Architecture dilemma: serving images in a 3-tier (mvc3 webapp -> webservice -> couchdb) setup

Question

I have a project with a 3-tier architecture. User front-ends (one of them is a regular ASP.NET MVC3 web app) communicate with a common ASP.NET web service which acts as an intermediary to a CouchDB data store.

Until now, I've only been transferring textual data which didn't require any special handling and has worked well. But now, for the first time, I also have to serve images along with text. The images are stored as attachments to CouchDB documents and can be accessed by REST-ful URLs.

The problem is, those REST-ful URLs are only valid from the middle tier (the web service). How do I best expose them to client tiers that have no direct access to the CouchDB back-end (and should stay that way)?

I've thought about implementing some sort of URL rewriting/forwarding scheme, but I'm not quite sure how to do that or even if it's the appropriate solution.

All ideas are welcome!

Answer 1

It seems people don't enjoy open questions like this one... :)

For what is worth, I decided to upgrade my web service to support MVC3-style REST routing. All requests that come to /Images/{document}/{id} are mapped to their equivalent CouchDB URLs.

Later on, I'll maybe throw in a caching layer to relieve the web service and the data store from serving the same images again and again.

I'm still open to better ideas, of course. :)