def __init__(self,
amqp_url='amqp://*****:*****@localhost:5672/%2f',
chrome_exe='chromium-browser',
max_active_browsers=1,
queue_name='urls',
exchange_name='umbra',
routing_key='urls'):
self.amqp_url = amqp_url
self.queue_name = queue_name
self.exchange_name = exchange_name
self.routing_key = routing_key
self.max_active_browsers = max_active_browsers
self._browser_pool = BrowserPool(size=max_active_browsers,
chrome_exe=chrome_exe)
def __init__(self, amqp_url='amqp://*****:*****@localhost:5672/%2f',
chrome_exe='chromium-browser', max_active_browsers=1,
queue_name='urls', exchange_name='umbra'):
self.amqp_url = amqp_url
self.queue_name = queue_name
self.exchange_name = exchange_name
self.max_active_browsers = max_active_browsers
self._browser_pool = BrowserPool(size=max_active_browsers, chrome_exe=chrome_exe)
class AmqpBrowserController:
"""
Consumes amqp messages representing requests to browse urls, from the
specified amqp queue (default: "urls") on the specified amqp exchange
(default: "umbra"). Incoming amqp message is a json object with 3
attributes:
{
"clientId": "umbra.client.123",
"url": "http://example.com/my_fancy_page",
"behaviorParameters": {"some":"parameter","another":"thing"},
"metadata": {"arbitrary":"fields", "etc":4}
}
"url" is the url to browse.
"clientId" uniquely identifies the client of umbra. Umbra uses the clientId
as the amqp routing key, to direct information via amqp back to the client.
It sends this information on the same specified amqp exchange (default:
"umbra").
"behaviorParameters" are used to populate the javascript behavior template.
Each url requested in the browser is published to amqp this way. The
outgoing amqp message is a json object:
{
"url": "http://example.com/images/embedded_thing.jpg",
"method": "GET",
"headers": {"User-Agent": "...", "Accept": "...", ...},
"parentUrl": "http://example.com/my_fancy_page",
"parentUrlMetadata": {"arbitrary":"fields", "etc":4, ...}
}
POST requests have an additional field, postData.
"""
logger = logging.getLogger(__module__ + "." + __qualname__)
def __init__(self,
amqp_url='amqp://*****:*****@localhost:5672/%2f',
chrome_exe='chromium-browser',
max_active_browsers=1,
queue_name='urls',
exchange_name='umbra',
routing_key='urls'):
self.amqp_url = amqp_url
self.queue_name = queue_name
self.exchange_name = exchange_name
self.routing_key = routing_key
self.max_active_browsers = max_active_browsers
self._browser_pool = BrowserPool(size=max_active_browsers,
chrome_exe=chrome_exe)
def start(self):
self._browsing_threads = set()
self._browsing_threads_lock = threading.Lock()
self._exchange = kombu.Exchange(name=self.exchange_name,
type='direct',
durable=True)
self._reconnect_requested = False
self._producer = None
self._producer_lock = threading.Lock()
with self._producer_lock:
self._producer_conn = kombu.Connection(self.amqp_url)
self._producer = self._producer_conn.Producer(serializer='json')
self._consumer_thread = threading.Thread(target=self._consume_amqp,
name='AmqpConsumerThread')
self._consumer_stop = threading.Event()
self._consumer_thread.start()
def shutdown(self):
self.logger.info("shutting down amqp consumer {}".format(
self.amqp_url))
self._consumer_stop.set()
self._consumer_thread.join()
def shutdown_now(self):
self._consumer_stop.set()
self._browser_pool.shutdown_now()
self._consumer_thread.join()
def reconnect(self, *args, **kwargs):
self._reconnect_requested = True
self._browser_pool.shutdown_now()
def _wait_for_and_browse_urls(self, conn, consumer, timeout):
start = time.time()
browser = None
consumer.qos(prefetch_count=self.max_active_browsers)
while not self._consumer_stop.is_set(
) and time.time() - start < timeout and not self._reconnect_requested:
try:
browser = self._browser_pool.acquire(
) # raises KeyError if none available
browser.start()
def callback(body, message):
try:
client_id = body.get('clientId')
url = body['url']
metadata = body.get('metadata')
behavior_parameters = body.get('behaviorParameters')
except:
self.logger.error("unable to decipher message %s",
message,
exc_info=True)
self.logger.error("discarding bad message")
message.reject()
browser.stop()
self._browser_pool.release(browser)
return
self._start_browsing_page(browser, message, client_id, url,
metadata, behavior_parameters)
consumer.callbacks = [callback]
while True:
try:
conn.drain_events(timeout=0.5)
break # out of "while True" to acquire another browser
except socket.timeout:
pass
except socket.error:
self.logger.error(
"problem consuming messages from AMQP, will try reconnecting after active browsing finishes",
exc_info=True)
self._reconnect_requested = True
if self._consumer_stop.is_set() or time.time(
