def _page_load_event_fired(self, message):
self.logger.info(
"Page.loadEventFired, moving on to starting behaviors url={}".
format(self.url))
self._behavior = Behavior(self.url, self)
self._behavior.start(self.behavior_parameters)
self._waiting_on_document_url_msg_id = self.send_to_chrome(
method="Runtime.evaluate", params={"expression": "document.URL"})
def _page_load_event_fired(self, message):
def page_url_after_load_event(message):
if message["result"]["result"]["value"] != self.url:
if self.on_url_change:
self.on_url_change(message["result"]["result"]["value"])
msg_id = self.send_to_chrome(
method="Runtime.evaluate",
params={"expression":"document.URL"})
self._waiting_on_result_messages[msg_id] = page_url_after_load_event
self.logger.info("Page.loadEventFired, moving on to starting behaviors url={}".format(self.url))
self._behavior = Behavior(self.url, self)
self._behavior.start(self.behavior_parameters)
def _handle_result_message(self, message):
if message["id"] == self._waiting_on_screenshot_msg_id:
if self.on_screenshot:
self.on_screenshot(base64.b64decode(message["result"]["data"]))
self._waiting_on_screenshot_msg_id = None
self.logger.info("got screenshot, moving on to starting behaviors url={}".format(self.url))
self._behavior = Behavior(self.url, self)
self._behavior.start()
elif message["id"] == self._waiting_on_outlinks_msg_id:
self.logger.debug("got outlinks message=%s", message)
self._outlinks = frozenset(message["result"]["result"]["value"].split(" "))
elif message["id"] == self._waiting_on_document_url_msg_id:
if message["result"]["result"]["value"] != self.url:
if self.on_url_change:
self.on_url_change(message["result"]["result"]["value"])
self._waiting_on_document_url_msg_id = None
elif self._behavior and self._behavior.is_waiting_on_result(message["id"]):
self._behavior.notify_of_result(message)
class Browser:
"""
Runs chrome/chromium to synchronously browse one page at a time using
worker.browse_page(). Should not be accessed from multiple threads.
"""
logger = logging.getLogger(__module__ + "." + __qualname__)
HARD_TIMEOUT_SECONDS = 20 * 60
def __init__(
self, chrome_port=9222, chrome_exe='chromium-browser', proxy=None,
ignore_cert_errors=False):
self.command_id = itertools.count(1)
self.chrome_port = chrome_port
self.chrome_exe = chrome_exe
self.proxy = proxy
self.ignore_cert_errors = ignore_cert_errors
self._behavior = None
self._websock = None
self._abort_browse_page = False
self._chrome_instance = None
self._aw_snap_hes_dead_jim = None
self._work_dir = None
self._websocket_url = None
def __repr__(self):
return "{}.{}:{}".format(Browser.__module__, Browser.__qualname__, self.chrome_port)
def __enter__(self):
self.start()
return self
def __exit__(self, *args):
self.stop()
def start(self, proxy=None, cookie_db=None):
if not self._chrome_instance:
self._chrome_instance = Chrome(
port=self.chrome_port, executable=self.chrome_exe,
ignore_cert_errors=self.ignore_cert_errors,
proxy=proxy or self.proxy, cookie_db=None)
try:
self._websocket_url = self._chrome_instance.start()
except:
self._chrome_instance = None
raise
def stop(self):
try:
if self.is_running():
self._chrome_instance.stop()
self._chrome_instance = None
self._websocket_url = None
except:
self.logger.error("problem stopping", exc_info=True)
def is_running(self):
return bool(self._websocket_url)
def abort_browse_page(self):
self._abort_browse_page = True
def persist_and_read_cookie_db(self):
if self._chrome_instance:
return self._chrome_instance.persist_and_read_cookie_db()
else:
return None
def browse_page(
self, url, extra_headers=None, behavior_parameters=None,
user_agent=None,
on_request=None, on_response=None, on_screenshot=None,
on_url_change=None):
"""
Synchronously loads a page, runs behaviors, and takes a screenshot.
Raises BrowsingException if browsing the page fails in a non-critical
way.
Returns extracted outlinks.
