Lesson 19: Docker & CI/CD for Django

Django: From Basics to Advanced

Part 5: Testing, Deployment & Production

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1. Dockerfile (Multi-stage)

FROM python:3.12-slim AS base
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1
WORKDIR /app

FROM base AS builder
RUN pip install --upgrade pip
COPY requirements.txt .
RUN pip install --prefix=/install -r requirements.txt

FROM base AS runtime
COPY --from=builder /install /usr/local
COPY . .
RUN python manage.py collectstatic --noinput

EXPOSE 8000
CMD ["gunicorn", "config.wsgi:application", "--bind", "0.0.0.0:8000", "--workers", "4"]

2. Docker Compose

services:
  web:
    build: .
    ports:
      - "8000:8000"
    env_file: .env
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_started
    command: gunicorn config.wsgi:application --bind 0.0.0.0:8000

  db:
    image: postgres:16-alpine
    volumes:
      - postgres_data:/var/lib/postgresql/data
    environment:
      POSTGRES_DB: ${DB_NAME}
      POSTGRES_USER: ${DB_USER}
      POSTGRES_PASSWORD: ${DB_PASSWORD}
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${DB_USER}"]
      interval: 5s
      retries: 5

  redis:
    image: redis:7-alpine

  celery:
    build: .
    command: celery -A config worker -l info
    env_file: .env
    depends_on:
      - redis
      - db

  celery-beat:
    build: .
    command: celery -A config beat -l info
    env_file: .env
    depends_on:
      - redis

volumes:
  postgres_data:

3. GitHub Actions CI/CD

name: Django CI/CD

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest
    services:
      postgres:
        image: postgres:16
        env:
          POSTGRES_DB: test_db
          POSTGRES_USER: test_user
          POSTGRES_PASSWORD: test_pass
        ports: ["5432:5432"]
        options: --health-cmd pg_isready --health-interval 10s

    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install -r requirements.txt
      - run: pytest --cov=. --cov-report=xml
        env:
          DATABASE_URL: postgres://test_user:test_pass@localhost/test_db

  deploy:
    needs: test
    if: github.ref == 'refs/heads/main'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Deploy to production
        run: |
          ssh ${{ secrets.SERVER_HOST }} "cd /app && git pull && docker compose up -d --build"

4. Environment Management

# settings.py
import os
from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent.parent

SECRET_KEY = os.environ['DJANGO_SECRET_KEY']
DEBUG = os.environ.get('DEBUG', 'False') == 'True'
ALLOWED_HOSTS = os.environ.get('ALLOWED_HOSTS', '').split(',')

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': os.environ['DB_NAME'],
        'USER': os.environ['DB_USER'],
        'PASSWORD': os.environ['DB_PASSWORD'],
        'HOST': os.environ.get('DB_HOST', 'localhost'),
        'PORT': os.environ.get('DB_PORT', '5432'),
    },
}

Next article: Production Deployment & Monitoring.