containerizing-django-app

My hands-on journey of learning how to containerize a Django app using Docker — from writing a Dockerfile to running the app on localhost, with real mistakes and fixes along the way.

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Containerizing a Django Web App Using Docker

This project demonstrates how to containerize a Django application from scratch using Docker. It’s not just a working container — it's an educational deep dive into how Docker works under the hood when packaging a real-world Python web application.

Whether we're exploring DevOps, backend engineering, or full-stack development, this repository showcases key concepts like:

• Writing a clean, production-ready Dockerfile
• Installing and managing Python dependencies securely
• Understanding Docker image layers and virtual environments
• Running containers with proper networking and port mapping
• Avoiding common pitfalls (like missing ports or system-wide installs)

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Project Overview

This is a basic Django app — already set up and functional. The focus of this repo is containerization, not Django development.

Key Features:

• Simple Django app with a view that returns an HTML page
• URL path routed via /demo/
• Custom requirements.txt for dependency management
• Virtual environment created inside the Docker container
• Clean Dockerfile with Bash shell configuration
• Exposed port and run commands clearly defined

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Technologies Used

• Python 3
• Django
• pip (Python Package Manager)
• Docker
• Ubuntu (as base image)

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File Structure

devops/
├── manage.py
├── devops/
│   ├── settings.py
│   ├── urls.py
├── demo/
│   ├── views.py
│   ├── urls.py
│   └── templates/
│       └── demo\_site.html
requirements.txt
Dockerfile

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How to Run the Project Locally Using Docker

1. Clone the Repo

git clone https://github.com/arnab-logs/containerizing-django-app.git
cd containerizing-django-app

2. Build the Docker Image

docker build -t django-container .

This step uses the Dockerfile to create a custom image with Python, Django, and all dependencies installed in a virtual environment inside the container.

3. Run the Container

docker run -p 8000:8000 django-container

The -p flag maps container port 8000 to your localhost port 8000, making the app accessible via your browser.

4. Open in Browser

Visit: http://localhost:8000/demo

You’ll see a simple HTML page with LinkedIn and blog links, and a message that says:

“Learning to Containerize Django App Using Docker”

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What I Learned

This project wasn’t just about getting a Django app to work — it was about learning why certain things matter in containerization. Here are a few key takeaways:

• Why system Python installs can fail in Docker (PEP 668 errors)
• How virtual environments solve system dependency issues
• The importance of switching to bash shell inside Docker for source to work
• Why port forwarding is essential (-p 8000:8000)
• How to interpret Django URL routing inside containers (/demo/ path)

Check the blog for detailed explanations and lessons learned!

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Dockerfile Highlights

FROM ubuntu
WORKDIR /app

COPY requirements.txt /app/
COPY devops /app/

RUN apt-get update && apt-get install -y python3 python3-pip python3-venv

SHELL ["/bin/bash", "-c"]

RUN python3 -m venv venv1 && \
    source venv1/bin/activate && \
    pip install --no-cache-dir -r requirements.txt

EXPOSE 8000

CMD source venv1/bin/activate && python3 manage.py runserver 0.0.0.0:8000

This Dockerfile is intentionally built from the ground up using a base ubuntu image to showcase what it takes to install and configure Python and Django manually — rather than relying on prebuilt python base images.

About Me

• LinkedIn
• Blog

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