Dockerizing a Python Django Web Application

Follow this tutorial or the docs.

If you don't want to setup basic Django app together - clone mine from here.

cd Documents
mkdir djangodocker
cd djangodocker
django-admin startproject djangodocker
cd djangodocker
python3 manage.py runserver
# visit http://127.0.0.1:8000/
# C-c C-c to kill the running process
cd ..
python3 -m venv venv
source env/bin/activate
cd djangodocker
pip list
pip install django
pip freeze > requirements.txt

Create Dockerfile (without any file extensions, and with the D being capital) close to your manage.py file. This file will contain commands and instructions to assemble our IMAGE.

Whatever we put in it - docker will run through each of these commands and run through each them.

Result will be an image prepared and ready to be run on a Docker Container.

Dockerfile contents:

# remove ALL the comments if you want to use the code below.

FROM python:3.8-slim-buster     # OS from docker hub

WORKDIR /app                    #working directory of the OS created above

COPY requirements.txt requirements.txt #copy across from our local dir over to the image
RUN pip3 install -r requirements.txt

COPY . .                        #copy everything from current dir to working dir (/app)

CMD ["python3", "manage.py", "runserver", "0.0.0.0:8000"] #m0000 making our app externally visible from outside of the container

Create .dockerignore file to exclude any folders you want. .venv for example.

.dockerignore contents:

*/venv

To build an image, run this command while inside of the folder in which manage.py and Dockerfile is present. –tag basically give a name to the image. Don't forget the . at the end.

docker build --tag python-django .

It will take up to ~30 seconds. The image will be visible in "Docker Desktop" app.

A single command will do it.

docker run --publish 8000:8000 python-django

# or to run in detached(run in the background without occupying the terminal) mode
docker run -d --publish 8000:8000 python-django

Open up Django Desktop - you will see the container we have just created in "Container tab".

So now we are running a django application in a docker container. Go to a browser, 127.0.0.1:8000 to see your django app running.

Create the machine.

• Create a simple Linode node(choosing linode just because I have free credits for it, choose any other provider you want). In my case I have chosen Linode 2GB plan and a Docker image. ($10/month)
• When your Docker node is running, connect to it through SSH in it.

Let's pull the container we have created and pushed to Docker Hub in the previous steps.

docker pull arvydasg/django-docker-starter:latest

Adding :latest tag at the end. It is basically a version. It's useful to be able to choose a different version.

To run this container(a web app), we do this.

docker run -t -d -p 9999:8000 arvydasg/django-docker-starter:latest

We have specified additional switch -p which stands for ports. 9999:8000.

• 8000 is the port of the django app (specified in Dockerfile)
• 9999 is the port on which we want to reach the

Basically saying match port 80 with port 80.

Now grab your IP address from your linode dashboard, enter it in the browser.

That container not only has all the cpu, memory etc, but also all the settings the creator has applied(debian, nginx, website files, etc), web configuration, all prerequisites, all dependencies.. packaged together in a neat little package. And you can run it on any linux machine.