In this recent post to her blog Lineke Kerckhoffs-Willems talks about some recent Symfony2 development she's been doing and some of the trials she's come across when trying to implement the SonataAdminBundle to build on their pre-existing Doctrine2 entities.

I have been doing a lot of Symfony2 development lately for our project ProTalk and one of the things we needed was a backend for our database. This should be a fairly simple backend to start with, just an easy way to get data into the database. So I thought I would use the SonataAdminBundle to easy generate this backend based on the doctrine2 entities that we already have. Eventually, I got it working, but it took me some time to find out exactly how, so I thought I'd share my experiences.

Based on some information she found in this other post, she was able to configure and connect it to a "tag" entity. To make it work, however, she needed an empty controller to move forward.