Source code for logging.handlers
From Get docs
< Source code for loggingPython/docs/2.7/ modules/logging/handlers
Source code for logging.handlers
# Copyright 2001-2016 by Vinay Sajip. All Rights Reserved.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appear in all copies and that
# both that copyright notice and this permission notice appear in
# supporting documentation, and that the name of Vinay Sajip
# not be used in advertising or publicity pertaining to distribution
# of the software without specific, written prior permission.
# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
"""
Additional handlers for the logging package for Python. The core package is
based on PEP 282 and comments thereto in comp.lang.python.
Copyright (C) 2001-2016 Vinay Sajip. All Rights Reserved.
To use, simply 'import logging.handlers' and log away!
"""
import logging, socket, os, pickle, struct, time, re
from stat import ST_DEV, ST_INO, ST_MTIME
import queue
import threading
import copy
#
# Some constants...
#
DEFAULT_TCP_LOGGING_PORT = 9020
DEFAULT_UDP_LOGGING_PORT = 9021
DEFAULT_HTTP_LOGGING_PORT = 9022
DEFAULT_SOAP_LOGGING_PORT = 9023
SYSLOG_UDP_PORT = 514
SYSLOG_TCP_PORT = 514
_MIDNIGHT = 24 * 60 * 60 # number of seconds in a day
class BaseRotatingHandler(logging.FileHandler):
"""
Base class for handlers that rotate log files at a certain point.
Not meant to be instantiated directly. Instead, use RotatingFileHandler
or TimedRotatingFileHandler.
"""
namer = None
rotator = None
def __init__(self, filename, mode, encoding=None, delay=False, errors=None):
"""
Use the specified filename for streamed logging
"""
logging.FileHandler.__init__(self, filename, mode=mode,
encoding=encoding, delay=delay,
errors=errors)
self.mode = mode
self.encoding = encoding
self.errors = errors
def emit(self, record):
"""
Emit a record.
Output the record to the file, catering for rollover as described
in doRollover().
"""
try:
if self.shouldRollover(record):
self.doRollover()
logging.FileHandler.emit(self, record)
except Exception:
self.handleError(record)
def rotation_filename(self, default_name):
"""
Modify the filename of a log file when rotating.
This is provided so that a custom filename can be provided.
The default implementation calls the 'namer' attribute of the
handler, if it's callable, passing the default name to
it. If the attribute isn't callable (the default is None), the name
is returned unchanged.
:param default_name: The default name for the log file.
"""
if not callable(self.namer):
result = default_name
else:
result = self.namer(default_name)
return result
def rotate(self, source, dest):
"""
When rotating, rotate the current log.
The default implementation calls the 'rotator' attribute of the
handler, if it's callable, passing the source and dest arguments to
it. If the attribute isn't callable (the default is None), the source
is simply renamed to the destination.
:param source: The source filename. This is normally the base
filename, e.g. 'test.log'
:param dest: The destination filename. This is normally
what the source is rotated to, e.g. 'test.log.1'.
"""
if not callable(self.rotator):
# Issue 18940: A file may not have been created if delay is True.
if os.path.exists(source):
os.rename(source, dest)
else:
self.rotator(source, dest)
[docs]class RotatingFileHandler(BaseRotatingHandler):
"""
Handler for logging to a set of files, which switches from one file
to the next when the current file reaches a certain size.
"""
def __init__(self, filename, mode='a', maxBytes=0, backupCount=0,
encoding=None, delay=False, errors=None):
"""
Open the specified file and use it as the stream for logging.
By default, the file grows indefinitely. You can specify particular
values of maxBytes and backupCount to allow the file to rollover at
a predetermined size.
Rollover occurs whenever the current log file is nearly maxBytes in
length. If backupCount is >= 1, the system will successively create
new files with the same pathname as the base file, but with extensions
".1", ".2" etc. appended to it. For example, with a backupCount of 5
and a base file name of "app.log", you would get "app.log",
"app.log.1", "app.log.2", ... through to "app.log.5". The file being
written to is always "app.log" - when it gets filled up, it is closed
and renamed to "app.log.1", and if files "app.log.1", "app.log.2" etc.
exist, then they are renamed to "app.log.2", "app.log.3" etc.
respectively.
