Got it but unfortunately I don’t think that a solution like the one you’re suggesting would fit my needs 
I’ve quite a lot ENV vars that I need to pass to my script, mainly DB related stuff as well as some REST API config.
Just for you to know I’m actually trying to use the ENV RELX_REPLACE_OS_VARS=true inside my build and then get the vars out with System.get_env("VAR") but right now I didn’t had any success 
I’ve also tried to use Mix.Config but considering that I don’t have an application running but only a simple script it seems that it would not fit my needs either.
