Book Image

Node.js Web Development - Fourth Edition

By : David Herron
Book Image

Node.js Web Development - Fourth Edition

By: David Herron

Overview of this book

Node.js is a server-side JavaScript platform using an event-driven, non-blocking I/O model allowing users to build fast and scalable data-intensive applications running in real time. This book gives you an excellent starting point, bringing you straight to the heart of developing web applications with Node.js. You will progress from a rudimentary knowledge of JavaScript and server-side development to being able to create, maintain, deploy and test your own Node.js application.You will understand the importance of transitioning to functions that return Promise objects, and the difference between fs, fs/promises and fs-extra. With this book you'll learn how to use the HTTP Server and Client objects, data storage with both SQL and MongoDB databases, real-time applications with Socket.IO, mobile-first theming with Bootstrap, microservice deployment with Docker, authenticating against third-party services using OAuth, and use some well known tools to beef up security of Express 4.16 applications.
Table of Contents (14 chapters)

HTTP Sniffer – listening to the HTTP conversation

The events emitted by the HTTPServer object can be used for additional purposes beyond the immediate task of delivering a web application. The following code demonstrates a useful module that listens to all the HTTP Server events. It could be a useful debugging tool, which also demonstrates how HTTP server objects operate.

Node.js's HTTP Server object is an EventEmitter and the HTTP Sniffer simply listens to every server event, printing out information pertinent to each event.

What we're about to do is:

  1. Create a module, httpsniffer, that prints information about HTTP requests.
  2. Add that module to the server.js script we just created.
  3. Rerun that server to view a trace of HTTP activity.

Create a file named httpsniffer.js containing the following code:

const util = require('util'); ...