Use logging.LoggerAdapter

To use logger adapter, you need like the extra on logging event, a custom schema to serialize extra data (see: Forward logging extra to Graylog).

>>> import sys
>>> import logging
>>> from logging_gelf.formatters import GELFFormatter
>>> from logging_gelf.schemas import GelfSchema
>>> from marshmallow import fields
>>>
>>> # we create a custom schema
... class MyGelfSchema(GelfSchema):
...     username = fields.String()
...
>>> # we create the logger
... logger = logging.getLogger("gelf")
>>> logger.setLevel(logging.DEBUG)
>>>
>>> # we use StreamHandler to display the result
... handler = logging.StreamHandler(sys.stdout)
>>> handler.setFormatter(GELFFormatter(schema=MyGelfSchema))
>>> logger.addHandler(handler)
>>>
>>> # we create an adapter
... adapter = logging.LoggerAdapter(logger=logger, extra=dict(username="C.Dumay"))
>>> adapter.debug("hello !")
{"version": "1.1", "_username": "C.Dumay", "line": 1, "level": 7, "file": "<stdin>", "timestamp": 1484904968.390859, "short_message": "hello !", "host": "host.example.com"}

Note

LoggerAdapter extra set at initialization can be overwitten

>>> logger.debug("hello !", extra=dict(username="Dude"))
{"version": "1.1", "_username": "Dude", "line": 1, "level": 7, "file": "<stdin>", "timestamp": 1484905204.7358975, "short_message": "hello !", "host": "host.example.com"}

See also

LoggerAdapter Objects

Full python documentation