If maxBytes is zero, rollover never occurs.
"""
# If rotation/rollover is wanted, it doesn't make sense to use another
# mode. If for example 'w' were specified, then if there were multiple
# runs of the calling application, the logs from previous runs would be
# lost if the 'w' is respected, because the log file would be truncated
# on each run.
if maxBytes > 0:
mode = 'a'
BaseRotatingHandler.__init__(self, filename, mode, encoding=encoding,
delay=delay, errors=errors)
self.maxBytes = maxBytes
self.backupCount = backupCount
[docs] def doRollover(self):
"""
Do a rollover, as described in __init__().
"""
if self.stream:
self.stream.close()
self.stream = None
if self.backupCount > 0:
for i in range(self.backupCount - 1, 0, -1):
sfn = self.rotation_filename("%s.%d" % (self.baseFilename, i))
dfn = self.rotation_filename("%s.%d" % (self.baseFilename,
i + 1))
if os.path.exists(sfn):
if os.path.exists(dfn):
os.remove(dfn)
os.rename(sfn, dfn)
dfn = self.rotation_filename(self.baseFilename + ".1")
if os.path.exists(dfn):
os.remove(dfn)
self.rotate(self.baseFilename, dfn)
if not self.delay:
self.stream = self._open()
def shouldRollover(self, record):
"""
Determine if rollover should occur.
Basically, see if the supplied record would cause the file to exceed
the size limit we have.
"""
if self.stream is None: # delay was set...
self.stream = self._open()
if self.maxBytes > 0: # are we rolling over?
msg = "%s\n" % self.format(record)
self.stream.seek(0, 2) #due to non-posix-compliant Windows feature
if self.stream.tell() + len(msg) >= self.maxBytes:
return 1
return 0
[docs]class TimedRotatingFileHandler(BaseRotatingHandler):
"""
Handler for logging to a file, rotating the log file at certain timed
intervals.
If backupCount is > 0, when rollover is done, no more than backupCount
files are kept - the oldest ones are deleted.
"""
def __init__(self, filename, when='h', interval=1, backupCount=0,
encoding=None, delay=False, utc=False, atTime=None,
errors=None):
BaseRotatingHandler.__init__(self, filename, 'a', encoding=encoding,
delay=delay, errors=errors)
self.when = when.upper()
