Running Django with Docker

Why Use Docker for Django?

Docker is a containerization tool that simplifies development, deployment, and scaling. Running Django inside a Docker container helps maintain consistency across different environments, makes dependency management easier, and allows for seamless deployment.

Benefits of Using Docker for Django

1. Consistency Across Environments

   • Docker ensures that the Django app runs the same way on every machine, eliminating the "works on my machine" problem.

2. Simplified Dependency Management

   • No need to manually install Python, Django, PostgreSQL, Redis, or other dependencies—everything is packaged inside the container.

3. Easy Deployment

   • Containers make it easy to deploy Django applications across different servers or cloud platforms without configuration issues.

4. Isolation of Services

   • You can run Django, a database (PostgreSQL, MySQL), Redis, and other services in separate containers without conflicts.

5. Scalability

   • Using Docker Compose or Kubernetes, you can scale different components of your Django application as needed.

6. Faster Onboarding & Development

   • New developers can quickly set up a local development environment using docker-compose up.

7. CI/CD Integration

   • Docker integrates well with CI/CD pipelines for automated testing and deployment.

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Basic Usage of Docker with Django

1. Install Docker

Ensure Docker and Docker Compose are installed on your system.

2. Create a Dockerfile

This defines how the Django application should be built inside a container.

FROM python:3.11.7-slim-bookworm
ENV PYTHONUNBUFFERED 1
WORKDIR /backend
COPY . /backend
RUN python -m venv /opt/venv
RUN python3 -m venv /opt/venv && \
    /opt/venv/bin/pip install --upgrade pip && \
    /opt/venv/bin/pip install -r requirements.txt && \
    chmod +x /backend/entrypoint.sh
CMD [ "/backend/entrypoint.sh" ]

3. Creating a Django runner (entrypoint.sh) file

#!/bin/bash

APP_PORT=${PORT:-8000}

echo "Waiting for postgres..."

sleep 5

echo "PostgreSQL started"

echo "Migrating database..."

/opt/venv/bin/python manage.py makemigrations --noinput

/opt/venv/bin/python manage.py migrate --noinput

echo "Database migrated"

echo "Creating superuser..."

/opt/venv/bin/python manage.py createsuperuser || true

echo "Superuser created"

echo "Collecting static files..."

/opt/venv/bin/python manage.py collectstatic --noinput

echo "Static files collected"

echo "Starting server..."

/opt/venv/bin/gunicorn app.wsgi:application --bind "0.0.0.0:${APP_PORT}"

4. Run the Django App in Docker

docker-compose up --build

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Next Steps

• Set up Gunicorn and Nginx for production
• Use environment variables to manage secrets
• Implement Docker volumes for persistent storage
• Deploy to AWS, DigitalOcean, or GCP using Docker