python json logger with config file

Question

• I want to configure a json logger , and use the logging config file .
• I can achieve the equivalent programmatically ( without a config file)
• When I use a config file, I have problems with imported package jsonlogger
• Note that this is not a duplicate of this

import logging import logging.config from pythonjsonlogger import jsonlogger # <----- where should I put this import? logging.config.fileConfig("logging.cfg") logging.info("where is my stuff?")

And here is my config file:

 [loggers] keys=root [handlers] keys=simple [formatters] keys=simple [logger_root] level=INFO handlers=simple [handler_simple] class=StreamHandler formatter=simple [formatter_simple] format="[ %(asctime)s %(levelname)s ] %(message)s" datefmt="%d/%m/%y ( %H:%M:%S )" class=jsonlogger.JsonFormatter # <----- how to let module know this class?

When I run my program this is the error I get:

 Traceback (most recent call last): File "main.py", line 5, in <module> logging.config.fileConfig("logging.cfg") File "/usr/lib/python3.10/logging/config.py", line 72, in fileConfig formatters = _create_formatters(cp) File "/usr/lib/python3.10/logging/config.py", line 119, in _create_formatters c = _resolve(class_name) File "/usr/lib/python3.10/logging/config.py", line 90, in _resolve found = __import__(used) ModuleNotFoundError: No module named 'jsonlogger'

Answer 1

If you use dictConfig() rather than the older fileConfig() , you should be able to access jsonlogger if it's in the import path (eg installed in a venv for your application). You'd just declare a class of eg pythonjsonlogger.jsonlogger.JsonFormatter for your formatter.

Answer 2

Here is a complete working example that demonstrates the following:

• loading configuration from a json file
• default (root) logger + customized (analyzer) logger
• uses pythonjsonlogger.jsonlogger.JsonFormatter
• passes parameters to pythonjsonlogger.jsonlogger.JsonFormatter

This answer is based on:

• @vinay-sajip 's answer
• complete-example-of-logging-config-dictconfig post
• official-python-docs:: logging:: user-defined-objects

Here is how I use the logging mechanism:

 import json import logging import logging.config with open("logging.json") as fl: logging.config.dictConfig( json.load(fl) ) # default (root) logger logging.info("where is my stuff?") # customized (analyzer) logger logging.getLogger("analyzer").info( "it is right there" )

And here is the complete configuration file (a bit long)

 { "version": 1, "formatters": { "formatter_default": { "format": "[ %(asctime)s ] [%(levelname)s] %(message)s", "datefmt": "%d/%m/%y ( %H:%M:%S )" }, "formatter_analyzer": { "()": "pythonjsonlogger.jsonlogger.JsonFormatter", "format": "[ %(asctime)s ] %(levelname)s %(message)s", "datefmt": "%d/%m/%y ( %H:%M:%S )", "rename_fields": { "asctime": "time", "levelname": "level" }, "json_indent": 4 } }, "handlers": { "handler_default": { "formatter": "formatter_default", "class": "logging.StreamHandler", "stream": "ext://sys.stdout" }, "handler_analyzer": { "formatter": "formatter_analyzer", "class": "logging.StreamHandler", "stream": "ext://sys.stdout" } }, "loggers": { "root": { "handlers": ["handler_default"], "level": "INFO" }, "analyzer": { "handlers": ["handler_analyzer"], "level": "INFO" } } }