Nginx as reverse proxy in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a basic Express server that listens on port 3000.

Express

const express = require('express');
const app = express();

app.get('/', (req, res) => {
  res.send('Hello from Express!');
});

app.listen([1], () => {
  console.log('Server running');
});

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

A5000

B8080

C80

D3000

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 80 directly in Express without root permissions.

Choosing a port number that conflicts with other services.

The Express server listens on port 3000, which is a common default for development.

2fill in blank

medium

Complete the Nginx configuration line to set the proxy pass URL to the Express server running on localhost port 3000.

Express

location / {
    proxy_pass http://[1];
}

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

A127.0.0.1:8080

Blocalhost:3000

C0.0.0.0:3000

Dlocalhost:80

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong port numbers in proxy_pass.

Using IP 0.0.0.0 which is not routable.

The proxy_pass should point to the Express server URL, which is localhost on port 3000.

3fill in blank

hard

Fix the error in the Nginx proxy configuration to correctly forward headers.

Express

location /api/ {
    proxy_pass http://localhost:3000/;
    proxy_set_header Host [1];
}

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

A$host

B$http_host

C$remote_addr

D$server_name

Attempts:

3 left

💡 Hint

Common Mistakes

Using $remote_addr which is the client IP, not host.

Using $server_name which is the Nginx server name, not the request host.

The proxy_set_header Host should be set to $host to preserve the original host header.

4fill in blank

hard

Fill both blanks to complete the Nginx configuration that forwards requests and sets headers for proxying.

Express

location /app/ {
    proxy_pass http://localhost:[1]/;
    proxy_set_header X-Real-IP [2];
}

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

A3000

B$remote_addr

C$host

D8080

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong port number in proxy_pass.

Setting X-Real-IP to $host instead of $remote_addr.

The proxy_pass port should be 3000 to match Express, and X-Real-IP header should be set to $remote_addr to pass client IP.

5fill in blank

hard

Fill in the blanks to complete the Express middleware that trusts the proxy and logs the real client IP.

Express

const express = require('express');
const app = express();

app.set('[1]', true);

app.use((req, res, next) => {
  console.log('Client IP:', req.[2]);
  next();
});

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

Atrust proxy

Bconnection

Cip

Dsocket

Attempts:

3 left

💡 Hint

Common Mistakes

Not setting 'trust proxy' causes Express to see proxy IP.

Using incorrect property names to get client IP.

Setting 'trust proxy' to true tells Express to trust the proxy headers. The client IP is accessed via req.ip.