DjangoHow-ToBeginner · 4 min read

How to Deploy Django Using Docker: Step-by-Step Guide

To deploy a Django app using Docker, create a Dockerfile that sets up Python, installs dependencies, and runs the app. Use docker-compose.yml to define services like the Django app and database, then run docker-compose up to start everything together.

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Syntax

A typical Docker deployment for Django involves two main files:

Dockerfile: Defines the environment, installs Python, copies your code, installs dependencies, and runs the server.
docker-compose.yml: Defines services like the Django app and database, networking, and volumes.

These files work together to build and run your Django app inside containers.

dockerfile

FROM python:3.11-slim

WORKDIR /app

COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt

COPY . .

CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]

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Example

This example shows a simple Docker setup for Django with a PostgreSQL database using docker-compose. It demonstrates building the Django image, installing dependencies, and running the app with the database service.

yaml

version: '3.9'
services:
  db:
    image: postgres:15
    environment:
      POSTGRES_DB: mydb
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password
    volumes:
      - postgres_data:/var/lib/postgresql/data

  web:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
      - .:/app
    ports:
      - "8000:8000"
    depends_on:
      - db

volumes:
  postgres_data:

Output

Starting db ... done Starting web ... done web_1 | Watching for file changes with StatReloader web_1 | Performing system checks... web_1 | System check identified no issues (0 silenced). web_1 | April 27, 2024 - 12:00:00 web_1 | Django version 4.x, using settings 'myproject.settings' web_1 | Starting development server at http://0.0.0.0:8000/ web_1 | Quit the server with CONTROL-C.

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Common Pitfalls

Common mistakes when deploying Django with Docker include:

Not exposing the correct port in Dockerfile or docker-compose.yml, so the app is unreachable.
Forgetting to add ALLOWED_HOSTS in Django settings to allow connections.
Not using volumes properly, causing code changes not to reflect inside the container.
Missing database environment variables or not waiting for the database to be ready before Django starts.

dockerfile

## Wrong: Missing port exposure and ALLOWED_HOSTS
CMD ["python", "manage.py", "runserver"]

## Right: Expose port and set ALLOWED_HOSTS in settings.py
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]

# settings.py
ALLOWED_HOSTS = ['*']

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Quick Reference

Tips for smooth Django Docker deployment:

Use python:3.11-slim base image for smaller size.
Keep dependencies in requirements.txt and install in Dockerfile.
Use docker-compose to manage multi-container apps (web + db).
Map ports and volumes for development convenience.
Set ALLOWED_HOSTS properly in Django settings.

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Key Takeaways

Create a Dockerfile to set up Python, install dependencies, and run Django on 0.0.0.0:8000.

Use docker-compose.yml to define Django and database services for easy multi-container deployment.

Expose ports and set ALLOWED_HOSTS in Django settings to allow external access.

Use volumes in docker-compose for live code updates during development.

Ensure the database service is ready before Django starts to avoid connection errors.