import logging
from logging.handlers import RotatingFileHandler, SysLogHandler
import os
-import pytz
import random
import sys
from typing import Callable, Iterable, Mapping, Optional
from overrides import overrides
+import pytz
# This module is commonly used by others in here and should avoid
# taking any unnecessary dependencies back on them.
cfg.add_argument(
'--logging_format',
type=str,
- default='%(levelname).1s:%(asctime)s: %(message)s',
- help='The format for lines logged via the logger module.'
+ default=None,
+ help='The format for lines logged via the logger module. See: https://docs.python.org/3/library/logging.html#formatter-objects'
)
cfg.add_argument(
'--logging_date_format',
default=False,
help='Should we log to localhost\'s syslog.'
)
+cfg.add_argument(
+ '--logging_syslog_facility',
+ type=str,
+ default = 'USER',
+ choices=['NOTSET', 'AUTH', 'AUTH_PRIV', 'CRON', 'DAEMON', 'FTP', 'KERN', 'LPR', 'MAIL', 'NEWS',
+ 'SYSLOG', 'USER', 'UUCP', 'LOCAL0', 'LOCAL1', 'LOCAL2', 'LOCAL3', 'LOCAL4', 'LOCAL5',
+ 'LOCAL6', 'LOCAL7'],
+ metavar='SYSLOG_FACILITY_LIST',
+ help='The default syslog message facility identifier',
+)
cfg.add_argument(
'--logging_debug_threads',
action=argparse_utils.ActionNoYes,
help='logging.info also prints to stdout.'
)
cfg.add_argument(
- '--logging_squelch_repeats_enabled',
+ '--logging_squelch_repeats',
action=argparse_utils.ActionNoYes,
default=True,
help='Do we allow code to indicate that it wants to squelch repeated logging messages or should we always log?'
)
cfg.add_argument(
- '--logging_probabilistically_enabled',
+ '--logging_probabilistically',
action=argparse_utils.ActionNoYes,
default=True,
help='Do we allow probabilistic logging (for code that wants it) or should we always log?'
'module:function, or :function and <level> is a logging level (e.g. INFO, DEBUG...)'
)
)
-
+cfg.add_argument(
+ '--logging_clear_preexisting_handlers',
+ action=argparse_utils.ActionNoYes,
+ default=True,
+ help=(
+ 'Should logging code clear preexisting global logging handlers and thus insist that is ' +
+ 'alone can add handlers. Use this to work around annoying modules that insert global ' +
+ 'handlers with formats and logging levels you might now want. Caveat emptor, this may ' +
+ 'cause you to miss logging messages.'
+ )
+)
built_in_print = print
-
-
-def function_identifier(f: Callable) -> str:
- """
- Given a callable function, return a string that identifies it.
- Usually that string is just __module__:__name__ but there's a
- corner case: when __module__ is __main__ (i.e. the callable is
- defined in the same module as __main__). In this case,
- f.__module__ returns "__main__" instead of the file that it is
- defined in. Work around this using pathlib.Path (see below).
-
- >>> function_identifier(function_identifier)
- 'logging_utils:function_identifier'
-
- """
- if f.__module__ == '__main__':
- from pathlib import Path
- import __main__
- module = __main__.__file__
- module = Path(module).stem
- return f'{module}:{f.__name__}'
- else:
- return f'{f.__module__}:{f.__name__}'
+logging_initialized = False
# A map from logging_callsite_id -> count of logged messages.
"""
def squelch_logging_wrapper(f: Callable):
- identifier = function_identifier(f)
+ import function_utils
+ identifier = function_utils.function_identifier(f)
squelched_logging_counts[identifier] = squelch_after_n_repeats
return f
return squelch_logging_wrapper
This filter only affects logging messages that repeat more than
a threshold number of times from functions that are tagged with
- the @logging_utils.squelched_logging_ok decorator.
+ the @logging_utils.squelched_logging_ok decorator; others are
+ ignored.
+
+ This functionality is enabled by default but can be disabled via
+ the --no_logging_squelch_repeats commandline flag.
"""
def __init__(self) -> None:
class DynamicPerScopeLoggingLevelFilter(logging.Filter):
- """Only interested in seeing logging messages from an allow list of
- module names or module:function names. Block others.
+ """This filter only allows logging messages from an allow list of
+ module names or module:function names. Blocks others.
"""
@staticmethod
(i.e. they do not always unconditionally log) but rather are
probabilistic (i.e. they log N% of the time randomly).
+ Note that this functionality can be disabled (forcing all logged
+ messages to produce output) via the --no_logging_probabilistically
+ cmdline argument.
+
This affects *ALL* logging statements within the marked function.
"""
def probabilistic_logging_wrapper(f: Callable):
- identifier = function_identifier(f)
+ import function_utils
+ identifier = function_utils.function_identifier(f)
probabilistic_logging_levels[identifier] = probability_of_logging
return f
return probabilistic_logging_wrapper
class MillisecondAwareFormatter(logging.Formatter):
"""
- A formatter for adding milliseconds to log messages.
+ A formatter for adding milliseconds to log messages which, for
+ whatever reason, the default python logger doesn't do.
