Docker Compose Environment

Docker Compose’s environment key sets environment variables inside your container. It has two equivalent syntaxes.

There’s map syntax:

environment:
  RACK_ENV: development
  SHOW: "true"
  USER_INPUT:

And array syntax:

environment:
  - RACK_ENV=development
  - SHOW=true
  - USER_INPUT

I prefer the map syntax, since it looks like YAML a bit more to me, and is slightly more readable, again to me.

environment docs