Using docker compose to mount current working directory dynamically into the container

gistfile1.txt

# mount volume PWD on host to /app in container.
shai@lappy ~/tmp/example-working-docker-compose-environment-vars [master *] ± % cat docker-compose.yml
version: "3"
services:
  some_server:
...
    volumes:
      - $PWD:/app

# so using this from which/wherever you run this from, PWD should be updated and reflected within the container it runs in.
# /app within container should be reflected to be wherever you run this command from.
docker-compose -f ~/tmp/example-working-docker-compose-environment-vars/docker-compose.yml