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+<?php
+
+/* Icinga PDF Export | (c) 2018 Icinga GmbH | GPLv2 */
+
+namespace Icinga\Module\Pdfexport;
+
+use Exception;
+use Icinga\Application\Logger;
+use Icinga\Application\Platform;
+use Icinga\File\Storage\StorageInterface;
+use Icinga\File\Storage\TemporaryLocalFileStorage;
+use ipl\Html\HtmlString;
+use LogicException;
+use React\ChildProcess\Process;
+use React\EventLoop\Factory;
+use React\EventLoop\TimerInterface;
+use WebSocket\Client;
+use WebSocket\ConnectionException;
+
+class HeadlessChrome
+{
+ /**
+ * Line of stderr output identifying the websocket url
+ *
+ * First matching group is the used port and the second one the browser id.
+ */
+ const DEBUG_ADDR_PATTERN = '/DevTools listening on ws:\/\/((?>\d+\.?){4}:\d+)\/devtools\/browser\/([\w-]+)/';
+
+ /** @var string */
+ const WAIT_FOR_NETWORK = 'wait-for-network';
+
+ /** @var string Javascript Promise to wait for layout initialization */
+ const WAIT_FOR_LAYOUT = <<<JS
+new Promise((fulfill, reject) => {
+ let timeoutId = setTimeout(() => reject('fail'), 10000);
+
+ if (document.documentElement.dataset.layoutReady === 'yes') {
+ clearTimeout(timeoutId);
+ fulfill(null);
+ return;
+ }
+
+ document.addEventListener('layout-ready', e => {
+ clearTimeout(timeoutId);
+ fulfill(e.detail);
+ }, {
+ once: true
+ });
+})
+JS;
+
+ /** @var string Path to the Chrome binary */
+ protected $binary;
+
+ /** @var array Host and port to the remote Chrome */
+ protected $remote;
+
+ /**
+ * The document to print
+ *
+ * @var PrintableHtmlDocument
+ */
+ protected $document;
+
+ /** @var string Target Url */
+ protected $url;
+
+ /** @var StorageInterface */
+ protected $fileStorage;
+
+ /** @var array */
+ private $interceptedRequests = [];
+
+ /** @var array */
+ private $interceptedEvents = [];
+
+ /**
+ * Get the path to the Chrome binary
+ *
+ * @return string
+ */
+ public function getBinary()
+ {
+ return $this->binary;
+ }
+
+ /**
+ * Set the path to the Chrome binary
+ *
+ * @param string $binary
+ *
+ * @return $this
+ */
+ public function setBinary($binary)
+ {
+ $this->binary = $binary;
+
+ return $this;
+ }
+
+ /**
+ * Get host and port combination of the remote chrome
+ *
+ * @return array
+ */
+ public function getRemote()
+ {
+ return $this->remote;
+ }
+
+ /**
+ * Set host and port combination of a remote chrome
+ *
+ * @param string $host
+ * @param int $port
+ *
+ * @return $this
+ */
+ public function setRemote($host, $port)
+ {
+ $this->remote = [$host, $port];
+
+ return $this;
+ }
+
+ /**
+ * Get the target Url
+ *
+ * @return string
+ */
+ public function getUrl()
+ {
+ return $this->url;
+ }
+
+ /**
+ * Set the target Url
+ *
+ * @param string $url
+ *
+ * @return $this
+ */
+ public function setUrl($url)
+ {
+ $this->url = $url;
+
+ return $this;
+ }
+
+ /**
+ * Get the file storage
+ *
+ * @return StorageInterface
+ */
+ public function getFileStorage()
+ {
+ if ($this->fileStorage === null) {
+ $this->fileStorage = new TemporaryLocalFileStorage();
+ }
+
+ return $this->fileStorage;
+ }
+
+ /**
+ * Set the file storage
+ *
+ * @param StorageInterface $fileStorage
+ *
+ * @return $this
+ */
+ public function setFileStorage($fileStorage)
+ {
+ $this->fileStorage = $fileStorage;
+
+ return $this;
+ }
+
+ /**
+ * Render the given argument name-value pairs as shell-escaped string
+ *
+ * @param array $arguments
+ *
+ * @return string
+ */
+ public static function renderArgumentList(array $arguments)
+ {
+ $list = [];
+
+ foreach ($arguments as $name => $value) {
+ if ($value !== null) {
+ $value = escapeshellarg($value);
