Just make sure the naming convention is respected. And you do not need your controller for maintenance. The controllers must capture the Request and return a Response .
Imagine you have a default controller.
 namespace Renoir\SiteBundle\Controller; use Symfony\Bundle\FrameworkBundle\Controller\Controller; use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route; use Sensio\Bundle\FrameworkExtraBundle\Configuration\Template; class DefaultController extends Controller {  
In a view that you could invoke using
 {% render 'RenoirSiteBundle:Default:randomNameRender' %} 
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