Rerouter

A minimal, rack-based domain-redirecter. Generates 301 redirects from a set of source hostnames to their corresponding destination hostnames while preserving paths and querystrings.

Steps for setting up your own rerouter on Heroku:

git clone https://github.com/joeyAghion/rerouter.git
cd rerouter
gem install heroku
heroku apps:create
git push heroku master
heroku config:set REDIRECTS="{'old.domain.com'=>'new.domain.com'}"
heroku domains:add old.domain.com

Then, update the DNS of old.domain.com to be a CNAME pointing to the new heroku app.