AcquiaCloudBalancerMiddleware.php in Acquia Purge 8

Namespace

Drupal\acquia_purge\Http

File

src/Http/AcquiaCloudBalancerMiddleware.php

<?php

namespace Drupal\acquia_purge\Http;

use Psr\Http\Message\ResponseInterface;

/**
 * HTTP middleware which asserts correct responses from Acquia Cloud.
 */
class AcquiaCloudBalancerMiddleware {

  /**
   * {@inheritdoc}
   */
  public function __invoke() {
    return function (callable $handler) {
      return function ($req, array $options) use ($handler) {

        // Don't interfere on requests not going to Acquia Load balancers.
        if (!isset($options['acquia_purge_balancer_middleware'])) {
          return $handler($req, $options);
        }

        // Return a handler that throws exceptions on bad responses.
        return $handler($req, $options)
          ->then(function (ResponseInterface $rsp) use ($req) {
          $status = $rsp
            ->getStatusCode();
          $method = $req
            ->getMethod();

          // Define a tiny closure that throws exceptions for us.
          $e = function ($msg) use ($req, $rsp) {
            throw new AcquiaCloudBalancerException($msg, $req, $rsp);
          };

          // Flag up suspicious response types.
          if ($status === 403) {
            $e('Invalid response (403), please contact Acquia Support.');
          }
          elseif ($status == 405) {
            $e('Invalid response (405), please contact Acquia Support.');
          }

          // Test response codes and reply messages per type of invalidation.
          if ($method == 'PURGE') {
            if (!in_array($status, [
              200,
              404,
            ])) {
              $e('Invalid response (no 200/404), please contact Acquia Support.');
            }
          }
          elseif ($method == 'BAN') {
            $path = $req
              ->getRequestTarget();
            $reply = $rsp
              ->getReasonPhrase();
            if ($status !== 200) {
              $e('Invalid response (not 200), please contact Acquia Support.');
            }
            elseif ($path == '/site' && $reply !== 'Site banned.') {
              $e("Reply mismatch for /site.");
            }
            elseif ($path == '/tags' && $reply !== 'Tags banned.') {
              $e("Reply mismatch for /tags.");
            }
            elseif (!in_array($path, [
              '/site',
              '/tags',
            ])) {
              if (!in_array($reply, [
                'WILDCARD URL banned.',
                'URL banned.',
              ])) {
                $e("Reply mismatch for (wildcard)URL.");
              }
            }
          }
          else {
            $e("Unsupported HTTP method!");
          }
          return $rsp;
        });
      };
    };
  }

}

Classes

Name	Description
AcquiaCloudBalancerMiddleware	HTTP middleware which asserts correct responses from Acquia Cloud.