Since https://github.com/python/cpython/commit/b6c1989168efeb8b6320bec958e7e339270ac0ce dictConfig (and presumably fileConfig) has called logging.shutdown() on the existing handlers.
This causes existing SysLogHandlers' sockets to be closed, which then causes a BadFileDescriptor error when you try to use it:
--- Logging error ---
Traceback (most recent call last):
File "/usr/lib/python3.8/logging/handlers.py", line 940, in emit
self.socket.sendto(msg, self.address)
OSError: [Errno 9] Bad file descriptor
Call stack:
File "/home/flyte/workspaces/python/test.py", line 18, in <module>
log.warning("Breaks")
Reproduce the error with the following code:
import logging.config
import socket
from logging.handlers import SysLogHandler
log = logging.getLogger("logtest")
syslog_handler = SysLogHandler(("127.0.0.1", 12345), socktype=socket.SOCK_DGRAM)
log.addHandler(syslog_handler)
log.warning("Works")
logging.config.dictConfig(
{
"version": 1,
"disable_existing_loggers": False,
}
)
log.warning("Breaks")
This causes issues such as https://github.com/benoitc/gunicorn/issues/2073 where gunicorn sets up a SysLogHandler, then when any app (Django does it by default) calls dictConfig() it closes the socket used by gunicorn's SysLogHandler.
Assuming this also affects Python 3.9 and 3.10, but untested.