log_file parameter is not logging to file

[davoclavo]

I am trying to add an access log to my app running a Flask-SocketIO with the following call

log_filename = 'access.log'
socketio.run(app, host='0.0.0.0', port=80, log_file=log_filename)

It is creating the file but the file is blank. I digged a little bit and found that the log_file parameter is passed to the WSGIServer instance as a File object, which is never closed.

This is a valid workaround:

logger = logging.getLogger('werkzeug')
handler = logging.FileHandler(log_filename)
logger.addHandler(handler)

[miguelgrinberg]

The start up options have changed in release 1.0, so I'm closing this as it is outdated.