version: "3"

volumes:
  db_data: {}

services:
  # The PostgreSQL container creates the codebuddies database on first launch.
  # All data is stored in the db_data volume on the host machine. This ensures
  # data is persisted across container restarts.
  db:
    image: postgres:11-alpine
    container_name: db
    restart: on-failure
    ports:
      - "5432:5432"
    volumes:
      - db_data:/var/lib/postgresql/data
    environment:
      - POSTGRES_PASSWORD=mysecretpassword
      - POSTGRES_USER=babyyoda
      - POSTGRES_DB=codebuddies

  # The app container uses uwsgi to run the Django application. It is configured
  # to run migrations on first start-up and to use Mailhog as the mail server.
  # The application is not exposed to the host as all traffic is proxied through
  # nginx. The local project folder is mounted into the container as a volume to
  # allow development to be done on the host machine.
  app:
    build: ./project
    container_name: app
    restart: on-failure
    command: >
      sh -c "python /opt/codebuddies/manage.py migrate &&
             uwsgi --ini /opt/codebuddies/uwsgi.ini"
    volumes:
      - ./project:/opt/codebuddies
    environment:
      - DATABASE_URL=postgres://babyyoda:mysecretpassword@db:5432/codebuddies
      - EMAIL_HOST=mailhog
    depends_on:
      - db

  # The nginx front-end is configured to proxy all traffic to the Django application.
  # We may want to use this to host static content. It is configured to reload
  # configuration every 6 hours.
  web:
    image: nginx:1.17-alpine
    container_name: web
    restart: on-failure
    ports:
      - "8000:80"
    volumes:
      - ./nginx:/etc/nginx/conf.d
    command: '/bin/sh -c ''while :; do sleep 6h & wait $${!}; nginx -s reload; done & nginx -g "daemon off;"'''
    depends_on:
      - app

  # Adminer is a front-end for PostgreSQL.
  # It isn't required to run CodeBuddies but may be useful as a graphical interface
  # to the database.
  adminer:
    image: adminer:latest
    container_name: adminer
    restart: on-failure
    ports:
      - 8001:8080

  # Mailhog is a mail server that traps all outbound mail and presents it in a web
  # interface that is easily browsable. This may prove useful when testing functionality
  # that results in emails to users.
  mailhog:
    image: mailhog/mailhog:latest
    container_name: mailhog
    restart: on-failure
    ports:
      - 8025:8025

  # Manager allows you to run Django management tasks on the application.
  manage:
    container_name: manage
    restart: on-failure
    build: ./project
    command: shell
    entrypoint: /usr/local/bin/python3 /opt/codebuddies/manage.py
    volumes:
      - ./project:/opt/codebuddies
    environment:
      - DATABASE_URL=postgres://babyyoda:mysecretpassword@db:5432/codebuddies
      - EMAIL_HOST=mailhog
    depends_on:
      - db