import hashlib import os import re import time import urllib3 from changedetectionio import content_fetcher, html_tools urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning) # Some common stuff here that can be moved to a base class class perform_site_check(): def __init__(self, *args, datastore, **kwargs): super().__init__(*args, **kwargs) self.datastore = datastore def run(self, uuid): timestamp = int(time.time()) # used for storage etc too changed_detected = False screenshot = False # as bytes stripped_text_from_html = "" watch = self.datastore.data['watching'][uuid] # Protect against file:// access if re.search(r'^file', watch['url'], re.IGNORECASE) and not os.getenv('ALLOW_FILE_URI', False): raise Exception( "file:// type access is denied for security reasons." ) # Unset any existing notification error update_obj = {'last_notification_error': False, 'last_error': False} extra_headers = self.datastore.get_val(uuid, 'headers') # Tweak the base config with the per-watch ones request_headers = self.datastore.data['settings']['headers'].copy() request_headers.update(extra_headers) # https://github.com/psf/requests/issues/4525 # Requests doesnt yet support brotli encoding, so don't put 'br' here, be totally sure that the user cannot # do this by accident. if 'Accept-Encoding' in request_headers and "br" in request_headers['Accept-Encoding']: request_headers['Accept-Encoding'] = request_headers['Accept-Encoding'].replace(', br', '') timeout = self.datastore.data['settings']['requests']['timeout'] url = self.datastore.get_val(uuid, 'url') request_body = self.datastore.get_val(uuid, 'body') request_method = self.datastore.get_val(uuid, 'method') ignore_status_code = self.datastore.get_val(uuid, 'ignore_status_codes') # Pluggable content fetcher prefer_backend = watch['fetch_backend'] if hasattr(content_fetcher, prefer_backend): klass = getattr(content_fetcher, prefer_backend) else: # If the klass doesnt exist, just use a default klass = getattr(content_fetcher, "html_requests") fetcher = klass() fetcher.run(url, timeout, request_headers, request_body, request_method, ignore_status_code) # Fetching complete, now filters # @todo move to class / maybe inside of fetcher abstract base? # @note: I feel like the following should be in a more obvious chain system # - Check filter text # - Is the checksum different? # - Do we convert to JSON? # https://stackoverflow.com/questions/41817578/basic-method-chaining ? # return content().textfilter().jsonextract().checksumcompare() ? is_json = 'application/json' in fetcher.headers.get('Content-Type', '') is_html = not is_json css_filter_rule = watch['css_filter'] subtractive_selectors = watch.get( "subtractive_selectors", [] ) + self.datastore.data["settings"]["application"].get( "global_subtractive_selectors", [] ) has_filter_rule = css_filter_rule and len(css_filter_rule.strip()) has_subtractive_selectors = subtractive_selectors and len(subtractive_selectors[0].strip()) if is_json and not has_filter_rule: css_filter_rule = "json:$" has_filter_rule = True if has_filter_rule: if 'json:' in css_filter_rule: stripped_text_from_html = html_tools.extract_json_as_string(content=fetcher.content, jsonpath_filter=css_filter_rule) is_html = False if is_html: # CSS Filter, extract the HTML that matches and feed that into the existing inscriptis::get_text html_content = fetcher.content # If not JSON, and if it's not text/plain.. if 'text/plain' in fetcher.headers.get('Content-Type', '').lower(): # Don't run get_text or xpath/css filters on plaintext stripped_text_from_html = html_content else: # Then we assume HTML if has_filter_rule: # For HTML/XML we offer xpath as an option, just start a regular xPath "/.." if css_filter_rule[0] == '/': html_content = html_tools.xpath_filter(xpath_filter=css_filter_rule, html_content=fetcher.content) else: # CSS Filter, extract the HTML that matches and feed that into the existing inscriptis::get_text html_content = html_tools.css_filter(css_filter=css_filter_rule, html_content=fetcher.content) if has_subtractive_selectors: html_content = html_tools.element_removal(subtractive_selectors, html_content) # extract text stripped_text_from_html = \ html_tools.html_to_text( html_content, render_anchor_tag_content=self.datastore.data["settings"][ "application"].get( "render_anchor_tag_content", False) ) # Re #340 - return the content before the 'ignore text' was applied text_content_before_ignored_filter = stripped_text_from_html.encode('utf-8') # We rely on the actual text in the html output.. many sites have random script vars etc, # in the future we'll implement other mechanisms. update_obj["last_check_status"] = fetcher.get_last_status_code() # If there's text to skip # @todo we could abstract out the get_text() to handle this cleaner text_to_ignore = watch.get('ignore_text', []) + self.datastore.data['settings']['application'].get('global_ignore_text', []) if len(text_to_ignore): stripped_text_from_html = html_tools.strip_ignore_text(stripped_text_from_html, text_to_ignore) else: stripped_text_from_html = stripped_text_from_html.encode('utf8') # Re #133 - if we should strip whitespaces from triggering the change detected comparison if self.datastore.data['settings']['application'].get('ignore_whitespace', False): fetched_md5 = hashlib.md5(stripped_text_from_html.translate(None, b'\r\n\t ')).hexdigest() else: fetched_md5 = hashlib.md5(stripped_text_from_html).hexdigest() # On the first run of a site, watch['previous_md5'] will be an empty string, set it the current one. if not len(watch['previous_md5']): watch['previous_md5'] = fetched_md5 update_obj["previous_md5"] = fetched_md5 blocked_by_not_found_trigger_text = False if len(watch['trigger_text']): # Yeah, lets block first until something matches blocked_by_not_found_trigger_text = True # Filter and trigger works the same, so reuse it result = html_tools.strip_ignore_text(content=str(stripped_text_from_html), wordlist=watch['trigger_text'], mode="line numbers") if result: blocked_by_not_found_trigger_text = False if not blocked_by_not_found_trigger_text and watch['previous_md5'] != fetched_md5: changed_detected = True update_obj["previous_md5"] = fetched_md5 update_obj["last_changed"] = timestamp # Extract title as title if is_html: if self.datastore.data['settings']['application']['extract_title_as_title'] or watch['extract_title_as_title']: if not watch['title'] or not len(watch['title']): update_obj['title'] = html_tools.extract_element(find='title', html_content=fetcher.content) if self.datastore.data['settings']['application'].get('real_browser_save_screenshot', True): screenshot = fetcher.screenshot() fetcher.quit() return changed_detected, update_obj, text_content_before_ignored_filter, screenshot