Is it possible to set global settings for services in a docker compose file?

Docker Engine Compose
1

Is it possible to specify global settings for services in a Docker compose file?

For example, take this Docker Compose file:

version: "3.9"

services:
  test1:
    env_file: /path/to/env/file
    image: test
    container_name: test1
    ports:
      - "1234:22"
    networks:
      - dmz
    restart: always
  test2:
    env_file: /path/to/env/file
    image: test
    container_name: test2
    ports:
      - "2345:22"
    networks:
      - trust
    restart: always

networks:
  dmz:
    driver: bridge
  trust:
    driver: bridge

I don’t want to have env_file: /path/to/env/file for every service and would like to make it apply to all services. I know I can pass it in the docker-compose command line but I’m hoping to do it from within the Docker compose file.

2

You could declare one or more placeholders between version and services and use yaml anchors to “reuse” its/their content, see this blog post for example usage: https://nickjanetakis.com/blog/docker-tip-82-using-yaml-anchors-and-x-properties-in-docker-compose

The first control questions would be: why would you want global environment variables for your services? Wouldn’t you leak environment variables into containers that don’t necessarily need them?

1 Like
3

Not just for environmental variables but for any setting. What you linked works great cause I can create different global templates and apply them to containers as needed. Thanks!