Deployment

🚀 Django Deployment: From Your Computer to the World!

Analogy: Think of deploying Django like opening a restaurant. Your kitchen (development) works great for testing recipes, but serving real customers needs a professional setup — proper equipment, safety standards, and a team that works together smoothly.

🌍 What is Deployment?

Imagine you built an amazing treehouse in your backyard. Right now, only you can play in it. But what if kids from all over the world wanted to play too?

Deployment = Moving your treehouse to a public park where everyone can visit!

Your Django Journey So Far:

Your Computer (Development)
      ↓
   Testing locally
      ↓
   Works great for YOU
      ↓
   But nobody else can see it! 😢

After Deployment:

Cloud Server (Production)
      ↓
   Running 24/7
      ↓
   Anyone with internet can visit! 🎉

🔧 Deployment Overview

The Big Picture

When you type python manage.py runserver, Django starts a tiny, simple server. It’s perfect for testing — like riding a bicycle to the corner store.

But for real users? You need a race car. That’s what production deployment gives you.

graph TD
    A["Your Code"] --> B["Web Server"]
    B --> C["Application Server"]
    C --> D["Django App"]
    D --> E["Database"]
    F["User Browser"] --> B

Key Players in Production

🎯 Simple Rule: Development server = training wheels. Production = the real bike!

🔌 WSGI and ASGI: The Translators

The Problem

Web servers (like Nginx) speak HTTP. Django speaks Python. They need a translator!

Analogy: Imagine a French chef (Django) working with a Chinese waiter (Web Server). They need someone who speaks both languages to work together. That’s WSGI/ASGI!

WSGI: Web Server Gateway Interface

WSGI is the old reliable translator. It handles one conversation at a time.

# wsgi.py - Django creates this for you!
import os
from django.core.wsgi import get_wsgi_application

os.environ.setdefault(
    'DJANGO_SETTINGS_MODULE',
    'myproject.settings'
)

application = get_wsgi_application()

How WSGI Works:

Request comes in → WSGI translates → Django processes
      ↓
Response goes out ← WSGI translates ← Django responds

ASGI: Asynchronous Server Gateway Interface

ASGI is the newer, faster translator. It can handle many conversations at once!

# asgi.py - For async Django
import os
from django.core.asgi import get_asgi_application

os.environ.setdefault(
    'DJANGO_SETTINGS_MODULE',
    'myproject.settings'
)

application = get_asgi_application()

When to Use Each?

🎯 Rule of Thumb: Start with WSGI. Move to ASGI only if you need real-time features like live chat!

⚙️ Production Settings: Safety First!

Development vs Production

Development = Your house with doors wide open, lights on, showing everything.

Production = A secure building with guards, locked doors, and security cameras.

The Most Important Setting: DEBUG

# ❌ NEVER do this in production!
DEBUG = True   # Shows all your secrets!

# ✅ ALWAYS do this in production!
DEBUG = False  # Keeps secrets safe!

What happens with DEBUG = True?

• Shows detailed error pages (hackers love these!)
• Reveals your code structure
• Displays database queries
• Exposes file paths

ALLOWED_HOSTS: Who Can Visit?

# Development - anything goes
ALLOWED_HOSTS = ['*']

# Production - be specific!
ALLOWED_HOSTS = [
    'mysite.com',
    'www.mysite.com',
]

Analogy: It’s like a guest list at a party. Only names on the list get in!

Security Settings Checklist

# Production settings.py

# 1. Debug OFF
DEBUG = False

# 2. Specify allowed hosts
ALLOWED_HOSTS = ['mysite.com']

# 3. Force HTTPS
SECURE_SSL_REDIRECT = True

# 4. Secure cookies
SESSION_COOKIE_SECURE = True
CSRF_COOKIE_SECURE = True

# 5. Prevent clickjacking
X_FRAME_OPTIONS = 'DENY'

# 6. Add security headers
SECURE_BROWSER_XSS_FILTER = True
SECURE_CONTENT_TYPE_NOSNIFF = True

Static Files in Production

Development server serves static files automatically. Production? You need extra setup!

# settings.py
STATIC_URL = '/static/'
STATIC_ROOT = '/var/www/mysite/static/'

# Then run:
# python manage.py collectstatic

🔐 Environment Variables: Keeping Secrets Safe

The Problem with Hardcoding

# ❌ TERRIBLE! Never do this!
SECRET_KEY = 'abc123-super-secret-key-here'
DATABASE_PASSWORD = 'mypassword123'

If someone sees your code, they see your secrets! 😱

The Solution: Environment Variables

Environment variables are like secret notes that only your server knows.

# ✅ PERFECT! Safe and secure!
import os

SECRET_KEY = os.environ.get('SECRET_KEY')
DATABASE_PASSWORD = os.environ.get('DB_PASSWORD')

How to Set Environment Variables

Method 1: Export in Terminal

export SECRET_KEY='your-super-secret-key'
export DB_PASSWORD='secure-password-here'

Method 2: .env File (Recommended)

# .env file (NEVER commit this!)
SECRET_KEY=your-super-secret-key
DB_PASSWORD=secure-password-here
DEBUG=False

Using python-dotenv:

# settings.py
from dotenv import load_dotenv
load_dotenv()

SECRET_KEY = os.getenv('SECRET_KEY')

Common Environment Variables

The .gitignore Rule

# .gitignore - ALWAYS include this!
.env
*.env
.env.local
secrets.py

🎯 Golden Rule: If it’s secret, it goes in environment variables, NEVER in your code!

🎯 Putting It All Together

Complete Production Setup

graph TD
    A["User"] --> B["Nginx - Web Server"]
    B --> C["Gunicorn - WSGI"]
    C --> D["Django App"]
    D --> E["#40;PostgreSQL#41;"]
    D --> F["Static Files"]

    style A fill:#e1f5fe
    style B fill:#fff9c4
    style C fill:#f3e5f5
    style D fill:#c8e6c9
    style E fill:#ffccbc
    style F fill:#d7ccc8

Deployment Checklist

✅ Before Going Live:

1. Set DEBUG = False
2. Set ALLOWED_HOSTS properly
3. Use environment variables for secrets
4. Run collectstatic
5. Use PostgreSQL (not SQLite)
6. Enable HTTPS
7. Configure WSGI/ASGI properly

Example Production settings.py

import os
from dotenv import load_dotenv

load_dotenv()

DEBUG = False
SECRET_KEY = os.getenv('SECRET_KEY')

ALLOWED_HOSTS = [
    os.getenv('DOMAIN_NAME')
]

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': os.getenv('DB_NAME'),
        'USER': os.getenv('DB_USER'),
        'PASSWORD': os.getenv('DB_PASSWORD'),
        'HOST': os.getenv('DB_HOST'),
        'PORT': '5432',
    }
}

# Security
SECURE_SSL_REDIRECT = True
SESSION_COOKIE_SECURE = True
CSRF_COOKIE_SECURE = True

🏆 You Did It!

You now understand:

• ✅ Deployment = Making your app available to everyone
• ✅ WSGI/ASGI = Translators between web server and Django
• ✅ Production Settings = Security-first configuration
• ✅ Environment Variables = Keeping secrets safe

🚀 Next Step: Practice deploying to platforms like Heroku, Railway, or DigitalOcean. Start small, learn big!

Remember: Every expert was once a beginner. You’re on your way to becoming a Django deployment pro! 🎉