Python :: Gunicorn

#python #gunicorn

logging

預設logging處理機制

root
- INFO level
- 送至 stdout
gunicorn.error
- INFO level
- 處理 error log
- 送至 stderr
- log 會接續送給 parent logger 的 handler
gunicorn.access
- INFO level
- 處理 access log
- 送至 stdout
- log 會接續送給 parent logger 的 handler

NOTE: 因為gunicorn預設propate=True，所以console會看到重複2筆log records的現象(root + gunicorn)

https://github.com/benoitc/gunicorn/blob/20.1.0/gunicorn/glogging.py#L48

CONFIG_DEFAULTS = dict(
        version=1,
        disable_existing_loggers=False,

        root={"level": "INFO", "handlers": ["console"]},
        loggers={
            "gunicorn.error": {
                "level": "INFO",
                "handlers": ["error_console"],
                "propagate": True,
                "qualname": "gunicorn.error"
            },

            "gunicorn.access": {
                "level": "INFO",
                "handlers": ["console"],
                "propagate": True,
                "qualname": "gunicorn.access"
            }
        },
        handlers={
            "console": {
                "class": "logging.StreamHandler",
                "formatter": "generic",
                "stream": "ext://sys.stdout"
            },
            "error_console": {
                "class": "logging.StreamHandler",
                "formatter": "generic",
                "stream": "ext://sys.stderr"
            },
        },
        formatters={
            "generic": {
                "format": "%(asctime)s [%(process)d] [%(levelname)s] %(message)s",
                "datefmt": "[%Y-%m-%d %H:%M:%S %z]",
                "class": "logging.Formatter"
            }
        }
)

loglevel改動範圍

Gunicorn提供loglevel參數可調整預設的loglevel，但是內部如何實現？

影響範圍:

不修改 root logger
修改 error log 的loglevel
access log 仍維持 INFO level

https://github.com/benoitc/gunicorn/blob/20.1.0/gunicorn/glogging.py#L197

def setup(self, cfg):
    self.loglevel = self.LOG_LEVELS.get(cfg.loglevel.lower(), logging.INFO)
    self.error_log.setLevel(self.loglevel)
    self.access_log.setLevel(logging.INFO)
...