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changedetection.io/changedetectionio/update_worker.py

309 lines
17 KiB

import os
import threading
import queue
import time
from changedetectionio import content_fetcher
from changedetectionio.fetch_site_status 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)
import logging
import sys
class update_worker(threading.Thread):
current_uuid = None
def __init__(self, q, notification_q, app, datastore, *args, **kwargs):
logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)
self.q = q
self.app = app
self.notification_q = notification_q
self.datastore = datastore
super().__init__(*args, **kwargs)
def send_content_changed_notification(self, t, watch_uuid):
from changedetectionio import diff
from changedetectionio.notification import (
default_notification_format_for_watch
)
n_object = {}
watch = self.datastore.data['watching'].get(watch_uuid, False)
if not watch:
return
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?"
)
n_object['notification_urls'] = watch['notification_urls'] if len(watch['notification_urls']) else \
self.datastore.data['settings']['application']['notification_urls']
n_object['notification_title'] = watch['notification_title'] if watch['notification_title'] else \
self.datastore.data['settings']['application']['notification_title']
n_object['notification_body'] = watch['notification_body'] if watch['notification_body'] else \
self.datastore.data['settings']['application']['notification_body']
n_object['notification_format'] = watch['notification_format'] if watch['notification_format'] != default_notification_format_for_watch else \
self.datastore.data['settings']['application']['notification_format']
# Only prepare to notify if the rules above matched
if 'notification_urls' in n_object and n_object['notification_urls']:
# HTML needs linebreak, but MarkDown and Text can use a linefeed
if n_object['notification_format'] == 'HTML':
line_feed_sep = "</br>"
else:
line_feed_sep = "\n"
with open(watch_history[dates[-1]], 'rb') as f:
snapshot_contents = f.read()
n_object.update({
'watch_url': watch['url'],
'uuid': watch_uuid,
'screenshot': watch.get_screenshot_as_jpeg() if watch.get('notification_screenshot') else None,
'current_snapshot': snapshot_contents.decode('utf-8'),
'diff': diff.render_diff(watch_history[dates[-2]], watch_history[dates[-1]], line_feed_sep=line_feed_sep),
'diff_full': diff.render_diff(watch_history[dates[-2]], watch_history[dates[-1]], True, line_feed_sep=line_feed_sep)
})
logging.info (">> SENDING NOTIFICATION")
self.notification_q.put(n_object)
else:
logging.info (">> NO Notification sent, notification_url was empty in both watch and system")
def send_filter_failure_notification(self, watch_uuid):
threshold = self.datastore.data['settings']['application'].get('filter_failure_notification_threshold_attempts')
watch = self.datastore.data['watching'].get(watch_uuid, False)
if not watch:
return
n_object = {'notification_title': 'Changedetection.io - Alert - CSS/xPath filter was not present in the page',
'notification_body': "Your configured CSS/xPath filters 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(
", ".join(watch['include_filters']),
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': watch_uuid,
'screenshot': None
})
self.notification_q.put(n_object)
print("Sent filter not found notification for {}".format(watch_uuid))
def cleanup_error_artifacts(self, uuid):
# All went fine, remove error artifacts
cleanup_files = ["last-error-screenshot.png", "last-error.txt"]
for f in cleanup_files:
full_path = os.path.join(self.datastore.datastore_path, uuid, f)
if os.path.isfile(full_path):
os.unlink(full_path)
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:
priority, 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
print("> Processing UUID {} Priority {} URL {}".format(uuid, priority, self.datastore.data['watching'][uuid]['url']))
now = time.time()
try:
changed_detected, update_obj, contents = 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 (With {} reply code).".format(e.status_code)})
if e.screenshot:
self.datastore.save_screenshot(watch_uuid=uuid, screenshot=e.screenshot)
process_changedetection_results = False
except content_fetcher.Non200ErrorCodeReceived as e:
if e.status_code == 403:
err_text = "Error - 403 (Access denied) received"
elif e.status_code == 404:
err_text = "Error - 404 (Page not found) received"
elif e.status_code == 500:
err_text = "Error - 500 (Internal server Error) received"
else:
err_text = "Error - Request returned a HTTP error code {}".format(str(e.status_code))
if e.screenshot:
self.datastore.save_screenshot(watch_uuid=uuid, screenshot=e.screenshot, as_error=True)
if e.xpath_data:
self.datastore.save_xpath_data(watch_uuid=uuid, data=e.xpath_data, as_error=True)
if e.page_text:
self.datastore.save_error_text(watch_uuid=uuid, contents=e.page_text)
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': ''})
process_changedetection_results = False
except FilterNotFoundInResponse as e:
if not self.datastore.data['watching'].get(uuid):
continue
err_text = "Warning, no filters were found, no change detection ran."
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:
if not self.datastore.data['watching'][uuid].get('notification_muted'):
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.JSActionExceptions as e:
err_text = "Error running JS Actions - Page request - "+e.message
if e.screenshot:
self.datastore.save_screenshot(watch_uuid=uuid, screenshot=e.screenshot, as_error=True)
self.datastore.update_watch(uuid=uuid, update_obj={'last_error': err_text,
'last_check_status': e.status_code})
except content_fetcher.PageUnloadable as e:
err_text = "Page request from server didnt respond correctly"
if e.message:
err_text = "{} - {}".format(err_text, e.message)
if e.screenshot:
self.datastore.save_screenshot(watch_uuid=uuid, screenshot=e.screenshot, as_error=True)
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:
# Crash protection, the watch entry could have been removed by this point (during a slow chrome fetch etc)
if not self.datastore.data['watching'].get(uuid):
continue
# Mark that we never had any failures
if not self.datastore.data['watching'][uuid].get('ignore_status_codes'):
update_obj['consecutive_filter_failures'] = 0
self.cleanup_error_artifacts(uuid)
# 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
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:
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:
if not self.datastore.data['watching'][uuid].get('notification_muted'):
self.send_content_changed_notification(self, watch_uuid=uuid)
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)})
if self.datastore.data['watching'].get(uuid):
# Always record that we atleast tried
count = self.datastore.data['watching'][uuid].get('check_count', 0) + 1
self.datastore.update_watch(uuid=uuid, update_obj={'fetch_time': round(time.time() - now, 3),
'last_checked': round(time.time()),
'check_count': count
})
# Always save the screenshot if it's available
if update_handler.screenshot:
self.datastore.save_screenshot(watch_uuid=uuid, screenshot=update_handler.screenshot)
if update_handler.xpath_data:
self.datastore.save_xpath_data(watch_uuid=uuid, data=update_handler.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)