+
+ if (! is_int($name)) {
+ if (substr($name, -1) === '=') {
+ $glue = '';
+ } else {
+ $glue = ' ';
+ }
+
+ $list[] = escapeshellarg($name) . $glue . $value;
+ } else {
+ $list[] = $value;
+ }
+ } else {
+ $list[] = escapeshellarg($name);
+ }
+ }
+
+ return implode(' ', $list);
+ }
+
+ /**
+ * Use the given HTML as input
+ *
+ * @param string|PrintableHtmlDocument $html
+ * @param bool $asFile
+ * @return $this
+ */
+ public function fromHtml($html, $asFile = false)
+ {
+ if ($html instanceof PrintableHtmlDocument) {
+ $this->document = $html;
+ } else {
+ $this->document = (new PrintableHtmlDocument())
+ ->setContent(HtmlString::create($html));
+ }
+
+ if ($asFile) {
+ $path = uniqid('icingaweb2-pdfexport-') . '.html';
+ $storage = $this->getFileStorage();
+
+ $storage->create($path, $this->document->render());
+
+ $path = $storage->resolvePath($path, true);
+
+ $this->setUrl("file://$path");
+ }
+
+ return $this;
+ }
+
+ /**
+ * Export to PDF
+ *
+ * @return string
+ * @throws Exception
+ */
+ public function toPdf()
+ {
+ switch (true) {
+ case $this->remote !== null:
+ try {
+ $result = $this->jsonVersion($this->remote[0], $this->remote[1]);
+ $parts = explode('/', $result['webSocketDebuggerUrl']);
+ $pdf = $this->printToPDF(join(':', $this->remote), end($parts), isset($this->document)
+ ? $this->document->getPrintParameters()
+ : []);
+ break;
+ } catch (Exception $e) {
+ if ($this->binary === null) {
+ throw $e;
+ } else {
+ Logger::warning(
+ 'Failed to connect to remote chrome: %s:%d (%s)',
+ $this->remote[0],
+ $this->remote[1],
+ $e
+ );
+ }
+ }
+
+ // Fallback to the local binary if a remote chrome is unavailable
+ case $this->binary !== null:
+ $browserHome = $this->getFileStorage()->resolvePath('HOME');
+ $commandLine = join(' ', [
+ escapeshellarg($this->getBinary()),
+ static::renderArgumentList([
+ '--bwsi',
+ '--headless',
+ '--disable-gpu',
+ '--no-sandbox',
+ '--no-first-run',
+ '--disable-dev-shm-usage',
+ '--remote-debugging-port=0',
+ '--homedir=' => $browserHome,
+ '--user-data-dir=' => $browserHome
+ ])
+ ]);
+
+ if (Platform::isLinux()) {
+ Logger::debug('Starting browser process: HOME=%s exec %s', $browserHome, $commandLine);
+ $chrome = new Process('exec ' . $commandLine, null, ['HOME' => $browserHome]);
+ } else {
+ Logger::debug('Starting browser process: %s', $commandLine);
+ $chrome = new Process($commandLine);
+ }
+
+ $loop = Factory::create();
+
+ $killer = $loop->addTimer(10, function (TimerInterface $timer) use ($chrome) {
+ $chrome->terminate(6); // SIGABRT
+ Logger::error(
+ 'Terminated browser process after %d seconds elapsed without the expected output',
+ $timer->getInterval()
+ );
+ });
+
+ $chrome->start($loop);
+
+ $pdf = null;
+ $chrome->stderr->on('data', function ($chunk) use (&$pdf, $chrome, $loop, $killer) {
+ Logger::debug('Caught browser output: %s', $chunk);
+
+ if (preg_match(self::DEBUG_ADDR_PATTERN, trim($chunk), $matches)) {
+ $loop->cancelTimer($killer);
+
+ try {
+ $pdf = $this->printToPDF($matches[1], $matches[2], isset($this->document)
+ ? $this->document->getPrintParameters()
+ : []);
+ } catch (Exception $e) {
+ Logger::error('Failed to print PDF. An error occurred: %s', $e);
+ }
+
+ $chrome->terminate();
+ }
+ });
+
+ $chrome->on('exit', function ($exitCode, $termSignal) use ($loop, $killer) {
+ $loop->cancelTimer($killer);
+
+ Logger::debug('Browser terminated by signal %d and exited with code %d', $termSignal, $exitCode);
+ });
+
+ $loop->run();
+ }
+
+ if (empty($pdf)) {
+ throw new Exception(
+ 'Received empty response or none at all from browser.'
