🔙 Quay lại trang tải sách pdf ebook Node.js Notes for Professionals Ebooks Nhóm Zalo Notes for Professionals Node.js Node.js Notes for Professionals 300+ pages of professional hints and tricks GoalKicker.com Free Programming Books Disclaimer This is an unocial free book created for educational purposes and is not aliated with ocial Node.js group(s) or company(s). All trademarks and registered trademarks are the property of their respective owners Contents About ................................................................................................................................................................................... 1 Chapter 1: Getting started with Node.js ............................................................................................................ 2 Section 1.1: Hello World HTTP server ........................................................................................................................... 4 Section 1.2: Hello World command line ....................................................................................................................... 5 Section 1.3: Hello World with Express .......................................................................................................................... 6 Section 1.4: Installing and Running Node.js ................................................................................................................. 6 Section 1.5: Debugging Your NodeJS Application ...................................................................................................... 7 Section 1.6: Hello World basic routing ......................................................................................................................... 7 Section 1.7: Hello World in the REPL ............................................................................................................................ 8 Section 1.8: Deploying your application online ........................................................................................................... 9 Section 1.9: Core modules ............................................................................................................................................. 9 Section 1.10: TLS Socket: server and client ................................................................................................................ 14 Section 1.11: How to get a basic HTTPS web server up and running! ..................................................................... 16 Chapter 2: npm ............................................................................................................................................................ 19 Section 2.1: Installing packages ................................................................................................................................. 19 Section 2.2: Uninstalling packages ............................................................................................................................ 22 Section 2.3: Setting up a package configuration ..................................................................................................... 23 Section 2.4: Running scripts ....................................................................................................................................... 24 Section 2.5: Basic semantic versioning ..................................................................................................................... 24 Section 2.6: Publishing a package ............................................................................................................................. 25 Section 2.7: Removing extraneous packages .......................................................................................................... 26 Section 2.8: Listing currently installed packages ..................................................................................................... 26 Section 2.9: Updating npm and packages ............................................................................................................... 26 Section 2.10: Scopes and repositories ....................................................................................................................... 27 Section 2.11: Linking projects for faster debugging and development .................................................................. 27 Section 2.12: Locking modules to specific versions ................................................................................................. 28 Section 2.13: Setting up for globally installed packages ......................................................................................... 28 Chapter 3: Web Apps With Express .................................................................................................................... 30 Section 3.1: Getting Started ......................................................................................................................................... 30 Section 3.2: Basic routing ........................................................................................................................................... 31 Section 3.3: Modular express application ................................................................................................................. 32 Section 3.4: Using a Template Engine ....................................................................................................................... 33 Section 3.5: JSON API with ExpressJS ....................................................................................................................... 34 Section 3.6: Serving static files ................................................................................................................................... 35 Section 3.7: Adding Middleware ................................................................................................................................. 36 Section 3.8: Error Handling ......................................................................................................................................... 36 Section 3.9: Getting info from the request ................................................................................................................ 37 Section 3.10: Error handling in Express ...................................................................................................................... 38 Section 3.11: Hook: How to execute code before any req and after any res ........................................................ 38 Section 3.12: Setting cookies with cookie-parser ..................................................................................................... 39 Section 3.13: Custom middleware in Express ............................................................................................................ 39 Section 3.14: Named routes in Django-style ............................................................................................................. 39 Section 3.15: Hello World ............................................................................................................................................. 40 Section 3.16: Using middleware and the next callback ............................................................................................ 40 Section 3.17: Error handling ........................................................................................................................................ 42 Section 3.18: Handling POST Requests ...................................................................................................................... 43 Chapter 4: Filesystem I/O ...................................................................................................................................... 45 Section 4.1: Asynchronously Read from Files ........................................................................................................... 45 Section 4.2: Listing Directory Contents with readdir or readdirSync ..................................................................... 45 Section 4.3: Copying files by piping streams ............................................................................................................ 46 Section 4.4: Reading from a file synchronously ...................................................................................................... 47 Section 4.5: Check Permissions of a File or Directory ............................................................................................. 47 Section 4.6: Checking if a file or a directory exists .................................................................................................. 48 Section 4.7: Determining the line count of a text file ............................................................................................... 49 Section 4.8: Reading a file line by line ....................................................................................................................... 49 Section 4.9: Avoiding race conditions when creating or using an existing directory ........................................... 49 Section 4.10: Cloning a file using streams ................................................................................................................. 50 Section 4.11: Writing to a file using writeFile or writeFileSync ................................................................................. 51 Section 4.12: Changing contents of a text file .......................................................................................................... 51 Section 4.13: Deleting a file using unlink or unlinkSync ........................................................................................... 52 Section 4.14: Reading a file into a Buer using streams ......................................................................................... 52 Chapter 5: Exporting and Consuming Modules ........................................................................................... 53 Section 5.1: Creating a hello-world.js module ........................................................................................................... 53 Section 5.2: Loading and using a module ................................................................................................................ 54 Section 5.3: Folder as a module ................................................................................................................................. 55 Section 5.4: Every module injected only once .......................................................................................................... 55 Section 5.5: Module loading from node_modules ................................................................................................... 56 Section 5.6: Building your own modules ................................................................................................................... 56 Section 5.7: Invalidating the module cache .............................................................................................................. 57 Chapter 6: Exporting and Importing Module in node.js .......................................................................... 58 Section 6.1: Exporting with ES6 syntax ...................................................................................................................... 58 Section 6.2: Using a simple module in node.js ......................................................................................................... 58 Chapter 7: How modules are loaded ................................................................................................................ 59 Section 7.1: Global Mode ............................................................................................................................................. 59 Section 7.2: Loading modules .................................................................................................................................... 59 Chapter 8: Cluster Module ..................................................................................................................................... 60 Section 8.1: Hello World .............................................................................................................................................. 60 Section 8.2: Cluster Example ...................................................................................................................................... 60 Chapter 9: Readline ................................................................................................................................................... 62 Section 9.1: Line-by-line file reading .......................................................................................................................... 62 Section 9.2: Prompting user input via CLI ................................................................................................................. 