Node.js

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Description

Node.js est un canevas événementiel (mono-thread) pour réaliser des applications serveur en Javascript. L'ensemble des événements est traité par une seule thread: Node.js privilégie les appels non bloquants. Node.js facilite le push (serveur --> client Web)

Cours

Docs

Alternatives

Modules

Des nombreuses bibliothèques sont disponibles : Assertion Testing, Buffer, C/C++ Addons, Child Processes, Cluster, Crypto, Debugger, DNS, Domain, Events, File System, Globals, HTTP, HTTPS, Modules, Net, OS, Path, Process, Punycode, Query Strings, Readline, REPL, STDIO, Stream, String Decoder, Timers, TLS/SSL, TTY, UDP/Datagram, URL, Utilities, VM, ZLIB

Canevas

Des nombreux canevas sont construits sur Node.js

Installeur / Manager de version de Node.js

détails

nvm script

Registre NPM

Plusieurs modules sont catalogués depuis le registre https://npmjs.org/ et installables avec npm (Node Package Manager) 

# Voir les packages disponibles 
npm ls

# Voir les packages installés
npm ls installed

# Rechercher un package
npm search duino

# Installer un package pour le contrôle d'une carte Arduino
npm install duino

# Installer un package
npm publish mypackage

Modules pour les projets AIR

  • node-serialport access serial ports for reading and writing
  • duino A framework for working with Arduinos in node.js
  • firmata A Node library to interact with an Arduino running the firmata protocol.

Usine logicielle

Debugging

Debug with [github.com/dannycoates/node-inspector Node Inspector]
node debug script_to_debug.js

sudo npm install -g node-inspector
node-inspector

Browse http://127.0.0.1:8080/debug?port=5XXX 

pgrep -l node
node -e "process._debugProcess(NODEPID)"

Builders

Déploiement sur PaaS

Installation

dpkg --get-selections | grep node
sudo apt-get remove --purge node
dpkg --get-selections | grep nodejs
sudo apt-get remove --purge nodejs

sudo apt-get install build-essential checkinstall
sudo apt-get install libssl-dev
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.31.0/install.sh | bash
exit

Se logger 

command -v nvm
nvm install 5.0
nvm use 5.0	
nvm alias default node

Exemples

Lancement

Aide 

node --help

Interactif 

node

En ligne 

node -p -e "Boolean(process.stdout.isTTY)"

En argument (process.argv[1]) 

node httpserver.js 8080

En mode debug 

node debug script_to_debug.js


HTTP script

var port = process.argv[2];

var http = require("http");

function onRequest(request, response) {
  console.log("Receiving a request");
  response.writeHead(200, {"Content-Type": "text/plain"});
  response.write("Hello World");
  response.end();
}

http.createServer(onRequest).listen(port);
console.log("Server started. ^C to kill it");

node hello.js 8888


Express

var express = require('express');
var app = express();
app.get('/hello.txt', function(req, res){
  res.send('Hello World');
});
app.listen(8080);



npm install express
node webserver.js 8080

start http://localhost:3000/hello.txt

Un peu plus avec Express.js

Express en HTTPS

Générer un certificat en répondant aux questions 

openssl req -newkey rsa:2048 -new -nodes -x509 -days 365 -keyout key.pem -out cert.pem

Editer securehttpd.js 


   var fs = require('fs'),
    https = require('https'),
    express = require('express'),
    app = express();

    https.createServer({
      key: fs.readFileSync('key.pem'),
      cert: fs.readFileSync('cert.pem')
    }, app).listen(8443);

    app.get('/', function (req, res) {
      res.header('Content-type', 'text/html');
      return res.end('<h1>Hello, Secure World!</h1>');
    });


node securehttpd.js

Naviguer sur https://localhost:8443/ en acceptant le certificat

UDP Datagrams

// udpreceiver.js <port>
var port = process.argv[2];

var dgram = require("dgram");

var server = dgram.createSocket("udp4");

server.on("message", function (msg, rinfo) {
  console.log("server got: " + msg + " from " +
    rinfo.address + ":" + rinfo.port);
});

server.on("listening", function () {
  var address = server.address();
  console.log("server listening " +
      address.address + ":" + address.port);
});

server.bind(port);




