Ever wake up on the symmetrical side of the bed? Like at the middle? Yep. That�s when you decide that you are never going to (ever) code in constants in your application. So how do you get them? Configuration files? JSONs? Yamls? Environment variables are more elegant and easier with a docker-compose no? 12 factor apps are what cool kids are doing these days (read three years ago). And it makes sense that you put your configurable variables into the environment and do a getenv.