如何从文件读取docker-compose的配置

Question

I have a docker-compose file which looks like below

services:
  service1:
    image: image_name:image_tag
    container_name: cname

image_tag and cname can change from deployment to deployment, so I want to have a configuration file (in format of key=value) and read the value of image_tag and cname from it. How can I fo that?

Answer 1

From the docs: https://docs.docker.com/compose/environment-variables/#the-env-file

You can put an .env file near the docker-compose file. eg:

.env:

image_tag=1.0.0
cname=cname

docker-compose.yml:

services:
  service1:
    image: image_name:${image_tag}
    container_name: ${cname}