Nginx as reverse proxy in Flask - Mini Project: Build & Apply

Nginx as Reverse Proxy for Flask App

📖 Scenario: You want to make your Flask web app accessible through a friendly web address and improve security by using Nginx as a reverse proxy. This means Nginx will receive web requests and forward them to your Flask app running on a local port.

🎯 Goal: Set up a simple Flask app and configure Nginx to act as a reverse proxy that forwards requests to the Flask app.

📋 What You'll Learn

Create a basic Flask app with one route

Define the port number where Flask app will run

Write the Nginx server block configuration to proxy requests to Flask

Include the final Nginx configuration with proxy settings

💡 Why This Matters

🌍 Real World

Using Nginx as a reverse proxy is common in web hosting to improve security, performance, and manageability of web applications.

💼 Career

Many web developer and DevOps roles require knowledge of configuring Nginx to serve and proxy web applications like Flask.

1

Create a basic Flask app

Create a Flask app in a file called app.py. Import Flask from flask, create an app instance called app, and define a route / that returns the text "Hello from Flask!".

Flask

# Your code here

Need a hint?

Remember to import Flask, create the app, and use the @app.route decorator for the home page.

2

Set the Flask app port

Add code to run the Flask app on port 5000 by calling app.run(host='127.0.0.1', port=5000) inside the if __name__ == '__main__': block.

Flask

from flask import Flask

app = Flask(__name__)

@app.route('/')
def home():
    return "Hello from Flask!"

# Add the app.run block below

Need a hint?

Use the if __name__ == '__main__': guard to run the app on localhost port 5000.

3

Write Nginx reverse proxy config

Create an Nginx server block configuration that listens on port 80 and proxies all requests to http://127.0.0.1:5000. Use proxy_pass http://127.0.0.1:5000; inside the location / block.

Flask

# Write the Nginx server block configuration below
# Your code here

Need a hint?

Use proxy_pass inside location / to forward requests to Flask.

4

Complete Nginx config with proxy headers

Add the proxy headers proxy_set_header Host $host;, proxy_set_header X-Real-IP $remote_addr;, proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;, and proxy_set_header X-Forwarded-Proto $scheme; inside the location / block to complete the Nginx reverse proxy configuration.

Flask

server {
    listen 80;

    location / {
        proxy_pass http://127.0.0.1:5000;
        # Add proxy_set_header lines below
    }
}

Need a hint?

These headers help pass client info to the Flask app through Nginx.