERVER['REMOTE_ADDR']);
    }
  }
}