How to use environment variables in docker compose

Question

I'd like to be able to use env variables in docker-compose.yml, with values passed in when docker-compose is started. This is an illustration.

Today, I'm doing it with a standard Docker run command wrapped around my own script. Is there a way to do it without using bash wrappers and compose?

proxy:
  hostname: $hostname
  volumes:
    - /mnt/data/logs/$hostname:/logs
    - /mnt/data/$hostname:/data