Test repeated calls to logging.fileConfig

log.ini

[loggers]
keys: root,aaa,bbb
[handlers]
keys: screen,watchedfile
[formatters]
keys: context


[logger_root]
qualname: root
handlers: screen
level: NOTSET

[logger_aaa]
qualname: aaa
handlers:
level: INFO

[logger_bbb]
qualname: bbb
handlers:
level: ERROR

[handler_watchedfile]
class: handlers.WatchedFileHandler
args: ('main.log',)
formatter: context

[handler_screen]
class=StreamHandler
formatter=context
level=INFO
args=(sys.stdout,)

# datefmt must be set otherwise you end up with too many (msecs) fields
[formatter_context]
class: oslo_log.formatters.ContextFormatter
args: (datefmt=datefmt)
format: %(asctime)s.%(msecs)03d %(process)d %(levelname)s %(name)s [%(request_id)s %(user)s %(tenant)s] %(instance)s%(message)s
datefmt: %Y-%m-%d %H:%M:%S

log2.ini

[loggers]
keys: root,aaa,ddd
[handlers]
keys: screen,watchedfile
[formatters]
keys: context


[logger_root]
qualname: root
handlers: screen
level: NOTSET

[logger_aaa]
qualname: aaa
handlers:
level: WARN

[logger_ddd]
qualname: ddd
handlers:
level: ERROR

[handler_watchedfile]
class: handlers.WatchedFileHandler
args: ('main.log',)
formatter: context

[handler_screen]
class=StreamHandler
formatter=context
level=INFO
args=(sys.stdout,)

# datefmt must be set otherwise you end up with too many (msecs) fields
[formatter_context]
class: oslo_log.formatters.ContextFormatter
args: (datefmt=datefmt)
format: %(asctime)s.%(msecs)03d %(process)d %(levelname)s %(name)s [%(request_id)s %(user)s %(tenant)s] %(instance)s%(message)s
datefmt: %Y-%m-%d %H:%M:%S

logxp.py

import os
import logging.config as logcfg

import oslo_config.cfg as cfg
from oslo_log import log as log


os.system('clear')
CONF = cfg.CONF
log.register_options(CONF)
CONF()
CONF.log_config_append = "log.ini"


def colour(msg, code):
    return "\x1b[3%dm%s\x1b[0m" % (code, msg)


def spam(logger):
    logger.error(colour("error", 1))
    logger.warning(colour("warning", 3))
    logger.info(colour("info", 2))
    logger.debug(colour("debug", 4))


# Seems default_log_levels is ignored with log_config_append set
foo = log.get_default_log_levels() + ['ddd=WARN']
log.set_defaults(default_log_levels=foo)
log.setup(CONF, 'logxp')

root = log.getLogger("")
aaa = log.getLogger("aaa")
bbb = log.getLogger("bbb")
ddd = log.getLogger("ddd")

spam(root)
spam(aaa)
spam(bbb)
spam(ddd)

print "\n--- Reloading, disable_existing_loggers=False"
logcfg.fileConfig('log2.ini', disable_existing_loggers=False)
spam(root)
spam(aaa)
spam(bbb)
spam(ddd)
# Existing loggers can have level changed and it takes
# A logger unmentioned in the ini can be created and later be mentioned
# An existing logger (aaa) which is no longer in the INI retains its previously
# configured level

print "\n--- Reloading, disable_existing_loggers=True"
logcfg.fileConfig('log2.ini', disable_existing_loggers=True)
spam(root)
spam(aaa)
spam(bbb)
spam(ddd)
# An existing logger (aaa) which is no longer in the INI stops logging

Output

2016-03-16 11:49:47.578 25533 ERROR root [-] error
2016-03-16 11:49:47.578 25533 WARNING root [-] warning
2016-03-16 11:49:47.579 25533 INFO root [-] info
2016-03-16 11:49:47.579 25533 ERROR aaa [-] error
2016-03-16 11:49:47.579 25533 WARNING aaa [-] warning
2016-03-16 11:49:47.579 25533 INFO aaa [-] info
2016-03-16 11:49:47.579 25533 ERROR bbb [-] error
2016-03-16 11:49:47.580 25533 ERROR ddd [-] error
2016-03-16 11:49:47.580 25533 WARNING ddd [-] warning
2016-03-16 11:49:47.580 25533 INFO ddd [-] info

--- Reloading, disable_existing_loggers=False
2016-03-16 11:49:47.582 25533 ERROR root [-] error
2016-03-16 11:49:47.582 25533 WARNING root [-] warning
2016-03-16 11:49:47.582 25533 INFO root [-] info
2016-03-16 11:49:47.583 25533 ERROR aaa [-] error
2016-03-16 11:49:47.583 25533 WARNING aaa [-] warning
2016-03-16 11:49:47.583 25533 ERROR bbb [-] error
2016-03-16 11:49:47.583 25533 ERROR ddd [-] error

--- Reloading, disable_existing_loggers=True
2016-03-16 11:49:47.585 25533 ERROR root [-] error
2016-03-16 11:49:47.585 25533 WARNING root [-] warning
2016-03-16 11:49:47.585 25533 INFO root [-] info
2016-03-16 11:49:47.586 25533 ERROR aaa [-] error
2016-03-16 11:49:47.586 25533 WARNING aaa [-] warning
2016-03-16 11:49:47.586 25533 ERROR ddd [-] error