Environment variables

You can set environment variables directly in your container's environment with the environment attribute within the services top-level element in your Compose file.

environment can use either an array or a map. Any boolean values; true, false, yes, no, should be enclosed in quotes to ensure they are not converted to True or False by the YAML parser.

Environment variables can be declared by a single key (no value to equals sign). In this case Levv relies on you to resolve the value. If the value is not resolved, the variable is unset and is removed from the service container environment.

Map syntax:

services:
  frontend:
    image: example/webapp
    environment:
      RACK_ENV: development
      SHOW: "true"
      USER_INPUT:

Array syntax:

services:
  frontend:
    image: example/webapp
    environment:
      - RACK_ENV=development
      - SHOW=true
      - USER_INPUT