production.rb

production.rb

#put all the shared bits in: config/environments/productionable.rb

YourApp::Application.configure do 

  config.assets.compile = false
  config.serve_static_assets = false

end


#and only environment specific bits at config/environments/production.rb
require_relative 'productionable'

YourApp::Application.configure do 
  config.google_api_key = 'super_secret_key'  
end

Cool, this is simple and I can keep these important values under source control.