62 Chapter 10: package.json ....................................................................................................................................... 63 Section 10.1: Exploring package.json ......................................................................................................................... 63 Section 10.2: Scripts ..................................................................................................................................................... 66 Section 10.3: Basic project definition ......................................................................................................................... 67 Section 10.4: Dependencies ........................................................................................................................................ 67 Section 10.5: Extended project definition .................................................................................................................. 68 Chapter 11: Event Emitters ..................................................................................................................................... 69 Section 11.1: Basics ....................................................................................................................................................... 69 Section 11.2: Get the names of the events that are subscribed to .......................................................................... 69 Section 11.3: HTTP Analytics through an Event Emitter ........................................................................................... 70 Section 11.4: Get the number of listeners registered to listen for a specific event ............................................... 70 Chapter 12: Autoreload on changes .................................................................................................................. 72 Section 12.1: Autoreload on source code changes using nodemon ....................................................................... 72 Section 12.2: Browsersync .......................................................................................................................................... 72 Chapter 13: Environment ......................................................................................................................................... 74 Section 13.1: Accessing environment variables ......................................................................................................... 74 Section 13.2: process.argv command line arguments ............................................................................................. 74 Section 13.3: Loading environment properties from a "property file" ................................................................... 75 Section 13.4: Using dierent Properties/Configuration for dierent environments like dev, qa, staging etc ................................................................................................................................................................................ 75 Chapter 14: Callback to Promise ........................................................................................................................ 77 Section 14.1: Promisifying a callback ......................................................................................................................... 77 Section 14.2: Manually promisifying a callback ........................................................................................................ 77 Section 14.3: setTimeout promisified ......................................................................................................................... 78 Chapter 15: Executing files or commands with Child Processes ......................................................... 79 Section 15.1: Spawning a new process to execute a command .............................................................................. 79 Section 15.2: Spawning a shell to execute a command ........................................................................................... 79 Section 15.3: Spawning a process to run an executable ......................................................................................... 80 Chapter 16: Exception handling ........................................................................................................................... 82 Section 16.1: Handling Exception In Node.Js ............................................................................................................. 82 Section 16.2: Unhanded Exception Management ..................................................................................................... 83 Section 16.3: Errors and Promises .............................................................................................................................. 84 Chapter 17: Keep a node application constantly running ..................................................................... 86 Section 17.1: Use PM2 as a process manager ........................................................................................................... 86 Section 17.2: Running and stopping a Forever daemon ......................................................................................... 87 Section 17.3: Continuous running with nohup ........................................................................................................... 88 Chapter 18: Uninstalling Node.js ......................................................................................................................... 89 Section 18.1: Completely uninstall Node.js on Mac OSX ........................................................................................... 89 Section 18.2: Uninstall Node.js on Windows .............................................................................................................. 89 Chapter 19: nvm - Node Version Manager ..................................................................................................... 90 Section 19.1: Install NVM .............................................................................................................................................. 90 Section 19.2: Check NVM version ............................................................................................................................... 90 Section 19.3: Installing an specific Node version ...................................................................................................... 90 Section 19.4: Using an already installed node version ............................................................................................ 90 Section 19.5: Install nvm on Mac OSX ........................................................................................................................ 91 Section 19.6: Run any arbitrary command in a subshell with the desired version of node ................................. 91 Section 19.7: Setting alias for node version .............................................................................................................. 92 Chapter 20: http .......................................................................................................................................................... 93 Section 20.1: http server .............................................................................................................................................. 93 Section 20.2: http client .............................................................................................................................................. 94 Chapter 21: Using Streams ..................................................................................................................................... 95 Section 21.1: Read Data from TextFile with Streams ............................................................................................... 95 Section 21.2: Piping streams ....................................................................................................................................... 95 Section 21.3: Creating your own readable/writable stream ................................................................................... 96 Section 21.4: Why Streams? ....................................................................................................................................... 97 Chapter 22: Deploying Node.js applications in production ................................................................... 99 Section 22.1: Setting NODE_ENV="production" ........................................................................................................ 99 Section 22.2: Manage app with process manager ................................................................................................ 100 Section 22.3: Deployment using process manager ............................................................................................... 100 Section 22.4: Deployment using PM2 ...................................................................................................................... 101 Section 22.5: Using dierent Properties/Configuration for dierent environments like dev, qa, staging etc ............................................................................................................................................................................. 102 Section 22.6: Taking advantage of clusters ........................................................................................................... 103 Chapter 23: Securing Node.js applications .................................................................................................. 104 Section 23.1: SSL/TLS in Node.js .............................................................................................................................. 104 Section 23.2: Preventing Cross Site Request Forgery (CSRF) .............................................................................. 104 Section 23.3: Setting up an HTTPS server .............................................................................................................. 105 Section 23.4: Using HTTPS ....................................................................................................................................... 107 Section 23.5: Secure express.js 3 Application ......................................................................................................... 107 Chapter 24: Mongoose Library ......................................................................................................................... 109 Section 24.1: Connect to MongoDB Using Mongoose ........................................................................................... 109 Section 24.2: Find Data in MongoDB Using Mongoose, Express.js Routes and $text Operator ....................... 109 Section 24.3: Save Data to MongoDB using Mongoose and Express.js Routes ................................................. 111 Section 24.4: Find Data in MongoDB Using Mongoose and Express.js Routes .................................................. 113 Section 24.5: Useful Mongoose functions ............................................................................................................... 115 Section 24.6: Indexes in models ............................................................................................................................... 115 Section 24.7: find data in mongodb using promises ............................................................................................. 117 Chapter 25: async.js ................................................................................................................................................ 120 Section 25.1: Parallel : multi-tasking ........................................................................................................................ 120 Section 25.2: async.each(To handle array of data eciently) ............................................................................ 121 Section 25.3: Series : independent mono-tasking .................................................................................................. 122 Section 25.4: Waterfall : dependent mono-tasking ............................................................................................... 123 Section 25.5: async.times(To handle for loop in better way) ............................................................................... 124 Section 25.6: async.series(To handle events one by one) .................................................................................... 124 Chapter 26: File upload .......................................................................................................................................... 125 Section 26.1: Single File Upload using multer ......................................................................................................... 