import threading import queue import time from changedetectionio import content_fetcher from changedetectionio.html_tools import FilterNotFoundInResponse # A single update worker # # Requests for checking on a single site(watch) from a queue of watches # (another process inserts watches into the queue that are time-ready for checking) class update_worker(threading.Thread): current_uuid = None def __init__(self, q, notification_q, app, datastore, *args, **kwargs): self.q = q self.app = app self.notification_q = notification_q self.datastore = datastore super().__init__(*args, **kwargs) def send_filter_failure_notification(self, uuid): threshold = self.datastore.data['settings']['application'].get('filter_failure_notification_threshold_attempts') watch = self.datastore.data['watching'].get(uuid, False) n_object = {'notification_title': 'Changedetection.io - Alert - CSS/xPath filter was not present in the page', 'notification_body': "Your configured CSS/xPath filter of '{}' for {{watch_url}} did not appear on the page after {} attempts, did the page change layout?\n\nLink: {{base_url}}/edit/{{watch_uuid}}\n\nThanks - Your omniscient changedetection.io installation :)\n".format( watch['css_filter'], threshold), 'notification_format': 'text'} if len(watch['notification_urls']): n_object['notification_urls'] = watch['notification_urls'] elif len(self.datastore.data['settings']['application']['notification_urls']): n_object['notification_urls'] = self.datastore.data['settings']['application']['notification_urls'] # Only prepare to notify if the rules above matched if 'notification_urls' in n_object: n_object.update({ 'watch_url': watch['url'], 'uuid': uuid }) self.notification_q.put(n_object) print("Sent filter not found notification for {}".format(uuid)) def run(self): from changedetectionio import fetch_site_status update_handler = fetch_site_status.perform_site_check(datastore=self.datastore) while not self.app.config.exit.is_set(): try: uuid = self.q.get(block=False) except queue.Empty: pass else: self.current_uuid = uuid if uuid in list(self.datastore.data['watching'].keys()): changed_detected = False contents = b'' screenshot = False update_obj= {} xpath_data = False process_changedetection_results = True now = time.time() try: changed_detected, update_obj, contents, screenshot, xpath_data = update_handler.run(uuid) # Re #342 # In Python 3, all strings are sequences of Unicode characters. There is a bytes type that holds raw bytes. # We then convert/.decode('utf-8') for the notification etc if not isinstance(contents, (bytes, bytearray)): raise Exception("Error - returned data from the fetch handler SHOULD be bytes") except PermissionError as e: self.app.logger.error("File permission error updating", uuid, str(e)) process_changedetection_results = False except content_fetcher.ReplyWithContentButNoText as e: # Totally fine, it's by choice - just continue on, nothing more to care about # Page had elements/content but no renderable text # Backend (not filters) gave zero output self.datastore.update_watch(uuid=uuid, update_obj={'last_error': "Got HTML content but no text found."}) process_changedetection_results = False except FilterNotFoundInResponse as e: err_text = "Warning, filter '{}' not found".format(str(e)) self.datastore.update_watch(uuid=uuid, update_obj={'last_error': err_text, # So that we get a trigger when the content is added again 'previous_md5': ''}) # Only when enabled, send the notification if self.datastore.data['watching'][uuid].get('filter_failure_notification_send', False): c = self.datastore.data['watching'][uuid].get('consecutive_filter_failures', 5) c += 1 # Send notification if we reached the threshold? threshold = self.datastore.data['settings']['application'].get('filter_failure_notification_threshold_attempts', 0) print("Filter for {} not found, consecutive_filter_failures: {}".format(uuid, c)) if threshold > 0 and c >= threshold: self.send_filter_failure_notification(uuid) c = 0 self.datastore.update_watch(uuid=uuid, update_obj={'consecutive_filter_failures': c}) process_changedetection_results = True except content_fetcher.EmptyReply as e: # Some kind of custom to-str handler in the exception handler that does this? err_text = "EmptyReply - try increasing 'Wait seconds before extracting text', Status Code {}".format(e.status_code) self.datastore.update_watch(uuid=uuid, update_obj={'last_error': err_text, 'last_check_status': e.status_code}) except content_fetcher.ScreenshotUnavailable as e: err_text = "Screenshot unavailable, page did not render fully in the expected time - try increasing 'Wait