Variable substitution in docker-compose.yml file when running docker-compose with sudo

Question

I'm currently trying to use variable substitution in a docker-compse.yml file. This file contains the following:

jenkins:
  image: "jenkins:${JENKINS_VERSION}"
  external_links:
      - mongodb:mongo
  ports:
    - 8000:8080

The image below shows what happens when I try to start everything up.

As you can see, docker-compose shows a warning saying that the variable is not set. I suspect this is caused due to the use of sudo to start docker-compose. My setup (a Jenkins docker container which has access to docker and docker-compose via volume mounts) currently requires the use of sudo. Would it be better to stop docker requiring sudo, or is there another way to fix this without changing the current setup?

Answer 1

sudo -E preserve the user environment when running the command. It should do what you want.