+ . ' Please check the logs for further details.'
+ );
+ }
+
+ return $pdf;
+ }
+
+ /**
+ * Export to PDF and save as file on disk
+ *
+ * @return string The path to the file on disk
+ */
+ public function savePdf()
+ {
+ $path = uniqid('icingaweb2-pdfexport-') . '.pdf';
+
+ $storage = $this->getFileStorage();
+ $storage->create($path, '');
+
+ $path = $storage->resolvePath($path, true);
+ file_put_contents($path, $this->toPdf());
+
+ return $path;
+ }
+
+ private function printToPDF($socket, $browserId, array $parameters)
+ {
+ $browser = new Client(sprintf('ws://%s/devtools/browser/%s', $socket, $browserId));
+
+ // Open new tab, get its id
+ $result = $this->communicate($browser, 'Target.createTarget', [
+ 'url' => 'about:blank'
+ ]);
+ if (isset($result['targetId'])) {
+ $targetId = $result['targetId'];
+ } else {
+ throw new Exception('Expected target id. Got instead: ' . json_encode($result));
+ }
+
+ $page = new Client(sprintf('ws://%s/devtools/page/%s', $socket, $targetId), ['timeout' => 300]);
+
+ // enable various events
+ $this->communicate($page, 'Log.enable');
+ $this->communicate($page, 'Network.enable');
+ $this->communicate($page, 'Page.enable');
+
+ try {
+ $this->communicate($page, 'Console.enable');
+ } catch (Exception $_) {
+ // Deprecated, might fail
+ }
+
+ if (($url = $this->getUrl()) !== null) {
+ // Navigate to target
+ $result = $this->communicate($page, 'Page.navigate', [
+ 'url' => $url
+ ]);
+ if (isset($result['frameId'])) {
+ $frameId = $result['frameId'];
+ } else {
+ throw new Exception('Expected navigation frame. Got instead: ' . json_encode($result));
+ }
+
+ // wait for page to fully load
+ $this->waitFor($page, 'Page.frameStoppedLoading', ['frameId' => $frameId]);
+ } elseif (isset($this->document)) {
+ // If there's no url to load transfer the document's content directly
+ $this->communicate($page, 'Page.setDocumentContent', [
+ 'frameId' => $targetId,
+ 'html' => $this->document->render()
+ ]);
+
+ // wait for page to fully load
+ $this->waitFor($page, 'Page.loadEventFired');
+ } else {
+ throw new LogicException('Nothing to print');
+ }
+
+ // Wait for network activity to finish
+ $this->waitFor($page, self::WAIT_FOR_NETWORK);
+
+ // Wait for layout to initialize
+ if (isset($this->document)) {
+ // Ensure layout scripts work in the same environment as the pdf printing itself
+ $this->communicate($page, 'Emulation.setEmulatedMedia', ['media' => 'print']);
+
+ $this->communicate($page, 'Runtime.evaluate', [
+ 'timeout' => 1000,
+ 'expression' => 'setTimeout(() => new Layout().apply(), 0)'
+ ]);
+
+ $promisedResult = $this->communicate($page, 'Runtime.evaluate', [
+ 'awaitPromise' => true,
+ 'returnByValue' => true,
+ 'timeout' => 1000, // Failsafe, doesn't apply to `await` it seems
+ 'expression' => static::WAIT_FOR_LAYOUT
+ ]);
+ if (isset($promisedResult['exceptionDetails'])) {
+ if (isset($promisedResult['exceptionDetails']['exception']['description'])) {
+ Logger::error(
+ 'PDF layout failed to initialize: %s',
+ $promisedResult['exceptionDetails']['exception']['description']
+ );
+ } else {
+ Logger::warning('PDF layout failed to initialize. Pages might look skewed.');
+ }
+ }
+
+ // Reset media emulation, this may prevent the real media from coming into effect?
