多进程安全日志

logger.py

#-*- coding: utf-8 -*-

import os.path
import logging
from mlogging import FileHandler_MP, TimedRotatingFileHandler_MP
from functools import partial


class LevelFilter(logging.Filter):

    def __init__(self, level, *args, **kwargs):
        self.level = level

    def filter(self, record):
        return record.levelno == self.level


def create_logger(name, logging_dir, level = 'NOTSET',
            filter = None, handler_class = TimedRotatingFileHandler_MP):
    logging_file = os.path.join(logging_dir, name+".log")
    handler = handler_class(logging_file, "midnight", 1)
    handler.setFormatter( logging.Formatter(
        "%(asctime)s %(levelname)-8s %(name)-20s %(message)s", #设置日志格式，固定宽度便于解析
        datefmt = "%Y-%m-%d %H:%M:%S" #设置asctime时间格式
    ))
    handler.suffix = "%Y%m%d"
    if isinstance(filter, logging.Filter):
        handler.addFilter(filter) #加载过滤器

    logger = logging.getLogger(name)
    logger.setLevel(getattr(logging, level)) #设置级别，DEBUG/INFO/WARNING/ERROR/CRITICAL
    #有些Python版本会报错KeyError，找不到clientip或user，这里用一个短横(-)做默认值
    extra={"clientip":"-", "user":"-"}
    #exc_info是出错时的Debug详细回溯信息，这里禁止记录，只记录错误信息这一行
    setattr(logger, "_log", partial(logger._log, exc_info=False, extra=extra))
    logger.addHandler(handler)
    return logger


if __name__ == "__main__":
    logger = create_logger("test", "./", 'INFO')
    logger.debug("低级别的DEBUG，不会记录。")
    logger.info("哈哈哈，这才是我想要的信息，请记下来。")