"""
if not self.is_running():
raise BrowsingException("browser has not been started")
self.url = url
self.extra_headers = extra_headers
self.user_agent = user_agent
self.on_request = on_request
self.on_screenshot = on_screenshot
self.on_url_change = on_url_change
self.on_response = on_response
self.behavior_parameters = behavior_parameters
self._outlinks = None
self._reached_limit = None
self._aw_snap_hes_dead_jim = None
self._abort_browse_page = False
self._has_screenshot = False
self._waiting_on_result_messages = {}
self._result_message_timeout = None
self._websock = websocket.WebSocketApp(
self._websocket_url, on_open=self._visit_page,
on_message=self._wrap_handle_message)
thread_name = "WebsockThread:{}-{:%Y%m%d%H%M%S}".format(
self.chrome_port, datetime.datetime.utcnow())
websock_thread = threading.Thread(
target=self._websock.run_forever, name=thread_name,
kwargs={'ping_timeout':0.5})
websock_thread.start()
self._start = time.time()
aborted = False
try:
while True:
time.sleep(0.5)
if self._browse_interval_func():
return self._outlinks
finally:
if (self._websock and self._websock.sock
and self._websock.sock.connected):
try:
self._websock.close()
except BaseException as e:
self.logger.error(
"exception closing websocket %s - %s" % (
self._websock, e))
websock_thread.join(timeout=30)
if websock_thread.is_alive():
self.logger.error(
"%s still alive 30 seconds after closing %s, will "
"forcefully nudge it again" % (
websock_thread, self._websock))
self._websock.keep_running = False
websock_thread.join(timeout=30)
if websock_thread.is_alive():
self.logger.critical(
"%s still alive 60 seconds after closing %s" % (
websock_thread, self._websock))
self._behavior = None
OUTLINKS_JS = r"""
var __brzl_framesDone = new Set();
var __brzl_compileOutlinks = function(frame) {
__brzl_framesDone.add(frame);
if (frame && frame.document) {
var outlinks = Array.prototype.slice.call(
frame.document.querySelectorAll('a[href]'));
for (var i = 0; i < frame.frames.length; i++) {
if (frame.frames[i] && !__brzl_framesDone.has(frame.frames[i])) {
outlinks = outlinks.concat(__brzl_compileOutlinks(frame.frames[i]));
}
}
}
return outlinks;
}
__brzl_compileOutlinks(window).join('\n');
"""
def _chain_chrome_messages(self, chain):
"""
Sends a series of messages to chrome/chromium on the debugging protocol
websocket. Waits for a reply from each one before sending the next.
Enforces a timeout waiting for each reply. If the timeout is hit, sets
self._result_message_timeout with a ResultMessageTimeout (an exception
class). Takes an array of dicts, each of which should look like this:
{
"info": "human readable description",
"chrome_msg": { ... }, # message to send to chrome, as a dict
"timeout": 30, # timeout in seconds
"callback": my_callback, # takes one arg, the result message
}
The code is rather convoluted because of the asynchronous nature of the
whole thing. See how it's used in _start_postbehavior_chain.
"""
timer = None
def callback(message):
if timer:
timer.cancel()
if "callback" in chain[0]:
chain[0]["callback"](message)
self._chain_chrome_messages(chain[1:])
def timeout():
self._result_message_timeout = ResultMessageTimeout(
"timed out after %.1fs waiting for result message "
"for %s", chain[0]["timeout"], chain[0]["chrome_msg"])
if chain:
msg_id = self.send_to_chrome(**chain[0]["chrome_msg"])
self._waiting_on_result_messages[msg_id] = callback
self.logger.info(
"msg_id=%s for message %s", msg_id, chain[0]["chrome_msg"])
timer = threading.Timer(chain[0]["timeout"], timeout)
timer.daemon = True
timer.start()
else:
self.logger.info("finished chrome message chain")
def _start_postbehavior_chain(self):
if self.on_screenshot:
chain = [{
"info": "scrolling to top",
"chrome_msg": {
"method": "Runtime.evaluate",
"params": {"expression": "window.scrollTo(0, 0);"},
},
"timeout": 30,
"callback": lambda message: None,
}, {
"info": "requesting screenshot",
"chrome_msg": {"method": "Page.captureScreenshot"},
"timeout": 30,
"callback": lambda message: (
self.on_screenshot and self.on_screenshot(
base64.b64decode(message["result"]["data"]))),
}]
else:
chain = []
def set_outlinks(message):
if message["result"]["result"]["value"]:
self._outlinks = frozenset(
message["result"]["result"]["value"].split("\n"))
else:
self._outlinks = frozenset()
chain.append({
"info": "retrieving outlinks",
"chrome_msg": {
"method": "Runtime.evaluate",
"params": {"expression": self.OUTLINKS_JS},
},
"timeout": 60,
"callback": set_outlinks,
})
self._chain_chrome_messages(chain)
def _browse_interval_func(self):
"""Called periodically while page is being browsed. Returns True when
finished browsing."""
if (not self._websock or not self._websock.sock
or not self._websock.sock.connected):
raise BrowsingException(
"websocket closed, did chrome die? {}".format(
self._websocket_url))
elif self._result_message_timeout:
raise self._result_message_timeout
elif self._aw_snap_hes_dead_jim:
raise BrowsingException(
"""chrome tab went "aw snap" or "he's dead jim"!""")