self.backupCount = backupCount
self.utc = utc
self.atTime = atTime
# Calculate the real rollover interval, which is just the number of
# seconds between rollovers. Also set the filename suffix used when
# a rollover occurs. Current 'when' events supported:
# S - Seconds
# M - Minutes
# H - Hours
# D - Days
# midnight - roll over at midnight
# W{0-6} - roll over on a certain day; 0 - Monday
#
# Case of the 'when' specifier is not important; lower or upper case
# will work.
if self.when == 'S':
self.interval = 1 # one second
self.suffix = "%Y-%m-%d_%H-%M-%S"
self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}(\.\w+)?$"
elif self.when == 'M':
self.interval = 60 # one minute
self.suffix = "%Y-%m-%d_%H-%M"
self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}(\.\w+)?$"
elif self.when == 'H':
self.interval = 60 * 60 # one hour
self.suffix = "%Y-%m-%d_%H"
self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}(\.\w+)?$"
elif self.when == 'D' or self.when == 'MIDNIGHT':
self.interval = 60 * 60 * 24 # one day
self.suffix = "%Y-%m-%d"
self.extMatch = r"^\d{4}-\d{2}-\d{2}(\.\w+)?$"
elif self.when.startswith('W'):
self.interval = 60 * 60 * 24 * 7 # one week
if len(self.when) != 2:
raise ValueError("You must specify a day for weekly rollover from 0 to 6 (0 is Monday): %s" % self.when)
if self.when[1] < '0' or self.when[1] > '6':
raise ValueError("Invalid day specified for weekly rollover: %s" % self.when)
self.dayOfWeek = int(self.when[1])
self.suffix = "%Y-%m-%d"
self.extMatch = r"^\d{4}-\d{2}-\d{2}(\.\w+)?$"
else:
raise ValueError("Invalid rollover interval specified: %s" % self.when)
self.extMatch = re.compile(self.extMatch, re.ASCII)
self.interval = self.interval * interval # multiply by units requested
# The following line added because the filename passed in could be a
# path object (see Issue #27493), but self.baseFilename will be a string
filename = self.baseFilename
if os.path.exists(filename):
t = os.stat(filename)[ST_MTIME]
else:
t = int(time.time())
self.rolloverAt = self.computeRollover(t)
def computeRollover(self, currentTime):
"""
Work out the rollover time based on the specified time.
"""
result = currentTime + self.interval
# If we are rolling over at midnight or weekly, then the interval is already known.
# What we need to figure out is WHEN the next interval is. In other words,
# if you are rolling over at midnight, then your base interval is 1 day,
# but you want to start that one day clock at midnight, not now. So, we
# have to fudge the rolloverAt value in order to trigger the first rollover
# at the right time. After that, the regular interval will take care of
# the rest. Note that this code doesn't care about leap seconds. :)
if self.when == 'MIDNIGHT' or self.when.startswith('W'):
# This could be done with less code, but I wanted it to be clear
if self.utc:
t = time.gmtime(currentTime)
else:
t = time.localtime(currentTime)
currentHour = t[3]
currentMinute = t[4]
currentSecond = t[5]
currentDay = t[6]
# r is the number of seconds left between now and the next rotation
if self.atTime is None:
rotate_ts = _MIDNIGHT
else:
rotate_ts = ((self.atTime.hour * 60 + self.atTime.minute)*60 +
self.atTime.second)
r = rotate_ts - ((currentHour * 60 + currentMinute) * 60 +
currentSecond)
if r < 0:
# Rotate time is before the current time (for example when
# self.rotateAt is 13:45 and it now 14:15), rotation is
# tomorrow.
r += _MIDNIGHT
currentDay = (currentDay + 1) % 7
result = currentTime + r
# If we are rolling over on a certain day, add in the number of days until
# the next rollover, but offset by 1 since we just calculated the time
# until the next day starts. There are three cases:
# Case 1) The day to rollover is today; in this case, do nothing
# Case 2) The day to rollover is further in the interval (i.e., today is
# day 2 (Wednesday) and rollover is on day 6 (Sunday). Days to
# next rollover is simply 6 - 2 - 1, or 3.
# Case 3) The day to rollover is behind us in the interval (i.e., today
# is day 5 (Saturday) and rollover is on day 3 (Thursday).
# Days to rollover is 6 - 5 + 3, or 4. In this case, it's the
# number of days left in the current week (1) plus the number
# of days in the next week until the rollover day (3).
# The calculations described in 2) and 3) above need to have a day added.
# This is because the above time calculation takes us to midnight on this
# day, i.e. the start of the next day.
if self.when.startswith('W'):
day = currentDay # 0 is Monday
if day != self.dayOfWeek:
if day < self.dayOfWeek:
daysToWait = self.dayOfWeek - day
else:
daysToWait = 6 - day + self.dayOfWeek + 1
newRolloverAt = result + (daysToWait * (60 * 60 * 24))
if not self.utc:
dstNow = t[-1]
dstAtRollover = time.localtime(newRolloverAt)[-1]
if dstNow != dstAtRollover:
if not dstNow: # DST kicks in before next rollover, so we need to deduct an hour
addend = -3600
else: # DST bows out before next rollover, so we need to add an hour
addend = 3600
newRolloverAt += addend
result = newRolloverAt
return result
def shouldRollover(self, record):
"""
Determine if rollover should occur.
record is not used, as we are just comparing times, but it is needed so
the method signatures are the same
"""
t = int(time.time())
if t >= self.rolloverAt:
return 1
return 0
def getFilesToDelete(self):
"""
Determine the files to delete when rolling over.
