Nginx as reverse proxy in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the main role of Nginx when used as a reverse proxy for a Django app?

Imagine you have a Django app running on a server. You put Nginx in front of it as a reverse proxy. What does Nginx do in this setup?

A It replaces the Django app and generates HTML pages on its own.

B It directly runs the Django app code and serves pages to users.

C It stores the Django app's database and handles data queries.

D It forwards client requests to the Django app and sends back the app's responses to clients.

💡 Hint

Think of Nginx as a helpful messenger between users and your Django app.

Nginx acts as a middleman that receives requests from users, passes them to the Django app, then sends the app's responses back to users. It does not run the Django code or store data.

❓ component_behavior

intermediate

What happens if Nginx is not configured to forward the correct headers to Django?

You set up Nginx as a reverse proxy but forget to forward the Host header. What problem might occur when Django processes requests?

A Django will receive the wrong host info and may generate incorrect URLs or fail security checks.

B Django will crash with a syntax error.

C Nginx will stop forwarding requests entirely.

D Django will ignore the missing header and work normally.

💡 Hint

Headers tell Django important info about the request origin.

If Nginx does not forward the Host header, Django may not know the correct domain name. This can cause wrong URL generation or security issues like CSRF failures.

📝 Syntax

advanced

Which Nginx configuration snippet correctly forwards requests to a Django app running on port 8000?

Choose the Nginx location block that properly proxies requests to Django on localhost:8000.

Django

location / {
    proxy_pass http://localhost:8000;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

A

location / {
    proxy_pass http://localhost:8000;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

B

location / {
    proxy_pass http://localhost:8000;
    proxy_set_header Host $remote_addr;
}

C

location / {
    proxy_pass http://localhost:8000/;
    proxy_set_header Host $host;
}

D

location / {
    proxy_pass http://localhost:8000;
    proxy_set_header Host $host;
}

💡 Hint

Check for missing semicolons and correct header forwarding.

Option A includes all necessary headers and proper syntax with semicolons. Option A misses a semicolon after proxy_pass. Option A adds a trailing slash which can change URL behavior. Option A forwards wrong header for Host.

🔧 Debug

advanced

Why does Django show a 400 Bad Request error behind Nginx reverse proxy?

You set up Nginx as a reverse proxy for Django. When accessing the site, Django returns a 400 Bad Request error. What is the most likely cause?

A Nginx is forwarding requests without the <code>X-Forwarded-For</code> header.

B Django's ALLOWED_HOSTS setting does not include the domain used in the request.

C The Django app is not listening on the correct port.

D Nginx is not running on the server.

💡 Hint

Check Django's security settings for allowed domains.

Django returns 400 Bad Request if the Host header in the request is not in ALLOWED_HOSTS. Behind Nginx, if the domain is missing from ALLOWED_HOSTS, Django rejects the request.

❓ state_output

expert

What is the value of request.META['REMOTE_ADDR'] in Django when behind Nginx reverse proxy?

Assuming Nginx is configured as a reverse proxy forwarding requests to Django, what IP address will request.META['REMOTE_ADDR'] contain inside Django?

A Always 127.0.0.1 regardless of client IP.

B The IP address of the original client making the request.

C The IP address of the Nginx server acting as reverse proxy.

D An empty string because Nginx hides the IP.

💡 Hint

Think about which server actually connects directly to Django.

When Nginx proxies requests, Django sees the connection coming from Nginx's IP, not the original client. To get the real client IP, Django must read the X-Forwarded-For header.