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changedetection.io/changedetectionio/store.py

451 lines
18 KiB

from os import unlink, path, mkdir
import json
import uuid as uuid_builder
from threading import Lock
from copy import deepcopy
import logging
import time
import threading
import os
from changedetectionio.notification import default_notification_format, default_notification_body, default_notification_title
# Is there an existing library to ensure some data store (JSON etc) is in sync with CRUD methods?
# Open a github issue if you know something :)
# https://stackoverflow.com/questions/6190468/how-to-trigger-function-on-value-change
class ChangeDetectionStore:
lock = Lock()
def __init__(self, datastore_path="/datastore", include_default_watches=True, version_tag="0.0.0"):
# Should only be active for docker
# logging.basicConfig(filename='/dev/stdout', level=logging.INFO)
self.needs_write = False
self.datastore_path = datastore_path
self.json_store_path = "{}/url-watches.json".format(self.datastore_path)
self.stop_thread = False
self.__data = {
'note': "Hello! If you change this file manually, please be sure to restart your changedetection.io instance!",
'watching': {},
'settings': {
'headers': {
'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36',
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9',
'Accept-Encoding': 'gzip, deflate', # No support for brolti in python requests yet.
'Accept-Language': 'en-GB,en-US;q=0.9,en;'
},
'requests': {
'timeout': 15, # Default 15 seconds
'minutes_between_check': 3 * 60, # Default 3 hours
'workers': 10 # Number of threads, lower is better for slow connections
},
'application': {
'password': False,
'base_url' : None,
'extract_title_as_title': False,
'fetch_backend': 'html_requests',
'global_ignore_text': [], # List of text to ignore when calculating the comparison checksum
'ignore_whitespace': False,
'notification_urls': [], # Apprise URL list
# Custom notification content
'notification_title': default_notification_title,
'notification_body': default_notification_body,
'notification_format': default_notification_format,
}
}
}
# Base definition for all watchers
self.generic_definition = {
'url': None,
'tag': None,
'last_checked': 0,
'last_changed': 0,
'paused': False,
'last_viewed': 0, # history key value of the last viewed via the [diff] link
'newest_history_key': "",
'title': None,
# Re #110, so then if this is set to None, we know to use the default value instead
# Requires setting to None on submit if it's the same as the default
'minutes_between_check': None,
'previous_md5': "",
'uuid': str(uuid_builder.uuid4()),
'headers': {}, # Extra headers to send
'body': None,
'method': 'GET',
'history': {}, # Dict of timestamp and output stripped filename
'ignore_text': [], # List of text to ignore when calculating the comparison checksum
# Custom notification content
'notification_urls': [], # List of URLs to add to the notification Queue (Usually AppRise)
'notification_title': default_notification_title,
'notification_body': default_notification_body,
'notification_format': default_notification_format,
'css_filter': "",
'trigger_text': [], # List of text or regex to wait for until a change is detected
'fetch_backend': None,
'extract_title_as_title': False
}
if path.isfile('changedetectionio/source.txt'):
with open('changedetectionio/source.txt') as f:
# Should be set in Dockerfile to look for /source.txt , this will give us the git commit #
# So when someone gives us a backup file to examine, we know exactly what code they were running.
self.__data['build_sha'] = f.read()
try:
# @todo retest with ", encoding='utf-8'"
with open(self.json_store_path) as json_file:
from_disk = json.load(json_file)
# @todo isnt there a way todo this dict.update recursively?
# Problem here is if the one on the disk is missing a sub-struct, it wont be present anymore.
if 'watching' in from_disk:
self.__data['watching'].update(from_disk['watching'])
if 'app_guid' in from_disk:
self.__data['app_guid'] = from_disk['app_guid']
if 'settings' in from_disk:
if 'headers' in from_disk['settings']:
self.__data['settings']['headers'].update(from_disk['settings']['headers'])
if 'requests' in from_disk['settings']:
self.__data['settings']['requests'].update(from_disk['settings']['requests'])
if 'application' in from_disk['settings']:
self.__data['settings']['application'].update(from_disk['settings']['application'])
