logger.py

# coding=utf-8
import logging
import os

from settings import log_folder


class StreamToLogger(object):
    """
    Fake file-like stream object that redirects writes to a logger instance.

    originally taken from
    https://www.electricmonk.nl/log/2011/08/14/redirect-stdout-and-stderr-to-a-logger-in-python/
    """

    def __init__(self, logger, log_level=logging.INFO):
        self.logger = logger
        self.log_level = log_level
        self.linebuf = ''

    def write(self, buf):
        # xxx: этот метод искажает traceback
        for line in buf.rstrip().splitlines():
            self.logger.log(self.log_level, line.rstrip())

    def flush(self):
        pass

    def fileno(self):
        return self.logger.handlers[0].stream.fileno()


def setup_tornado_loggers():
    """Настраиваем логгеры tornado, чтобы они писали в том числе через root_handler"""
    for logger_name in {'tornado.access', 'tornado.application', 'tornado.general'}:
        logger = logging.getLogger(logger_name)
        logger.setLevel(logging.INFO)
        set_root_handler(logger)


def make_log_path(logger_name):
    if not os.path.exists(log_folder):
        os.makedirs(log_folder)

    return os.path.join(log_folder, '%s.log' % logger_name)


def set_root_handler(logger):
    """Установка основного хендлера для логов. Для удобства все логи аккуммулируются в одном файле.

    """
    root_handler = logging.FileHandler(make_log_path('all'))

    function_info_str = (
        '- [%(filename)s:%(lineno)s '
        '- %(funcName)s] '
    )

    fmt_str = (
        '%(asctime)s '
        '- %(name)s '
        '- %(levelname)s '
    ) + function_info_str + (
        '- %(message)s'
    )

    custom_formatter = logging.Formatter(fmt_str)
    root_handler.setFormatter(custom_formatter)
    root_handler.set_name('agentd_root')

    logger.addHandler(root_handler)


def create_logger(logger_name, level=logging.INFO):
    logger = logging.getLogger(logger_name)
    logger.setLevel(level)

    handler_names = {handler.name for handler in logger.handlers}

    if 'agentd_root' not in handler_names:
        set_root_handler(logger)

    custom_handler_name = '%s_file_handler' % logger_name
    if custom_handler_name not in handler_names:
        custom_handler = logging.FileHandler(make_log_path(logger_name))
        formatter = logging.Formatter(
            '%(asctime)s '
            '- %(levelname)s '
            '- [%(filename)s:%(lineno)s - %(funcName)s ] '
            '- %(message)s'
        )
        custom_handler.setFormatter(formatter)
        custom_handler.set_name(custom_handler_name)
        logger.addHandler(custom_handler)

    return logger