Source: 📖 Django for Professionals ch1 p20

Creating docker-compose.yml file

The compose file is responsible for running a container based on an image. It is a YAML file, which is essentially a JSON-like dictionary-based file type.

# 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

First we specify version, which version of Docker Compose to use.

The services key contains the containers we want within our Docker host — in this case, we create a web container but you might have a separate container for a database or anything else that your app may need.

We tell Docker to look in the current directory for the Dockerfile with the . next to build. Then we specify a command to run, telling Docker to start our Django server (our source code exists inside the code directory as set up in Building a Docker image).

The volumes key tells Docker to sync its filesystem with our local computer's filesystem — we are telling it to look in the current directory . and sync it to /code. This means that we don't have to rebuild the image with every change to a file, as changes will automatically sync to our container. This works in a bi-directional way, so any changes that happen inside Docker will also be synced to our local filesystem. The leading - is just syntax for starting a list of items.

Finally we tell Docker to use port 8000, which is the Django default.