125 Section 26.2: Using formidable module .................................................................................................................. 126 Chapter 27: Socket.io communication ........................................................................................................... 128 Section 27.1: "Hello world!" with socket messages ................................................................................................. 128 Chapter 28: Mongodb integration ................................................................................................................... 129 Section 28.1: Simple connect .................................................................................................................................... 129 Section 28.2: Simple connect, using promises ....................................................................................................... 129 Section 28.3: Connect to MongoDB ......................................................................................................................... 129 Section 28.4: Insert a document .............................................................................................................................. 130 Section 28.5: Read a collection ................................................................................................................................ 131 Section 28.6: Update a document ........................................................................................................................... 131 Section 28.7: Delete a document ............................................................................................................................. 132 Section 28.8: Delete multiple documents ............................................................................................................... 132 Chapter 29: Handling POST request in Node.js ......................................................................................... 134 Section 29.1: Sample node.js server that just handles POST requests ................................................................ 134 Chapter 30: Simple REST based CRUD API .................................................................................................. 135 Section 30.1: REST API for CRUD in Express 3+ ...................................................................................................... 135 Chapter 31: Template frameworks .................................................................................................................. 136 Section 31.1: Nunjucks ................................................................................................................................................ 136 Chapter 32: Node.js Architecture & Inner Workings ............................................................................... 138 Section 32.1: Node.js - under the hood .................................................................................................................... 138 Section 32.2: Node.js - in motion ............................................................................................................................. 138 Chapter 33: Debugging Node.js application ............................................................................................... 139 Section 33.1: Core node.js debugger and node inspector ..................................................................................... 139 Chapter 34: Node server without framework ........................................................................................... 142 Section 34.1: Framework-less node server ............................................................................................................. 142 Section 34.2: Overcoming CORS Issues .................................................................................................................. 143 Chapter 35: Node.JS with ES6 ............................................................................................................................ 144 Section 35.1: Node ES6 Support and creating a project with Babel ..................................................................... 144 Section 35.2: Use JS es6 on your NodeJS app ...................................................................................................... 145 Chapter 36: Interacting with Console ............................................................................................................. 148 Section 36.1: Logging ................................................................................................................................................ 148 Chapter 37: Cassandra Integration ................................................................................................................. 150 Section 37.1: Hello world ........................................................................................................................................... 150 Chapter 38: Creating API's with Node.js ........................................................................................................ 151 Section 38.1: GET api using Express ......................................................................................................................... 151 Section 38.2: POST api using Express ..................................................................................................................... 151 Chapter 39: Graceful Shutdown ........................................................................................................................ 153 Section 39.1: Graceful Shutdown - SIGTERM ........................................................................................................... 153 Chapter 40: Using IISNode to host Node.js Web Apps in IIS .............................................................. 154 Section 40.1: Using an IIS Virtual Directory or Nested Application via ....................................... 154 Section 40.2: Getting Started ................................................................................................................................... 155 Section 40.3: Basic Hello World Example using Express ....................................................................................... 155 Section 40.4: Using Socket.io with IISNode ............................................................................................................. 157 Chapter 41: CLI ........................................................................................................................................................... 158 Section 41.1: Command Line Options ....................................................................................................................... 158 Chapter 42: NodeJS Frameworks .................................................................................................................... 161 Section 42.1: Web Server Frameworks .................................................................................................................... 161 Section 42.2: Command Line Interface Frameworks ............................................................................................ 161 Chapter 43: grunt ..................................................................................................................................................... 163 Section 43.1: Introduction To GruntJs ...................................................................................................................... 163 Section 43.2: Installing gruntplugins ........................................................................................................................ 164 Chapter 44: Using WebSocket's with Node.JS .......................................................................................... 165 Section 44.1: Installing WebSocket's ........................................................................................................................ 165 Section 44.2: Adding WebSocket's to your file's .................................................................................................... 165 Section 44.3: Using WebSocket's and WebSocket Server's .................................................................................. 165 Section 44.4: A Simple WebSocket Server Example .............................................................................................. 165 Chapter 45: metalsmith ........................................................................................................................................ 166 Section 45.1: Build a simple blog .............................................................................................................................. 166 {{ title }} ......................................................................................................................................................................... 166 Chapter 46: Parsing command line arguments ....................................................................................... 167 Section 46.1: Passing action (verb) and values ...................................................................................................... 167 Section 46.2: Passing boolean switches .................................................................................................................. 167 Chapter 47: Client-server communication .................................................................................................. 168 Section 47.1: /w Express, jQuery and Jade ............................................................................................................. 168 Chapter 48: Node.js Design Fundamental .................................................................................................. 170 Section 48.1: The Node.js philosophy ...................................................................................................................... 170 Chapter 49: Connect to Mongodb ................................................................................................................... 171 Section 49.1: Simple example to Connect mongoDB from Node.JS .................................................................... 171 Section 49.2: Simple way to Connect mongoDB with core Node.JS ................................................................... 171 Chapter 50: Performance challenges ............................................................................................................ 172 Section 50.1: Processing long running queries with Node ..................................................................................... 172 Chapter 51: Send Web Notification .................................................................................................................. 176 Section 51.1: Send Web notification using GCM ( Google Cloud Messaging System) ........................................ 176 Chapter 52: Remote Debugging in Node.JS ............................................................................................... 178 Section 52.1: Use the proxy for debugging via port on Linux ............................................................................... 178 Section 52.2: NodeJS run configuration ................................................................................................................. 178 Section 52.3: IntelliJ/Webstorm Configuration ...................................................................................................... 178 Chapter 53: Database (MongoDB with Mongoose) ................................................................................. 180 Section 53.1: Mongoose connection ........................................................................................................................ 180 Section 53.2: Model ................................................................................................................................................... 180 Section 53.3: Insert data ........................................................................................................................................... 181 Section 53.4: Read data ............................................................................................................................................ 181 Chapter 54: Good coding style ......................................................................................................................... 183 Section 54.1: Basic program for signup .................................................................................................................. 183 Chapter 55: Restful API Design: Best Practices ........................................................................................ 187 Section 55.1: Error Handling: GET all resources ...................................................................................................... 