elif self._outlinks is not None:
# setting self._outlinks is the last thing that happens in the
# post-behavior chain
return True
elif (self._behavior != None and self._behavior.is_finished()
or time.time() - self._start > Browser.HARD_TIMEOUT_SECONDS):
if self._behavior and self._behavior.is_finished():
self.logger.info(
"behavior decided it's finished with %s", self.url)
else:
self.logger.info(
"reached hard timeout of %s seconds url=%s",
Browser.HARD_TIMEOUT_SECONDS, self.url)
self._behavior = None
self._start_postbehavior_chain()
return False
elif self._reached_limit:
raise self._reached_limit
elif self._abort_browse_page:
raise BrowsingAborted("browsing page aborted")
else:
return False
def send_to_chrome(self, suppress_logging=False, **kwargs):
msg_id = next(self.command_id)
kwargs["id"] = msg_id
msg = json.dumps(kwargs)
if not suppress_logging:
self.logger.debug("sending message to %s: %s", self._websock, msg)
self._websock.send(msg)
return msg_id
def _visit_page(self, websock):
# navigate to about:blank here to avoid situation where we navigate to
# the same page that we're currently on, perhaps with a different
# #fragment, which prevents Page.loadEventFired from happening
self.send_to_chrome(method="Page.navigate", params={"url": "about:blank"})
self.send_to_chrome(method="Network.enable")
self.send_to_chrome(method="Page.enable")
self.send_to_chrome(method="Console.enable")
self.send_to_chrome(method="Debugger.enable")
self.send_to_chrome(method="Runtime.enable")
headers = self.extra_headers or {}
headers['Accept-Encoding'] = 'identity'
self.send_to_chrome(
method="Network.setExtraHTTPHeaders",
params={"headers":headers})
if self.user_agent:
self.send_to_chrome(method="Network.setUserAgentOverride", params={"userAgent": self.user_agent})
# disable google analytics, see _handle_message() where breakpoint is caught "Debugger.paused"
self.send_to_chrome(method="Debugger.setBreakpointByUrl", params={"lineNumber": 1, "urlRegex":"https?://www.google-analytics.com/analytics.js"})
# navigate to the page!
self.send_to_chrome(method="Page.navigate", params={"url": self.url})
def _wrap_handle_message(self, websock, message):
try:
self._handle_message(websock, message)
except:
self.logger.error(
"uncaught exception in _handle_message message=%s",
message, exc_info=True)
self.abort_browse_page()
def _network_request_will_be_sent(self, message):
if self._behavior:
self._behavior.notify_of_activity()
if message["params"]["request"]["url"].lower().startswith("data:"):
self.logger.debug("ignoring data url {}".format(message["params"]["request"]["url"][:80]))
elif self.on_request:
self.on_request(message)
def _network_response_received(self, message):
if (not self._reached_limit
and message["params"]["response"]["status"] == 420
and "Warcprox-Meta" in CaseInsensitiveDict(
message["params"]["response"]["headers"])):
warcprox_meta = json.loads(CaseInsensitiveDict(
message["params"]["response"]["headers"])["Warcprox-Meta"])
self._reached_limit = brozzler.ReachedLimit(
warcprox_meta=warcprox_meta)
self.logger.info("reached limit %s", self._reached_limit)
if self.on_response:
self.on_response(message)
def _page_load_event_fired(self, message):
def page_url_after_load_event(message):
if message["result"]["result"]["value"] != self.url:
if self.on_url_change:
self.on_url_change(message["result"]["result"]["value"])
msg_id = self.send_to_chrome(
method="Runtime.evaluate",
params={"expression":"document.URL"})
self._waiting_on_result_messages[msg_id] = page_url_after_load_event
self.logger.info("Page.loadEventFired, moving on to starting behaviors url={}".format(self.url))
self._behavior = Behavior(self.url, self)
self._behavior.start(self.behavior_parameters)
def _console_message_added(self, message):
self.logger.debug("%s console.%s %s", self._websock.url,
message["params"]["message"]["level"],
message["params"]["message"]["text"])
def _debugger_paused(self, message):
# We hit the breakpoint set in visit_page. Get rid of google
# analytics script!
self.logger.debug("debugger paused! message={}".format(message))
scriptId = message['params']['callFrames'][0]['location']['scriptId']
# replace script
self.send_to_chrome(method="Debugger.setScriptSource", params={"scriptId": scriptId, "scriptSource":"console.log('google analytics is no more!');"})
# resume execution
self.send_to_chrome(method="Debugger.resume")
def _handle_message(self, websock, json_message):
message = json.loads(json_message)
if "method" in message:
if message["method"] == "Network.requestWillBeSent":
self._network_request_will_be_sent(message)
elif message["method"] == "Network.responseReceived":
self._network_response_received(message)
elif message["method"] == "Page.loadEventFired":
self._page_load_event_fired(message)
elif message["method"] == "Console.messageAdded":
self._console_message_added(message)
elif message["method"] == "Debugger.paused":
self._debugger_paused(message)
elif message["method"] == "Inspector.targetCrashed":
self._aw_snap_hes_dead_jim = message
# elif message["method"] in (
# "Network.dataReceived", "Network.responseReceived",
# "Network.loadingFinished"):
# pass
# else:
# self.logger.debug("%s %s", message["method"], json_message)
elif "result" in message:
if message["id"] in self._waiting_on_result_messages:
callback = self._waiting_on_result_messages[message["id"]]
del self._waiting_on_result_messages[message["id"]]
self.logger.debug(
"received result for message id=%s, calling %s",
message["id"], callback)
callback(message)
elif self._behavior and self._behavior.is_waiting_on_result(
message["id"]):
self._behavior.notify_of_result(message)
class Browser:
"""
Runs chrome/chromium to synchronously browse one page at a time using
worker.browse_page(). Should not be accessed from multiple threads.
