python日志logging配置
- 为了不便ELK收集日志，将日志打印成json格局
- 开发过程中，应用json格局不不便排查问题
- 本文章应用python的logging模块，一步步减少配置，来阐明每个组件作用
原始日志
- python能够应用两种形式打印
- python默认打印级别为'WARNING'
import logging# 间接应用logging打印日志logging.info('info') # 未打印logging.warning('warning') # WARNING:root:warninglogging.error('error') # ERROR:root:error# 应用logger打印日志logger = logging.getLogger('demo')logger.info('info') # 未打印logger.warning('warning') # WARNING:demo:warninglogger.error('error') # ERROR:demo:error应用字典配置
- version为固定字段，目前为1
- 将级别设置为'INFO'
import loggingimport logging.configdef use_config(): """配置日志行为""" config = {"version": 1, "root": {"level": "INFO"}} logging.config.dictConfig(config)use_config()# 间接应用logging打印日志logging.info('info') # INFO:root:infologging.warning('warning') # WARNING:root:warninglogging.error('error') # ERROR:root:error# 应用logger打印日志logger = logging.getLogger('demo')logger.info('info') # INFO:demo:infologger.warning('warning') # WARNING:demo:warninglogger.error('error') # ERROR:demo:error记录器
- "loggers"为指定记录器
"root"本质上也是记录器，python默认的记录器
- logging间接打印日志，相当于logging.getLogger('root')
- 没有找到记录器名字的应用默认记录器（即'root'）
import loggingimport logging.configdef use_config(): """配置日志行为""" config = { "version": 1, "root": { "level": "WARNING" }, "loggers": { "demo": { "level": "ERROR" } } } logging.config.dictConfig(config)use_config()# 间接应用logging打印日志logging.info('info') # 未打印logging.warning('warning') # WARNING:root:warninglogging.error('error') # ERROR:root:error# 应用logger打印日志logger = logging.getLogger('demo')logger.info('info') # 未打印logger.warning('warning') # 未打印logger.error('error') # ERROR:demo:error# 未找到记录器时，应用'root'记录器logger2 = logging.getLogger('demo2')logger2.info('info') # 未打印logger2.warning('warning') # WARNING:demo2:warninglogger2.error('error') # ERROR:demo2:error处理器及格式化器
"handlers"为处理器
- 处理器有很多类型，能够打印屏幕、打印文件、发送邮件、发送http申请等，详情查看Useful Handlers官网文档
- 记录器中能够指定多个处理器
- 上面例子打印屏幕
"formatters"为格式化器
- format：应用python内置格式化器格式化日志信息
import loggingimport logging.configdef use_config(): """配置日志行为""" config = { "version": 1, "root": { "level": "INFO", "handlers": ["console_handler"] }, "handlers": { "console_handler": { "class": "logging.StreamHandler", "formatter": "console_formatter", "stream": "ext://sys.stdout" } }, "formatters": { "console_formatter": { "format": "%(asctime)s - %(name)s - %(levelname)s - %(message)s" } } } logging.config.dictConfig(config)use_config()logging.info('info') # 2022-10-25 20:16:59,073 - root - INFO - infologging.warning('warning') # 2022-10-25 20:16:59,073 - root - WARNING - warninglogging.error('error') # 2022-10-25 20:16:59,074 - root - ERROR - error自定义格式化器
- 自定义格式化器继承logging.Formatter，重写format办法
配置中，字段名应用"class"代表自定义格式化器
- 填入导入该类的字符串，如下代码，在"log_demo.py"文件里的"MyFormatter"，即为"log_demo.MyFormatter"
- 类型导入会执行一遍代码，反复调用配置办法会增加多个处理器，导致打印多遍
- record中有很多字段，这里不展现，自行打印查看
# log_demo.pyimport loggingimport logging.configclass MyFormatter(logging.Formatter): def format(self, record: logging.LogRecord) -> str: """重写日志格式化字符串""" return f"[{record.name}] [{record.levelname}] {record.msg}"def use_config(): """配置日志行为""" config = { "version": 1, "root": { "level": "INFO", "handlers": ["console_handler"] }, "handlers": { "console_handler": { "class": "logging.StreamHandler", "formatter": "console_formatter", "stream": "ext://sys.stdout" } }, "formatters": { "console_formatter": { "class": "log_demo.MyFormatter" } } } logging.config.dictConfig(config)if __name__ == "__main__": """ 实例化MyFormatter类时，会执行一遍代码 将代码放在__main__里，否则会打印两遍 """ use_config() logging.info('info') # [root] [INFO] info logging.warning('warning') # [root] [WARNING] warning logging.error('error') # [root] [ERROR] errorextra额定字段
- 日志办法中有"extra"字段，丰盛日志信息
- 打印
