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changedetection.io/changedetectionio/update_worker.py

452 lines
25 KiB

import os
import threading
import queue
import time
from changedetectionio import content_fetcher, html_tools
from .processors.text_json_diff import FilterNotFoundInResponse
from .processors.restock_diff import UnableToExtractRestockData
# 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 queue_notification_for_watch(self, n_object, watch):
from changedetectionio import diff
watch_history = watch.history
dates = list(watch_history.keys())
# Add text that was triggered
snapshot_contents = watch.get_history_snapshot(dates[-1])
# HTML needs linebreak, but MarkDown and Text can use a linefeed
if n_object['notification_format'] == 'HTML':
line_feed_sep = "<br>"
# Snapshot will be plaintext on the disk, convert to some kind of HTML
snapshot_contents = snapshot_contents.replace('\n', line_feed_sep)
else:
line_feed_sep = "\n"
trigger_text = watch.get('trigger_text', [])
triggered_text = ''
if len(trigger_text):
from . import html_tools
triggered_text = html_tools.get_triggered_text(content=snapshot_contents, trigger_text=trigger_text)
if triggered_text:
triggered_text = line_feed_sep.join(triggered_text)
n_object.update({
'current_snapshot': snapshot_contents,
'diff': diff.render_diff(watch.get_history_snapshot(dates[-2]), watch.get_history_snapshot(dates[-1]), line_feed_sep=line_feed_sep),
'diff_added': diff.render_diff(watch.get_history_snapshot(dates[-2]), watch.get_history_snapshot(dates[-1]), include_removed=False, line_feed_sep=line_feed_sep),
'diff_full': diff.render_diff(watch.get_history_snapshot(dates[-2]), watch.get_history_snapshot(dates[-1]), include_equal=True, line_feed_sep=line_feed_sep),
'diff_patch': diff.render_diff(watch.get_history_snapshot(dates[-2]), watch.get_history_snapshot(dates[-1]), line_feed_sep=line_feed_sep, patch_format=True),
'diff_removed': diff.render_diff(watch.get_history_snapshot(dates[-2]), watch.get_history_snapshot(dates[-1]), include_added=False, line_feed_sep=line_feed_sep),
'screenshot': watch.get_screenshot() if watch.get('notification_screenshot') else None,
'triggered_text': triggered_text,
'uuid': watch.get('uuid'),
'watch_url': watch.get('url'),
})
logging.info (">> SENDING NOTIFICATION")
self.notification_q.put(n_object)
# Prefer - Individual watch settings > Tag settings > Global settings (in that order)
def _check_cascading_vars(self, var_name, watch):
from changedetectionio.notification import (
default_notification_format_for_watch,
default_notification_body,
default_notification_title
)
# Would be better if this was some kind of Object where Watch can reference the parent datastore etc
v = watch.get(var_name)
if v and not watch.get('notification_muted'):
if var_name == 'notification_format' and v == default_notification_format_for_watch:
return self.datastore.data['settings']['application'].get('notification_format')
return v
tags = self.datastore.get_all_tags_for_watch(uuid=watch.get('uuid'))
if tags:
for tag_uuid, tag in tags.items():
v = tag.get(var_name)
if v and not tag.get('notification_muted'):
return v
if self.datastore.data['settings']['application'].get(var_name):
return self.datastore.data['settings']['application'].get(var_name)
# Otherwise could be defaults
if var_name == 'notification_format':
return default_notification_format_for_watch
if var_name == 'notification_body':
return default_notification_body
if var_name == 'notification_title':
return default_notification_title
return None
def send_content_changed_notification(self, watch_uuid):
n_object = {}
watch = self.datastore.data['watching'].get(watch_uuid)
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?"