"""
logger = logging.getLogger(__module__ + "." + __qualname__)
HARD_TIMEOUT_SECONDS = 20 * 60
def __init__(self, chrome_port=9222, chrome_exe='chromium-browser', proxy=None, ignore_cert_errors=False):
self.command_id = itertools.count(1)
self.chrome_port = chrome_port
self.chrome_exe = chrome_exe
self.proxy = proxy
self.ignore_cert_errors = ignore_cert_errors
self._behavior = None
self._websock = None
self._abort_browse_page = False
self._chrome_instance = None
self._aw_snap_hes_dead_jim = None
self._work_dir = None
self._websocket_url = None
def __repr__(self):
return "{}.{}:{}".format(Browser.__module__, Browser.__qualname__, self.chrome_port)
def __enter__(self):
self.start()
return self
def __exit__(self, *args):
self.stop()
def start(self, proxy=None):
if not self._chrome_instance:
# these can raise exceptions
self.chrome_port = self._find_available_port()
self._work_dir = tempfile.TemporaryDirectory()
self._chrome_instance = Chrome(port=self.chrome_port,
executable=self.chrome_exe,
user_home_dir=self._work_dir.name,
user_data_dir=os.sep.join([self._work_dir.name, "chrome-user-data"]),
ignore_cert_errors=self.ignore_cert_errors,
proxy=proxy or self.proxy)
self._websocket_url = self._chrome_instance.start()
def stop(self):
try:
if self.is_running():
self._chrome_instance.stop()
self._chrome_instance = None
try:
self._work_dir.cleanup()
except:
self.logger.error("exception deleting %s", self._work_dir,
exc_info=True)
self._work_dir = None
self._websocket_url = None
except:
self.logger.error("problem stopping", exc_info=True)
def _find_available_port(self):
port_available = False
port = self.chrome_port
try:
conns = psutil.net_connections(kind="tcp")
except psutil.AccessDenied:
return port
for p in range(port, 65535):
if any(connection.laddr[1] == p for connection in conns):
self.logger.warn("port %s already open, will try %s", p, p+1)
else:
port = p
break
return port
def is_running(self):
return bool(self._websocket_url)
def abort_browse_page(self):
self._abort_browse_page = True
def browse_page(
self, url, extra_headers=None, behavior_parameters=None,
on_request=None, on_response=None, on_screenshot=None,
on_url_change=None):
"""Synchronously loads a page, takes a screenshot, and runs behaviors.
Raises BrowsingException if browsing the page fails in a non-critical
way.
Returns extracted outlinks.
"""
if not self.is_running():
raise BrowsingException("browser has not been started")
self.url = url
self.extra_headers = extra_headers
self.on_request = on_request
self.on_screenshot = on_screenshot
self.on_url_change = on_url_change
self.on_response = on_response
self.behavior_parameters = behavior_parameters
self._waiting_on_scroll_to_top_msg_id = None
self._waiting_on_screenshot_msg_id = None
self._waiting_on_document_url_msg_id = None
self._waiting_on_outlinks_msg_id = None
self._outlinks = None
self._reached_limit = None
self._aw_snap_hes_dead_jim = None
self._abort_browse_page = False
self._has_screenshot = False
self._websock = websocket.WebSocketApp(self._websocket_url,
on_open=self._visit_page, on_message=self._wrap_handle_message)
threadName = "WebsockThread{}-{}".format(self.chrome_port,
''.join((random.choice('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789') for _ in range(6))))
websock_thread = threading.Thread(target=self._websock.run_forever, name=threadName, kwargs={'ping_timeout':0.5})
websock_thread.start()
self._start = time.time()
aborted = False
try:
while True:
time.sleep(0.5)
if self._browse_interval_func():
break
while True:
time.sleep(0.5)
if self._post_behavior_interval_func():
return self._outlinks
finally:
if self._websock and self._websock.sock and self._websock.sock.connected:
try:
self._websock.close()
except BaseException as e:
self.logger.error("exception closing websocket {} - {}".format(self._websock, e))
websock_thread.join(timeout=30)
if websock_thread.is_alive():
self.logger.error("{} still alive 30 seconds after closing {}, will forcefully nudge it again".format(websock_thread, self._websock))
self._websock.keep_running = False
websock_thread.join(timeout=30)
if websock_thread.is_alive():
self.logger.critical("{} still alive 60 seconds after closing {}".format(websock_thread, self._websock))
self._behavior = None
def _post_behavior_interval_func(self):
"""Called periodically after behavior is finished on the page. Returns
true when post-behavior tasks are finished."""
if not self._has_screenshot and (
not self._waiting_on_scroll_to_top_msg_id
and not self._waiting_on_screenshot_msg_id):
if time.time() - self._start > Browser.HARD_TIMEOUT_SECONDS:
self.logger.info(
"reached hard timeout of {} seconds url={}".format(
Browser.HARD_TIMEOUT_SECONDS, self.url))
else:
self.logger.info(
"behavior decided it's finished with %s", self.url)
self.logger.info(
"scrolling to the top, then requesting screenshot %s",
self.url)
self._waiting_on_scroll_to_top_msg_id = self.send_to_chrome(
method="Runtime.evaluate",
params={"expression":"window.scrollTo(0, 0);"})
return False
elif not self._has_screenshot and (
self._waiting_on_scroll_to_top_msg_id
or self._waiting_on_screenshot_msg_id):
return False
if self._outlinks:
self.logger.info("got outlinks, finished browsing %s", self.url)
return True
elif not self._waiting_on_outlinks_msg_id:
self.logger.info("retrieving outlinks for %s", self.url)
self._waiting_on_outlinks_msg_id = self.send_to_chrome(
method="Runtime.evaluate",
params={"expression":"Array.prototype.slice.call(document.querySelectorAll('a[href]')).join(' ')"})
return False
else: # self._waiting_on_outlinks_msg_id
return False
def _browse_interval_func(self):
"""Called periodically while page is being browsed. Returns True when
finished browsing."""
