Morgan for HTTP request logging in Express - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Morgan in Express.js?

Morgan is a middleware for Express.js that logs HTTP requests to the console or a file, helping developers see details about incoming requests.

beginner

How do you install Morgan in an Express project?

You install Morgan using npm with the command: npm install morgan.

beginner

How do you use Morgan to log all HTTP requests in Express?

You add Morgan as middleware in your Express app like this:<br><pre>const morgan = require('morgan');
app.use(morgan('dev'));</pre><br>This logs requests in a concise colored format.

intermediate

What does the 'dev' format in Morgan do?

The 'dev' format logs HTTP method, URL, status code, response time, and response length in a colored, easy-to-read style.

intermediate

How can you log HTTP requests to a file using Morgan?

You create a write stream and pass it to Morgan like this:<br><pre>const fs = require('fs');
const path = require('path');
const accessLogStream = fs.createWriteStream(path.join(__dirname, 'access.log'), { flags: 'a' });
app.use(morgan('combined', { stream: accessLogStream }));</pre><br>This saves logs in Apache combined format to 'access.log'.

What is the primary purpose of Morgan in an Express app?

A To log HTTP requests

B To handle database connections

C To serve static files

D To manage user sessions

Morgan is used to log HTTP requests for monitoring and debugging.

Which command installs Morgan in a Node.js project?

A npm install morgan

B npm install logger

C npm install express

D npm install http

Morgan is installed with npm install morgan.

What does the 'combined' format in Morgan include?

A Only HTTP method and URL

B Only IP address and date

C Only status code and response time

D HTTP method, URL, status, response time, and user agent

The 'combined' format logs detailed info including user agent.

How do you add Morgan middleware to an Express app?

A app.get(morgan)

B app.use(morgan('dev'))

C app.listen(morgan)

D app.post(morgan)

Morgan is added as middleware using app.use(morgan('dev')).

Which Node.js module is used to create a write stream for logging Morgan output to a file?

A http

B url

C fs

D path

The 'fs' module creates write streams for file operations.

Explain how to set up Morgan in an Express app to log HTTP requests to the console.

Think about npm install, require, and middleware usage.

Describe how to configure Morgan to save HTTP request logs to a file instead of the console.

Consider how to write logs to a file using Node.js modules.