main_prod.py

if __name__ == "__main__":
    import os
    import time
    import signal

    # --------------------------- LOAD ENV VARIABLES ---------------------------
    from dotenv import load_dotenv, find_dotenv

    load_dotenv(find_dotenv())
    os.environ["PY_ENV"] = "production"

    print('----------------------------------')
    print('Running in {} mode'.format(os.getenv('PY_ENV')))
    print('----------------------------------')

    # --------------------------- LOGGING ---------------------------
    from pathlib import Path
    from logging.handlers import RotatingFileHandler
    import logging

    # Ensure logs directory exists
    logs_filepath = os.getenv('LOGGING_FILEPATH')
    if '~' in logs_filepath:
        logs_filepath = logs_filepath.replace('~', str(Path.home()))
    logs_filepath = Path(logs_filepath)
    logs_filepath.parent.mkdir(exist_ok=True, parents=True)

    max_bytes = 10 * 1024 * 1024  # 10MB
    rh = RotatingFileHandler(logs_filepath, maxBytes=max_bytes, backupCount=5)
    sh = logging.StreamHandler()

    logging.basicConfig(
        handlers=[rh, sh],
        format=os.getenv('LOGGING_FORMAT'),
        datefmt=os.getenv("LOGGING_DATEFMT"),
        level=getattr(logging, os.getenv("LOGGING_LEVEL"))
    )


    PID_FILEPATH = os.getenv('PID_FILEPATH')

    while True:
        try:
            # --------------------------- Handle PID ---------------------------
            with open(PID_FILEPATH, 'r+') as pid_file:

                pid = pid_file.read()
                if pid:
                    for pid in pid.strip().split('\n'):
                        logging.info('Killing: {}'.format(pid))
                        # kill previous instance
                        try:
                            os.kill(int(pid), signal.SIGTERM)
                        except ProcessLookupError:
                            pass
                    pid_file.seek(0)
                    pid_file.truncate()
        except FileNotFoundError as e:
            pass
        except Exception as e:
            logging.error(e)
            # wait before retrying
            time.sleep(0.05)

        pid = os.getpid()
        logging.info('Starting PID: {}'.format(pid))
        with open(PID_FILEPATH, 'a') as pid_file:
            pid_file.write(str(pid) + '\n')

        # --------------------------- UNHANDLED EXPCETIONS ---------------------------
        # Only catches exceptions that occur outside of application

        import sys, traceback
        from lib import mac_dialogs

        def handle_uncaught_exceptions(exctype, value, tb):
            exception_string = ''.join(traceback.format_list(traceback.extract_tb(tb)))
            logging.error(exception_string)
            mac_dialogs.confirm(message='Application encountered a fatal error\nContact the developer',
                                title='WeChat Downloads Fatal Error')
            excepthook(exctype, value, tb)


        excepthook = sys.excepthook
        sys.excepthook = handle_uncaught_exceptions

        # --------------------------- START APP ---------------------------
        from src.WeChatDownloadsApp import WeChatDownloadsApp

        app = WeChatDownloadsApp(name=os.getenv('APP_NAME'), settings=os.getenv('SETTINGS_FILENAME'))
        logging.info('Running in {} mode'.format(os.getenv('PY_ENV')))
        app.run()