if not self._websock or not self._websock.sock or not self._websock.sock.connected:
raise BrowsingException("websocket closed, did chrome die? {}".format(self._websocket_url))
elif self._aw_snap_hes_dead_jim:
raise BrowsingException("""chrome tab went "aw snap" or "he's dead jim"!""")
elif (self._behavior != None and self._behavior.is_finished()
or time.time() - self._start > Browser.HARD_TIMEOUT_SECONDS):
return True
elif self._reached_limit:
raise self._reached_limit
elif self._abort_browse_page:
raise BrowsingAborted("browsing page aborted")
else:
return False
def send_to_chrome(self, suppress_logging=False, **kwargs):
msg_id = next(self.command_id)
kwargs['id'] = msg_id
msg = json.dumps(kwargs)
if not suppress_logging:
self.logger.debug('sending message to {}: {}'.format(self._websock, msg))
self._websock.send(msg)
return msg_id
def _visit_page(self, websock):
# navigate to about:blank here to avoid situation where we navigate to
# the same page that we're currently on, perhaps with a different
# #fragment, which prevents Page.loadEventFired from happening
self.send_to_chrome(method="Page.navigate", params={"url": "about:blank"})
self.send_to_chrome(method="Network.enable")
self.send_to_chrome(method="Page.enable")
self.send_to_chrome(method="Console.enable")
self.send_to_chrome(method="Debugger.enable")
self.send_to_chrome(method="Runtime.enable")
if self.extra_headers:
self.send_to_chrome(method="Network.setExtraHTTPHeaders", params={"headers":self.extra_headers})
# disable google analytics, see _handle_message() where breakpoint is caught "Debugger.paused"
self.send_to_chrome(method="Debugger.setBreakpointByUrl", params={"lineNumber": 1, "urlRegex":"https?://www.google-analytics.com/analytics.js"})
# navigate to the page!
self.send_to_chrome(method="Page.navigate", params={"url": self.url})
def _wrap_handle_message(self, websock, message):
try:
self._handle_message(websock, message)
except:
self.logger.error("uncaught exception in _handle_message", exc_info=True)
self.abort_browse_page()
def _network_request_will_be_sent(self, message):
if self._behavior:
self._behavior.notify_of_activity()
if message["params"]["request"]["url"].lower().startswith("data:"):
self.logger.debug("ignoring data url {}".format(message["params"]["request"]["url"][:80]))
elif self.on_request:
self.on_request(message)
def _network_response_received(self, message):
if (not self._reached_limit
and message["params"]["response"]["status"] == 420
and "Warcprox-Meta" in CaseInsensitiveDict(
message["params"]["response"]["headers"])):
warcprox_meta = json.loads(CaseInsensitiveDict(
message["params"]["response"]["headers"])["Warcprox-Meta"])
self._reached_limit = brozzler.ReachedLimit(
warcprox_meta=warcprox_meta)
self.logger.info("reached limit %s", self._reached_limit)
if self.on_response:
self.on_response(message)
def _page_load_event_fired(self, message):
self.logger.info("Page.loadEventFired, moving on to starting behaviors url={}".format(self.url))
self._behavior = Behavior(self.url, self)
self._behavior.start()
self._waiting_on_document_url_msg_id = self.send_to_chrome(method="Runtime.evaluate", params={"expression":"document.URL"})
def _console_message_added(self, message):
self.logger.debug("%s console.%s %s", self._websock.url,
message["params"]["message"]["level"],
message["params"]["message"]["text"])
def _debugger_paused(self, message):
# We hit the breakpoint set in visit_page. Get rid of google
# analytics script!
self.logger.debug("debugger paused! message={}".format(message))
scriptId = message['params']['callFrames'][0]['location']['scriptId']
# replace script
self.send_to_chrome(method="Debugger.setScriptSource", params={"scriptId": scriptId, "scriptSource":"console.log('google analytics is no more!');"})
# resume execution
self.send_to_chrome(method="Debugger.resume")
def _handle_result_message(self, message):
if message["id"] == self._waiting_on_screenshot_msg_id:
if self.on_screenshot:
self.on_screenshot(base64.b64decode(message["result"]["data"]))
self._waiting_on_screenshot_msg_id = None
self._has_screenshot = True
self.logger.info("got screenshot, moving on to getting outlinks url={}".format(self.url))
elif message["id"] == self._waiting_on_scroll_to_top_msg_id:
self._waiting_on_screenshot_msg_id = self.send_to_chrome(method="Page.captureScreenshot")
self._waiting_on_scroll_to_top_msg_id = None
elif message["id"] == self._waiting_on_outlinks_msg_id:
self.logger.debug("got outlinks message=%s", message)
self._outlinks = frozenset(message["result"]["result"]["value"].split(" "))
elif message["id"] == self._waiting_on_document_url_msg_id:
if message["result"]["result"]["value"] != self.url:
if self.on_url_change:
self.on_url_change(message["result"]["result"]["value"])
self._waiting_on_document_url_msg_id = None
elif self._behavior and self._behavior.is_waiting_on_result(message["id"]):
self._behavior.notify_of_result(message)
def _handle_message(self, websock, json_message):
message = json.loads(json_message)
if "method" in message and message["method"] == "Network.requestWillBeSent":
self._network_request_will_be_sent(message)
elif "method" in message and message["method"] == "Network.responseReceived":
self._network_response_received(message)
elif "method" in message and message["method"] == "Page.loadEventFired":
self._page_load_event_fired(message)
elif "method" in message and message["method"] == "Console.messageAdded":
self._console_message_added(message)
elif "method" in message and message["method"] == "Debugger.paused":
self._debugger_paused(message)
elif "method" in message and message["method"] == "Inspector.targetCrashed":
self._aw_snap_hes_dead_jim = message
elif "result" in message:
self._handle_result_message(message)
def _page_load_event_fired(self, message):
self.logger.info("Page.loadEventFired, moving on to starting behaviors url={}".format(self.url))
self._behavior = Behavior(self.url, self)
self._behavior.start()
self._waiting_on_document_url_msg_id = self.send_to_chrome(method="Runtime.evaluate", params={"expression":"document.URL"})
class Browser:
"""
Runs chrome/chromium to synchronously browse one page at a time using
worker.browse_page(). Should not be accessed from multiple threads.