187 Chapter 56: Deliver HTML or any other sort of file ................................................................................ 189 Section 56.1: Deliver HTML at specified path .......................................................................................................... 189 Chapter 57: TCP Sockets ...................................................................................................................................... 190 Section 57.1: A simple TCP server ............................................................................................................................ 190 Section 57.2: A simple TCP client ............................................................................................................................. 190 Chapter 58: Hack ...................................................................................................................................................... 192 Section 58.1: Add new extensions to require() ........................................................................................................ 192 Chapter 59: Bluebird Promises .......................................................................................................................... 193 Section 59.1: Converting nodeback library to Promises ........................................................................................ 193 Section 59.2: Functional Promises ........................................................................................................................... 193 Section 59.3: Coroutines (Generators) .................................................................................................................... 193 Section 59.4: Automatic Resource Disposal (Promise.using) ............................................................................... 193 Section 59.5: Executing in series .............................................................................................................................. 194 Chapter 60: Async/Await ...................................................................................................................................... 195 Section 60.1: Comparison between Promises and Async/Await .......................................................................... 195 Section 60.2: Async Functions with Try-Catch Error Handling ............................................................................. 195 Section 60.3: Stops execution at await ................................................................................................................... 196 Section 60.4: Progression from Callbacks .............................................................................................................. 196 Chapter 61: Koa Framework v2 ......................................................................................................................... 198 Section 61.1: Hello World example ........................................................................................................................... 198 Section 61.2: Handling errors using middleware .................................................................................................... 198 Chapter 62: Unit testing frameworks ............................................................................................................. 199 Section 62.1: Mocha Asynchronous (async/await) ................................................................................................ 199 Section 62.2: Mocha synchronous ........................................................................................................................... 199 Section 62.3: Mocha asynchronous (callback) ...................................................................................................... 199 Chapter 63: ECMAScript 2015 (ES6) with Node.js ...................................................................................... 200 Section 63.1: const/let declarations ......................................................................................................................... 200 Section 63.2: Arrow functions ................................................................................................................................... 200 Section 63.3: Arrow Function Example .................................................................................................................... 200 Section 63.4: destructuring ....................................................................................................................................... 201 Section 63.5: flow ....................................................................................................................................................... 201 Section 63.6: ES6 Class .............................................................................................................................................. 201 Chapter 64: Routing AJAX requests with Express.JS ............................................................................. 203 Section 64.1: A simple implementation of AJAX ..................................................................................................... 203 Chapter 65: Sending a file stream to client ................................................................................................ 205 Section 65.1: Using fs And pipe To Stream Static Files From The Server ............................................................ 205 Section 65.2: Streaming Using fluent-mpeg ........................................................................................................ 206 Chapter 66: NodeJS with Redis ......................................................................................................................... 207 Section 66.1: Getting Started .................................................................................................................................... 207 Section 66.2: Storing Key-Value Pairs ..................................................................................................................... 207 Section 66.3: Some more important operations supported by node_redis ....................................................... 209 Chapter 67: Using Browserfiy to resolve 'required' error with browsers .................................... 211 Section 67.1: Example - file.js .................................................................................................................................... 211 Chapter 68: Node.JS and MongoDB. .............................................................................................................. 213 Section 68.1: Connecting To a Database ................................................................................................................ 213 Section 68.2: Creating New Collection .................................................................................................................... 213 Section 68.3: Inserting Documents .......................................................................................................................... 214 Section 68.4: Reading ............................................................................................................................................... 214 Section 68.5: Updating .............................................................................................................................................. 215 Section 68.6: Deleting ............................................................................................................................................... 216 Chapter 69: Passport integration ..................................................................................................................... 218 Section 69.1: Local authentication ........................................................................................................................... 218 Section 69.2: Getting started .................................................................................................................................... 219 Section 69.3: Facebook authentication ................................................................................................................... 220 Section 69.4: Simple Username-Password Authentication ................................................................................... 221 Section 69.5: Google Passport authentication ....................................................................................................... 221 Chapter 70: Dependency Injection .................................................................................................................. 224 Section 70.1: Why Use Dependency Injection ......................................................................................................... 224 Chapter 71: NodeJS Beginner Guide ............................................................................................................... 225 Section 71.1: Hello World ! .......................................................................................................................................... 225 Chapter 72: Use Cases of Node.js .................................................................................................................... 226 Section 72.1: HTTP server ......................................................................................................................................... 226 Section 72.2: Console with command prompt ....................................................................................................... 226 Chapter 73: Sequelize.js ........................................................................................................................................ 228 Section 73.1: Defining Models ................................................................................................................................... 228 Section 73.2: Installation ........................................................................................................................................... 229 Chapter 74: PostgreSQL integration ............................................................................................................. 230 Section 74.1: Connect To PostgreSQL ..................................................................................................................... 230 Section 74.2: Query with Connection Object .......................................................................................................... 230 Chapter 75: MySQL integration ......................................................................................................................... 231 Section 75.1: Connect to MySQL .............................................................................................................................. 231 Section 75.2: Using a connection pool .................................................................................................................... 231 Section 75.3: Query a connection object with parameters ................................................................................... 232 Section 75.4: Query a connection object without parameters ............................................................................. 233 Section 75.5: Run a number of queries with a single connection from a pool ................................................... 233 Section 75.6: Export Connection Pool ...................................................................................................................... 233 Section 75.7: Return the query when an error occurs ........................................................................................... 234 Chapter 76: MySQL Connection Pool .............................................................................................................. 235 Section 76.1: Using a connection pool without database ...................................................................................... 235 Chapter 77: MSSQL Intergration ...................................................................................................................... 236 Section 77.1: Connecting with SQL via. mssql npm module .................................................................................. 236 Chapter 78: Node.js with Oracle ....................................................................................................................... 238 Section 78.1: Connect to Oracle DB ......................................................................................................................... 238 Section 78.2: Using a local module for easier querying ....................................................................................... 238 Section 78.3: Query a connection object without parameters ............................................................................. 239 Chapter 79: Synchronous vs Asynchronous programming in nodejs ............................................ 