This guide will show you how to install Django inside Docker with docker-compose and without installing any dependencies on the host system. Since there are a few quirks and I have to look it up myself every damn time, here's a guide hopefully helping me and other the next time.

This guide will:

• help you install the newest version of django inside your docker container
• be independent of your host OS and python version, so you can always get the newest version inside docker
• provide a basic setup of django inside docker with docker-compose to build upon

Basic requirements file

Start with a requirements.txt file containing only:

django

Save it as requirements.txt.

Basic Dockerfile

Firstly, a Dockerfile is needed to set up and run our project. We'll use a basic version you can expand later. It uses Python 3.8, installs all dependencies from your requirements.txt file, and then copies your project files into the image.

So copy this in your Dockerfile:

FROM python:3.8

WORKDIR /code

# copy and install requirements first
# -> speeds up build if requirements haven't changed
COPY requirements.txt /code/
RUN pip install -r requirements.txt

# copy rest of files
# (not needed since we also mount a volume,
# but you won't mount in production)
COPY . /code/

Basic docker-compose

In docker-compose.yml:

version: "3"

services:
  web:
    build: .
    volumes:
      - .:/code/
    command: bash
    tty: True
    ports:
      # external is the port you use on your host, i.e. localhost:8000
      # internal is the port django uses inside the container
      # format: external:internal
      - "8000:8000"

Running it all

After having set up the above files, run the following steps:

1. Run docker-compose build to build the images.
2. Run docker-compose up to start the container, leave it running.
3. Run docker-compose exec web pip freeze > requirements.txt to pin the installed dependencies to their actual version. requirements.txt should now contain version numbers.
4. Run docker-compose exec web django-admin startproject YOURNAME . (mind the dot!) to start a new django project in the current directory.
5. Run sudo chown -R $USER ./ to own the docker-generated files. Otherwise you'll get file permission problems when working with the generated files on your host (outside of docker).
6. Run docker-compose exec web python ./manage.py runserver 0.0.0.0:8000.

You should now be able to access a congratulations page at localhost:8000.

Next steps

If you're interested in setting up Django for production, feel free to check out my guide on how to set up Django deployment for production for the same stack.

Note: Changing ports

If you want to change the port to access your Django application, you only have to change the external port, i.e. the docker-compose.yml file. So to switch to port 80, change the line below ports: to

ports:
  - "80:8000"

Then the container can be accessed with localhost:80 or just localhost (as 80 is the default).