) - start >= timeout or self._reconnect_requested:
browser.stop()
self._browser_pool.release(browser)
break
except KeyError:
# no browsers available
time.sleep(0.5)
except:
self.logger.critical("problem with browser initialization",
exc_info=True)
time.sleep(0.5)
finally:
consumer.callbacks = None
def _wait_for_active_browsers(self):
self.logger.info("waiting for browsing threads to finish")
while True:
with self._browsing_threads_lock:
if len(self._browsing_threads) == 0:
break
time.sleep(0.5)
self.logger.info("active browsing threads finished")
def _consume_amqp(self):
# XXX https://webarchive.jira.com/browse/ARI-3811
# After running for some amount of time (3 weeks in the latest case),
# consumer looks normal but doesn't consume any messages. Not clear if
# it's hanging in drain_events() or not. As a temporary measure for
# mitigation (if it works) or debugging (if it doesn't work), close and
# reopen the connection every 2.5 hours
RECONNECT_AFTER_SECONDS = 150 * 60
url_queue = kombu.Queue(self.queue_name,
exchange=self._exchange,
routing_key=self.routing_key)
while not self._consumer_stop.is_set():
try:
self.logger.info("connecting to amqp exchange={} at {}".format(
self._exchange.name, self.amqp_url))
self._reconnect_requested = False
with kombu.Connection(self.amqp_url) as conn:
with conn.Consumer(url_queue) as consumer:
self._wait_for_and_browse_urls(
conn, consumer, timeout=RECONNECT_AFTER_SECONDS)
# need to wait for browsers to finish here, before closing
# the amqp connection, because they use it to do
# message.ack() after they finish browsing a page
self._wait_for_active_browsers()
except BaseException as e:
self.logger.error("caught exception {}".format(e),
exc_info=True)
time.sleep(0.5)
self.logger.error("attempting to reopen amqp connection")
def _start_browsing_page(self, browser, message, client_id, url,
parent_url_metadata, behavior_parameters):
def on_response(chrome_msg):
if (chrome_msg['params']['response']['url'].lower().startswith(
'data:')
or chrome_msg['params']['response']['fromDiskCache'] or
not 'requestHeaders' in chrome_msg['params']['response']):
return
payload = {
'url': chrome_msg['params']['response']['url'],
'headers': chrome_msg['params']['response']['requestHeaders'],
'parentUrl': url,
'parentUrlMetadata': parent_url_metadata,
}
if ':method' in chrome_msg['params']['response']['requestHeaders']:
# happens when http transaction is http 2.0
payload['method'] = chrome_msg['params']['response'][
'requestHeaders'][':method']
elif 'requestHeadersText' in chrome_msg['params']['response']:
req = chrome_msg['params']['response']['requestHeadersText']
payload['method'] = req[:req.index(' ')]
else:
self.logger.warn(
'unable to identify http method (assuming GET) chrome_msg=%s',
chrome_msg)
payload['method'] = 'GET'
self.logger.debug(
'sending to amqp exchange=%s routing_key=%s payload=%s',
self.exchange_name, client_id, payload)
with self._producer_lock:
publish = self._producer_conn.ensure(self._producer,
self._producer.publish)
publish(payload,
exchange=self._exchange,
routing_key=client_id)
def browse_page_sync():
self.logger.info(
'browser=%s client_id=%s url=%s behavior_parameters=%s',
browser, client_id, url, behavior_parameters)
try:
browser.browse_page(url,
on_response=on_response,
behavior_parameters=behavior_parameters)
message.ack()
except BrowsingException as e:
self.logger.warn(
"browsing did not complete normally, requeuing url {} - {}"
.format(url, e))
message.requeue()
except:
self.logger.critical(
"problem browsing page, requeuing url {}, may have lost browser process"
.format(url),
exc_info=True)
message.requeue()
finally:
browser.stop()
self._browser_pool.release(browser)
def browse_thread_run_then_cleanup():
browse_page_sync()
with self._browsing_threads_lock:
self._browsing_threads.remove(threading.current_thread())
import random
thread_name = "BrowsingThread{}-{}".format(
browser.chrome_port, ''.join((random.choice(
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
) for _ in range(6))))
th = threading.Thread(target=browse_thread_run_then_cleanup,
name=thread_name)
with self._browsing_threads_lock:
self._browsing_threads.add(th)
th.start()
class AmqpBrowserController:
"""
Consumes amqp messages representing requests to browse urls, from the
specified amqp queue (default: "urls") on the specified amqp exchange
(default: "umbra"). Incoming amqp message is a json object with 3
attributes:
{
"clientId": "umbra.client.123",
"url": "http://example.com/my_fancy_page",
"behaviorParameters": {"some":"parameter","another":"thing"},
"metadata": {"arbitrary":"fields", "etc":4}
}
"url" is the url to browse.