+ $this->communicate($page, 'Emulation.setEmulatedMedia', ['media' => '']);
+ }
+
+ // print pdf
+ $result = $this->communicate($page, 'Page.printToPDF', array_merge(
+ $parameters,
+ ['transferMode' => 'ReturnAsBase64', 'printBackground' => true]
+ ));
+ if (isset($result['data']) && !empty($result['data'])) {
+ $pdf = base64_decode($result['data']);
+ } else {
+ throw new Exception('Expected base64 data. Got instead: ' . json_encode($result));
+ }
+
+ // close tab
+ $result = $this->communicate($browser, 'Target.closeTarget', [
+ 'targetId' => $targetId
+ ]);
+ if (! isset($result['success'])) {
+ throw new Exception('Expected close confirmation. Got instead: ' . json_encode($result));
+ }
+
+ try {
+ $browser->close();
+ } catch (ConnectionException $e) {
+ // For some reason, the browser doesn't send a response
+ Logger::debug(sprintf('Failed to close browser connection: ' . $e->getMessage()));
+ }
+
+ return $pdf;
+ }
+
+ private function renderApiCall($method, $options = null)
+ {
+ $data = [
+ 'id' => time(),
+ 'method' => $method,
+ 'params' => $options ?: []
+ ];
+
+ return json_encode($data, JSON_FORCE_OBJECT);
+ }
+
+ private function parseApiResponse($payload)
+ {
+ $data = json_decode($payload, true);
+ if (isset($data['method']) || isset($data['result'])) {
+ return $data;
+ } elseif (isset($data['error'])) {
+ throw new Exception(sprintf(
+ 'Error response (%s): %s',
+ $data['error']['code'],
+ $data['error']['message']
+ ));
+ } else {
+ throw new Exception(sprintf('Unknown response received: %s', $payload));
+ }
+ }
+
+ private function registerEvent($method, $params)
+ {
+ if (Logger::getInstance()->getLevel() === Logger::DEBUG) {
+ $shortenValues = function ($params) use (&$shortenValues) {
+ foreach ($params as &$value) {
+ if (is_array($value)) {
+ $value = $shortenValues($value);
+ } elseif (is_string($value)) {
+ $shortened = substr($value, 0, 256);
+ if ($shortened !== $value) {
+ $value = $shortened . '...';
+ }
+ }
+ }
+
+ return $params;
+ };
+ $shortenedParams = $shortenValues($params);
+
+ Logger::debug(
+ 'Received CDP event: %s(%s)',
+ $method,
+ join(',', array_map(function ($param) use ($shortenedParams) {
+ return $param . '=' . json_encode($shortenedParams[$param]);
+ }, array_keys($shortenedParams)))
+ );
+ }
+
+ if ($method === 'Network.requestWillBeSent') {
+ $this->interceptedRequests[$params['requestId']] = $params;
+ } elseif ($method === 'Network.loadingFinished') {
+ unset($this->interceptedRequests[$params['requestId']]);
+ } elseif ($method === 'Network.loadingFailed') {
+ $requestData = $this->interceptedRequests[$params['requestId']];
+ unset($this->interceptedRequests[$params['requestId']]);
+
+ Logger::error(
+ 'Headless Chrome was unable to complete a request to "%s". Error: %s',
+ $requestData['request']['url'],
+ $params['errorText']
+ );
+ } else {
+ $this->interceptedEvents[] = ['method' => $method, 'params' => $params];
+ }
+ }
+
+ private function communicate(Client $ws, $method, $params = null)
+ {
+ Logger::debug('Transmitting CDP call: %s(%s)', $method, $params ? join(',', array_keys($params)) : '');
+ $ws->send($this->renderApiCall($method, $params));
+
+ do {
