Source: 📖 Django for Professionals ch2 p29

Creating a Docker PostgreSQL database service

We can create a designated container for our database by assigning it a service in our docker-compose.yml file. The below compose file creates a service for the Django server and another for the database.

# docker-compose.yml

version: '3.8'

services:
	web:
		build: .
		command: python /code/manage.py runserver 0.0.0.0:8000
		volumes:


.:/code


		ports:


8000:8000


		depends_on:


db


	db:
		image: postgres:11
		environment:


"POSTGRES_HOST_AUTH_METHOD=trust"

First we create the web service (see Creating docker-compose.yml file for explanations), but we add a depends_on key to tell Docker that the web service depends on the db service, meaning that db will be started up before web.

For our db service, we use the postgres image pinned to version 11. If no version is specified then the latest version will be selected, but it's a good idea to always pin a specific version to ensure that the container remains the same every time.

We then set up the environment variable POSTGRES_HOST_AUTH_METHOD=trust with the environment key. This allows us to connect without a password, which is a convenient step to take for development.

When docker-compose up is ran, it will create two containers — one for our web service and one for our db service.