puppeteer: Can not render a WebGL image for PDF -- get a black box instead

Summary:

I am trying to get a PDF of a page that has a panoramic image on it using Puppeteer. The panoramic image is rendered using WebGL, which I suspect to be the issue. All I get is a black box instead of the image (see the bottom of this post for screen image). But, I can use Puppeteer to get a screenshot of that same page and the panorama looks great. I am not sure why it won’t render when I attempt getting a PDF, but works for screenshot.

Steps to reproduce

Tell us about your environment:

• Puppeteer version: puppeteer@0.10.2
• Platform / OS version: Linux c1301da96bb5 4.9.49-moby running in a Docker container
• URLs (if applicable):
• Node.js version: 8.8.1 (NOTE: the code below was originally developed in 6.1, but we now run 8.8.1)

What steps will reproduce the problem?

Please include code that reproduces the issue.

1. Using this code:

var page, browser;
return Puppeteer.launch({args: options.chromeArgs})
    .then(res => {
        if (!res) {
            return reject(new Error("No browser to open"));
        }
        browser = res;
        return browser.newPage();
    })
    .then(res => {
        if (!res) {
            throw new Error("No browswer available");
         }
        page = res;
        return page.setViewport({
            height: 720,
            width: 1280,
            isLandscape: true,
        ));
    })
    .then(() => {
        return page.goto(url,{"waitUntil":"networkidle0"});
    })
    .then(() => {
        return page.pdf(options);
    })
    .then(buffer => {
       if (browser) {
           browser.close();
       }
       return resolve(buffer);
    })
    .catch(err => {
        if (browser) {
            browser.close();
        }
        return reject(err);
    });

1. I have tried these options:

            "pageTimeout": 120000,
            "chromeArgs": ["--disable-gpu","--disable-setuid-sandbox","--no-sandbox"],
            "headless": true,
            "printBackground": true,
            "displayHeaderFooter": true,
            "landscape": true,
            "margin": {
                "top": 0,
                "bottom": 0,
                "left": 0,
                "right": 0
            }
        }

1. I have also tried adding these the the chromeArgs: --use-gl=swiftshader --use-gl=osmesa --use-gl=swiftshader-webgl

What is the expected result? I would expect the PDF to look like the screenshot – like this

Here is the screenshot from Puppeteer (NOTE: the html page is formatted slightly differently for PDF rendering, but the panoramic image is the same)

What happens instead? The PDF has a black box where the panoramic image should be.