title: dockerized postgres - lock file "postmaster.pid" is empty
body: <p>I'm experiencing issues using the official Postgres docker image, something that never happened on this machine. 
  I'm using that through docker-compose but when running <code>docker-compose up</code>, the db container does not start, here's the error:</p>
  
  <pre><code>db_1         | 2019-04-19 22:20:27.180 UTC [1] FATAL:  lock file "postmaster.pid" is empty
  db_1         | 2019-04-19 22:20:27.180 UTC [1] HINT:  Either another server is starting, or the lock file is the remnant of a previous server startup crash.
  </code></pre>
  
  <p>I tried several times to remove the image so it then will be re-pulled, but hasn't solved the problem.</p>
  
  <p>I'm using Docker for Mac 2.0.0.3 (31259)</p>
  
  <p>here's the <code>docker-compose.yml</code>:</p>
  
  <pre><code>version: '2'
  services:
    web:
      build: .
      entrypoint: sh -c "python3 /var/www/my_project/manage.py migrate --noinput &amp;&amp;
                  python3 /var/www/my_project/manage.py runserver 0.0.0.0:8000"
      restart: on-failure
      ports:
        - "9001:8000"
      volumes:
        - .:/var/www/my_project
      depends_on:
      - db
      env_file:
        - ./.env
      environment:
        - DB_SERVER=db
        - DB_NAME=postgres
        - DB_USER=postgres
    db:
      ports:
          - "9432:5432"
      image: postgres
      volumes:
        - database:/var/lib/postgresql
  volumes:
    database:
  </code></pre>
  
  <p>Any help on this?</p>