"""
converter = datetime.datetime.fromtimestamp
def initialize_logging(logger=None) -> logging.Logger:
- assert config.has_been_parsed()
+ global logging_initialized
+ if logging_initialized:
+ return
+ logging_initialized = True
+
if logger is None:
- logger = logging.getLogger() # Root logger
+ logger = logging.getLogger()
+
+ preexisting_handlers_count = 0
+ assert config.has_been_parsed()
+ if config.config['logging_clear_preexisting_handlers']:
+ while logger.hasHandlers():
+ logger.removeHandler(logger.handlers[0])
+ preexisting_handlers_count += 1
if config.config['logging_config_file'] is not None:
logging.config.fileConfig('logging.conf')
if not isinstance(default_logging_level, int):
raise ValueError('Invalid level: %s' % config.config['logging_level'])
- fmt = config.config['logging_format']
+ if config.config['logging_format']:
+ fmt = config.config['logging_format']
+ else:
+ if config.config['logging_syslog']:
+ fmt = '%(levelname).1s:%(filename)s[%(process)d]: %(message)s'
+ else:
+ fmt = '%(levelname).1s:%(asctime)s: %(message)s'
if config.config['logging_debug_threads']:
fmt = f'%(process)d.%(thread)d|{fmt}'
if config.config['logging_debug_modules']:
if config.config['logging_syslog']:
if sys.platform not in ('win32', 'cygwin'):
- handler = SysLogHandler()
+ if config.config['logging_syslog_facility']:
+ facility_name = 'LOG_' + config.config['logging_syslog_facility']
+ facility = SysLogHandler.__dict__.get(facility_name, SysLogHandler.LOG_USER)
+ handler = SysLogHandler(facility=facility, address='/dev/log')
handler.setFormatter(
MillisecondAwareFormatter(
fmt=fmt,
handler.addFilter(OnlyInfoFilter())
logger.addHandler(handler)
- if config.config['logging_squelch_repeats_enabled']:
+ if config.config['logging_squelch_repeats']:
for handler in handlers:
handler.addFilter(SquelchRepeatedMessagesFilter())
- if config.config['logging_probabilistically_enabled']:
+ if config.config['logging_probabilistically']:
for handler in handlers:
handler.addFilter(ProbabilisticFilter())
built_in_print(*arg, **kwarg)
builtins.print = print_and_also_log
+ # At this point the logger is ready, handlers are set up,
+ # etc... so log about the logging configuration.
+
+ level_name = logging._levelToName.get(default_logging_level, str(default_logging_level))
+ logger.debug(
+ f'Initialized global logging; default logging level is {level_name}.'
+ )
+ if config.config['logging_clear_preexisting_handlers'] and preexisting_handlers_count > 0:
+ msg = f'Logging cleared {preexisting_handlers_count} global handlers (--logging_clear_preexisting_handlers)'
+ logger.warning(msg)
+ logger.debug(f'Logging format specification is "{fmt}"')
+ if config.config['logging_debug_threads']:
+ logger.debug('...Logging format spec captures tid/pid (--logging_debug_threads)')
+ if config.config['logging_debug_modules']:
+ logger.debug('...Logging format spec captures files/functions/lineno (--logging_debug_modules)')
+ if config.config['logging_syslog']:
+ logger.debug(f'Logging to syslog as {facility_name} with priority mapping based on level')
+ if config.config['logging_filename']:
+ logger.debug(f'Logging to filename {config.config["logging_filename"]}')
+ logger.debug(f'...with {config.config["logging_filename_maxsize"]} bytes max file size.')
+ logger.debug(f'...and {config.config["logging_filename_count"]} rotating backup file count.')
+ if config.config['logging_console']:
+ logger.debug('Logging to the console (stderr).')
+ if config.config['logging_info_is_print']:
+ logger.debug(
+ 'Logging logger.info messages will be repeated on stdout (--logging_info_is_print)'
+ )
+ if config.config['logging_squelch_repeats']:
+ logger.debug(
+ 'Logging code allowed to request repeated messages be squelched (--logging_squelch_repeats)'
+ )
+ else:
+ logger.debug(
+ 'Logging code forbidden to request messages be squelched; all messages logged (--no_logging_squelch_repeats)'
+ )
+ if config.config['logging_probabilistically']:
+ logger.debug(
+ 'Logging code is allowed to request probabilistic logging (--logging_probabilistically)'
+ )
+ else:
+ logger.debug(
+ 'Logging code is forbidden to request probabilistic logging; messages always logged (--no_logging_probabilistically)'
+ )
+ if config.config['lmodule']:
+ logger.debug(
+ 'Logging dynamic per-module logging enabled (--lmodule={config.config["lmodule"]})'
+ )
+ if config.config['logging_captures_prints']:
+ logger.debug('Logging will capture printed data as logger.info messages (--logging_captures_prints)')
return logger
def tprint(*args, **kwargs) -> None:
- """Legacy function for printing a message augmented with thread id."""
+ """Legacy function for printing a message augmented with thread id
+ still needed by some code. Please use --logging_debug_threads in
+ new code.
+ """
if config.config['logging_debug_threads']:
from thread_utils import current_thread_id
print(f'{current_thread_id()}', end="")
def dprint(*args, **kwargs) -> None:
- """Legacy function used to print to stderr."""
+ """Legacy function used to print to stderr still needed by some code.
+ Please just use normal logging with --logging_console which
+ accomplishes the same thing in new code.
+ """
print(*args, file=sys.stderr, **kwargs)
"""
A class that broadcasts printed messages to several sinks (including
various logging levels, different files, different file handles,
- the house log, etc...)
+ the house log, etc...). See also OutputMultiplexerContext for an
+ easy usage pattern.
"""
class Destination(enum.IntEnum):
def hlog(message: str) -> None:
- """Write a message to the house log."""
+ """Write a message to the house log (syslog facility local7 priority
+ info) by calling /usr/bin/logger. This is pretty hacky but used
+ by a bunch of code. Another way to do this would be to use
+ --logging_syslog and --logging_syslog_facility but I can't
+ actually say that's easier.
+ """
message = message.replace("'", "'\"'\"'")
os.system(f"/usr/bin/logger -p local7.info -- '{message}'")