"clientId" uniquely identifies the client of umbra. Umbra uses the clientId
as the amqp routing key, to direct information via amqp back to the client.
It sends this information on the same specified amqp exchange (default:
"umbra").
"behaviorParameters" are used to populate the javascript behavior template.
Each url requested in the browser is published to amqp this way. The
outgoing amqp message is a json object:
{
"url": "http://example.com/images/embedded_thing.jpg",
"method": "GET",
"headers": {"User-Agent": "...", "Accept": "...", ...},
"parentUrl": "http://example.com/my_fancy_page",
"parentUrlMetadata": {"arbitrary":"fields", "etc":4, ...}
}
POST requests have an additional field, postData.
"""
logger = logging.getLogger(__module__ + "." + __qualname__)
def __init__(self, amqp_url='amqp://*****:*****@localhost:5672/%2f',
chrome_exe='chromium-browser', max_active_browsers=1,
queue_name='urls', exchange_name='umbra', routing_key='urls'):
self.amqp_url = amqp_url
self.queue_name = queue_name
self.exchange_name = exchange_name
self.routing_key = routing_key
self.max_active_browsers = max_active_browsers
self._browser_pool = BrowserPool(size=max_active_browsers, chrome_exe=chrome_exe)
def start(self):
self._browsing_threads = set()
self._browsing_threads_lock = threading.Lock()
self._exchange = kombu.Exchange(name=self.exchange_name, type='direct',
durable=True)
self._reconnect_requested = False
self._producer = None
self._producer_lock = threading.Lock()
with self._producer_lock:
self._producer_conn = kombu.Connection(self.amqp_url)
self._producer = self._producer_conn.Producer(serializer='json')
self._consumer_thread = threading.Thread(target=self._consume_amqp, name='AmqpConsumerThread')
self._consumer_stop = threading.Event()
self._consumer_thread.start()
def shutdown(self):
self.logger.info("shutting down amqp consumer {}".format(self.amqp_url))
self._consumer_stop.set()
self._consumer_thread.join()
def shutdown_now(self):
self._consumer_stop.set()
self._browser_pool.shutdown_now()
self._consumer_thread.join()
def reconnect(self, *args, **kwargs):
self._reconnect_requested = True
self._browser_pool.shutdown_now()
def _wait_for_and_browse_urls(self, conn, consumer, timeout):
start = time.time()
browser = None
consumer.qos(prefetch_count=self.max_active_browsers)
while not self._consumer_stop.is_set() and time.time() - start < timeout and not self._reconnect_requested:
try:
browser = self._browser_pool.acquire() # raises KeyError if none available
browser.start()
def callback(body, message):
try:
client_id = body.get('clientId')
url = body['url']
metadata = body.get('metadata')
behavior_parameters = body.get('behaviorParameters')
except:
self.logger.error("unable to decipher message %s",
message, exc_info=True)
self.logger.error("discarding bad message")
message.reject()
browser.stop()
self._browser_pool.release(browser)
return
self._start_browsing_page(browser, message, client_id, url,
metadata, behavior_parameters)
consumer.callbacks = [callback]
while True:
try:
conn.drain_events(timeout=0.5)
break # out of "while True" to acquire another browser
except socket.timeout:
pass
except socket.error:
self.logger.error("problem consuming messages from AMQP, will try reconnecting after active browsing finishes", exc_info=True)
self._reconnect_requested = True
if self._consumer_stop.is_set() or time.time() - start >= timeout or self._reconnect_requested:
browser.stop()
self._browser_pool.release(browser)
break
except KeyError:
# no browsers available
time.sleep(0.5)
except:
self.logger.critical("problem with browser initialization", exc_info=True)
time.sleep(0.5)
finally:
consumer.callbacks = None
def _wait_for_active_browsers(self):
self.logger.info("waiting for browsing threads to finish")