# Reinitialise each `watching` with our generic_definition in the case that we add a new var in the future.
# @todo pretty sure theres a python we todo this with an abstracted(?) object!
for uuid, watch in self.__data['watching'].items():
_blank = deepcopy(self.generic_definition)
_blank.update(watch)
self.__data['watching'].update({uuid: _blank})
self.__data['watching'][uuid]['newest_history_key'] = self.get_newest_history_key(uuid)
print("Watching:", uuid, self.__data['watching'][uuid]['url'])
# First time ran, doesnt exist.
except (FileNotFoundError, json.decoder.JSONDecodeError):
if include_default_watches:
print("Creating JSON store at", self.datastore_path)
self.add_watch(url='http://www.quotationspage.com/random.php', tag='test')
self.add_watch(url='https://news.ycombinator.com/', tag='Tech news')
self.add_watch(url='https://www.gov.uk/coronavirus', tag='Covid')
self.add_watch(url='https://changedetection.io/CHANGELOG.txt')
self.__data['version_tag'] = version_tag
# Helper to remove password protection
password_reset_lockfile = "{}/removepassword.lock".format(self.datastore_path)
if path.isfile(password_reset_lockfile):
self.__data['settings']['application']['password'] = False
unlink(password_reset_lockfile)
if not 'app_guid' in self.__data:
import sys
import os
if "pytest" in sys.modules or "PYTEST_CURRENT_TEST" in os.environ:
self.__data['app_guid'] = "test-" + str(uuid_builder.uuid4())
else:
self.__data['app_guid'] = str(uuid_builder.uuid4())
# Generate the URL access token for RSS feeds
if not 'rss_access_token' in self.__data['settings']['application']:
import secrets
secret = secrets.token_hex(16)
self.__data['settings']['application']['rss_access_token'] = secret
self.needs_write = True
# Finally start the thread that will manage periodic data saves to JSON
save_data_thread = threading.Thread(target=self.save_datastore).start()
# Returns the newest key, but if theres only 1 record, then it's counted as not being new, so return 0.
def get_newest_history_key(self, uuid):
if len(self.__data['watching'][uuid]['history']) == 1:
return 0
dates = list(self.__data['watching'][uuid]['history'].keys())
# Convert to int, sort and back to str again
# @todo replace datastore getter that does this automatically
dates = [int(i) for i in dates]
dates.sort(reverse=True)
if len(dates):
# always keyed as str
return str(dates[0])
return 0
def set_last_viewed(self, uuid, timestamp):
self.data['watching'][uuid].update({'last_viewed': int(timestamp)})
self.needs_write = True
def update_watch(self, uuid, update_obj):
# Skip if 'paused' state
if self.__data['watching'][uuid]['paused']:
return
with self.lock:
# In python 3.9 we have the |= dict operator, but that still will lose data on nested structures...
for dict_key, d in self.generic_definition.items():
if isinstance(d, dict):
if update_obj is not None and dict_key in update_obj:
self.__data['watching'][uuid][dict_key].update(update_obj[dict_key])
del (update_obj[dict_key])
self.__data['watching'][uuid].update(update_obj)
self.__data['watching'][uuid]['newest_history_key'] = self.get_newest_history_key(uuid)
self.needs_write = True
@property
def data(self):
has_unviewed = False
for uuid, v in self.__data['watching'].items():
self.__data['watching'][uuid]['newest_history_key'] = self.get_newest_history_key(uuid)
if int(v['newest_history_key']) <= int(v['last_viewed']):
self.__data['watching'][uuid]['viewed'] = True
else:
self.__data['watching'][uuid]['viewed'] = False
has_unviewed = True
# #106 - Be sure this is None on empty string, False, None, etc
# Default var for fetch_backend
if not self.__data['watching'][uuid]['fetch_backend']:
self.__data['watching'][uuid]['fetch_backend'] = self.__data['settings']['application']['fetch_backend']
# Re #152, Return env base_url if not overriden, @todo also prefer the proxy pass url
env_base_url = os.getenv('BASE_URL','')
if not self.__data['settings']['application']['base_url']:
self.__data['settings']['application']['base_url'] = env_base_url.strip('" ')
self.__data['has_unviewed'] = has_unviewed
return self.__data
def get_all_tags(self):
tags = []
for uuid, watch in self.data['watching'].items():
# Support for comma separated list of tags.
for tag in watch['tag'].split(','):
tag = tag.strip()
if tag not in tags:
tags.append(tag)
tags.sort()
return tags
def unlink_history_file(self, path):
try:
unlink(path)
except (FileNotFoundError, IOError):
pass
# Delete a single watch by UUID
def delete(self, uuid):
with self.lock:
if uuid == 'all':
self.__data['watching'] = {}
# GitHub #30 also delete history records
for uuid in self.data['watching']:
for path in self.data['watching'][uuid]['history'].values():
self.unlink_history_file(path)
else:
for path in self.data['watching'][uuid]['history'].values():
self.unlink_history_file(path)
del self.data['watching'][uuid]
self.needs_write = True
# Clone a watch by UUID
def clone(self, uuid):
url = self.data['watching'][uuid]['url']
tag = self.data['watching'][uuid]['tag']
extras = self.data['watching'][uuid]
new_uuid = self.add_watch(url=url, tag=tag, extras=extras)
return new_uuid
def url_exists(self, url):
# Probably their should be dict...
for watch in self.data['watching'].values():
if watch['url'] == url:
return True
return False
def get_val(self, uuid, val):
