public function AcquiaCloudBalancerMiddleware::__invoke in Acquia Purge 8

File

src/Http/AcquiaCloudBalancerMiddleware.php, line 15

Class

AcquiaCloudBalancerMiddleware

HTTP middleware which asserts correct responses from Acquia Cloud.

Namespace

Drupal\acquia_purge\Http

Code

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;
      });
    };
  };
}