241 Section 79.1: Using async .......................................................................................................................................... 241 Chapter 80: Node.js Error Management ...................................................................................................... 242 Section 80.1: try...catch block .................................................................................................................................... 242 Section 80.2: Creating Error object ......................................................................................................................... 242 Section 80.3: Throwing Error .................................................................................................................................... 243 Chapter 81: Node.js v6 New Features and Improvement .................................................................... 244 Section 81.1: Default Function Parameters ............................................................................................................. 244 Section 81.2: Rest Parameters ................................................................................................................................. 244 Section 81.3: Arrow Functions ................................................................................................................................... 244 Section 81.4: "this" in Arrow Function ...................................................................................................................... 245 Section 81.5: Spread Operator ................................................................................................................................. 246 Chapter 82: Eventloop ........................................................................................................................................... 247 Section 82.1: How the concept of event loop evolved ........................................................................................... 247 Chapter 83: Nodejs History ................................................................................................................................. 249 Section 83.1: Key events in each year ..................................................................................................................... 249 Chapter 84: passport.js ........................................................................................................................................ 252 Section 84.1: Example of LocalStrategy in passport.js .......................................................................................... 252 Chapter 85: Asynchronous programming ................................................................................................... 253 Section 85.1: Callback functions ............................................................................................................................... 253 Section 85.2: Callback hell ........................................................................................................................................ 255 Section 85.3: Native Promises .................................................................................................................................. 256 Section 85.4: Code example ..................................................................................................................................... 257 Section 85.5: Async error handling ......................................................................................................................... 258 Chapter 86: Node.js code for STDIN and STDOUT without using any library .......................... 259 Section 86.1: Program ............................................................................................................................................... 259 Chapter 87: MongoDB Integration for Node.js/Express.js .................................................................. 260 Section 87.1: Installing MongoDB ............................................................................................................................. 260 Section 87.2: Creating a Mongoose Model ............................................................................................................. 260 Section 87.3: Querying your Mongo Database ...................................................................................................... 261 Chapter 88: Lodash ................................................................................................................................................. 262 Section 88.1: Filter a collection ................................................................................................................................. 262 Chapter 89: csv parser in node js ..................................................................................................................... 263 Section 89.1: Using FS to read in a CSV .................................................................................................................. 263 Chapter 90: Loopback - REST Based connector ...................................................................................... 264 Section 90.1: Adding a web based connector ........................................................................................................ 264 Chapter 91: Running node.js as a service ..................................................................................................... 266 Section 91.1: Node.js as a systemd dæmon ............................................................................................................ 266 Chapter 92: Node.js with CORS .......................................................................................................................... 267 Section 92.1: Enable CORS in express.js .................................................................................................................. 267 Chapter 93: Getting started with Nodes profiling ................................................................................... 268 Section 93.1: Profiling a simple node application ................................................................................................... 268 Chapter 94: Node.js Performance ................................................................................................................... 270 Section 94.1: Enable gzip .......................................................................................................................................... 270 Section 94.2: Event Loop .......................................................................................................................................... 270 Section 94.3: Increase maxSockets ......................................................................................................................... 271 Chapter 95: Yarn Package Manager .............................................................................................................. 273 Section 95.1: Creating a basic package .................................................................................................................. 273 Section 95.2: Yarn Installation .................................................................................................................................. 273 Section 95.3: Install package with Yarn .................................................................................................................. 275 Chapter 96: OAuth 2.0 ............................................................................................................................................ 276 Section 96.1: OAuth 2 with Redis Implementation - grant_type: password ........................................................ 276 Chapter 97: Node JS Localization .................................................................................................................... 282 Section 97.1: using i18n module to maintains localization in node js app ............................................................ 282 Chapter 98: Deploying Node.js application without downtime. ....................................................... 283 Section 98.1: Deployment using PM2 without downtime ....................................................................................... 283 Chapter 99: Node.js (express.js) with angular.js Sample code ......................................................... 285 Section 99.1: Creating our project ............................................................................................................................ 285 Chapter 100: NodeJs Routing ............................................................................................................................. 288 Section 100.1: Express Web Server Routing ............................................................................................................ 288 Chapter 101: Creating a Node.js Library that Supports Both Promises and Error-First Callbacks ....................................................................................................................................................................... 292 Section 101.1: Example Module and Corresponding Program using Bluebird ..................................................... 292 Chapter 102: Project Structure .......................................................................................................................... 295 Section 102.1: A simple nodejs application with MVC and API .............................................................................. 295 Chapter 103: Avoid callback hell ....................................................................................................................... 297 Section 103.1: Async module ..................................................................................................................................... 297 Section 103.2: Async Module .................................................................................................................................... 297 Chapter 104: Arduino communication with nodeJs ................................................................................ 299 Section 104.1: Node Js communication with Arduino via serialport ..................................................................... 299 Chapter 105: N-API ................................................................................................................................................... 301 Section 105.1: Hello to N-API ..................................................................................................................................... 301 Chapter 106: Multithreading ................................................................................................................................ 303 Section 106.1: Cluster ................................................................................................................................................. 303 Section 106.2: Child Process ..................................................................................................................................... 303 Chapter 107: Windows authentication under node.js ............................................................................ 305 Section 107.1: Using activedirectory ........................................................................................................................ 305 Chapter 108: Require() ........................................................................................................................................... 306 Section 108.1: Beginning require() use with a function and file ............................................................................ 306 Section 108.2: Beginning require() use with an NPM package ............................................................................. 307 Chapter 109: Route-Controller-Service structure for ExpressJS ..................................................... 308 Section 109.1: Model-Routes-Controllers-Services Directory Structure ............................................................... 308 Section 109.2: Model-Routes-Controllers-Services Code Structure ..................................................................... 308 Chapter 110: Push notifications .......................................................................................................................... 310 Section 110.1: Web notification .................................................................................................................................. 310 Section 110.2: Apple ................................................................................................................................................... 311 Appendix A: Installing Node.js ............................................................................................................................ 