seconds before extracting text'" self.datastore.update_watch(uuid=uuid, update_obj={'last_error': err_text, 'last_check_status': e.status_code}) process_changedetection_results = False except content_fetcher.PageUnloadable as e: err_text = "Page request from server didnt respond correctly" self.datastore.update_watch(uuid=uuid, update_obj={'last_error': err_text, 'last_check_status': e.status_code}) except Exception as e: self.app.logger.error("Exception reached processing watch UUID: %s - %s", uuid, str(e)) self.datastore.update_watch(uuid=uuid, update_obj={'last_error': str(e)}) # Other serious error process_changedetection_results = False else: # Mark that we never had any failures update_obj['consecutive_filter_failures'] = 0 # Different exceptions mean that we may or may not want to bump the snapshot, trigger notifications etc if process_changedetection_results: try: watch = self.datastore.data['watching'][uuid] fname = "" # Saved history text filename # For the FIRST time we check a site, or a change detected, save the snapshot. if changed_detected or not watch['last_checked']: # A change was detected fname = watch.save_history_text(contents=contents, timestamp=str(round(time.time()))) self.datastore.update_watch(uuid=uuid, update_obj=update_obj) # A change was detected if changed_detected: n_object = {} print (">> Change detected in UUID {} - {}".format(uuid, watch['url'])) # Notifications should only trigger on the second time (first time, we gather the initial snapshot) if watch.history_n >= 2: # Atleast 2, means there really was a change self.datastore.update_watch(uuid=uuid, update_obj={'last_changed': round(now)}) watch_history = watch.history dates = list(watch_history.keys()) # Theoretically it's possible that this could be just 1 long, # - In the case that the timestamp key was not unique if len(dates) == 1: raise ValueError( "History index had 2 or more, but only 1 date loaded, timestamps were not unique? maybe two of the same timestamps got written, needs more delay?" ) prev_fname = watch_history[dates[-2]] # Did it have any notification alerts to hit? if len(watch['notification_urls']): print(">>> Notifications queued for UUID from watch {}".format(uuid)) n_object['notification_urls'] = watch['notification_urls'] n_object['notification_title'] = watch['notification_title'] n_object['notification_body'] = watch['notification_body'] n_object['notification_format'] = watch['notification_format'] # No? maybe theres a global setting, queue them all elif len(self.datastore.data['settings']['application']['notification_urls']): print(">>> Watch notification URLs were empty, using GLOBAL notifications for UUID: {}".format(uuid)) n_object['notification_urls'] = self.datastore.data['settings']['application']['notification_urls'] n_object['notification_title'] = self.datastore.data['settings']['application']['notification_title'] n_object['notification_body'] = self.datastore.data['settings']['application']['notification_body'] n_object['notification_format'] = self.datastore.data['settings']['application']['notification_format'] else: print(">>> NO notifications queued, watch and global notification URLs were empty.") # Only prepare to notify if the rules above matched if 'notification_urls' in n_object: # HTML needs linebreak, but MarkDown and Text can use a linefeed if n_object['notification_format'] == 'HTML': line_feed_sep = "
" else: line_feed_sep = "\n" from changedetectionio import diff n_object.update({ 'watch_url': watch['url'], 'uuid': uuid, 'current_snapshot': contents.decode('utf-8'), 'diff': diff.render_diff(prev_fname, fname, line_feed_sep=line_feed_sep), 'diff_full': diff.render_diff(prev_fname, fname, True, line_feed_sep=line_feed_sep) }) self.notification_q.put(n_object) except Exception as e: # Catch everything possible here, so that if a worker crashes, we don't lose it until restart! print("!!!! Exception in update_worker !!!\n", e) self.app.logger.error("Exception reached processing watch UUID: %s - %s", uuid, str(e)) self.datastore.update_watch(uuid=uuid, update_obj={'last_error': str(e)}) # Always record that we atleast tried self.datastore.update_watch(uuid=uuid, update_obj={'fetch_time': round(time.time() - now, 3), 'last_checked': round(time.time())}) # Always save the screenshot if it's available if screenshot: self.datastore.save_screenshot(watch_uuid=uuid, screenshot=screenshot) if xpath_data: self.datastore.save_xpath_data(watch_uuid=uuid, data=xpath_data) self.current_uuid = None # Done self.q.task_done() # Give the CPU time to interrupt time.sleep(0.1) self.app.config.exit.wait(1)