Nginx as reverse proxy in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a simple Flask app that returns 'Hello World'.

Flask

from flask import Flask
app = Flask(__name__)

@app.route('/')
def home():
    return [1]

Drag options to blanks, or click blank then click option'

Aprint('Hello World')

BHello World

C'Hello World'

Dreturn 'Hello World'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the string

Using print instead of return

The Flask route function must return a string. Using quotes around 'Hello World' returns the string correctly.

2fill in blank

medium

Complete the Nginx server block to listen on port 80.

Flask

server {
    listen [1];
    server_name example.com;

    location / {
        proxy_pass http://127.0.0.1:5000;
    }
}

Drag options to blanks, or click blank then click option'

A80

B443 ssl

C8080

D5000

Attempts:

3 left

💡 Hint

Common Mistakes

Using HTTPS port 443 without SSL configuration

Using Flask app port 5000 instead of Nginx port

Port 80 is the default HTTP port that Nginx listens on for web traffic.

3fill in blank

hard

Fix the error in the proxy_pass directive to correctly forward requests to the Flask app.

Flask

location / {
    proxy_pass [1];
}

Drag options to blanks, or click blank then click option'

Ahttp://127.0.0.1:80

Blocalhost:5000

Chttp://localhost:5000/

Dhttp://localhost:5000

Attempts:

3 left

💡 Hint

Common Mistakes

Adding trailing slash in proxy_pass

Missing http:// in URL

Using wrong port

The proxy_pass URL should not have a trailing slash to correctly forward requests to the Flask app.

4fill in blank

hard

Fill both blanks to set headers for the reverse proxy to pass the original host and client IP.

Flask

location / {
    proxy_set_header [1] $host;
    proxy_set_header [2] $remote_addr;
}

Drag options to blanks, or click blank then click option'

AHost

BX-Real-IP

CX-Forwarded-For

DServer

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Server' header incorrectly

Confusing 'X-Forwarded-For' with 'X-Real-IP'

Setting 'Host' passes the original host header, and 'X-Real-IP' passes the client IP to the Flask app.

5fill in blank

hard

Fill all three blanks to complete the Nginx config for proxy buffering and timeouts.

Flask

location / {
    proxy_buffering [1];
    proxy_connect_timeout [2]s;
    proxy_read_timeout [3]s;
}

Drag options to blanks, or click blank then click option'

Aon

B30

C60

Doff

Attempts:

3 left

💡 Hint

Common Mistakes

Setting proxy_buffering to 'on' when real-time is needed

Using wrong units for timeouts

Disabling proxy_buffering with 'off' helps with real-time responses. The connect timeout is 30 seconds, and read timeout is 60 seconds.