required_env_fetcher

https://github.com/ezcater/required_env_fetcher-ruby

In certain situations it makes sense to allow default values of environment variables that are otherwise required. For example, imagine we're precompiling assets as part of CI when we don't have access to some environment variables we require for the app be up and accepting requests, but aren't required for asset compilation. Using this library we can designate it safe to use default values in those situations.