)
# Should be a better parent getter in the model object
# Prefer - Individual watch settings > Tag settings > Global settings (in that order)
n_object['notification_urls'] = self._check_cascading_vars('notification_urls', watch)
n_object['notification_title'] = self._check_cascading_vars('notification_title', watch)
n_object['notification_body'] = self._check_cascading_vars('notification_body', watch)
n_object['notification_format'] = self._check_cascading_vars('notification_format', watch)
# (Individual watch) Only prepare to notify if the rules above matched
queued = False
if n_object and n_object.get('notification_urls'):
queued = True
self.queue_notification_for_watch(n_object, watch)
return queued
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)
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 send_step_failure_notification(self, watch_uuid, step_n):
watch = self.datastore.data['watching'].get(watch_uuid, False)
if not watch:
return
threshold = self.datastore.data['settings']['application'].get('filter_failure_notification_threshold_attempts')
n_object = {'notification_title': "Changedetection.io - Alert - Browser step at position {} could not be run".format(step_n+1),
'notification_body': "Your configured browser step at position {} for {{watch['url']}} "
"did not appear on the page after {} attempts, did the page change layout? "
"Does it need a delay added?\n\nLink: {{base_url}}/edit/{{watch_uuid}}\n\n"
"Thanks - Your omniscient changedetection.io installation :)\n".format(step_n+1, 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
})
self.notification_q.put(n_object)
print("Sent step 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 .processors import text_json_diff, restock_diff
while not self.app.config.exit.is_set():
try:
queued_item_data = self.q.get(block=False)
except queue.Empty:
pass
else:
uuid = queued_item_data.item.get('uuid')
self.current_uuid = uuid
if uuid in list(self.datastore.data['watching'].keys()) and self.datastore.data['watching'][uuid].get('url'):
changed_detected = False
contents = b''
process_changedetection_results = True
update_obj = {}
print("> Processing UUID {} Priority {} URL {}".format(uuid, queued_item_data.priority,
self.datastore.data['watching'][uuid]['url']))
now = time.time()
try:
processor = self.datastore.data['watching'][uuid].get('processor','text_json_diff')
# @todo some way to switch by name
if processor == 'restock_diff':
update_handler = restock_diff.perform_site_check(datastore=self.datastore)
else:
# Used as a default and also by some tests
update_handler = text_json_diff.perform_site_check(datastore=self.datastore)
changed_detected, update_obj, contents = update_handler.run(uuid, skip_when_checksum_same=queued_item_data.item.get('skip_when_checksum_same'))
# 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
extra_help = ""
if e.has_filters:
# Maybe it contains an image? offer a more helpful link
has_img = html_tools.include_filters(include_filters='img',
html_content=e.html_content)
if has_img:
extra_help = ", it's possible that the filters you have give an empty result or contain only an image <a href=\"https://github.com/dgtlmoon/changedetection.io/wiki/Detecting-changes-in-images\">more help here</a>."
else:
extra_help = ", it's possible that the filters were found, but contained no usable text."
self.datastore.update_watch(uuid=uuid, update_obj={
'last_error': f"Got HTML content but no text found (With {e.status_code} reply code){extra_help}"
})
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})
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 - Did the page change layout? update your Visual Filter if necessary."
self.datastore.update_watch(uuid=uuid, update_obj={'last_error': err_text})
# 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 = False
except content_fetcher.checksumFromPreviousCheckWasTheSame as e:
# Yes fine, so nothing todo, don't continue to process.
process_changedetection_results = False
changed_detected = False
self.datastore.update_watch(uuid=uuid, update_obj={'last_error': False})
except content_fetcher.BrowserStepsStepTimout as e:
if not self.datastore.data['watching'].get(uuid):
continue
err_text = "Warning, browser step at position {} could not run, target not found, check the watch, add a delay if necessary.".format(e.step_n+1)
self.datastore.update_watch(uuid=uuid, update_obj={'last_error': err_text})
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("Step 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_step_failure_notification(watch_uuid=uuid, step_n=e.step_n)
c = 0
self.datastore.update_watch(uuid=uuid, update_obj={'consecutive_filter_failures': c})
process_changedetection_results = False
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})
process_changedetection_results = False
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})
process_changedetection_results = False
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,
'has_ldjson_price_data': None})
process_changedetection_results = False
except UnableToExtractRestockData as e:
# Usually when fetcher.instock_data returns empty
self.app.logger.error("Exception reached processing watch UUID: %s - %s", uuid, str(e))
self.datastore.update_watch(uuid=uuid, update_obj={'last_error': f"Unable to extract restock data for this page unfortunately. (Got code {e.status_code} from server)"})
process_changedetection_results = False
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
# Everything ran OK, clean off any previous error
update_obj['last_error'] = False
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'].get(uuid)
self.datastore.update_watch(uuid=uuid, update_obj=update_obj)
# Also save the snapshot on the first time checked
if changed_detected or not watch['last_checked']:
watch.save_history_text(contents=contents,
timestamp=str(round(time.time())),
snapshot_id=update_obj.get('previous_md5', 'none'))
# 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(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)