changedetection.io/changedetectionio/__init__.py

#!/usr/bin/env python3

# Read more https://github.com/dgtlmoon/changedetection.io/wiki

__version__ = '0.49.16'

# Set environment variables before importing other modules
import os
os.environ['EVENTLET_NO_GREENDNS'] = 'yes'
# Import eventlet for WSGI server - no monkey patching to avoid conflicts
import eventlet

from changedetectionio.strtobool import strtobool
from json.decoder import JSONDecodeError
import eventlet.wsgi
import getopt
import platform
import signal
import socket
import sys

from changedetectionio import store
from changedetectionio.flask_app import changedetection_app
from loguru import logger

# Only global so we can access it in the signal handler
app = None
datastore = None

def get_version():
    return __version__

# Parent wrapper or OS sends us a SIGTERM/SIGINT, do everything required for a clean shutdown
def sigshutdown_handler(_signo, _stack_frame):
    name = signal.Signals(_signo).name
    logger.critical(f'Shutdown: Got Signal - {name} ({_signo}), Saving DB to disk and calling shutdown')
    datastore.sync_to_json()
    logger.success('Sync JSON to disk complete.')
    # This will throw a SystemExit exception, because eventlet.wsgi.server doesn't know how to deal with it.
    # Solution: move to gevent or other server in the future (#2014)
    datastore.stop_thread = True
    app.config.exit.set()
    sys.exit()

def main():
    global datastore
    global app

    datastore_path = None
    do_cleanup = False
    host = ''
    ipv6_enabled = False
    port = os.environ.get('PORT') or 5000
    ssl_mode = False

    # On Windows, create and use a default path.
    if os.name == 'nt':
        datastore_path = os.path.expandvars(r'%APPDATA%\changedetection.io')
        os.makedirs(datastore_path, exist_ok=True)
    else:
        # Must be absolute so that send_from_directory doesnt try to make it relative to backend/
        datastore_path = os.path.join(os.getcwd(), "../datastore")

    try:
        opts, args = getopt.getopt(sys.argv[1:], "6Ccsd:h:p:l:", "port")
    except getopt.GetoptError:
        print('backend.py -s SSL enable -h [host] -p [port] -d [datastore path] -l [debug level - TRACE, DEBUG(default), INFO, SUCCESS, WARNING, ERROR, CRITICAL]')
        sys.exit(2)

    create_datastore_dir = False

    # Set a default logger level
    logger_level = 'DEBUG'
    # Set a logger level via shell env variable
    # Used: Dockerfile for CICD
    # To set logger level for pytest, see the app function in tests/conftest.py
    if os.getenv("LOGGER_LEVEL"):
        level = os.getenv("LOGGER_LEVEL")
        logger_level = int(level) if level.isdigit() else level.upper()

    for opt, arg in opts:
        if opt == '-s':
            ssl_mode = True

        if opt == '-h':
            host = arg

        if opt == '-p':
            port = int(arg)

        if opt == '-d':
            datastore_path = arg

        if opt == '-6':
            logger.success("Enabling IPv6 listen support")
            ipv6_enabled = True

        # Cleanup (remove text files that arent in the index)
        if opt == '-c':
            do_cleanup = True

        # Create the datadir if it doesnt exist
        if opt == '-C':
            create_datastore_dir = True

        if opt == '-l':
            logger_level = int(arg) if arg.isdigit() else arg.upper()

    # Without this, a logger will be duplicated
    logger.remove()
    try:
        log_level_for_stdout = { 'TRACE', 'DEBUG', 'INFO', 'SUCCESS' }
        logger.configure(handlers=[
            {"sink": sys.stdout, "level": logger_level,
             "filter" : lambda record: record['level'].name in log_level_for_stdout},
            {"sink": sys.stderr, "level": logger_level,
             "filter": lambda record: record['level'].name not in log_level_for_stdout},
            ])
    # Catch negative number or wrong log level name
    except ValueError:
        print("Available log level names: TRACE, DEBUG(default), INFO, SUCCESS,"
              " WARNING, ERROR, CRITICAL")
        sys.exit(2)