More specific than the earlier method, which just used glob.glob().
"""
dirName, baseName = os.path.split(self.baseFilename)
fileNames = os.listdir(dirName)
result = []
prefix = baseName + "."
plen = len(prefix)
for fileName in fileNames:
if fileName[:plen] == prefix:
suffix = fileName[plen:]
if self.extMatch.match(suffix):
result.append(os.path.join(dirName, fileName))
if len(result) < self.backupCount:
result = []
else:
result.sort()
result = result[:len(result) - self.backupCount]
return result
[docs] def doRollover(self):
"""
do a rollover; in this case, a date/time stamp is appended to the filename
when the rollover happens. However, you want the file to be named for the
start of the interval, not the current time. If there is a backup count,
then we have to get a list of matching filenames, sort them and remove
the one with the oldest suffix.
"""
if self.stream:
self.stream.close()
self.stream = None
# get the time that this sequence started at and make it a TimeTuple
currentTime = int(time.time())
dstNow = time.localtime(currentTime)[-1]
t = self.rolloverAt - self.interval
if self.utc:
timeTuple = time.gmtime(t)
else:
timeTuple = time.localtime(t)
dstThen = timeTuple[-1]
if dstNow != dstThen:
if dstNow:
addend = 3600
else:
addend = -3600
timeTuple = time.localtime(t + addend)
dfn = self.rotation_filename(self.baseFilename + "." +
time.strftime(self.suffix, timeTuple))
if os.path.exists(dfn):
os.remove(dfn)
self.rotate(self.baseFilename, dfn)
if self.backupCount > 0:
for s in self.getFilesToDelete():
os.remove(s)
if not self.delay:
self.stream = self._open()
newRolloverAt = self.computeRollover(currentTime)
while newRolloverAt <= currentTime:
newRolloverAt = newRolloverAt + self.interval
#If DST changes and midnight or weekly rollover, adjust for this.
if (self.when == 'MIDNIGHT' or self.when.startswith('W')) and not self.utc:
dstAtRollover = time.localtime(newRolloverAt)[-1]
if dstNow != dstAtRollover:
if not dstNow: # DST kicks in before next rollover, so we need to deduct an hour
addend = -3600
else: # DST bows out before next rollover, so we need to add an hour
addend = 3600
newRolloverAt += addend
self.rolloverAt = newRolloverAt
[docs]class WatchedFileHandler(logging.FileHandler):
"""
A handler for logging to a file, which watches the file
to see if it has changed while in use. This can happen because of
usage of programs such as newsyslog and logrotate which perform
log file rotation. This handler, intended for use under Unix,
watches the file to see if it has changed since the last emit.
(A file has changed if its device or inode have changed.)
If it has changed, the old file stream is closed, and the file
opened to get a new stream.
This handler is not appropriate for use under Windows, because
under Windows open files cannot be moved or renamed - logging
opens the files with exclusive locks - and so there is no need
for such a handler. Furthermore, ST_INO is not supported under
Windows; stat always returns zero for this value.
This handler is based on a suggestion and patch by Chad J.
Schroeder.
"""
def __init__(self, filename, mode='a', encoding=None, delay=False,
errors=None):
logging.FileHandler.__init__(self, filename, mode=mode,
encoding=encoding, delay=delay,
errors=errors)
self.dev, self.ino = -1, -1
self._statstream()
def _statstream(self):
if self.stream:
sres = os.fstat(self.stream.fileno())
self.dev, self.ino = sres[ST_DEV], sres[ST_INO]
def reopenIfNeeded(self):
"""
Reopen log file if needed.
Checks if the underlying file has changed, and if it
has, close the old stream and reopen the file to get the
current stream.
