NODE.JS A hands-on introduction 

LUC CASTERA • Full-stack software developer & entrepreneur • Electrical Engineering: UVA / Georgia Tech • I work at Intellum on TribeSocial • Co-founder of job509.com & visit509.com • luccastera.com 

MEETUP GOALS • To build and develop a community of node.js experts in Miami that contribute to the global node.js ecosystem • “Learn and build together” • Example: the Seattle Ruby group 

AGENDA • Introductions • Basic Intro to node.js • Pair Programming • Prize Ceremony 

INTRODUCTIONS name
 profession
 node.js expertise (beginner, intermediate, advanced)
 why are you here? who do you want to win the world cup? 

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WHAT IS NODE.JS? 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

V8 

SERVER SIDE JAVASCRIPT 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

LIBUV libuv is a multi-platform support library with a focus on asynchronous I/O. 

CALLBACKS 

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– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

TYPICAL BLOCKING SERVER 

NON-BLOCKING SERVER 

ADVANTAGES 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

C10K PROBLEM 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

NETWORKING LIBRARIES • net • query string • url • UDP • DNS • HTTP(S) • … 

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WHY USE NODE.JS? 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

– nodejs.org “Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non- blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.” 

JAVASCRIPT Low barrier to entry 

JS EVERYWHERE Our stack: MongoDB, node.js, JSON, Backbone.js 

STRONG COMMUNITY 80,000+ npm packages 

MAC, LINUX, AND WINDOWS 

SMALL & STABLE 

WELL DOCUMENTED 

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HOW TO USE NODE.JS 

INSTALLING NODE.JS 

NPM npm install express 

DEMO 

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HELLO WORLD 

Beginner Intermediate Advanced 1. Install node.js 2. Write a program that prints ‘Hello Miami’ to the console 3. Write a web server that says ‘Hello Miami’ at the root URL http://localhost:3000/ 1. Write a web server that says ‘Hello Miami’ at the root URL http://localhost:3000/ 2. Use the cluster module to start a cluster of 4 servers serving the ‘Hello Miami’ app at http://localhost:3000/ 1. Use the cluster module to start a cluster of 4 servers serving the ‘Hello Miami’ app at http://localhost:3000/ 

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FAVORITE MODULES • async - avoid callback hell • underscore - JavaScript++ / utility belt • express - small web application framework • connect - middleware framework • mocha - testing (server-side and in browser) • grunt - task runner • sinon - test spies, stubs, and mocks • gleak - global variable leak detection • kue - priority job queue backed by redis • mongoose - mongodb ORM 

LESSONS LEARNED • calllback(err, data) • jshint is your friend (include in build process) • always use ‘return’ on callback • use streams when you should (.e.g mongoose) • move CPU intensive sections to separate process 

DEPLOYING NODE • Process handling: fail and restart (upstart, monit) • Use multiple node processes (kue) • Use a load balancer (haproxy) • upstart ulimit gotcha • stunnel for SSH • lock down npm dependencies (or shrinkwrap) 

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PAIR PROGRAMMING Form teams 

WORLD CUP FEVER! • Write a program that when passed the name of a country, prints out the list of players currently in their national football/soccer team along with their age and current club (comma delimited) • Usage: 
 roster Chile • Output:
 Claudio Bravo, 31, Barcelona
 Eugenio Mena, 28, Santos
 Mauricio Isla, 26, Juventus • Tip: Wikipedia pages URL: 
 http://en.wikipedia.org/wiki/Chile_national_football_team#Current_squad • If you are stuck and want a hint, ask me ;-)