title: 3rd Party Script Caching in Rails 3.1
body: <p>I have a script 3rd party websites are using: <code>/assets/script.js</code>. For obvious reasons, I can't ask them to change the link every time I deploy to point to the latest fingerprinted version of the script. I got a few caching issues where users still see old versions of <code>/script.js</code>. Are there any ways to make the cache go away directly for <code>script.js</code> instead of  <code>script-9dc5afea3571ba2a883a72b0da0bb623.js</code>?</p>
  
  <p><strong>More Information</strong>: Rails on Passenger + Nginx. Looking for ways to serve the <code>script.js</code> file instead if the finger-printed file and invalidate the cache on every deployment.</p>
  
  <p>I thought about adding ETags based on the deployment git revision, but have no idea how to do this. Nginx has no built in ETags support. There are unsupported old third party modules that do this. I can use <code>add_header Etag="something"</code> for this, but how do I add the git version there.</p>
  
  <p>Any other ideas and options?</p>
  
  <p>Thanks!</p>