Puppeteer doesn't close browser

Question

I'm running puppeteer on express/node/ubuntu as follow:

var puppeteer = require('puppeteer');
var express = require('express');
var router = express.Router();

/* GET home page. */
router.get('/', function(req, res, next) {
    (async () => {
        headless = true;
        const browser = await puppeteer.launch({headless: true, args:['--no-sandbox']});
        const page = await browser.newPage();
        url = req.query.url;
        await page.goto(url);
        let bodyHTML = await page.evaluate(() => document.body.innerHTML);
        res.send(bodyHTML)
        await browser.close();
    })();
});

running this script multiple times leaves hundred of Zombies:

$ pgrep chrome | wc -l
133

Which clogs the srv,

How do I fix this?

Running kill from a Express JS script could solve it?

Is there a better way to get the same result other than puppeteer and headless chrome?

Answer 1

Ahhh! This is a simple oversight. What if an error occurs and your await browser.close() never executes thus leaving you with zombies.

Using shell.js seems to be a hacky way of solving this issue.

The better practice is to use try..catch..finally. The reason being you would want the browser to be closed irrespective of a happy flow or an error being thrown. And unlike the other code snippet, you don't have to try and close the browser in the both the catch block and finally block. finally block is always executed irrespective of whether an error is thrown or not.

So, your code should look like,

const puppeteer = require('puppeteer');
const express = require('express');

const router = express.Router();

/* GET home page. */
router.get('/', function(req, res, next) {
  (async () => {
    try {
      headless = true;
      const browser = await puppeteer.launch({
        headless: true,
        args: ['--no-sandbox'],
      });
      const page = await browser.newPage();
      url = req.query.url;
      await page.goto(url);
      const bodyHTML = await page.evaluate(() => document.body.innerHTML);
      res.send(bodyHTML);
    } catch (e) {
      console.log(e);
    } finally {
      await browser.close();
    }
  })();
});

Hope this helps!