+ $response = $this->parseApiResponse($ws->receive());
+ $gotEvent = isset($response['method']);
+
+ if ($gotEvent) {
+ $this->registerEvent($response['method'], $response['params']);
+ }
+ } while ($gotEvent);
+
+ Logger::debug('Received CDP result: %s', empty($response['result'])
+ ? 'none'
+ : join(',', array_keys($response['result'])));
+
+ return $response['result'];
+ }
+
+ private function waitFor(Client $ws, $eventName, array $expectedParams = null)
+ {
+ if ($eventName !== self::WAIT_FOR_NETWORK) {
+ Logger::debug(
+ 'Awaiting CDP event: %s(%s)',
+ $eventName,
+ $expectedParams ? join(',', array_keys($expectedParams)) : ''
+ );
+ } elseif (empty($this->interceptedRequests)) {
+ return null;
+ }
+
+ $wait = true;
+ $interceptedPos = -1;
+
+ do {
+ if (isset($this->interceptedEvents[++$interceptedPos])) {
+ $response = $this->interceptedEvents[$interceptedPos];
+ $intercepted = true;
+ } else {
+ $response = $this->parseApiResponse($ws->receive());
+ $intercepted = false;
+ }
+
+ if (isset($response['method'])) {
+ $method = $response['method'];
+ $params = $response['params'];
+
+ if (! $intercepted) {
+ $this->registerEvent($method, $params);
+ }
+
+ if ($eventName === self::WAIT_FOR_NETWORK) {
+ $wait = ! empty($this->interceptedRequests);
+ } elseif ($method === $eventName) {
+ if ($expectedParams !== null) {
+ $diff = array_intersect_assoc($params, $expectedParams);
+ $wait = empty($diff);
+ } else {
+ $wait = false;
+ }
+ }
+
+ if (! $wait && $intercepted) {
+ unset($this->interceptedEvents[$interceptedPos]);
+ }
+ }
+ } while ($wait);
+
+ return $params;
+ }
+
+ /**
+ * Get the major version number of Chrome or false on failure
+ *
+ * @return int|false
+ *
+ * @throws Exception
+ */
+ public function getVersion()
+ {
+ switch (true) {
+ case $this->remote !== null:
+ try {
+ $result = $this->jsonVersion($this->remote[0], $this->remote[1]);
+ $version = $result['Browser'];
+ break;
+ } catch (Exception $e) {
+ if ($this->binary === null) {
+ throw $e;
+ } else {
+ Logger::warning(
+ 'Failed to connect to remote chrome: %s:%d (%s)',
+ $this->remote[0],
+ $this->remote[1],
+ $e
+ );
+ }
+ }
+
+ // Fallback to the local binary if a remote chrome is unavailable
+ case $this->binary !== null:
+ $command = new ShellCommand(
+ escapeshellarg($this->getBinary()) . ' ' . static::renderArgumentList(['--version']),
+ false
+ );
+
+ $output = $command->execute();
+
+ if ($command->getExitCode() !== 0) {
+ throw new \Exception($output->stderr);
+ }
+
+ $version = $output->stdout;
+ break;
+ default:
+ throw new LogicException('Set a binary or remote first');
+ }
+
+ if (preg_match('/(\d+)\.[\d.]+/', $version, $match)) {
+ return (int) $match[1];
+ }
+
+ return false;
+ }
+
+ /**
+ * Fetch result from the /json/version API endpoint
+ *
+ * @param string $host
+ * @param int $port
+ *
+ * @return bool|array
+ */
+ protected function jsonVersion($host, $port)
+ {
+ $client = new \GuzzleHttp\Client();
+ $response = $client->request('GET', sprintf('http://%s:%s/json/version', $host, $port));
+
+ if ($response->getStatusCode() !== 200) {
+ return false;
+ }
+
+ return json_decode($response->getBody(), true);
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 19:12:01 +0000