"""
# Reduce the chance of race conditions by stat'ing by path only
# once and then fstat'ing our new fd if we opened a new log stream.
# See issue #14632: Thanks to John Mulligan for the problem report
# and patch.
try:
# stat the file by path, checking for existence
sres = os.stat(self.baseFilename)
except FileNotFoundError:
sres = None
# compare file system stat with that of our stream file handle
if not sres or sres[ST_DEV] != self.dev or sres[ST_INO] != self.ino:
if self.stream is not None:
# we have an open file handle, clean it up
self.stream.flush()
self.stream.close()
self.stream = None # See Issue #21742: _open () might fail.
# open a new file handle and get new stat info from that fd
self.stream = self._open()
self._statstream()
[docs] def emit(self, record):
"""
Emit a record.
If underlying file has changed, reopen the file before emitting the
record to it.
"""
self.reopenIfNeeded()
logging.FileHandler.emit(self, record)
[docs]class SocketHandler(logging.Handler):
"""
A handler class which writes logging records, in pickle format, to
a streaming socket. The socket is kept open across logging calls.
If the peer resets it, an attempt is made to reconnect on the next call.
The pickle which is sent is that of the LogRecord's attribute dictionary
(__dict__), so that the receiver does not need to have the logging module
installed in order to process the logging event.
To unpickle the record at the receiving end into a LogRecord, use the
makeLogRecord function.
"""
def __init__(self, host, port):
"""
Initializes the handler with a specific host address and port.
When the attribute *closeOnError* is set to True - if a socket error
occurs, the socket is silently closed and then reopened on the next
logging call.
"""
logging.Handler.__init__(self)
self.host = host
self.port = port
if port is None:
self.address = host
else:
self.address = (host, port)
self.sock = None
self.closeOnError = False
self.retryTime = None
#
# Exponential backoff parameters.
#
self.retryStart = 1.0
self.retryMax = 30.0
self.retryFactor = 2.0
[docs] def makeSocket(self, timeout=1):
"""
A factory method which allows subclasses to define the precise
type of socket they want.
"""
if self.port is not None:
result = socket.create_connection(self.address, timeout=timeout)
else:
result = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
result.settimeout(timeout)
try:
result.connect(self.address)
except OSError:
result.close() # Issue 19182
raise
return result
[docs] def createSocket(self):
"""
Try to create a socket, using an exponential backoff with
a max retry time. Thanks to Robert Olson for the original patch
(SF #815911) which has been slightly refactored.
"""
now = time.time()
# Either retryTime is None, in which case this
# is the first time back after a disconnect, or
# we've waited long enough.
if self.retryTime is None:
attempt = True
else:
attempt = (now >= self.retryTime)
if attempt:
try:
self.sock = self.makeSocket()
self.retryTime = None # next time, no delay before trying
except OSError:
#Creation failed, so set the retry time and return.
if self.retryTime is None:
self.retryPeriod = self.retryStart
else:
self.retryPeriod = self.retryPeriod * self.retryFactor
if self.retryPeriod > self.retryMax:
self.retryPeriod = self.retryMax
self.retryTime = now + self.retryPeriod
[docs] def send(self, s):
"""
Send a pickled string to the socket.
This function allows for partial sends which can happen when the
network is busy.
"""
if self.sock is None:
self.createSocket()
#self.sock can be None either because we haven't reached the retry
#time yet, or because we have reached the retry time and retried,
#but are still unable to connect.
if self.sock:
try:
self.sock.sendall(s)
except OSError: #pragma: no cover
self.sock.close()
self.sock = None # so we can call createSocket next time
[docs] def makePickle(self, record):
"""
Pickles the record in binary format with a length prefix, and
returns it ready for transmission across the socket.
