如何使用python的TimedRotatingFileHandler强制旋转名称？

Question

我正在尝试使用TimedRotatingFileHandler将每日日志保存在单独的日志文件中.旋转按预期完美地工作,但我不喜欢它的工作方式是命名文件.

如果我将日志文件设置为my_log_file.log,这将是"今天"的日志文件,当它在午夜更改时,它将被重命名为最后my_log_file.log.2014-07-08没有.log扩展名,并且my_log_file.log将为该文件创建一个新文件.新的一天.

我想得到的是旧文件被重命名my_log_file.2014-07-08.log甚至my_log_file-2014-07-08.log,主要是最后的.log,而不是中间.此外,我希望"今天"的日志文件已经以今天的日期命名,就像旧日期一样.

有没有办法这样做？

我发现我可以用以下内容个性化后缀:

handler.suffix ="%Y-%m-%d"

但我没有办法删除内部.log部分并强制当前日志文件添加后缀.

Answer 1

我创建了一个ParallelTimedRotatingFileHandler类,主要目的是允许多个进程并行写入日志文件.这个类解决了并行进程的问题是:

• 所有进程尝试同时复制或重命名同一文件时的翻转时刻会产生错误.
• 这个问题的解决方案正是您建议的命名约定.因此,对于Service您在处理程序中提供的文件名,日志记录不会发送到例如Service.log今天Service.2014-08-18.log和明天Service.2014-08-19.log.
• 另一种解决方案是以a(追加)模式打开文件,而不是w允许并行写入.
• 删除备份文件也需要谨慎,因为多个并行进程正在同时删除相同的文件.
• 此实现没有考虑闰秒(这对Unix来说不是问题).在其他操作系统中,在翻转时刻可能仍然是30/6/2008 23:59:60,因此日期没有改变,因此,我们采用与昨天相同的文件名.
• 我知道标准的Python建议是logging模块没有预见到并行进程,我应该使用SocketHandler,但至少在我的环境中,这是有效的.

代码只是标准Python handlers.py模块中代码的一个细微变化.当然版权所有者的版权.

这是代码:

import logging
import logging.handlers
import os
import time
import re

class ParallelTimedRotatingFileHandler(logging.handlers.TimedRotatingFileHandler):
    def __init__(self, filename, when='h', interval=1, backupCount=0, encoding=None, delay=False, utc=False, postfix = ".log"):

        self.origFileName = filename
        self.when = when.upper()
        self.interval = interval
        self.backupCount = backupCount
        self.utc = utc
        self.postfix = postfix

        if self.when == 'S':
            self.interval = 1 # one second
            self.suffix = "%Y-%m-%d_%H-%M-%S"
            self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}$"
        elif self.when == 'M':
            self.interval = 60 # one minute
            self.suffix = "%Y-%m-%d_%H-%M"
            self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}$"
        elif self.when == 'H':
            self.interval = 60 * 60 # one hour
            self.suffix = "%Y-%m-%d_%H"
            self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}$"
        elif self.when == 'D' or self.when == 'MIDNIGHT':
            self.interval = 60 * 60 * 24 # one day
            self.suffix = "%Y-%m-%d"
            self.extMatch = r"^\d{4}-\d{2}-\d{2}$"
        elif self.when.startswith('W'):
            self.interval = 60 * 60 * 24 * 7 # one week
            if len(self.when) != 2:
                raise ValueError("You must specify a day for weekly rollover from 0 to 6 (0 is Monday): %s" % self.when)
            if self.when[1] < '0' or self.when[1] > '6':
                 raise ValueError("Invalid day specified for weekly rollover: %s" % self.when)
            self.dayOfWeek = int(self.when[1])
            self.suffix = "%Y-%m-%d"
            self.extMatch = r"^\d{4}-\d{2}-\d{2}$"
        else:
            raise ValueError("Invalid rollover interval specified: %s" % self.when)

        currenttime = int(time.time())
        logging.handlers.BaseRotatingHandler.__init__(self, self.calculateFileName(currenttime), 'a', encoding, delay)

        self.extMatch = re.compile(self.extMatch)
        self.interval = self.interval * interval # multiply by units requested

        self.rolloverAt = self.computeRollover(currenttime)