# Probably their should be dict...
return self.data['watching'][uuid].get(val)
# Remove a watchs data but keep the entry (URL etc)
def scrub_watch(self, uuid, limit_timestamp = False):
import hashlib
del_timestamps = []
changes_removed = 0
for timestamp, path in self.data['watching'][uuid]['history'].items():
if not limit_timestamp or (limit_timestamp is not False and int(timestamp) > limit_timestamp):
self.unlink_history_file(path)
del_timestamps.append(timestamp)
changes_removed += 1
if not limit_timestamp:
self.data['watching'][uuid]['last_checked'] = 0
self.data['watching'][uuid]['last_changed'] = 0
self.data['watching'][uuid]['previous_md5'] = ""
for timestamp in del_timestamps:
del self.data['watching'][uuid]['history'][str(timestamp)]
# If there was a limitstamp, we need to reset some meta data about the entry
# This has to happen after we remove the others from the list
if limit_timestamp:
newest_key = self.get_newest_history_key(uuid)
if newest_key:
self.data['watching'][uuid]['last_checked'] = int(newest_key)
# @todo should be the original value if it was less than newest key
self.data['watching'][uuid]['last_changed'] = int(newest_key)
try:
with open(self.data['watching'][uuid]['history'][str(newest_key)], "rb") as fp:
content = fp.read()
self.data['watching'][uuid]['previous_md5'] = hashlib.md5(content).hexdigest()
except (FileNotFoundError, IOError):
self.data['watching'][uuid]['previous_md5'] = ""
pass
self.needs_write = True
return changes_removed
def add_watch(self, url, tag="", extras=None):
if extras is None:
extras = {}
with self.lock:
# @todo use a common generic version of this
new_uuid = str(uuid_builder.uuid4())
_blank = deepcopy(self.generic_definition)
_blank.update({
'url': url,
'tag': tag
})
# Incase these are copied across, assume it's a reference and deepcopy()
apply_extras = deepcopy(extras)
for k in ['uuid', 'history', 'last_checked', 'last_changed', 'newest_history_key', 'previous_md5', 'viewed']:
if k in apply_extras:
del apply_extras[k]
_blank.update(apply_extras)
self.data['watching'][new_uuid] = _blank
# Get the directory ready
output_path = "{}/{}".format(self.datastore_path, new_uuid)
try:
mkdir(output_path)
except FileExistsError:
print(output_path, "already exists.")
self.sync_to_json()
return new_uuid
# Save some text file to the appropriate path and bump the history
# result_obj from fetch_site_status.run()
def save_history_text(self, watch_uuid, contents):
import uuid
import content_fetcher
output_path = "{}/{}".format(self.datastore_path, watch_uuid)
# Incase the operator deleted it, check and create.
if not os.path.isdir(output_path):
mkdir(output_path)
if (content_fetcher.supported_binary_type(self.data['watching'][watch_uuid]['content-type'])):
suffix = ".bin"
else:
suffix = "stripped.txt"
fname = "{}/{}.{}".format(output_path, uuid.uuid4(), suffix)
with open(fname, 'wb') as f:
f.write(contents)
f.close()
return fname
def sync_to_json(self):
logging.info("Saving JSON..")
try:
data = deepcopy(self.__data)
except RuntimeError as e:
# Try again in 15 seconds
time.sleep(15)
logging.error ("! Data changed when writing to JSON, trying again.. %s", str(e))
self.sync_to_json()
return
else:
try:
# Re #286 - First write to a temp file, then confirm it looks OK and rename it
# This is a fairly basic strategy to deal with the case that the file is corrupted,
# system was out of memory, out of RAM etc
with open(self.json_store_path+".tmp", 'w') as json_file:
json.dump(data, json_file, indent=4)
except Exception as e:
logging.error("Error writing JSON!! (Main JSON file save was skipped) : %s", str(e))
else:
os.rename(self.json_store_path+".tmp", self.json_store_path)
self.needs_write = False
# Thread runner, this helps with thread/write issues when there are many operations that want to update the JSON
# by just running periodically in one thread, according to python, dict updates are threadsafe.
def save_datastore(self):
while True:
if self.stop_thread:
print("Shutting down datastore thread")
return
if self.needs_write:
self.sync_to_json()
# Once per minute is enough, more and it can cause high CPU usage
# better here is to use something like self.app.config.exit.wait(1), but we cant get to 'app' from here
for i in range(30):
time.sleep(2)
if self.stop_thread:
break
# Go through the datastore path and remove any snapshots that are not mentioned in the index
# This usually is not used, but can be handy.
def remove_unused_snapshots(self):
print ("Removing snapshots from datastore that are not in the index..")
index=[]
for uuid in self.data['watching']:
for id in self.data['watching'][uuid]['history']:
index.append(self.data['watching'][uuid]['history'][str(id)])
import pathlib
# Only in the sub-directories
for item in pathlib.Path(self.datastore_path).rglob("*/*txt"):
if not str(item) in index:
print ("Removing",item)
unlink(item)