Matrix docker-compose with Postgres and docker network

docker-compose.yaml

### To use this file you need to run
### $ docker network create matrix-network

version: "2"
services:
  postgres:
    image: postgres:9.6.4
    restart: always
    
    # I like to be able to use psql on the host to connect to the database 
    # for maintenance. If you already have a postgres running you should remove 
    # the 'ports' section and uncomment 'expose'
    # expose:
    # - 5432
    
    # Adding 127.0.0.1 ensures the port isn't exposed ON the host
    ports:
      - "127.0.0.1:5432:5432"
    volumes:
     - /opt/matrix/pgdata:/var/lib/postgresql/data

    # These will be used on homeserver.yaml later on
    environment:
     - POSTGRES_PASSWORD=YOUR_PASSWORD_HERE
     - POSTGRES_USER=synapse

  synapse:
    image: silviof/docker-matrix
    # Exposing 8008 (no TLS) on localhost means we can reverse proxy with nginx
    # 8448 is for federation and should be exposed on host
    # 3478 is for TURN (voip calls)
    ports:
     - "127.0.0.1:8008:8008"
     - "8448:8448"
     - "3478:3478"
    volumes:
     - /opt/matrix/synapse:/data

# Our docker network!
networks:
  default:
    external:
      name: matrix-network