"""
logger = logging.getLogger(__module__ + "." + __qualname__)
HARD_TIMEOUT_SECONDS = 20 * 60
def __init__(self,
chrome_port=9222,
chrome_exe='chromium-browser',
proxy=None,
ignore_cert_errors=False):
self.command_id = itertools.count(1)
self.chrome_port = chrome_port
self.chrome_exe = chrome_exe
self.proxy = proxy
self.ignore_cert_errors = ignore_cert_errors
self._behavior = None
self._websock = None
self._abort_browse_page = False
self._chrome_instance = None
self._aw_snap_hes_dead_jim = None
self._work_dir = None
self._websocket_url = None
def __repr__(self):
return "{}.{}:{}".format(Browser.__module__, Browser.__qualname__,
self.chrome_port)
def __enter__(self):
self.start()
return self
def __exit__(self, *args):
self.stop()
def start(self, proxy=None, cookie_db=None):
if not self._chrome_instance:
# these can raise exceptions
self.chrome_port = self._find_available_port()
self._work_dir = tempfile.TemporaryDirectory()
if cookie_db is not None:
cookie_dir = os.path.join(self._work_dir.name,
"chrome-user-data", "Default")
cookie_location = os.path.join(cookie_dir, "Cookies")
self.logger.debug("cookie DB provided, writing to %s",
cookie_location)
os.makedirs(cookie_dir, exist_ok=True)
try:
with open(cookie_location, 'wb') as cookie_file:
cookie_file.write(cookie_db)
except OSError:
self.logger.error("exception writing cookie file at %s",
cookie_location,
exc_info=True)
self._chrome_instance = Chrome(
port=self.chrome_port,
executable=self.chrome_exe,
user_home_dir=self._work_dir.name,
user_data_dir=os.sep.join(
[self._work_dir.name, "chrome-user-data"]),
ignore_cert_errors=self.ignore_cert_errors,
proxy=proxy or self.proxy)
try:
self._websocket_url = self._chrome_instance.start()
except:
self._chrome_instance = None
raise
def stop(self):
try:
if self.is_running():
self._chrome_instance.stop()
self._chrome_instance = None
try:
self._work_dir.cleanup()
except:
self.logger.error("exception deleting %s",
self._work_dir,
exc_info=True)
self._work_dir = None
self._websocket_url = None
except:
self.logger.error("problem stopping", exc_info=True)
def persist_and_read_cookie_db(self):
cookie_location = os.path.join(self._work_dir.name, "chrome-user-data",
"Default", "Cookies")
self.logger.debug(
"marking cookies persistent then reading file into memory: %s ",
cookie_location)
try:
with sqlite3.connect(cookie_location) as conn:
cur = conn.cursor()
cur.execute("UPDATE cookies SET persistent = 1")
except sqlite3.Error:
self.logger.error("exception updating cookie DB", exc_info=True)
cookie_db = None
try:
with open(cookie_location, "rb") as cookie_file:
cookie_db = cookie_file.read()
except OSError:
self.logger.error("exception reading from cookie DB file %s",
cookie_location,
exc_info=True)
return cookie_db
def _find_available_port(self):
port_available = False
port = self.chrome_port
try:
conns = psutil.net_connections(kind="tcp")
except psutil.AccessDenied:
return port
for p in range(port, 65535):
if any(connection.laddr[1] == p for connection in conns):
self.logger.warn("port %s already open, will try %s", p, p + 1)
else:
port = p
break
return port
def is_running(self):
return bool(self._websocket_url)
def abort_browse_page(self):
self._abort_browse_page = True
def browse_page(self,
url,
extra_headers=None,
behavior_parameters=None,
on_request=None,
on_response=None,
on_screenshot=None,
on_url_change=None):
"""
Synchronously loads a page, takes a screenshot, and runs behaviors.
Raises BrowsingException if browsing the page fails in a non-critical
way.
Returns extracted outlinks.
