Node run multiple instances and close only requested instance - node.js

Question

I am using xvbf in node application to run a chrome client for capturing web site screens in background. From a web page i am passing data to my webservice as at the bottom of this code part to START_CAPTURE and STOP_CAPTURE.
const puppeteer = require('puppeteer');
const Xvfb = require('xvfb');
var exec = require('child_process').exec;
const os = require('os');
const homedir = os.homedir();
const platform = os.platform();
const http = require('http');
const StringDecoder = require('string_decoder').StringDecoder;
const http_port = 8000;
const ffmpegServer = config.ffmpegServer + ":" + config.ffmpegServerPort;
var xvfb = new Xvfb({
silent: true,
xvfb_args: ["-screen", "0", "1280x800x24", "-ac", "-nolisten", "tcp", "-dpi", "96", "+extension", "RANDR"]
});
var action = "";
var width = 1280;
var height = 720;
var options = {
headless: false,
args: [
'--enable-usermedia-screen-capturing',
'--allow-http-screen-capture',
'--load-extension=' + __dirname,
'--disable-extensions-except=' + __dirname,
'--disable-infobars',
'--start-fullscreen',
'--app=https://www.google.com/'`
],
}
options.executablePath = "/usr/bin/google-chrome"
async function main() {
try{
if(platform == "linux"){
xvfb.startSync()
}
var exportname = 'video.webm'
var url = 'https://www.google.com/';
var duration = 30;
const browser = await puppeteer.launch(options)
const pages = await browser.pages()
const page = pages[0]
page.on('console', msg => {
var m = msg.text();
console.log('PAGE LOG:', m)
});
await page._client.send('Emulation.clearDeviceMetricsOverride')
await page.goto(url, {waitUntil: 'networkidle2'})
await page.setBypassCSP(true);
if(duration > 0){
await page.waitFor((duration * 1000))
}else{
while(action!="STOP_CAPTURE"){
try {
await page.waitForSelector('[class^=modal] > [class^=content] > button[description="Logs you out"]', {
timeout: 1000
});
} catch (err) {
// Do nothing
}
}
}
await page.close()
await browser.close()
if(platform == "linux"){
xvfb.stopSync()
}
fs.unlinkSync(homedir + "/video.webm");
}catch(err) {
console.log(err)
}
}
// Instantiate the HTTP server.
const httpServer = http.createServer((req, res) => {
res.setHeader('Access-Control-Allow-Origin', '*');
if (req.method == 'POST') {
var jsonString = '';
var buffers = [];
req.on('data', function (chunk) {
buffers.push(chunk);
});
req.on('error', (err) => {
// This prints the error message and stack trace to `stderr`.
console.log("Error: %s \n" + err.stack);
});
req.on('end', function () {
try {
jsonString = JSON.parse(Buffer.concat(buffers).toString());
var action = jsonString.markers[0]['action'];
if(action=="START_CAPTURE"){
main();
}
}
catch(e) {
jsonString = JSON.parse(JSON.stringify(Buffer.concat(buffers).toString()));
console.log('\nError \n ' + JSON.stringify(jsonString));
}
});
}
res.end();
console.log('Response ended here. \n ');
});
httpServer.listen(http_port, () => {
console.log("Web server is listening on port %s \n", http_port);
});
This is how it works.
I am clicking a button (START_CAPTURE) from my web site to start capturing. Then capture start. Then i am clicking a button (STOP_CAPTURE) to stop capturing.
everything is working fine. If i do like this.
But if i click START_CAPTURE using two different browsers, then i clicked on STOP_CAPTURE button from any browser window, both instances are getting stop.
I know it is happened because of this lines.
while(action!="STOP_CAPTURE"){
try {
await page.waitForSelector('[class^=modal] > [class^=content] > button[description="Logs you out"]', {
timeout: 1000
});
} catch (err) {
// Do nothing
}
}
Is there anyway to stop only requested instance ? How can i achieve it ?