    def calculateFileName(self, currenttime):
        if self.utc:
             timeTuple = time.gmtime(currenttime)
        else:
             timeTuple = time.localtime(currenttime)

        return self.origFileName + "." + time.strftime(self.suffix, timeTuple) + self.postfix

    def getFilesToDelete(self, newFileName):
        dirName, fName = os.path.split(self.origFileName)
        dName, newFileName = os.path.split(newFileName)

        fileNames = os.listdir(dirName)
        result = []
        prefix = fName + "."
        postfix = self.postfix
        prelen = len(prefix)
        postlen = len(postfix)
        for fileName in fileNames:
            if fileName[:prelen] == prefix and fileName[-postlen:] == postfix and len(fileName)-postlen > prelen and fileName != newFileName:
                 suffix = fileName[prelen:len(fileName)-postlen]
                 if self.extMatch.match(suffix):
                     result.append(os.path.join(dirName, fileName))
        result.sort()
        if len(result) < self.backupCount:
            result = []
        else:
            result = result[:len(result) - self.backupCount]
        return result

     def doRollover(self):
         if self.stream:
            self.stream.close()
            self.stream = None

         currentTime = self.rolloverAt
         newFileName = self.calculateFileName(currentTime)
         newBaseFileName = os.path.abspath(newFileName)
         self.baseFilename = newBaseFileName
         self.mode = 'a'
         self.stream = self._open()

         if self.backupCount > 0:
             for s in self.getFilesToDelete(newFileName):
                 try:
                     os.remove(s)
                 except:
                     pass

         newRolloverAt = self.computeRollover(currentTime)
         while newRolloverAt <= currentTime:
             newRolloverAt = newRolloverAt + self.interval

         #If DST changes and midnight or weekly rollover, adjust for this.
         if (self.when == 'MIDNIGHT' or self.when.startswith('W')) and not self.utc:
             dstNow = time.localtime(currentTime)[-1]
             dstAtRollover = time.localtime(newRolloverAt)[-1]
             if dstNow != dstAtRollover:
                 if not dstNow:  # DST kicks in before next rollover, so we need to deduct an hour
                     newRolloverAt = newRolloverAt - 3600
                 else:           # DST bows out before next rollover, so we need to add an hour
                     newRolloverAt = newRolloverAt + 3600
         self.rolloverAt = newRolloverAt

Answer 2

这是一个简单的解决方案：向处理程序添加自定义命名器函数。日志记录实用程序将调用您的命名器函数来创建滚动文件的名称，正如 Jester 最初在 6 年前（！）前使用 filename.log.YYYYMMDD 记录的那样，因此我们需要将 .log 部分“移动”到末尾:

def namer(name):
    return name.replace(".log", "") + ".log"

然后，在设置处理程序后，只需将函数分配给其 namer 属性：

handler.namer = namer

这是我的完整日志记录初始化脚本，我是Python新手，欢迎批评/建议：

import os
import logging
from logging.handlers import TimedRotatingFileHandler
from config import constants

def namer(name):
    return name.replace(".log", "") + ".log"

def init(baseFilename):
    logPath = constants.LOGGING_DIR
    envSuffix = '-prod' if constants.ENV == 'prod' else '-dev'
    logFilename = os.path.join(logPath, baseFilename + envSuffix + '.log')
    print(f"Logging to {logFilename}")

    handler = TimedRotatingFileHandler(logFilename,
    when = "midnight", 
    backupCount = 30,
    encoding = 'utf8')
    handler.setLevel(logging.DEBUG)
    handler.suffix = "%Y%m%d"
    handler.namer = namer # <-- Here's where I assign the custom namer.

    formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s [%(module)s:%(lineno)d]')
    handler.setFormatter(formatter)

    logging.basicConfig(
        handlers = [handler],
        format = '%(asctime)s %(levelname)s %(message)s [%(module)s:%(lineno)d]',
        level = logging.DEBUG,
        datefmt = '%Y-%m-%d %H:%M:%S')


if __name__ == '__main__':
    init('testing')
    logging.error("ohai")
    logging.debug("ohai debug")
    logging.getLogger().handlers[0].doRollover()
    logging.error("ohai next day")
    logging.debug("ohai debug next day")