You will most probably need to have at least one particular case where you need to store configuration values for your Rails application. Saving these types of values in the environment is one of the principles of a twelve-factor app. It is thus recommended to use a separate file and use environment variables inside your code so that you do not have to change the same value in multiple places. This, however, is not something that you can do really easily unless you use something really helpful like dotenv.
