Symfony2 load external AppKernel file inside application

Question

I need to load an external AppKernel file inside my symfony application. This external AppKernel is responsible for handling requests. The problem is, It can't autoload the classes/bundles that the external application uses. Is there a way to use an external symfony 2 application inside another application?

This is what I tried so far:

    require_once '/path/to/external/AppKernel.php';

    $class = 'Namespace\AppKernel';
    $path = realpath(dirname('/path/to/external/AppKernel.php'));

    // I tried this, but this does not work...
    $loader = require_once $path . '/autoload.php';

     /**
     * @var HttpKernel $kernel
     */
    $kernel = new $class('dev', true);

    $response = $kernel->handle($request);

Steffen

EDIT

I've tried the following also, the Kernel is loaded correctly, but I get a 404 on every valid request. I think i'm somewhat closer, someone any tips?

// Get Class Loader
$loader = \ComposerAutoloaderInitea05f7b71e624f9c387fc10b8508d099::getLoader();

// Add src folder to fallback dirs
$loader->add(null, array(realpath($path . '/../src')));

/**
 * @var Kernel $kernel
 */
$kernel = new $class('prod', true);
$kernel->loadClassCache();

$response = $kernel->handle($request);
$response->send();

$kernel->terminate($request, $response);

return $response;