Blank chrome://version when running with --headless

[andymurd]

I want to use the Page.printToPDF method to dump my web pages for emailing/printing. This functionality is only available when running Chrome with the --headless flag.

However, when I add that flag to my chromeOptions.args, the devtools service cannot find the remote-debugging-port from chrome://version. I've hacked the _findChromePort() method to dump a screenshot, and found that it's just a blank white page.

If I remove the --headless flag from my options, I can see that the page loads correctly, the screenshot has the expected data and the port is found. Everything starts up OK and browser.cdp is injected. The process fails when trying to call Page.printToPDF (as expected).

I guess that loading chrome://version is not supported in headless mode, though I can't find any documentation to support that. It's not an easy phrase to google :)

Is there any other means of finding the debugging port? I'm running chrome using wdio-selenium-standalone so the port is changed often. All help is much appreciated.

[christian-bromann]

See https://github.com/webdriverio/wdio-devtools-service/pull/5/files .. we used to get the port this way. Maybe you can try implement this and propose a PR with a fallback to this approach