Intercept request for file download and send to Rails app?

Answer 1

Do you mean an entire Rails app just for that? Seems like overkill - you can use Sinatra, a single route, and their send_file function with much greater ease. It also deploys on Apache with Passenger.

If you have control over this thing, and you only plan to offer downloads in this way and not in any other, you should probably store the files in some non-public directory and instead allow your Rails/Sinatra app to access and push the files to the user. (Again, with send_file, that's easy.) Why put a file in your web root if your users will never access it that way?