312 Section A.1: Using Node Version Manager (nvm) .................................................................................................. 312 Section A.2: Installing Node.js on Mac using package manager ......................................................................... 313 Section A.3: Installing Node.js on Windows ............................................................................................................ 313 Section A.4: Install Node.js on Ubuntu .................................................................................................................... 314 Section A.5: Installing Node.js with n ....................................................................................................................... 314 Section A.6: Install Node.js From Source with APT package manager ............................................................... 315 Section A.7: Install Node.js from source on Centos, RHEL and Fedora ............................................................... 315 Section A.8: Installing with Node Version Manager under Fish Shell with Oh My Fish! ...................................... 316 Section A.9: Installing Node.js on Raspberry PI ..................................................................................................... 316 Credits ............................................................................................................................................................................ 318 You may also like ...................................................................................................................................................... 323 About Please feel free to share this PDF with anyone for free, latest version of this book can be downloaded from: https://goalkicker.com/NodeJSBook This Node.js Notes for Professionals book is compiled from Stack Overflow Documentation, the content is written by the beautiful people at Stack Overflow. Text content is released under Creative Commons BY-SA, see credits at the end of this book whom contributed to the various chapters. Images may be copyright of their respective owners unless otherwise specified This is an unofficial free book created for educational purposes and is not affiliated with official Node.js group(s) or company(s) nor Stack Overflow. All trademarks and registered trademarks are the property of their respective company owners The information presented in this book is not guaranteed to be correct nor accurate, use at your own risk Please send feedback and corrections to [email protected] GoalKicker.com – Node.js Notes for Professionals 1 Chapter 1: Getting started with Node.js Version Release Date v8.2.1 2017-07-20 v8.2.0 2017-07-19 v8.1.4 2017-07-11 v8.1.3 2017-06-29 v8.1.2 2017-06-15 v8.1.1 2017-06-13 v8.1.0 2017-06-08 v8.0.0 2017-05-30 v7.10.0 2017-05-02 v7.9.0 2017-04-11 v7.8.0 2017-03-29 v7.7.4 2017-03-21 v7.7.3 2017-03-14 v7.7.2 2017-03-08 v7.7.1 2017-03-02 v7.7.0 2017-02-28 v7.6.0 2017-02-21 v7.5.0 2017-01-31 v7.4.0 2017-01-04 v7.3.0 2016-12-20 v7.2.1 2016-12-06 v7.2.0 2016-11-22 v7.1.0 2016-11-08 v7.0.0 2016-10-25 v6.11.0 2017-06-06 v6.10.3 2017-05-02 v6.10.2 2017-04-04 v6.10.1 2017-03-21 v6.10.0 2017-02-21 v6.9.5 2017-01-31 v6.9.4 2017-01-05 v6.9.3 2017-01-05 v6.9.2 2016-12-06 v6.9.1 2016-10-19 v6.9.0 2016-10-18 v6.8.1 2016-10-14 v6.8.0 2016-10-12 v6.7.0 2016-09-27 v6.6.0 2016-09-14 v6.5.0 2016-08-26 v6.4.0 2016-08-12 v6.3.1 2016-07-21 GoalKicker.com – Node.js Notes for Professionals 2 v6.3.0 2016-07-06 v6.2.2 2016-06-16 v6.2.1 2016-06-02 v6.2.0 2016-05-17 v6.1.0 2016-05-05 v6.0.0 2016-04-26 v5.12.0 2016-06-23 v5.11.1 2016-05-05 v5.11.0 2016-04-21 v5.10.1 2016-04-05 v5.10 2016-04-01 v5.9 2016-03-16 v5.8 2016-03-09 v5.7 2016-02-23 v5.6 2016-02-09 v5.5 2016-01-21 v5.4 2016-01-06 v5.3 2015-12-15 v5.2 2015-12-09 v5.1 2015-11-17 v5.0 2015-10-29 v4.4 2016-03-08 v4.3 2016-02-09 v4.2 2015-10-12 v4.1 2015-09-17 v4.0 2015-09-08 io.js v3.3 2015-09-02 io.js v3.2 2015-08-25 io.js v3.1 2015-08-19 io.js v3.0 2015-08-04 io.js v2.5 2015-07-28 io.js v2.4 2015-07-17 io.js v2.3 2015-06-13 io.js v2.2 2015-06-01 io.js v2.1 2015-05-24 io.js v2.0 2015-05-04 io.js v1.8 2015-04-21 io.js v1.7 2015-04-17 io.js v1.6 2015-03-20 io.js v1.5 2015-03-06 io.js v1.4 2015-02-27 io.js v1.3 2015-02-20 io.js v1.2 2015-02-11 io.js v1.1 2015-02-03 io.js v1.0 2015-01-14 v0.12 2016-02-09 GoalKicker.com – Node.js Notes for Professionals3 v0.11 2013-03-28 v0.10 2013-03-11 v0.9 2012-07-20 v0.8 2012-06-22 v0.7 2012-01-17 v0.6 2011-11-04 v0.5 2011-08-26 v0.4 2011-08-26 v0.3 2011-08-26 v0.2 2011-08-26 v0.1 2011-08-26 Section 1.1: Hello World HTTP server First, install Node.js for your platform. In this example we'll create an HTTP server listening on port 1337, which sends Hello, World! to the browser. Note that, instead of using port 1337, you can use any port number of your choice which is currently not in use by any other service. The http module is a Node.js core module (a module included in Node.js's source, that does not require installing additional resources). The http module provides the functionality to create an HTTP server using the http.createServer() method. To create the application, create a file containing the following JavaScript code. const http = require('http'); // Loads the http module http.createServer((request, response) => { // 1. Tell the browser everything is OK (Status code 200), and the data is in plain text response.writeHead(200, { 'Content-Type': 'text/plain' }); // 2. Write the announced text to the body of the page response.write('Hello, World!\n'); // 3. Tell the server that all of the response headers and body have been sent response.end(); }).listen(1337); // 4. Tells the server what port to be on Save the file with any file name. In this case, if we name it hello.js we can run the application by going to the directory the file is in and using the following command: node hello.js The created server can then be accessed with the URL http://localhost:1337 or http://127.0.0.1:1337 in the browser. A simple web page will appear with a “Hello, World!” text at the top, as shown in the screenshot below. GoalKicker.com – Node.js Notes for Professionals 4 Editable online example. Section 1.2: Hello World command line Node.js can also be used to create command line utilities. The example below reads the first argument from the command line and prints a Hello message. To run this code on an Unix System: 1. Create a new file and paste the code below. The filename is irrelevant. 2. Make this file executable with chmod 700 FILE_NAME 3. Run the app with ./APP_NAME David On Windows you do step 1 and run it with node APP_NAME David #!/usr/bin/env node 'use strict'; /* The command line arguments are stored in the `process.argv` array, which has the following structure: [0] The path of the executable that started the Node.js process [1] The path to this application [2-n] the command line arguments Example: [ '/bin/node', '/path/to/yourscript', 'arg1', 'arg2', ... ] src: https://nodejs.org/api/process.html#process_process_argv */ // Store the first argument as username. var username = process.argv[2]; // Check if the username hasn't been provided. if (!username) { // Extract the filename var appName = process.argv[1].split(require('path').sep).pop(); GoalKicker.com – Node.js Notes for Professionals 5 // Give the user an example on how to use the app. console.error('Missing argument! Example: %s YOUR_NAME', appName); // Exit the app (success: 0, error: 1). // An error will stop the execution chain. For example: // ./app.js && ls -> won't execute ls // ./app.js David && ls -> will execute ls process.exit(1); } // Print the message to the console. console.log('Hello %s!', username); Section 1.3: Hello World with Express The following example uses Express to create an HTTP server listening on port 3000, which responds with "Hello, World!". Express is a commonly-used web framework that is useful for creating HTTP APIs. First, create a new folder, e.g. myApp. Go into myApp and make a new JavaScript file containing the following code (let's name it hello.js for example). Then install the express module using npm install --save express from the command line. Refer to this documentation for more information on how to install packages. // Import the top-level function of express const express = require('express'); // Creates an Express application using the top-level function const app = express(); // Define port number as 3000 const port = 3000; // Routes HTTP GET requests to the specified path "/" with the specified callback function app.get('/', function(request, response) { response.send('Hello, World!'); }); // Make the app listen on port 3000 app.listen(port, function() { console.log('Server listening on http://localhost:' + port); }); From the command line, run the following command: node hello.js Open your browser and navigate to http://localhost:3000 or http://127.0.0.1:3000 to see the response. For more information about the Express framework, you can check the Web Apps With Express section Section 1.4: Installing and Running Node.js To begin, install Node.js on your development computer. Windows: Navigate to the download page and download/run the installer. Mac: Navigate to the download page and download/run the installer. Alternatively, you can install Node via Homebrew using brew install node. Homebrew is a command-line package mananger for Macintosh, and more GoalKicker.com – Node.js Notes for Professionals 6 information about it can be found on the Homebrew website. Linux: Follow the instructions for your distro on the command line installation page. Running a Node Program To run a Node.js program, simply run node app.js or nodejs app.js, where app.js is the filename of your node app source code. You do not need to include the .js suffix for Node to find the script you'd like to run. Alternatively under UNIX-based operating systems, a Node program may be executed as a terminal script. To do so, it needs to begin with a shebang pointing to the Node interpreter, such as #!/usr/bin/env node. The file also has to be set as executable, which can be done using chmod. Now the script can be directly run from the command line. Section 1.5: Debugging Your NodeJS Application You can use the node-inspector. Run this command to install it via npm: npm install -g node-inspector Then you can debug your application using node-debug app.js The Github repository can be found here: https://github.com/node-inspector/node-inspector Debugging natively You can also debug node.js natively by starting it like this: node debug your-script.js To breakpoint your debugger exactly in a code line you want, use this: debugger; For more information see here. In node.js 8 use the following command: node --inspect-brk your-script.js Then open about://inspect in a recent version of Google Chrome and select your Node script to get the debugging experience of Chrome's DevTools. Section 1.6: Hello World basic routing Once you understand how to create an HTTP Server with node, it's important to understand how to make it "do" things based on the path that a user has navigated to. This phenomenon is called, "routing". The most basic example of this would be to check if (request.url === 'some/path/here'), and then call a function that responds with a new file. GoalKicker.com – Node.js Notes for Professionals 7 An example of this can be seen here: const http = require('http'); function index (request, response) { response.writeHead(200); response.end('Hello, World!'); } http.createServer(function (request, response) { if (request.url === '/') { return index(request, response); } response.writeHead(404); response.end(http.STATUS_CODES[404]); }).listen(1337); If you continue to define your "routes" like this, though, you'll end up with one massive callback function, and we don't want a giant mess like that, so let's see if we can clean this up. First, let's store all of our routes in an object: var routes = { '/': function index (request, response) { response.writeHead(200); response.end('Hello, World!'); }, '/foo': function foo (request, response) { response.writeHead(200); response.end('You are now viewing "foo"'); } } Now that we've stored 2 routes in an object, we can now check for them in our main callback: http.createServer(function (request, response) { if (request.url in routes) { return routes[request.url](request, response); } response.writeHead(404); response.end(http.STATUS_CODES[404]); }).listen(1337); Now every time you try to navigate your website, it will check for the existence of that path in your routes, and it will call the respective function. If no route is found, the server will respond with a 404 (Not Found). And there you have it--routing with the HTTP Server API is very simple. Section 1.7: Hello World in the REPL When called without arguments, Node.js starts a REPL (Read-Eval-Print-Loop) also known as the “Node shell”. GoalKicker.com – Node.js Notes for Professionals 8 At a command prompt type node. $ node > At the Node shell prompt > type "Hello World!" $ node > "Hello World!" 