Play framework on Heroku

Key points

Create the app on the cedar stack

heroku create --stack cedar
Give it a project.clj, to make it think it's a 'support' app configuration

(defproject ring-on-heroku "1.0.0-SNAPSHOT" :description "Example Ring app running on Heroku")
Create an app

play-1.2.2RC1/play new app
Setup procfile to start app from extracted play framework, and set port/JVM memory opts correctly

Procfile:

web: play-1.2.2RC1/play run scala_app --%prod -Xmx200m --http.port=$PORT

Create a Gemfile and Gemfile.lock to make heroku think it's a supported app:

Make scala work! Java only fine, scala strange memory errors. Check JVM config?
Parse out DB/memcache env vars in to java -D properties, then pick them up in app config via ${}