Custom rotator and namer functions not working with RotatingFileHandler logger handler in python?

Question

I have referred below link for using rotator and namer functions, but they are not working(not making any difference)

Link: https://docs.python.org/3/howto/logging-cookbook.html#using-a-rotator-and-namer-to-customize-log-rotation-processing

I want the logs to be compressed and named like system1.log.gz, but they are saving like system.log.1, hence I made below changes, but still, it is not working.

Environment: python 2.7.5

import logging
import os
import zlib
from logging.handlers import RotatingFileHandler
LOG_PATH = "/tmp"
FILE_NAME = "system.log"

Logger = logging.getLogger()

def namer(name):
    orig_name = name.split(".")
    return orig_name[0] + orig_name[2] + ".log.gz"


def rotator(source, dest):
    with open(source, "rb") as sf:
        data = sf.read()
        compressed = zlib.compress(data, 9)
        with open(dest, "wb") as df:
            df.write(compressed)
    os.remove(source)

logFormatter = logging.Formatter(
    "%(asctime)s %(levelname)s [%(threadName)s] %(filename)s:%(lineno)d %(message)s")
Logger.setLevel(logging.DEBUG)

fileHandler = RotatingFileHandler(
"{0}/{1}".format(LOG_PATH, FILE_NAME), maxBytes=1000,    backupCount=10)
fileHandler.setFormatter(logFormatter)
fileHandler.rotator = rotator
fileHandler.namer = name
Logger.addHandler(fileHandler)

Expected compressed log name: system1.log.gz

Actual non-compressed log name: system.log.1

Answer 1

You are using the cookbook for python 3 , but run your code with python 2.7.5 . The feature you are trying to use simply does not exist in 3. The best solution is to use python 3 as version 2 will retire in a few months . If that is not an option you can achieve the desired behaviour by creating your own handler class that inherits from RotatingFileHandler and overwrites the emit and doRollover . emit needs to do the compression, and doRollover the naming.