'Hello World!' Section 1.8: Deploying your application online When you deploy your app to a (Node.js-specific) hosted environment, this environment usually offers a PORT environment variable that you can use to run your server on. Changing the port number to process.env.PORT allows you to access the application. For example, http.createServer(function(request, response) { // your server code }).listen(process.env.PORT); Also, if you would like to access this offline while debugging, you can use this: http.createServer(function(request, response) { // your server code }).listen(process.env.PORT || 3000); where 3000 is the offline port number. Section 1.9: Core modules Node.js is a Javascript engine (Google's V8 engine for Chrome, written in C++) that allows to run Javascript outside the browser. While numerous libraries are available for extending Node's functionalities, the engine comes with a set of core modules implementing basic functionalities. There's currently 34 core modules included in Node: [ 'assert', 'buffer', 'c/c++_addons', 'child_process', 'cluster', 'console', 'crypto', 'deprecated_apis', 'dns', 'domain', 'Events', 'fs', 'http', 'https', 'module', 'net', 'os', 'path', GoalKicker.com – Node.js Notes for Professionals 9 'punycode', 'querystring', 'readline', 'repl', 'stream', 'string_decoder', 'timers', 'tls_(ssl)', 'tracing', 'tty', 'dgram', 'url', 'util', 'v8', 'vm', 'zlib' ] This list was obtained from the Node documentation API https://nodejs.org/api/all.html (JSON file: https://nodejs.org/api/all.json). All core modules at-a-glance assert The assert module provides a simple set of assertion tests that can be used to test invariants. buffer Prior to the introduction of TypedArray in ECMAScript 2015 (ES6), the JavaScript language had no mechanism for reading or manipulating streams of binary data. The Buffer class was introduced as part of the Node.js API to make it possible to interact with octet streams in the context of things like TCP streams and file system operations. Now that TypedArray has been added in ES6, the Buffer class implements the Uin t8Array API in a manner that is more optimized and suitable for Node.js' use cases. c/c++_addons Node.js Addons are dynamically-linked shared objects, written in C or C++, that can be loaded into Node.js using the require() function , and used just as if they were an ordinary Node.js module. They are used primarily to provide an interface between JavaScript running in Node.js and C/C++ libraries. child_process The child_process module provides the ability to spawn child processes in a manner that is similar, but not identical, to popen(3). cluster A single instance of Node.js runs in a single thread. To take advantage of multi-core systems the user will sometimes want to launch a cluster of Node.js processes to handle the load. The cluster module allows you to easily create child processes that all share server ports. GoalKicker.com – Node.js Notes for Professionals 10 console The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers. crypto The crypto module provides cryptographic functionality that includes a set of wrappers for OpenSSL's hash, HMAC, cipher, decipher, sign and verify functions. deprecated_apis Node.js may deprecate APIs when either: (a) use of the API is considered to be unsafe, (b) an improved alternative API has been made available, or (c) breaking changes to the API are expected in a future major release. dns The dns module contains functions belonging to two different categories: 1. Functions that use the underlying operating system facilities to perform name resolution, and that do not necessarily perform any network communication. This category contains only one function: dns.lookup(). 2. Functions that connect to an actual DNS server to perform name resolution, and that always use the network to perform DNS queries. This category contains all functions in the dns module except dns.lookup(). domain This module is pending deprecation. Once a replacement API has been finalized, this module will be fully deprecated. Most end users should not have cause to use this module. Users who absolutely must have the functionality that domains provide may rely on it for the time being but should expect to have to migrate to a different solution in the future. Events Much of the Node.js core API is built around an idiomatic asynchronous event-driven architecture in which certain kinds of objects (called "emitters") periodically emit named events that cause Function objects ("listeners") to be called. fs File I/O is provided by simple wrappers around standard POSIX functions. To use this module do require('fs'). All the methods have asynchronous and synchronous forms. http The HTTP interfaces in Node.js are designed to support many features of the protocol which have been traditionally difficult to use. In particular, large, possibly chunk-encoded, messages. The interface is careful to never buffer entire requests or responses--the user is able to stream data. https GoalKicker.com – Node.js Notes for Professionals 11 HTTPS is the HTTP protocol over TLS/SSL. In Node.js this is implemented as a separate module. module Node.js has a simple module loading system. In Node.js, files and modules are in one-to-one correspondence (each file is treated as a separate module). net The net module provides you with an asynchronous network wrapper. It contains functions for creating both servers and clients (called streams). You can include this module with require('net');. os The os module provides a number of operating system-related utility methods. path The path module provides utilities for working with file and directory paths. punycode The version of the punycode module bundled in Node.js is being deprecated. querystring The querystring module provides utilities for parsing and formatting URL query strings. readline The readline module provides an interface for reading data from a Readable stream (such as process.stdin) one line at a time. repl The repl module provides a Read-Eval-Print-Loop (REPL) implementation that is available both as a standalone program or includible in other applications. stream A stream is an abstract interface for working with streaming data in Node.js. The stream module provides a base API that makes it easy to build objects that implement the stream interface. There are many stream objects provided by Node.js. For instance, a request to an HTTP server and process.stdout are both stream instances. string_decoder The string_decoder module provides an API for decoding Buffer objects into strings in a manner that preserves encoded multi-byte UTF-8 and UTF-16 characters. timers GoalKicker.com – Node.js Notes for Professionals 12 The timer module exposes a global API for scheduling functions to be called at some future period of time. Because the timer functions are globals, there is no need to call require('timers') to use the API. The timer functions within Node.js implement a similar API as the timers API provided by Web Browsers but use a different internal implementation that is built around the Node.js Event Loop. tls_(ssl) The tls module provides an implementation of the Transport Layer Security (TLS) and Secure Socket Layer (SSL) protocols that is built on top of OpenSSL. tracing Trace Event provides a mechanism to centralize tracing information generated by V8, Node core, and userspace code. Tracing can be enabled by passing the --trace-events-enabled flag when starting a Node.js application. tty The tty module provides the tty.ReadStream and tty.WriteStream classes. In most cases, it will not be necessary or possible to use this module directly. dgram The dgram module provides an implementation of UDP Datagram sockets. url The url module provides utilities for URL resolution and parsing. util The util module is primarily designed to support the needs of Node.js' own internal APIs. However, many of the utilities are useful for application and module developers as well. v8 The v8 module exposes APIs that are specific to the version of V8 built into the Node.js binary. Note: The APIs and implementation are subject to change at any time. vm The vm module provides APIs for compiling and running code within V8 Virtual Machine contexts. JavaScript code can be compiled and run immediately or compiled, saved, and run later. Note: The vm module is not a security mechanism. Do not use it to run untrusted code. zlib The zlib module provides compression functionality implemented using Gzip and Deflate/Inflate. GoalKicker.com – Node.js Notes for Professionals 13 Section 1.10: TLS Socket: server and client The only major differences between this and a regular TCP connection are the private Key and the public certificate that you’ll have to set into an option object. How to Create a Key and Certificate The first step in this security process is the creation of a private Key. And what is this private key? Basically, it's a set of random noise that's used to encrypt information. In theory, you could create one key, and use it to encrypt whatever you want. But it is best practice to have different keys for specific things. Because if someone steals your private key, it's similar to having someone steal your house keys. Imagine if you used the same key to lock your car, garage, office, etc. openssl genrsa -out private-key.pem 1024 Once we have our private key, we can create a CSR (certificate signing request), which is our request to have the private key signed by a fancy authority. That is why you have to input information related to your company. This information will be seen by the signing authority, and used to verify you. In our case, it doesn’t matter what you type, since in the next step we're going to sign our certificate ourselves. openssl req -new -key private-key.pem -out csr.pem Now that we have our paper work filled out, it's time to pretend that we're a cool signing authority. openssl x509 -req -in csr.pem -signkey private-key.pem -out public-cert.pem Now that you have the private key and the public cert, you can establish a secure connection between two NodeJS apps. And, as you can see in the example code, it is a very simple process. Important! Since we created the public cert ourselves, in all honesty, our certificate is worthless, because we are nobodies. The NodeJS server won't trust such a certificate by default, and that is why we need to tell it to actually trust our cert with the following option rejectUnauthorized: false. Very important: never set this variable to true in a production environment. TLS Socket Server 'use strict'; var tls = require('tls'); var fs = require('fs'); const PORT = 1337; const HOST = '127.0.0.1' var options = { key: fs.readFileSync('private-key.pem'), cert: fs.readFileSync('public-cert.pem') }; var server = tls.createServer(options, function(socket) { // Send a friendly message socket.write("I am the server sending you a message."); // Print the data that we received socket.on('data', function(data) { GoalKicker.com – Node.js Notes for Professionals 14 console.log('Received: %s [it is %d bytes long]', data.toString().replace(/(\n)/gm,""), data.length); }); // Let us know when the transmission is over socket.on('end', function() { console.log('EOT (End Of Transmission)'); }); }); // Start listening on a specific port and address server.listen(PORT, HOST, function() { console.log("I'm listening at %s, on port %s", HOST, PORT); }); // When an error occurs, show it. server.on('error', function(error) { console.error(error); // Close the connection after the error occurred. server.destroy(); }); TLS Socket Client 'use strict'; var tls = require('tls'); var fs = require('fs'); const PORT = 1337; const HOST = '127.0.0.1' // Pass the certs to the server and let it know to process even unauthorized certs. var options = { key: fs.readFileSync('private-key.pem'), cert: fs.readFileSync('public-cert.pem'), rejectUnauthorized: false }; var client = tls.connect(PORT, HOST, options, function() { // Check if the authorization worked if (client.authorized) { console.log("Connection authorized by a Certificate Authority."); } else { console.log("Connection not authorized: " + client.authorizationError) } // Send a friendly message client.write("I am the client sending you a message."); }); GoalKicker.com – Node.js Notes for Professionals 15 client.on("data", function(data) { console.log('Received: %s [it is %d bytes long]', data.toString().replace(/(\n)/gm,""), data.length); // Close the connection after receiving the message client.end(); }); client.on('close', function() { console.log("Connection closed"); }); // When an error ocoures, show it. client.on('error', function(error) { console.error(error); // Close the connection after the error occurred. client.destroy(); }); Section 1.11: How to get a basic HTTPS web server up and running! Once you have node.js installed on your system, you can just follow the procedure below to get a basic web server running with support for both HTTP and HTTPS! Step 1 : Build a Certificate Authority 1. create the folder where you want to store your key & certificate : mkdir conf 