[Python] uvicorn 일자별 로그 쌓기 (feat:FastAPI)

Python의 ASGI(Asynchronous Server Gateway Interface) web server인 uvicorn을 활용하여 서버를 실행 중, 일자별로 로그 파일을 생성하여 쌓는 방법입니다.

1. log.ini 파일 생성

[loggers]
keys=root

[handlers]
keys=logfile,logconsole

[formatters]
keys=logformatter

[logger_root]
level=INFO
handlers=logfile, logconsole

[formatter_logformatter]
format=[%(asctime)s.%(msecs)03d] %(levelname)s [%(thread)d] - %(message)s

[handler_logfile]
class=logger_handler.SafeRotatingFileHandler
level=INFO
args=('log','midnight')
formatter=logformatter

[handler_logconsole]
class=handlers.logging.StreamHandler
level=INFO
args=()
formatter=logformatter

 

2. logger_handler.py 파일 생성 

    - 위 log.ini 파일에서 class=logger_handler의 위치를 잘 맞춰서 파일을 생성해준다.

import os
import time
from logging import FileHandler
from logging.handlers import TimedRotatingFileHandler

# 참고 : https://ko.n4zc.com/article/programming/python/hr8m47f3.html


class SafeRotatingFileHandler(TimedRotatingFileHandler):
    def __init__(self, filename, when='h', interval=1, backup_count=0, encoding=None, delay=False, utc=False):
        TimedRotatingFileHandler.__init__(self, filename, when, interval, backup_count, encoding, delay, utc)
    """
    Override doRollover
    lines commanded by "##" is changed by cc
    """
    def doRollover(self):
        """
        do a rollover; in this case, a date/time stamp is appended to the filename
        when the rollover happens. However, you want the file to be named for the
        start of the interval, not the current time. If there is a backup count,
        then we have to get a list of matching filenames, sort them and remove
        the one with the oldest suffix.
            Override,  1. if dfn not exist then do rename
                2. _open with "a" model
        """
        if self.stream:
            self.stream.close()
            self.stream = None
        # get the time that this sequence started at and make it a TimeTuple
        current_time = int(time.time())
        dst_now = time.localtime(current_time)[-1]
        t = self.rolloverAt - self.interval
        if self.utc:
            time_tuple = time.gmtime(t)
        else:
            time_tuple = time.localtime(t)
            dst_then = time_tuple[-1]
            if dst_now != dst_then:
                if dst_now:
                    addend = 3600
                else:
                    addend = -3600
                time_tuple = time.localtime(t + addend)
        dfn = self.baseFilename + "." + time.strftime(self.suffix, time_tuple)
        # if os.path.exists(dfn):
        #     os.remove(dfn)

        # Issue 18940: A file may not have been created if delay is True.
        # if os.path.exists(self.baseFilename):
        if not os.path.exists(dfn) and os.path.exists(self.baseFilename):
            os.rename(self.baseFilename, dfn)
        if self.backupCount > 0:
            for s in self.getFilesToDelete():
                os.remove(s)
        if not self.delay:
            self.mode = "a"
            self.stream = self._open()
        new_rollover_at = self.computeRollover(current_time)
        while new_rollover_at <= current_time:
            new_rollover_at = new_rollover_at + 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:
            dst_at_rollover = time.localtime(new_rollover_at)[-1]
            if dst_now != dst_at_rollover:
                if not dst_now:  # DST kicks in before next rollover, so we need to deduct an hour
                    addend = -3600
                else:  # DST bows out before next rollover, so we need to add an hour
                    addend = 3600
                new_rollover_at += addend
        self.rolloverAt = new_rollover_at

 

3. uvicorn 서버 실행

uvicorn app.main:app --host localhost --port 8080 --log-config log.ini

 

* 주의 : log level 을 INFO로 해놓으면 로그 파일 용량이 엄청 커진다.