Puppeteer pdf blank on Heroku

问题

I'm making a route in my webapp that turns some html into a pdf. This works great in development, but fails on Heroku. Other Puppeteer tasks work fine on heroku. The HTML I'm rendering is quite small.

  const generatePDF = asyncMiddleware(async (req, res) => {
    const browser = await puppeteer.launch({
      dumpio: true,
      headless: true,
      args: ['--no-sandbox', '--disable-setuid-sandbox']
    });
    const page = await browser.newPage();
    page.on('error', err => {
      console.error('err', err, err.stack)
      browser.close();
    });
    await page.goto(`data:text/html,${req.body.html}`, {
      waitUntil: 'networkidle2',
    });

    // stupid attempt at debugging, making sure page has time to render?
    await page.waitFor(6000);
    const pdf = await page.pdf();
    res.set('content-type', 'application/pdf');
    await browser.close();
    res.send(pdf);
  });

  module.exports = require('express')
    .Router()
    .post('/', generatePDF)

When I hit the route on Heroku, I get a blank PDF. Puppeteer produces the following stdout

[0131/123556.374089:ERROR:gpu_process_transport_factory.cc(1043)] Lost UI shared context.

When I wrote this code I was on version 0.10.x, but I thought upgrading might help, so I went up at 1.0.0. The problem persists on both versions. Node version is 8.x.x

I thought it might be a server memory issue, so I upgraded to a 2x dyno, but that didn't help.

I think it could be related to one of these two issues: - https://github.com/GoogleChrome/puppeteer/issues/1875 - https://github.com/GoogleChrome/puppeteer/issues/1925

But, these don't seem super related to Heroku, or explain how it works in one env and not another

Update: when I look at the payload, the data of the pdf looks like a UUID!

回答1:

I figured it out! The client to my server was axios. I needed to tell axios that I was serving up binary.

  const { data: pdf } = await req({
    method: 'post',
    url: 'api/pdfs',
    responseType: 'arraybuffer', // <-- this was missing
    data: { html }
  });

来源：https://stackoverflow.com/questions/48542991/puppeteer-pdf-blank-on-heroku

标签

node.js

heroku

Puppeteer