2. go to that directory : cd conf 3. grab this ca.cnf file to use as a configuration shortcut : wget https://raw.githubusercontent.com/anders94/https-authorized-clients/master/keys/ca.cnf GoalKicker.com – Node.js Notes for Professionals 16 4. create a new certificate authority using this configuration : openssl req -new -x509 -days 9999 -config ca.cnf -keyout ca-key.pem -out ca-cert.pem 5. now that we have our certificate authority in ca-key.pem and ca-cert.pem, let's generate a private key for the server : openssl genrsa -out key.pem 4096 6. grab this server.cnf file to use as a configuration shortcut : wget https://raw.githubusercontent.com/anders94/https-authorized-clients/master/keys/server.cnf 7. generate the certificate signing request using this configuration : openssl req -new -config server.cnf -key key.pem -out csr.pem 8. sign the request : openssl x509 -req -extfile server.cnf -days 999 -passin "pass:password" -in csr.pem -CA ca cert.pem -CAkey ca-key.pem -CAcreateserial -out cert.pem Step 2 : Install your certificate as a root certificate 1. copy your certificate to your root certificates' folder : sudo cp ca-crt.pem /usr/local/share/ca-certificates/ca-crt.pem 2. update CA store : sudo update-ca-certificates Step 3 : Starting your node server GoalKicker.com – Node.js Notes for Professionals 17 First, you want to create a server.js file that contains your actual server code. The minimal setup for an HTTPS server in Node.js would be something like this : var https = require('https'); var fs = require('fs'); var httpsOptions = { key: fs.readFileSync('path/to/server-key.pem'), cert: fs.readFileSync('path/to/server-crt.pem') }; var app = function (req, res) { res.writeHead(200); res.end("hello world\n"); } https.createServer(httpsOptions, app).listen(4433); If you also want to support http requests, you need to make just this small modification : var http = require('http'); var https = require('https'); var fs = require('fs'); var httpsOptions = { key: fs.readFileSync('path/to/server-key.pem'), cert: fs.readFileSync('path/to/server-crt.pem') }; var app = function (req, res) { res.writeHead(200); res.end("hello world\n"); } http.createServer(app).listen(8888); https.createServer(httpsOptions, app).listen(4433); 1. go to the directory where your server.js is located : cd /path/to 2. run server.js : node server.js GoalKicker.com – Node.js Notes for Professionals 18 Chapter 2: npm Parameter Example access npm publish --access=public bin npm bin -g edit npm edit connect help npm help init init npm init install npm install link npm link prune npm prune publish npm publish ./ restart npm restart start npm start stop npm start update npm update version npm version Node Package Manager (npm) provides following two main functionalities: Online repositories for node.js packages/modules which are searchable on search.nodejs.org. Command line utility to install Node.js packages, do version management and dependency management of Node.js packages. Section 2.1: Installing packages Introduction Package is a term used by npm to denote tools that developers can use for their projects. This includes everything from libraries and frameworks such as jQuery and AngularJS to task runners such as Gulp.js. The packages will come in a folder typically called node_modules, which will also contain a package.json file. This file contains information regarding all the packages including any dependencies, which are additional modules needed to use a particular package. Npm uses the command line to both install and manage packages, so users attempting to use npm should be familiar with basic commands on their operating system i.e.: traversing directories as well as being able to see the contents of directories. Installing NPM Note that in order to install packages, you must have NPM installed. The recommended way to install NPM is to use one of the installers from the Node.js download page. You can check to see if you already have node.js installed by running either the npm -v or the npm version command. After installing NPM via the Node.js installer, be sure to check for updates. This is because NPM gets updated more frequently than the Node.js installer. To check for updates run the following command: npm install npm@latest -g How to install packages GoalKicker.com – Node.js Notes for Professionals 19 To install one or more packages use the following: npm install # or npm i ... # e.g. to install lodash and express npm install lodash express Note: This will install the package in the directory that the command line is currently in, thus it is important to check whether the appropriate directory has been chosen If you already have a package.json file in your current working directory and dependencies are defined in it, then npm install will automatically resolve and install all dependencies listed in the file. You can also use the shorthand version of the npm install command which is: npm i If you want to install a specific version of a package use: npm install @ # e.g. to install version 4.11.1 of the package lodash npm install [email protected] If you want to install a version which matches a specific version range use: npm install @ # e.g. to install a version which matches "version >= 4.10.1" and "version < 4.11.1" # of the package lodash npm install lodash@">=4.10.1 <4.11.1" If you want to install the latest version use: npm install @latest The above commands will search for packages in the central npm repository at npmjs.com. If you are not looking to install from the npm registry, other options are supported, such as: # packages distributed as a tarball npm install npm install # packages available locally npm install # packages available as a git repository npm install # packages available on GitHub npm install / # packages available as gist (need a package.json) npm install gist: # packages from a specific repository npm install --registry=http://myreg.mycompany.com GoalKicker.com – Node.js Notes for Professionals 20 # packages from a related group of packages # See npm scope npm install @/(@) # Scoping is useful for separating private packages hosted on private registry from # public ones by setting registry for specific scope npm config set @mycompany:registry http://myreg.mycompany.com npm install @mycompany/ Usually, modules will be installed locally in a folder named node_modules, which can be found in your current working directory. This is the directory require() will use to load modules in order to make them available to you. If you already created a package.json file, you can use the --save (shorthand -S) option or one of its variants to automatically add the installed package to your package.json as a dependency. If someone else installs your package, npm will automatically read dependencies from the package.json file and install the listed versions. Note that you can still add and manage your dependencies by editing the file later, so it's usually a good idea to keep track of dependencies, for example using: npm install --save # Install dependencies # or npm install -S # shortcut version --save # or npm i -S In order to install packages and save them only if they are needed for development, not for running them, not if they are needed for the application to run, follow the following command: npm install --save-dev # Install dependencies for development purposes # or npm install -D # shortcut version --save-dev # or npm i -D Installing dependencies Some modules do not only provide a library for you to use, but they also provide one or more binaries which are intended to be used via the command line. Although you can still install those packages locally, it is often preferred to install them globally so the command-line tools can be enabled. In that case, npm will automatically link the binaries to appropriate paths (e.g. /usr/local/bin/) so they can be used from the command line. To install a package globally, use: npm install --global # or npm install -g # or npm i -g # e.g. to install the grunt command line tool npm install -g grunt-cli If you want to see a list of all the installed packages and their associated versions in the current workspace, use: npm list npm list Adding an optional name argument can check the version of a specific package. GoalKicker.com – Node.js Notes for Professionals 21 Note: If you run into permission issues while trying to install an npm module globally, resist the temptation to issue a sudo npm install -g ... to overcome the issue. Granting third-party scripts to run on your system with elevated privileges is dangerous. The permission issue might mean that you have an issue with the way npm itself was installed. If you're interested in installing Node in sandboxed user environments, you might want to try using nvm. If you have build tools, or other development-only dependencies (e.g. Grunt), you might not want to have them bundled with the application you deploy. If that's the case, you'll want to have it as a development dependency, which is listed in the package.json under devDependencies. To install a package as a development-only dependency, use --save-dev (or -D). npm install --save-dev // Install development dependencies which is not included in production # or npm install -D You will see that the package is then added to the devDependencies of your package.json. To install dependencies of a downloaded/cloned node.js project, you can simply use npm install # or npm i npm will automatically read the dependencies from package.json and install them. NPM Behind A Proxy Server If your internet access is through a proxy server, you might need to modify npm install commands that access remote repositories. npm uses a configuration file which can be updated via command line: npm config set You can locate your proxy settings from your browser's settings panel. Once you have obtained the proxy settings (server URL, port, username and password); you need to configure your npm configurations as follows. $ npm config set proxy http://:@: $ npm config set https-proxy http://:@: username, password, port fields are optional. Once you have set these, your npm install, npm i -g etc. would work properly. Section 2.2: Uninstalling packages To uninstall one or more locally installed packages, use: npm uninstall The uninstall command for npm has five aliases that can also be used: npm remove npm rm npm r npm unlink GoalKicker.com – Node.js Notes for Professionals 22 npm un If you would like to remove the package from the package.json file as part of the uninstallation, use the --save flag (shorthand: -S): npm uninstall --save npm uninstall -S For a development dependency, use the --save-dev flag (shorthand: -D): npm uninstall --save-dev npm uninstall -D For an optional dependency, use the --save-optional flag (shorthand: -O): npm uninstall --save-optional npm uninstall -O For packages that are installed globally use the --global flag (shorthand: -g): npm uninstall -g Section 2.3: Setting up a package configuration Node.js package configurations are contained in a file called package.json that you can find at the root of each project. You can setup a brand new configuration file by calling: npm init That will try to read the current working directory for Git repository information (if it exists) and environment variables to try and autocomplete some of the placeholder values for you. Otherwise, it will provide an input dialog for the basic options. If you'd like to create a package.json with default values use: npm init --yes # or npm init -y If you're creating a package.json for a project that you are not going to be publishing as an npm package (i.e. solely for the purpose of rounding up your dependencies), you can convey this intent in your package.json file: 1. Optionally set the private property to true to prevent accidental publishing. 2. Optionally set the license property to "UNLICENSED" to deny others the right to use your package. To install a package and automatically save it to your package.json, use: npm install --save The package and associated metadata (such as the package version) will appear in your dependencies. If you save if as a development dependency (using --save-dev), the package will instead appear in your devDependencies. With this bare-bones package.json, you will encounter warning messages when installing or upgrading packages, telling you that you are missing a description and the repository field. While it is safe to ignore these messages, you GoalKicker.com – Node.js Notes for Professionals 23 can get rid of them by opening the package.json in any text editor and adding the following lines to the JSON object: [...] "description": "No description", "repository": { "private": true }, [...] Section 2.4: Running scripts You may define scripts in your package.json, for example: { "name": "your-package", "version": "1.0.0", "description": "", "main": "index.js", "author": "", "license": "ISC", "dependencies": {}, "devDependencies": {}, "scripts": { "echo": "echo hello!" } } To run the echo script, run npm run echo from the command line. Arbitrary scripts, such as echo above, have to be be run with npm run