"""
if not self.is_running():
raise BrowsingException("browser has not been started")
self.url = url
self.extra_headers = extra_headers
self.on_request = on_request
self.on_screenshot = on_screenshot
self.on_url_change = on_url_change
self.on_response = on_response
self.behavior_parameters = behavior_parameters
self._outlinks = None
self._reached_limit = None
self._aw_snap_hes_dead_jim = None
self._abort_browse_page = False
self._has_screenshot = False
self._waiting_on_result_messages = {}
self._result_message_timeout = None
self._websock = websocket.WebSocketApp(
self._websocket_url,
on_open=self._visit_page,
on_message=self._wrap_handle_message)
threadName = "WebsockThread:{}-{:%Y%m%d%H%M%S}".format(
self.chrome_port, datetime.datetime.utcnow())
websock_thread = threading.Thread(target=self._websock.run_forever,
name=threadName,
kwargs={'ping_timeout': 0.5})
websock_thread.start()
self._start = time.time()
aborted = False
try:
while True:
time.sleep(0.5)
if self._browse_interval_func():
return self._outlinks
finally:
if (self._websock and self._websock.sock
and self._websock.sock.connected):
try:
self._websock.close()
except BaseException as e:
self.logger.error("exception closing websocket %s - %s" %
(self._websock, e))
websock_thread.join(timeout=30)
if websock_thread.is_alive():
self.logger.error(
"%s still alive 30 seconds after closing %s, will "
"forcefully nudge it again" %
(websock_thread, self._websock))
self._websock.keep_running = False
websock_thread.join(timeout=30)
if websock_thread.is_alive():
self.logger.critical(
"%s still alive 60 seconds after closing %s" %
(websock_thread, self._websock))
self._behavior = None
OUTLINKS_JS = """
var __brzl_framesDone = new Set();
var __brzl_compileOutlinks = function(frame) {
__brzl_framesDone.add(frame);
var outlinks = Array.prototype.slice.call(
frame.document.querySelectorAll('a[href]'));
for (var i = 0; i < frame.frames.length; i++) {
if (frame.frames[i] && !__brzl_framesDone.has(frame.frames[i])) {
outlinks = outlinks.concat(__brzl_compileOutlinks(frame.frames[i]));
}
}
return outlinks;
}
__brzl_compileOutlinks(window).join(' ');
"""
def _chain_chrome_messages(self, chain):
"""
Sends a series of messages to chrome/chromium on the debugging protocol
websocket. Waits for a reply from each one before sending the next.
Enforces a timeout waiting for each reply. If the timeout is hit, sets
self._result_message_timeout with a ResultMessageTimeout (an exception
class). Takes an array of dicts, each of which should look like this:
{
"info": "human readable description",
"chrome_msg": { ... }, # message to send to chrome, as a dict
"timeout": 30, # timeout in seconds
"callback": my_callback, # takes one arg, the result message
}
The code is rather convoluted because of the asynchronous nature of the
whole thing. See how it's used in _start_postbehavior_chain.
"""
timer = None
def callback(message):
if timer:
timer.cancel()
if message["id"] in self._waiting_on_result_messages:
del self._waiting_on_result_messages[message["id"]]
if "callback" in chain[0]:
chain[0]["callback"](message)
self._chain_chrome_messages(chain[1:])
def timeout():
self._result_message_timeout = ResultMessageTimeout(
"timed out after %.1fs waiting for result message "
"for %s", chain[0]["timeout"], chain[0]["chrome_msg"])
if chain:
msg_id = self.send_to_chrome(**chain[0]["chrome_msg"])
self._waiting_on_result_messages[msg_id] = callback
self.logger.info("msg_id=%s for message %s", msg_id,
chain[0]["chrome_msg"])
timer = threading.Timer(chain[0]["timeout"], timeout)
timer.daemon = True
timer.start()
else:
self.logger.info("finished chrome message chain")
def _start_postbehavior_chain(self):
if self.on_screenshot:
chain = [{
"info": "scrolling to top",
"chrome_msg": {
"method": "Runtime.evaluate",
"params": {
"expression": "window.scrollTo(0, 0);"
},
},
"timeout": 30,
"callback": lambda message: None,
}, {
"info":
"requesting screenshot",
"chrome_msg": {
"method": "Page.captureScreenshot"
},
"timeout":
30,
"callback":
lambda message: (self.on_screenshot and self.on_screenshot(
base64.b64decode(message["result"]["data"]))),
}]
else:
chain = []
def set_outlinks(message):
self._outlinks = frozenset(
message["result"]["result"]["value"].split())
chain.append({
"info": "retrieving outlinks",
"chrome_msg": {
"method": "Runtime.evaluate",
"params": {
"expression": self.OUTLINKS_JS
},
},
"timeout": 60,
"callback": set_outlinks,
})
self._chain_chrome_messages(chain)
def _browse_interval_func(self):
"""Called periodically while page is being browsed. Returns True when
finished browsing."""
if (not self._websock or not self._websock.sock
or not self._websock.sock.connected):
raise BrowsingException(
"websocket closed, did chrome die? {}".format(
self._websocket_url))
elif self._result_message_timeout:
raise self._result_message_timeout
elif self._aw_snap_hes_dead_jim:
raise BrowsingException(
"""chrome tab went "aw snap" or "he's dead jim"!""")