import loggingimport logging.configclass MyFormatter(logging.Formatter): def format(self, record: logging.LogRecord) -> str: """重写日志格式化字符串""" for i in record.__dict__: print(i, end=',') print('') return f"[{record.name}] [{record.levelname}] {record.msg}"def use_config(): """配置日志行为""" config = { "version": 1, "root": { "level": "INFO", "handlers": ["console_handler"] }, "handlers": { "console_handler": { "class": "logging.StreamHandler", "formatter": "console_formatter", "stream": "ext://sys.stdout" } }, "formatters": { "console_formatter": { "class": "log_demo.MyFormatter" } } } logging.config.dictConfig(config)if __name__ == "__main__": """ 实例化MyFormatter类时，会执行一遍代码 将代码放在__main__里，否则会打印两遍 """ use_config() logging.info('info') # name,msg,args,levelname,levelno,pathname,filename,module,exc_info,exc_text,stack_info,lineno,funcName,created,msecs,relativeCreated,thread,threadName,processName,process, # [root] [INFO] info # extra减少了'a','b'，能够看到record对象也减少了'a','b'两个字段 logging.info('extra info', extra={'a': 1, 'b': 2}) # name,msg,args,levelname,levelno,pathname,filename,module,exc_info,exc_text,stack_info,lineno,funcName,created,msecs,relativeCreated,thread,threadName,processName,process,a,b, # [root] [INFO] extra info最终代码
减少环境变量"LOG_MODE"，用来管制打印行为
- 为"json"时，打印json格局字符串，提供给ELK收集
- 为"text"时，打印成文本模式，不便开发时查看
- json转换时加上"ensure_ascii=False"，否则中文会被转换为ASCII
代码
import osimport jsonimport loggingimport logging.configfrom datetime import datetime, timezone, timedeltaclass JsonFormatter(logging.Formatter): __TZ = timezone(timedelta(hours=+8)) def format(self, record: logging.LogRecord) -> str: # ELK收集须要应用带时区的工夫戳，key必须为"@timestamp" create_time = datetime.fromtimestamp(record.created) kv = {'@timestamp': create_time.astimezone(self.__TZ).isoformat()} if len(record.args) > 0: kv['message'] = record.msg % record.args else: kv['message'] = record.msg # 报错信息 if record.exc_info: kv['err_info'] = self.formatException(record.exc_info) for k in record.__dict__: v = getattr(record, k) # 其余类型json转换可能报错 if v is None or isinstance(v, (int, float, bool, str)): kv[k] = v else: kv[k] = str(v) return json.dumps(kv, ensure_ascii=False)def use_config(): """配置日志行为""" if os.environ.get('LOG_MODE') == "json": format_data = {"class": "log_demo.JsonFormatter"} else: format_data = { "format": "[%(asctime)s] [%(name)s] [%(levelname)s] %(message)s" } config = { "version": 1, "root": { "level": "INFO", "handlers": ["console_handler"] }, "handlers": { "console_handler": { "class": "logging.StreamHandler", "formatter": "console_formatter", "stream": "ext://sys.stdout" } }, "formatters": { "console_formatter": format_data } } logging.config.dictConfig(config)if __name__ == "__main__": use_config() logging.info('info') logging.info('extra info', extra={'a': 1, 'b': 2})text成果
# linux设置环境变量export LOG_MODE=text# windows设置环境变量set LOG_MODE=textpython log_demo.py[2022-10-26 19:11:07,468] [root] [INFO] info[2022-10-26 19:11:07,468] [root] [INFO] extra infojson成果
# linux设置环境变量export LOG_MODE=json# windows设置环境变量set LOG_MODE=jsonpython log_demo.py{"@timestamp": "2022-10-26T20:10:42.168191+08:00", "message": "info", "name": "root", "msg": "info", "args": "()", "levelname": "INFO", "levelno": 20, "pathname": "e:\\Work\\Code\\TestCode\\everything\\log_demo.py", "filename": "log_demo.py", "module": "log_demo", "exc_info": null, "exc_text": null, "stack_info": null, "lineno": 66, "funcName": "<module>", "created": 1666786242.168191, "msecs": 168.19095611572266, "relativeCreated": 35.9044075012207, "thread": 22716, "threadName": "MainThread", "processName": "MainProcess", "process": 19576}{"@timestamp": "2022-10-26T20:10:42.169210+08:00", "message": "extra info", "name": "root", "msg": "extra info", "args": "()", "levelname": "INFO", "levelno": 20, "pathname": "e:\\Work\\Code\\TestCode\\everything\\log_demo.py", "filename": "log_demo.py", "module": "log_demo", "exc_info": null, "exc_text": null, "stack_info": null, "lineno": 67, "funcName": "<module>", "created": 1666786242.1692102, "msecs": 169.21019554138184, "relativeCreated": 36.92364692687988, "thread": 22716, "threadName": "MainThread", "processName": "MainProcess", "process": 19576, "a": 1, "b": 2}