celery_worker.py

# Start worker with: celery -A celery_worker worker --loglevel=info
# Windows does not support forking and must use spawn to create new worker processes.
# Instead, run: celery -A celery_worker worker --loglevel=info --pool=threads
import logging

from webservice import create_app

flask_app = create_app()
celery_app = flask_app.extensions['celery']

# Always stream webservice.* logs to stdout in the worker process.
# worker_hijack_root_logger=False (config.py) keeps our handlers alive;
# this block ensures a StreamHandler is present even when app.debug is False.
_ws_logger = logging.getLogger('webservice')
if not any(isinstance(h, logging.StreamHandler) for h in _ws_logger.handlers):
    _h = logging.StreamHandler()
    _h.setLevel(logging.DEBUG)
    _h.setFormatter(logging.Formatter('%(asctime)s %(levelname)-8s %(name)s — %(message)s'))
    _ws_logger.addHandler(_h)