the older, rails-influenced approach makes it challenging to handle different
configurations across many environments for one app. by using generic ENV
variables, but supporting more specific ones, and falling back on hard coded
values we can have it both ways.
this implementation should continue to support older configurations in exactly
the same way, but also allow users to adopt one variable name across
environments.
in general, we'd like to support 12-factor style configuration: https://12factor.net/config
the older, rails-influenced approach makes it challenging to handle different configurations across many environments for one app. by using generic ENV variables, but supporting more specific ones, and falling back on hard coded values we can have it both ways.
this implementation should continue to support older configurations in exactly the same way, but also allow users to adopt one variable name across environments.