Create entity relationships between bundles of differents providers - symfony

Question

I'm developing my first Symfony2 Bundle "distributable" by packagist.org and have a few questions regarding how to relate the "user entity" from: "the actual project", to: "this external bundle".
What I do:
I created a GIT repository specifically for my bundle.
I have created and configured the composer.json file, as explained in packagist.org
Set the user entity from the general config.yml /app/config/config.yml
to send as parameter to the bundle .
// KDRMKLabs\TicketBundle\DependencyInjection\Configuration.php
class Configuration implements ConfigurationInterface
{
public function getConfigTreeBuilder()
{
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->root('kdr_ticket');
$rootNode->children()
->scalarNode('user_class')->isRequired()->cannotBeEmpty()->end()
->end()
;
return $treeBuilder;
}
}
# app\config\config.yml
kdr_ticket:
user_class: AppBundle\Entity\User
// KDRMKLabs\TicketBundle\DependencyInjection\KDRTicketExtension.php
class KDRTicketExtension extends Extension
{
public function load(array $configs, ContainerBuilder $container)
{
$configuration = new Configuration();
$config = $this->processConfiguration($configuration, $configs);
$loader = new Loader\XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
$loader->load('services.xml');
$container->setParameter('kdr_ticket.model.user.class', $config['user_class']);
}
}
4. Ticket Entity
/**
* Ticket
*
* #ORM\Table(name="kdr_ticket")
* #ORM\Entity
*/
class Ticket
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* How I can tell to Doctrine that this object is the specified in config.yml ?
*/
private $user;
...
}
Using the User Entity when you install the bundle or when the database is updated for the first time after installation of the bundle
How Can I use the "user entity" specified in config.yml to create relations of the form "ManyToOne" when you update the database with the command doctrine:schema:update --force
I appreciate any help.
Thank you.