Create custom middleware in Drupal 8/9/10

By hari, 18 November, 2022

Middleware API adopted from PHP community https://stackphp.com and this will help you to filter every request from users before hitting to the application, suppose you want to block some request based on the request object parameter or you can add the proper headers to all responses leaving your application.

Middleware API is equivalent to hook_boot() in Drupal 7. That means this will trigger every request so adding Middlewares are very expensive. Effectively, Don't manage heavy or complex code inside the Middleware it will leads to performance issues on Drupal.

Code snippet that can be used to implement custom middleware to ban an IP address:

Create custom_module.service.yml file:

services:
  custom_module.custom_middleware:
    class: Drupal\mymodule\CustomMiddleware
    tags:
      - { name: http_middleware, priority: 150 }

Create src/CustomMiddleware.php file:

namespace Drupal\custom_module;

use Drupal\Core\StringTranslation\StringTranslationTrait;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\HttpKernelInterface;

/**
 * FirstMiddleware middleware.
 */
class CustomMiddleware implements HttpKernelInterface {

    use StringTranslationTrait;

    /**
     * The kernel.
     *
     * @var \Symfony\Component\HttpKernel\HttpKernelInterface
     */
    protected $httpKernel;

    /**
     * Constructs the FirstMiddleware object.
     *
     * @param \Symfony\Component\HttpKernel\HttpKernelInterface $http_kernel
     *   The decorated kernel.
     */
    public function __construct(HttpKernelInterface $http_kernel) {
        $this->httpKernel = $http_kernel;
    }

    /**
     * {@inheritdoc}
     */
    public function handle(Request $request, $type = self::MASTER_REQUEST, $catch = TRUE) {
        if ($request->getClientIp() == '127.0.0.1') {
            return new Response($this->t('hello world!'), 403);
        }
        return $this->httpKernel->handle($request, $type, $catch);
    }

}

Reference

https://www.drupal.org/docs/8/api/middleware-api/overview

Create custom middleware in Drupal 8/9/10

Create custom_module.service.yml file:

Create src/CustomMiddleware.php file:

Tags