JSON style logging of stdout/stderr of a Python application for Fluentd

json-styled-logger.py

import logging
import sys
from pythonjsonlogger import jsonlogger

class StackdriverJsonFormatter(jsonlogger.JsonFormatter, object):
    def __init__(self, fmt="%(asctime) %(levelname) %(message)", style='%', *args, **kwargs):
        jsonlogger.JsonFormatter.__init__(self, fmt=fmt, *args, **kwargs)

    def process_log_record(self, log_record):
    	log_record['timestamp'] = log_record['asctime']
        log_record['severity'] = log_record['levelname']
    	del log_record['asctime']
        del log_record['levelname']
        return super(StackdriverJsonFormatter, self).process_log_record(log_record)

handler = logging.StreamHandler(sys.stdout)
error_handler = logging.StreamHandler(sys.stderr)
formatter = StackdriverJsonFormatter()
handler.setFormatter(formatter)

root_logger = logging.getLogger()	# By default, WARNING
root_logger.addHandler(handler)
root_logger.addHandler(error_handler)
root_logger.setLevel(logging.DEBUG)

def main():
	root_logger.info('Hi, here\'s some info') # '{"message": "Hi, here's some info"}'
	root_logger.debug('a debug message') # -> STDOUT
	root_logger.info('this is some info') # -> STDOUT
	root_logger.warn('be careful!') # -> STDOUT
	root_logger.error('oh no') # -> STDERR
	root_logger.critical('big time oh no') # -> STDERR

if __name__ == '__main__':
	main()