while True:
with self._browsing_threads_lock:
if len(self._browsing_threads) == 0:
break
time.sleep(0.5)
self.logger.info("active browsing threads finished")
def _consume_amqp(self):
# XXX https://webarchive.jira.com/browse/ARI-3811
# After running for some amount of time (3 weeks in the latest case),
# consumer looks normal but doesn't consume any messages. Not clear if
# it's hanging in drain_events() or not. As a temporary measure for
# mitigation (if it works) or debugging (if it doesn't work), close and
# reopen the connection every 2.5 hours
RECONNECT_AFTER_SECONDS = 150 * 60
url_queue = kombu.Queue(self.queue_name, exchange=self._exchange, routing_key=self.routing_key)
while not self._consumer_stop.is_set():
try:
self.logger.info("connecting to amqp exchange={} at {}".format(self._exchange.name, self.amqp_url))
self._reconnect_requested = False
with kombu.Connection(self.amqp_url) as conn:
with conn.Consumer(url_queue) as consumer:
self._wait_for_and_browse_urls(conn, consumer, timeout=RECONNECT_AFTER_SECONDS)
# need to wait for browsers to finish here, before closing
# the amqp connection, because they use it to do
# message.ack() after they finish browsing a page
self._wait_for_active_browsers()
except BaseException as e:
self.logger.error("caught exception {}".format(e), exc_info=True)
time.sleep(0.5)
self.logger.error("attempting to reopen amqp connection")
def _start_browsing_page(self, browser, message, client_id, url, parent_url_metadata, behavior_parameters):
def on_response(chrome_msg):
if (chrome_msg['params']['response']['url'].lower().startswith('data:')
or chrome_msg['params']['response']['fromDiskCache']
or not 'requestHeaders' in chrome_msg['params']['response']):
return
payload = {
'url': chrome_msg['params']['response']['url'],
'headers': chrome_msg['params']['response']['requestHeaders'],
'parentUrl': url,
'parentUrlMetadata': parent_url_metadata,
}
if ':method' in chrome_msg['params']['response']['requestHeaders']:
# happens when http transaction is http 2.0
payload['method'] = chrome_msg['params']['response']['requestHeaders'][':method']
elif 'requestHeadersText' in chrome_msg['params']['response']:
req = chrome_msg['params']['response']['requestHeadersText']
payload['method'] = req[:req.index(' ')]
else:
self.logger.warn('unable to identify http method (assuming GET) chrome_msg=%s',
chrome_msg)
payload['method'] = 'GET'
self.logger.debug(
'sending to amqp exchange=%s routing_key=%s payload=%s',
self.exchange_name, client_id, payload)
with self._producer_lock:
publish = self._producer_conn.ensure(self._producer,
self._producer.publish)
publish(payload, exchange=self._exchange, routing_key=client_id)
def browse_page_sync():
self.logger.info(
'browser=%s client_id=%s url=%s behavior_parameters=%s',
browser, client_id, url, behavior_parameters)
try:
browser.browse_page(url, on_response=on_response,
behavior_parameters=behavior_parameters)
message.ack()
except BrowsingException as e:
self.logger.warn("browsing did not complete normally, requeuing url {} - {}".format(url, e))
message.requeue()
except:
self.logger.critical("problem browsing page, requeuing url {}, may have lost browser process".format(url), exc_info=True)
message.requeue()
finally:
browser.stop()
self._browser_pool.release(browser)
def browse_thread_run_then_cleanup():
browse_page_sync()
with self._browsing_threads_lock:
self._browsing_threads.remove(threading.current_thread())
import random
thread_name = "BrowsingThread{}-{}".format(browser.chrome_port,
''.join((random.choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789') for _ in range(6))))
th = threading.Thread(target=browse_thread_run_then_cleanup, name=thread_name)
with self._browsing_threads_lock:
self._browsing_threads.add(th)
th.start()