Nginx as reverse proxy in Flask - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a reverse proxy in the context of web servers?

A reverse proxy is a server that sits between clients and backend servers. It receives client requests and forwards them to the backend server, then sends the server's response back to the client. It helps with load balancing, security, and hiding backend details.

beginner

Why use Nginx as a reverse proxy for a Flask application?

Nginx can handle many client connections efficiently, serve static files quickly, and forward dynamic requests to the Flask app. It improves performance, security, and allows running Flask on a local port hidden from the internet.

intermediate

Which Nginx directive is used to forward requests to the Flask backend?

The proxy_pass directive is used inside a location block to forward client requests to the Flask backend server running on a specific address and port.

intermediate

How does Nginx improve security when used as a reverse proxy?

Nginx can hide the backend server's IP and details, filter bad requests, limit request rates, and handle SSL/TLS encryption. This protects the Flask app from direct attacks and improves overall security.

beginner

What is a common port configuration when using Nginx as a reverse proxy for Flask?

Nginx listens on port 80 (HTTP) or 443 (HTTPS) for client requests, while Flask runs on a local port like 5000. Nginx forwards requests from port 80/443 to Flask's port 5000 internally.

What role does Nginx play when used as a reverse proxy for Flask?

A It acts as a database for Flask

B It replaces Flask as the backend application

C It only serves static files without forwarding requests

D It forwards client requests to the Flask app and returns responses

Nginx forwards client requests to the Flask backend and sends back the responses, acting as a middleman.

Which Nginx directive forwards requests to the Flask server?

A proxy_pass

B listen

C server_name

D root

The proxy_pass directive tells Nginx where to send the incoming requests.

Why is it better to run Flask behind Nginx instead of exposing Flask directly?

A Flask only serves static files

B Flask cannot run on a server without Nginx

C Nginx handles many connections efficiently and adds security

D Nginx replaces Flask's functionality

Nginx is optimized for handling many connections and adds security features that Flask alone does not provide.

What port does Nginx usually listen on when acting as a reverse proxy for Flask?

A 5000

B 80 or 443

C 8080

D 3306

Nginx listens on standard web ports 80 (HTTP) or 443 (HTTPS) and forwards requests to Flask's port.

How does Nginx help with SSL/TLS when used as a reverse proxy?

A It terminates SSL connections and forwards plain requests to Flask

B It disables SSL for Flask

C It encrypts Flask's database

D It does not support SSL

Nginx handles SSL encryption and then forwards unencrypted requests to Flask, simplifying Flask's setup.

Explain how Nginx acts as a reverse proxy for a Flask application and why this setup is useful.

Think about Nginx as a middleman between users and your Flask app.

Describe the key Nginx configuration directives needed to set up a reverse proxy for Flask.

Focus on how Nginx forwards requests to Flask.