[BUG] Error when using PM2 process manager in cluster mode

[rtrag]

Context:

• Playwright Version: 1.6.1
• Operating System: Linux and Mac
• Node.js version: v15.2.0
• Browser: Chromium

Code Snippet

const browser_args = [
    "--disable-gpu",
    "--disable-web-security",
    "--disable-dev-shm-usage",
    "--disable-setuid-sandbox",
    "--no-first-run",
    "--no-sandbox",
    "--no-zygote",
    "--ignore-certificate-errors",
    "--ignore-certificate-errors-spki-list",
    "--enable-features=NetworkService",
]

 const browserServer = await playwright.chromium.launchServer({ headless: true, ignoreHTTPSErrors: true, args: browser_args })

Describe the bug

Getting error when using PM2 process manager in cluster mode, but works fine when using node to run

1|www | TypeError: Cannot read property 'port' of null
1|www | at new BrowserServerImpl (../node_modules/playwright/lib/browserServerImpl.js:52:108)
1|www | at BrowserServerLauncherImpl.launchServer (..node_modules/playwright/lib/browserServerImpl.js:41:16)

[aslushnikov]

@rtag what do I do to reproduce this locally? I tried just running browser server and launching it with

$ npx pm2 start a.js -i max

and this ran just fine.

[rtrag]

can I get your a.js @aslushnikov

CODE THAT DOES NOT WORK

const http = require('http');
const playwright = require('playwright');
const browser_args = [
    "--disable-gpu",
    "--disable-web-security",
    "--disable-dev-shm-usage",
    "--disable-setuid-sandbox",
    "--no-first-run",
    "--no-sandbox",
    "--no-zygote",
    "--ignore-certificate-errors",
    "--ignore-certificate-errors-spki-list",
    "--enable-features=NetworkService",
]
const server = http.createServer(async  (req, res) => {

    const browserServer = await playwright.chromium.launchServer({ headless: true, ignoreHTTPSErrors: true, args: browser_args })
    const wsEndpoint = (await browserServer).wsEndpoint()
    console.log("wsEndpoint", wsEndpoint);

});

server.listen(6000);

console.log('Node.js web server at port 6000 is running..')

[rtrag]

Not sure why but under PM2 address is null @aslushnikov

node_modules/playwright/lib/browserServerImpl.js

 this._server = new ws.Server({ port });
 const address = this._server.address();

[rtrag]

What I found so far is if cluster.fork() is used it breaks ws from require("ws"); @pavelfeldman . Maybe this is just a ws issue? Or I am doing something wrong?

node_modules/playwright/lib/browserServerImpl.js:52
this._wsEndpoint = typeof address === 'string' ? ${address}/${token} : ws://127.0.0.1:${address.port}/${token};

const http = require('http');
const playwright = require('playwright');
const cluster = require('cluster')

const browser_args = [
    "--disable-gpu",
    "--disable-web-security",
    "--disable-dev-shm-usage",
    "--disable-setuid-sandbox",
    "--no-first-run",
    "--no-sandbox",
    "--no-zygote",
    "--ignore-certificate-errors",
    "--ignore-certificate-errors-spki-list",
    "--enable-features=NetworkService",
]

const { chromium } = require('playwright');  // Or 'webkit' or 'firefox'.

const server = http.createServer(async  (req, res) => {

    const browserServer = await chromium.launchServer({ headless: true, ignoreHTTPSErrors: true, args: browser_args });
    const wsEndpoint = await browserServer.wsEndpoint();
    console.log(wsEndpoint);
    // Use web socket endpoint later to establish a connection.
    const browser = await chromium.connect({ wsEndpoint });
    const context = await browser.newContext();
    console.log("Number of contexts currently running in this browser: " + browser.contexts().length);

});


if (cluster.isMaster) {
    console.log(`Master ${process.pid} is running`);

    // Fork workers.
    for (let i = 0; i < 4; i++) {
        cluster.fork();
    }

    cluster.on('exit', (worker, code, signal) => {
        console.log(`worker ${worker.process.pid} died`);
    });
} else {
    // Workers can share any TCP connection
    // In this case it is an HTTP server
    server.listen(4000);

}

console.log('Node.js web server at port 4000 is running..')

[dgozman]

I can repro this, thank you for the script.