Problem

I have a Rails app on Heroku that is serving up a site on http and https. Google oAuth’s callback URL is for https, so attempting to log into the site from the http URL fails.

Solution

The intention was to serve up the site just from the https url, so the solution is to configure Rails to redirect all http traffic to https.

In config/production.rb:

  config.force_ssl = true

Resource: http://stackoverflow.com/questions/27377386/force-ssl-for-heroku-apps-running-in-eu-region