"""
ei = record.exc_info
if ei:
# just to get traceback text into record.exc_text ...
dummy = self.format(record)
# See issue #14436: If msg or args are objects, they may not be
# available on the receiving end. So we convert the msg % args
# to a string, save it as msg and zap the args.
d = dict(record.__dict__)
d['msg'] = record.getMessage()
d['args'] = None
d['exc_info'] = None
# Issue #25685: delete 'message' if present: redundant with 'msg'
d.pop('message', None)
s = pickle.dumps(d, 1)
slen = struct.pack(">L", len(s))
return slen + s
[docs] def handleError(self, record):
"""
Handle an error during logging.
An error has occurred during logging. Most likely cause -
connection lost. Close the socket so that we can retry on the
next event.
"""
if self.closeOnError and self.sock:
self.sock.close()
self.sock = None #try to reconnect next time
else:
logging.Handler.handleError(self, record)
[docs] def emit(self, record):
"""
Emit a record.
Pickles the record and writes it to the socket in binary format.
If there is an error with the socket, silently drop the packet.
If there was a problem with the socket, re-establishes the
socket.
"""
try:
s = self.makePickle(record)
self.send(s)
except Exception:
self.handleError(record)
[docs] def close(self):
"""
Closes the socket.
"""
self.acquire()
try:
sock = self.sock
if sock:
self.sock = None
sock.close()
logging.Handler.close(self)
finally:
self.release()
[docs]class DatagramHandler(SocketHandler):
"""
A handler class which writes logging records, in pickle format, to
a datagram socket. The pickle which is sent is that of the LogRecord's
attribute dictionary (__dict__), so that the receiver does not need to
have the logging module installed in order to process the logging event.
To unpickle the record at the receiving end into a LogRecord, use the
makeLogRecord function.
"""
def __init__(self, host, port):
"""
Initializes the handler with a specific host address and port.
"""
SocketHandler.__init__(self, host, port)
self.closeOnError = False
[docs] def makeSocket(self):
"""
The factory method of SocketHandler is here overridden to create
a UDP socket (SOCK_DGRAM).
"""
if self.port is None:
family = socket.AF_UNIX
else:
family = socket.AF_INET
s = socket.socket(family, socket.SOCK_DGRAM)
return s
[docs] def send(self, s):
"""
Send a pickled string to a socket.
This function no longer allows for partial sends which can happen
when the network is busy - UDP does not guarantee delivery and
can deliver packets out of sequence.
"""
if self.sock is None:
self.createSocket()
self.sock.sendto(s, self.address)
[docs]class SysLogHandler(logging.Handler):
"""
A handler class which sends formatted logging records to a syslog
server. Based on Sam Rushing's syslog module:
http://www.nightmare.com/squirl/python-ext/misc/syslog.py
Contributed by Nicolas Untz (after which minor refactoring changes
have been made).
"""
