Already existing "local google search" project using Rails and Ferret?

Hi everybody!

I'd like to setup a "local google search" at work:
- users would put data in shared directories on a samba server,
without really caring about folder structure
- ferret would index those directories every n hours
- users could still get access to those data via samba
- but in order to find them easily, some rails app would be used as a
front-end to show the most relevant matches for a given user query.

So, here is my question:

Do you know any FOSS project that could suit my need?
Am I trying to reinvent the wheel?