Source: 📖 Django for Professionals ch8 p127

Storing secret key in environment variable

To hide the Django secret key, it should be put into an environment variable. We can do this by installing the environs package as follows:

$ docker-compose exec {service_name} pipenv install 'environs[django]==8.0.0'
$ docker-compose down
$ docker-compose up -d --buld

Next we add the following lines to the top of settings.py:

# settings.py

from pathlib import Path
from environs import Env

env = Env()
env.read_env()

...

Then we copy the secret key and put it into the environment key in docker-compose.yml

# docker-compose.yml

...

services:
	web:
		...
		environment:
			="DJANGO_SECRET_KEY=fzxv+hlq2me@mf(1uw(7efxhx@hh7a4mov#q^(5\*qs=gh37f7c"

One thing to be aware of is that if your secret key includes a $ character, it should be doubled up $$, otherwise you will see an error.

Finally we replace SECRET_KEY in settings.py to import the environment variable.

# settings.py

...

SECRET_KEY = env("DJANGO_SECRET_KEY")

...