title: Call a Command from a Controller not work
body: <p>i have this code to run schema update command from controller i got help from <a href="http://symfony.com/doc/current/console/command_in_controller.html" rel="nofollow noreferrer">symfony document</a>
  i have this code:</p>
  
  <pre><code>namespace AdminBundle\Controller;
  
  use Symfony\Bundle\FrameworkBundle\Console\Application;
  use Symfony\Bundle\FrameworkBundle\Controller\Controller;
  use Symfony\Component\Console\Input\ArrayInput;
  use Symfony\Component\Console\Output\NullOutput;
  use Symfony\Component\HttpFoundation\Response;
  use Symfony\Component\HttpKernel\KernelInterface;
  use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
  
  class DefaultController extends Controller
  {
      /**
       * @Route("/admin")
       */
      public function indexAction(KernelInterface $kernel)
      {
          $application = new Application($kernal);
  
          $input = new ArrayInput(array(
              'command' =&gt; 'doctrine:schema:update'
          ));
  
          $output = new NullOutput();
          $application-&gt;run($input, $output);
  
          return new Response("");
      }
  }
  </code></pre>
  
  <p>it's not work for me i get this error after open this url (<a href="http://127.0.0.1:8000/admin" rel="nofollow noreferrer">http://127.0.0.1:8000/admin</a>):</p>
  
  <pre><code>Controller "AdminBundle\Controller\DefaultController::indexAction()" requires that you provide a value for the "$kernel" argument. Either the argument is nullable and no null value has been provided, no default value has been provided or because there is a non optional argument after this one.
  </code></pre>
  
  <p>how can i do?</p>