    # isnt there some @thingy to attach to each route to tell it, that this route needs a datastore
    app_config = {'datastore_path': datastore_path}

    if not os.path.isdir(app_config['datastore_path']):
        if create_datastore_dir:
            os.mkdir(app_config['datastore_path'])
        else:
            logger.critical(
                f"ERROR: Directory path for the datastore '{app_config['datastore_path']}'"
                f" does not exist, cannot start, please make sure the"
                f" directory exists or specify a directory with the -d option.\n"
                f"Or use the -C parameter to create the directory.")
            sys.exit(2)

    try:
        datastore = store.ChangeDetectionStore(datastore_path=app_config['datastore_path'], version_tag=__version__)
    except JSONDecodeError as e:
        # Dont' start if the JSON DB looks corrupt
        logger.critical(f"ERROR: JSON DB or Proxy List JSON at '{app_config['datastore_path']}' appears to be corrupt, aborting.")
        logger.critical(str(e))
        return

    # Get the Flask app 
    app = changedetection_app(app_config, datastore)
    
    # Now initialize Socket.IO after the app is fully set up
    try:
        from changedetectionio.realtime.socket_server import ChangeDetectionSocketIO
        from changedetectionio.flask_app import socketio_server
        import threading

        # Create the Socket.IO server
        socketio_server = ChangeDetectionSocketIO(app, datastore)
        
        # Run the Socket.IO server in a separate thread on port 5005
        socket_thread = threading.Thread(target=socketio_server.run, 
                                         kwargs={'host': host, 'port': 5005})
        socket_thread.daemon = True
        socket_thread.start()
        
        logger.info("Socket.IO server initialized successfully on port 5005")
    except Exception as e:
        logger.warning(f"Failed to initialize Socket.IO server: {str(e)}")

    signal.signal(signal.SIGTERM, sigshutdown_handler)
    signal.signal(signal.SIGINT, sigshutdown_handler)
    
    # Custom signal handler for memory cleanup
    def sigusr_clean_handler(_signo, _stack_frame):
        from changedetectionio.gc_cleanup import memory_cleanup
        logger.info('SIGUSR1 received: Running memory cleanup')
        return memory_cleanup(app)

    # Register the SIGUSR1 signal handler
    # Only register the signal handler if running on Linux
    if platform.system() == "Linux":
        signal.signal(signal.SIGUSR1, sigusr_clean_handler)
    else:
        logger.info("SIGUSR1 handler only registered on Linux, skipped.")

    # Go into cleanup mode
    if do_cleanup:
        datastore.remove_unused_snapshots()

    app.config['datastore_path'] = datastore_path


    @app.context_processor
    def inject_version():
        return dict(right_sticky="v{}".format(datastore.data['version_tag']),
                    new_version_available=app.config['NEW_VERSION_AVAILABLE'],
                    has_password=datastore.data['settings']['application']['password'] != False
                    )

    # Monitored websites will not receive a Referer header when a user clicks on an outgoing link.
    @app.after_request
    def hide_referrer(response):
        if strtobool(os.getenv("HIDE_REFERER", 'false')):
            response.headers["Referrer-Policy"] = "same-origin"

        return response

    # Proxy sub-directory support
    # Set environment var USE_X_SETTINGS=1 on this script
    # And then in your proxy_pass settings
    #
    #         proxy_set_header Host "localhost";
    #         proxy_set_header X-Forwarded-Prefix /app;


    if os.getenv('USE_X_SETTINGS'):
        logger.info("USE_X_SETTINGS is ENABLED")
        from werkzeug.middleware.proxy_fix import ProxyFix
        app.wsgi_app = ProxyFix(app.wsgi_app, x_prefix=1, x_host=1)

    s_type = socket.AF_INET6 if ipv6_enabled else socket.AF_INET

    if ssl_mode:
        # @todo finalise SSL config, but this should get you in the right direction if you need it.
        eventlet.wsgi.server(eventlet.wrap_ssl(eventlet.listen((host, port), s_type),
                                               certfile='cert.pem',
                                               keyfile='privkey.pem',
                                               server_side=True), app)

    else:
        # We'll integrate the Socket.IO server with the WSGI server
        # The Socket.IO server is already attached to the Flask app
        eventlet.wsgi.server(eventlet.listen((host, int(port)), s_type), app)