I want to pass default environment variable to use it if in -e variable wasn’t passed anything. So, I do something like this

services:
  db:
    environment:
      - DATABASES_FOLDER=/raw_databases

    image: postgres
    volumes:
      - "${DATABASES_FOLDER}/postgres:/var/lib/postgresql/data"

But when I do it, container sees just /postgres:/var/lib/postgresql/data”

$DATABASES_FOLDER and just without “” is not working