elif self._outlinks is not None:
# setting self._outlinks is the last thing that happens in the
# post-behavior chain
return True
elif (self._behavior != None and self._behavior.is_finished()
or time.time() - self._start > Browser.HARD_TIMEOUT_SECONDS):
if self._behavior and self._behavior.is_finished():
self.logger.info("behavior decided it's finished with %s",
self.url)
else:
self.logger.info("reached hard timeout of %s seconds url=%s",
Browser.HARD_TIMEOUT_SECONDS, self.url)
self._behavior = None
self._start_postbehavior_chain()
return False
elif self._reached_limit:
raise self._reached_limit
elif self._abort_browse_page:
raise BrowsingAborted("browsing page aborted")
else:
return False
def send_to_chrome(self, suppress_logging=False, **kwargs):
msg_id = next(self.command_id)
kwargs["id"] = msg_id
msg = json.dumps(kwargs)
if not suppress_logging:
self.logger.debug("sending message to %s: %s", self._websock, msg)
self._websock.send(msg)
return msg_id
def _visit_page(self, websock):
# navigate to about:blank here to avoid situation where we navigate to
# the same page that we're currently on, perhaps with a different
# #fragment, which prevents Page.loadEventFired from happening
self.send_to_chrome(method="Page.navigate",
params={"url": "about:blank"})
self.send_to_chrome(method="Network.enable")
self.send_to_chrome(method="Page.enable")
self.send_to_chrome(method="Console.enable")
self.send_to_chrome(method="Debugger.enable")
self.send_to_chrome(method="Runtime.enable")
if self.extra_headers:
self.send_to_chrome(method="Network.setExtraHTTPHeaders",
params={"headers": self.extra_headers})
# disable google analytics, see _handle_message() where breakpoint is caught "Debugger.paused"
self.send_to_chrome(
method="Debugger.setBreakpointByUrl",
params={
"lineNumber": 1,
"urlRegex": "https?://www.google-analytics.com/analytics.js"
})
# navigate to the page!
self.send_to_chrome(method="Page.navigate", params={"url": self.url})
def _wrap_handle_message(self, websock, message):
try:
self._handle_message(websock, message)
except:
self.logger.error(
"uncaught exception in _handle_message message=%s",
message,
exc_info=True)
self.abort_browse_page()
def _network_request_will_be_sent(self, message):
if self._behavior:
self._behavior.notify_of_activity()
if message["params"]["request"]["url"].lower().startswith("data:"):
self.logger.debug("ignoring data url {}".format(
message["params"]["request"]["url"][:80]))
elif self.on_request:
self.on_request(message)
def _network_response_received(self, message):
if (not self._reached_limit
and message["params"]["response"]["status"] == 420
and "Warcprox-Meta" in CaseInsensitiveDict(
message["params"]["response"]["headers"])):
warcprox_meta = json.loads(
CaseInsensitiveDict(
message["params"]["response"]["headers"])["Warcprox-Meta"])
self._reached_limit = brozzler.ReachedLimit(
warcprox_meta=warcprox_meta)
self.logger.info("reached limit %s", self._reached_limit)
if self.on_response:
self.on_response(message)
def _page_load_event_fired(self, message):
self.logger.info(
"Page.loadEventFired, moving on to starting behaviors url={}".
format(self.url))
self._behavior = Behavior(self.url, self)
self._behavior.start(self.behavior_parameters)
self._waiting_on_document_url_msg_id = self.send_to_chrome(
method="Runtime.evaluate", params={"expression": "document.URL"})
def _console_message_added(self, message):
self.logger.debug("%s console.%s %s", self._websock.url,
message["params"]["message"]["level"],
message["params"]["message"]["text"])
def _debugger_paused(self, message):
# We hit the breakpoint set in visit_page. Get rid of google
# analytics script!
self.logger.debug("debugger paused! message={}".format(message))
scriptId = message['params']['callFrames'][0]['location']['scriptId']
# replace script
self.send_to_chrome(method="Debugger.setScriptSource",
params={
"scriptId":
scriptId,
"scriptSource":
"console.log('google analytics is no more!');"
})
# resume execution
self.send_to_chrome(method="Debugger.resume")
def _handle_message(self, websock, json_message):
message = json.loads(json_message)
if "method" in message:
if message["method"] == "Network.requestWillBeSent":
self._network_request_will_be_sent(message)
elif message["method"] == "Network.responseReceived":
self._network_response_received(message)
elif message["method"] == "Page.loadEventFired":
self._page_load_event_fired(message)
elif message["method"] == "Console.messageAdded":
self._console_message_added(message)
elif message["method"] == "Debugger.paused":
self._debugger_paused(message)
elif message["method"] == "Inspector.targetCrashed":
self._aw_snap_hes_dead_jim = message
# elif message["method"] in (
# "Network.dataReceived", "Network.responseReceived",
# "Network.loadingFinished"):
# pass
# else:
# self.logger.debug("%s %s", message["method"], json_message)
elif "result" in message:
if message["id"] in self._waiting_on_result_messages:
callback = self._waiting_on_result_messages[message["id"]]
self.logger.debug(
"received result for message id=%s, calling %s",
message["id"], callback)
callback(message)
elif self._behavior and self._behavior.is_waiting_on_result(
message["id"]):
self._behavior.notify_of_result(message)