> Indeed, sometimes it seems like 90% of the Docker code out there is converting environment variables into configuration files. This is a consequence of Docke

> Indeed, sometimes it seems like 90% of the Docker code out there is converting environment variables into configuration files. This is a consequence of Docker's choice of the "image" as an abstraction layer. It's not trivial to say "run this image but with this config file added" (yes you could bind mount one in, or create a new derived image, but those are both harder and come with more pitfalls). In most common docker usage, there are exactly two ways to influence the operation of the program contained within the image: Environment variables, and command line arguments.