title: How can you block or filter IP addresses on Heroku?
body: <p>Is there a way to implement IP filtering or IP access rules much like I would with nginx/apache to restrict or block certain IPs on Heroku?</p>
  
  <p><strong>Note:</strong> I know this can be done from within my application (Rails 3.2) very easily but I don't think this is the most efficient use of my resources on Heroku.  Also, a Rack based solution would be better than implementing the filtering in Rails.</p>