title: Erlang, override environment
body: <p>I have an erlang node with some applications. I want to make my applications to fetch their environments variables from some centralized server (e.g. <code>hiera server</code>). Is there any way to override environment variables from <code>.app</code> file, replacing it with custom variables obtained from certain place?
  Of course, I don't want to make any changes in my applications code.</p>