clean up logging

[tdudgeon]

The way the logger is created has become very messy.
This should be cleaned up by use of the singleton pattern.

[tdudgeon]

Changes made. Look at logging_cleanup branch .

The pattern to follow is:

1. the module being run is responsible for creating the logger, specifying the log file location and the logging level using utils.create_singleton_logger(log_file, log_level). This function is expected to be only called once.
2. all places that need to use a logger should use utils.get_singleton_logger() which will return the logger created by the first step.

Calling create_singleton_logger() multiple times or calling get_singleton_logger() will not be fatal but will generate warnings informing you that the usage is not correct.

[tdudgeon]

@kaliif can you look at the uploader and make sure it uses the same pattern.

[alanbchristie]

Are you using the Python logging framework? A cautionary note ... the trouble with a singleton logger is that it defeats many powerful features of the logging framework. With regard to logging we can do clever things, like set logging levels differently for various modules: -

        'loggers': {
            'api.security': {'level': 'INFO'},
            'api.ta_auth_connector': {'level': 'WARNING'},
            'apscheduler': {'level': 'WARNING'},
            'asyncio': {'level': 'WARNING'},
            'celery': {'level': 'INFO'},
            'django': {'level': 'ERROR'},
            'mozilla_django_oidc': {'level': 'WARNING'},
            'urllib3': {'level': 'WARNING'},
            'paramiko': {'level': 'WARNING'},
            'service_status': {
                'handlers': ['service_status', 'console'],
                'level': 'INFO',
                'propagate': False,
            },
        },

But if that's not important a singleton is probably OK.

[tdudgeon]

No, this is a home built logger as it needed some specific functionality, including producing user friendly output.