For context, see http://slagwerks.com/blog/index.php/2010/12/10/heroku-refinery-ssl/

SSL_Refinery_Heroku.rb

  before_filter :refinery_use_ssl

  def refinery_use_ssl
    if (request.fullpath =~ /^\/refinery/) && (ENV['RAILS_ENV'] == 'production')
      ssl_rewrites = { 
        'mysite-dev.mydomain.com' => 'mysite-dev.heroku.com',
        'mysite-stage.mydomain.com' => 'mysite-stage.heroku.com',
        'mysite.com' => 'mysite.heroku.com',
        }
      if ssl_rewrites[request.host] && (request.port != 443)
        redirect_to 'https://' + ssl_rewrites[request.host] + request.fullpath
        return false
      end
    end
  end