PC Shutdown with Alexa and IFTTT

README.md

PC Shutdown

• ifttt-api.js:

Node server, must be hosted on a provider.

It exposes a TCP Server to send commands to the client, and an HTTP Server to receive commands from IFTTT.

• pc-client.js:

Node client, must be run on the target PC (on startup).

It connects to the TCP Server to receive commands. It reconnects in case of failure.

How To Use

Create a service on IFTTT Platform

• Go to platform.ifttt.com and create a new service
• Go to "API" > "General"
• Type the URL where the server is hosted
• Copy the Secret Key and paste it in ifttt-api.js (SECRET_IFTTT_KEY)
• Go to "API" > "Actions"
• Click on "New action"
• Fulfill the form, typing shutdown_pc in Endpoint field

Setup the server

• Run ifttt-api.js with PM2 on a server
• Open ports indicated in ifttt-api.js if necessary on the server

Setup the client on PC

• Open pc-client.js and set the value of TCP_ADDR
• Run pc-client.js on PC, better if at startup

Create an applet

• Go to https://ifttt.com/create
• Create an applet as usual, choosing the new service just created

Create an Alexa routine

• Open the Alexa app
• Go to Routines
• Create a new routine
• When a phrase of your choice is detected, run the IFTTT applet created before

ifttt-api.js

const net = require('net');
const http = require('http');

const HTTP_PORT = 56744;
const TCP_PORT  = 62710;
const TCP_KEEP_ALIVE = 60000; // 1 min

const IFTTT_ACTIONS = {
	'shutdown_pc': shutdown
};
const IFTTT_URL_PREFIX = '/ifttt/v1/actions/';
const IFTTT_HEADER = 'ifttt-service-key';
const SECRET_IFTTT_KEY = '<IFTTT SERVICE KEY>';

const clients = [];

http.createServer((req, res) => {
	if (req.headers[IFTTT_HEADER] !== SECRET_IFTTT_KEY) {
        res.statusCode = 401;
        res.end();
        return;
    }

    if (!req.url.startsWith(IFTTT_URL_PREFIX)) {
        res.statusCode = 404;
        res.end();
        return;
    }

    const actionName = req.url.replace(IFTTT_URL_PREFIX, '');
    if (!IFTTT_ACTIONS[actionName]) {
	res.statusCode = 404;
	res.end();
	return;
    }

    if (req.method !== 'POST') {
	res.statusCode = 405;
	res.end();
	return;
    }

    IFTTT_ACTIONS[actionName]();
    res.end();
}).listen(HTTP_PORT, () => {
    console.log(`HTTP ready on ${HTTP_PORT}`);
});

function shutdown() {
    clients.forEach(c => c.write('shutdown\n'));
}

// TCP Socket Client
const server = net.createServer(conn => {
    clients.push(conn);
    conn.on('close', () => {
        clients.splice(clients.indexOf(conn), 1);
    });
});

setInterval(() => {
    clients.forEach(c => c.write('keep-alive\n'));
}, TCP_KEEP_ALIVE);

server.listen(TCP_PORT, () => {
    console.log(`TCP server ready on ${TCP_PORT}`);
});

pc-client.js

const net = require('net');
const { execSync } = require('child_process');

const TCP_PORT = 62710;
const TCP_ADDR = '<DOMAIN NAME / IP>';
const RECONN_TIMEOUT = 5000; // 5 secs

const socket = new net.Socket();
socket.setEncoding('utf8');

let connected = false;
socket.on('connect', () => {
    connected = true;
});

socket.on('close', () => {
    connected = false;
    reconnect();
});

socket.on('error', reconnect);

let dataBuff = '';
socket.on('data', d => {
    dataBuff += d;
    
    if (dataBuff.indexOf('\n')) {
        const cmds = dataBuff.split('\n');
        dataBuff = cmds.pop();
        cmds.forEach(onCommand);
    }
});

function onCommand(cmd) {
    switch (cmd) {
        case 'shutdown':
            shutdown();
            break;
        case 'keep-alive':
            // No action required.
            break;
        default:
            console.error(`Unknown command: ${cmd}`);
    }
}

function shutdown() {
    execSync('cmd.exe /C "shutdown /s /hybrid /t 0"');
}

function connect() {
    if (!socket.connecting && !connected)
        socket.connect(TCP_PORT, TCP_ADDR);
}

function reconnect() {
    setTimeout(connect, RECONN_TIMEOUT);
}

connect();