Recommended PostgreSQL docker-compose service configuration

I use the following docker-compose.yml service:

services:
  postgres:
    image: postgres
    restart: unless-stopped
    volumes:
      - ./pg_data:/var/lib/postgresql/data
    environment:
      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
      - POSTGRES_DB=${POSTGRES_DB}
      - POSTGRES_USER=${POSTGRES_USER}

With the following .env:

POSTGRES_DB=headscale
POSTGRES_USER=headscale
POSTGRES_PASSWORD=vah2phuen3shesahc6Jeenaechecee

Using .env has the huge advantage that other services like my backup script can access the configuration in a standardized manner using environment variables.