https://docs.docker.com/samples/django/

Create a Django project docker-compose run web django-admin startproject myApp .

Connect the database inside settings.py replace DATABASES = ... with the following:

# settings.py
   
import os
   
[...]
   
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': os.environ.get('POSTGRES_NAME'),
        'USER': os.environ.get('POSTGRES_USER'),
        'PASSWORD': os.environ.get('POSTGRES_PASSWORD'),
        'HOST': 'db',
        'PORT': 5432,
    }
}