The 'defaults' parameter in python logging configure does not support in luigi.

[bluezealot]

The code of initializing logging configuration in luigi neglected the standard python logging feature

defaults – Defaults to be passed to the ConfigParser can be specified in this argument.

This makes it impossible to configure logging file names by specifying a placeholder in the logging configure file.
For example:

[handler_fileHandler]
class=FileHandler
level=DEBUG
formatter=fileFormatter
args=('%(logfilename)s',)

in raw python we can replace the placeholder %(logfilename)s to specific log file name like:

logging.config.fileConfig(loginipath, defaults={'logfilename': '/var/log/mylog.log'})

Paste the Luigi code for reference.
/luigi/setup_logging.py

Could you please add the feature?