// node udpsender.js <hostname ou ip address> <port>

var host = process.argv[2];
var port = process.argv[3];

var dgram = require("dgram");
var readline = require('readline');

var client = dgram.createSocket("udp4");
var rl = readline.createInterface(process.stdin,process.stdout);

rl.setPrompt('> ');
rl.prompt();

rl.on('line', function(line) {
  switch(line.trim()) {
    case 'exit':
      rl.close();
      break;
    default:
    
    var msg = {
  		payload: line,
  		timestamp: new Date(),
  		expires: "NEVER"
	};
    
    var message = new Buffer(JSON.stringify(msg));
    //if(message.length<=0) break;
	client.send(message, 0, message.length, port, host, function(err, bytes) {
	    console.log("message "+ message + " sent");
  		});
      break;
  }
  rl.prompt();
}).on('close', function() {
  console.log('Bye Bye!');
  process.exit(0);
});


Terminal 1 

npm install readline
node udpreceiver.js 5000


Terminal 2 

node udpsender.js localhost 5000

Terminal 3 

node udpsender.js 0.0.0.0 5000

DTLS

node-dtls

Remote Shell

https://gist.github.com/mastahyeti/1283301 

var port = process.argv[2];

var spawn = require('child_process').spawn;
var net = require('net');
var stream = require('stream');
var console = require('console');
 
var server = net.createServer(function(socket){
  var sh = spawn('/bin/sh');

  sh.stdin.resume();

  sh.stdout.on("data",function (data){
    //Node makes async stuff easy. 
    //You can do cool things like:
    //socket.write(Base64_encode(data));
    //or any other encoding/obfuscation
    //for that matter.
    socket.write(data);
  });

  sh.stderr.on("data",function (data){
    socket.write(data);
  });

  socket.on("data",function (data){
    sh.stdin.write(data);
  });

});

server.listen(port,'0.0.0.0');

node remoteshell.js 1337

nc localhost 1337

XMPP

var jid = process.argv[2];
var password = process.argv[3];
var friend = process.argv[4];


var xmpp = require('simple-xmpp');
//var readline = require('readline');

xmpp.on('online', function() {
    console.log('Yes, I\'m connected!');
});

xmpp.on('chat', function(from, message) {
   //  xmpp.send(from, 'echo: ' + message);
    console.log('%s says %s', from, message);
});

xmpp.on('stanza', function(stanza) {
        console.log(stanza);
});

xmpp.on('error', function(err) {
    console.error(err);
});

xmpp.on('subscribe', function(from) {
if (from === friend) {
    xmpp.acceptSubscription(from);
    }
});

xmpp.on('buddy', function(jid, state, statusText) {
    console.log('%s is in %s state - %s', jid, state, statusText);
});

xmpp.connect({
    jid         : jid,
    password    : password,
    host        : 'talk.google.com',
    port        : 5222
});

xmpp.subscribe(friend);
// check for incoming subscription requests
xmpp.getRoster();

// TO BE CONTINUED WITH readline





node install simple-xmpp
node minigtalk.js me@gmail.com MyPaSSwOrD my.friend@gmail.com

Crypto: SHA1 Hashing


var filename = process.argv[2];
var crypto = require('crypto');
var fs = require('fs');

var shasum = crypto.createHash('sha1');

var s = fs.ReadStream(filename);
s.on('data', function(d) {
  shasum.update(d);
});

s.on('end', function() {
  var d = shasum.digest('hex');
  console.log(d + '  ' + filename);
});



node hash.js hash.js

TTY

process.stdout.on('resize', function() {
  console.log('screen size has changed!');
  console.log(process.stdout.columns + 'x' + process.stdout.rows);
});



node resize.js



$ node -p -e "Boolean(process.stdout.isTTY)"
true
$ node -p -e "Boolean(process.stdout.isTTY)" | cat
false


