Capture screenshots of the webpage loaded into a running Chrome instance using https://github.com/jakubkulhan/chrome-devtools-protocol

chrome-devtools-protocol-screenshot.php

<?php
use ChromeDevtoolsProtocol\Context;
use ChromeDevtoolsProtocol\Instance\Instance;
use ChromeDevtoolsProtocol\Model\Page\CaptureScreenshotRequest;
use ChromeDevtoolsProtocol\Model\Page\NavigateRequest;
use ChromeDevtoolsProtocol\Model\Page\SetDeviceMetricsOverrideRequest;

$url = "...";

$ctx = Context::withTimeout(Context::background(), 30);
$instance = new Instance("127.0.0.1", 9222);
$session = $instance->createSession($ctx);
try {
	$session->page()->enable($ctx);

	$session->page()->setDeviceMetricsOverride(
		$ctx,
		SetDeviceMetricsOverrideRequest::builder()
			->setWidth(1200)
			->setHeight(630)
			->setDeviceScaleFactor(1.0)
			->setMobile(false)
			->build()
	);
	$session->page()->navigate(
		$ctx,
		NavigateRequest::builder()
			->setUrl($url)
			->build()
	);
	$session->page()->awaitLoadEventFired($ctx);

	$png = $session->page()->captureScreenshot(
		$ctx,
		CaptureScreenshotRequest::builder()
			->setFormat("png")
			->build()
	);

	$pngBinaryData = base64_decode($png->data);

	// ...

} finally {
	$session->close();
}

chrome.sh

docker run \
  -d \
  --cap-add SYS_ADMIN \
  --name chrome \
  -p 9222:9222 \
  jakubkulhan/chrome:63.0.3239.132 \
  --headless \
  --disable-gpu \
  --remote-debugging-address=0.0.0.0 \
  --remote-debugging-port=9222 \
  --lang=cs_CZ \
  --hide-scrollbars