REPL (Read-Eval-Print-Loop)

var net = require("net"),
    repl = require("repl");

connections = 0;

repl.start({
  prompt: "node via stdin> ",
  input: process.stdin,
  output: process.stdout
});

net.createServer(function (socket) {
  connections += 1;
  repl.start({
    prompt: "node via TCP socket> ",
    input: socket,
    output: socket
  }).on('exit', function() {
    connections -= 1;
    socket.end();
  });
}).listen(5001);



node repl.js

1+2+3+4+5



telnet localhost 5001

1+2+3+4+5

.help

.exit

Cluster

var port = process.argv[2];
var cluster = require('cluster');
var http = require('http');
var numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

  cluster.on('exit', function(worker, code, signal) {
    console.log('worker ' + worker.process.pid + ' died');
  });
} else {
  // Workers can share any TCP connection
  // In this case its a HTTP server
  http.createServer(function(req, res) {
    res.writeHead(200);
    res.end("hello world\n");
  }).listen(port);
}



node httpcluster.js 8080


Simple Arduino Test

Placez la patte du milieu d'un potentiomètre sur la pin analogique A0 (les pattes des bords sur GND et +5V). Téléversez l'exemple File > Examples > 01.Basics > AnalogReadSerial de l'IDE sur votre Arduino. 

// AnalogReadSerial.js <port>
var port = process.argv[2];
var serialport = require('serialport');

var sp = new serialport.SerialPort(port, {
                baudrate: 9600,
                parser: serialport.parsers.readline('\r\n')});

sp.on('data', function(line) {
    console.log(line);
});

npm install serialport
node AnalogReadSerial.js /dev/tty.usbmodemfa131

Arduino avec Firmata

Placez la patte du milieu d'un potentiomètre sur la pin analogique A0 (les pattes des bords sur GND et +5V). Téléversez l'exemple File > Examples > Firmata > StandardFirmata sur votre Arduino 

// testfirmata.js <port>
var port = process.argv[2];

var firmata = require('firmata');
var board = new firmata.Board(port,function(){
  //arduino is ready to communicate
  board.analogRead(0,function(data){
  	console.log(data);
  })
});  

npm install firmata
node testfirmata.js /dev/tty.usbmodemfa131
node testfirmata.js /dev/ttyACM0

Voir https://github.com/jgautier/firmata

NMEA 0183 Parsing

var nmea = require('nmea')

var sentences = [
"$GPGSA,A,1,,,,,,,,,,,,,,,*1E",
"$GPGSV,3,1,12,29,75,266,39,05,48,047,,26,43,108,,15,35,157,*78",
"$GPGSV,3,2,12,21,30,292,,18,21,234,,02,18,093,,25,13,215,*7F",
"$GPGSV,3,3,12,30,11,308,,16,,333,,12,,191,,07,-4,033,*62",
"$GPRMC,085542.023,V,,,,,,,041211,,,N*45",
"$GPGGA,085543.023,,,,,0,00,,,M,0.0,M,,0000*58",
];

for (var i=0; i < s.length; i++) {
    console.log(nmea.parse(sentences[i]));
};



npm install nmea
node testnmea.js



// serialnmea.js <port>
var port = process.argv[2];
var serialport = require('serialport');
var nmea = require('nmea');

var sp = new serialport.SerialPort(port, {
                baudrate: 4800,
                parser: serialport.parsers.readline('\r\n')});

sp.on('data', function(line) {
    console.log(nmea.parse(line));
});

npm install nmea
node serialnmea.js /dev/cu.usbserial


see also https://npmjs.org/package/coordinator

NFC RFID Readers

See: 

var HID = require('node-hid');
console.log(HID.devices());

npm install node-hid
node listhid.js

Autres

Robot

Robot Operating System

XMPP

Twitter

REST

MySQL

Terminal Notifier

Node-CoAP

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