# from <linux/sys/syslog.h>:
# ======================================================================
# priorities/facilities are encoded into a single 32-bit quantity, where
# the bottom 3 bits are the priority (0-7) and the top 28 bits are the
# facility (0-big number). Both the priorities and the facilities map
# roughly one-to-one to strings in the syslogd(8) source code. This
# mapping is included in this file.
#
# priorities (these are ordered)
LOG_EMERG = 0 # system is unusable
LOG_ALERT = 1 # action must be taken immediately
LOG_CRIT = 2 # critical conditions
LOG_ERR = 3 # error conditions
LOG_WARNING = 4 # warning conditions
LOG_NOTICE = 5 # normal but significant condition
LOG_INFO = 6 # informational
LOG_DEBUG = 7 # debug-level messages
# facility codes
LOG_KERN = 0 # kernel messages
LOG_USER = 1 # random user-level messages
LOG_MAIL = 2 # mail system
LOG_DAEMON = 3 # system daemons
LOG_AUTH = 4 # security/authorization messages
LOG_SYSLOG = 5 # messages generated internally by syslogd
LOG_LPR = 6 # line printer subsystem
LOG_NEWS = 7 # network news subsystem
LOG_UUCP = 8 # UUCP subsystem
LOG_CRON = 9 # clock daemon
LOG_AUTHPRIV = 10 # security/authorization messages (private)
LOG_FTP = 11 # FTP daemon
LOG_NTP = 12 # NTP subsystem
LOG_SECURITY = 13 # Log audit
LOG_CONSOLE = 14 # Log alert
LOG_SOLCRON = 15 # Scheduling daemon (Solaris)
# other codes through 15 reserved for system use
LOG_LOCAL0 = 16 # reserved for local use
LOG_LOCAL1 = 17 # reserved for local use
LOG_LOCAL2 = 18 # reserved for local use
LOG_LOCAL3 = 19 # reserved for local use
LOG_LOCAL4 = 20 # reserved for local use
LOG_LOCAL5 = 21 # reserved for local use
LOG_LOCAL6 = 22 # reserved for local use
LOG_LOCAL7 = 23 # reserved for local use
priority_names = {
"alert": LOG_ALERT,
"crit": LOG_CRIT,
"critical": LOG_CRIT,
"debug": LOG_DEBUG,
"emerg": LOG_EMERG,
"err": LOG_ERR,
"error": LOG_ERR, # DEPRECATED
"info": LOG_INFO,
"notice": LOG_NOTICE,
"panic": LOG_EMERG, # DEPRECATED
"warn": LOG_WARNING, # DEPRECATED
"warning": LOG_WARNING,
}
facility_names = {
"auth": LOG_AUTH,
"authpriv": LOG_AUTHPRIV,
"console": LOG_CONSOLE,
"cron": LOG_CRON,
"daemon": LOG_DAEMON,
"ftp": LOG_FTP,
"kern": LOG_KERN,
"lpr": LOG_LPR,
"mail": LOG_MAIL,
"news": LOG_NEWS,
"ntp": LOG_NTP,
"security": LOG_SECURITY,
"solaris-cron": LOG_SOLCRON,
"syslog": LOG_SYSLOG,
"user": LOG_USER,
"uucp": LOG_UUCP,
"local0": LOG_LOCAL0,
"local1": LOG_LOCAL1,
"local2": LOG_LOCAL2,
"local3": LOG_LOCAL3,
"local4": LOG_LOCAL4,
"local5": LOG_LOCAL5,
"local6": LOG_LOCAL6,
"local7": LOG_LOCAL7,
}
#The map below appears to be trivially lowercasing the key. However,
#there's more to it than meets the eye - in some locales, lowercasing
#gives unexpected results. See SF #1524081: in the Turkish locale,
#"INFO".lower() != "info"
priority_map = {
"DEBUG" : "debug",
"INFO" : "info",
"WARNING" : "warning",
"ERROR" : "error",
"CRITICAL" : "critical"
}
def __init__(self, address=('localhost', SYSLOG_UDP_PORT),
facility=LOG_USER, socktype=None):
"""
Initialize a handler.
If address is specified as a string, a UNIX socket is used. To log to a
local syslogd, "SysLogHandler(address="/dev/log")" can be used.
If facility is not specified, LOG_USER is used. If socktype is
specified as socket.SOCK_DGRAM or socket.SOCK_STREAM, that specific
socket type will be used. For Unix sockets, you can also specify a
socktype of None, in which case socket.SOCK_DGRAM will be used, falling
back to socket.SOCK_STREAM.
"""
logging.Handler.__init__(self)
self.address = address
self.facility = facility
self.socktype = socktype
if isinstance(address, str):
self.unixsocket = True
# Syslog server may be unavailable during handler initialisation.
# C's openlog() function also ignores connection errors.
# Moreover, we ignore these errors while logging, so it not worse
# to ignore it also here.
try:
self._connect_unixsocket(address)
except OSError:
pass
else:
self.unixsocket = False
if socktype is None:
socktype = socket.SOCK_DGRAM
host, port = address
ress = socket.getaddrinfo(host, port, 0, socktype)
if not ress:
raise OSError("getaddrinfo returns an empty list")
for res in ress:
af, socktype, proto, _, sa = res
err = sock = None
try:
sock = socket.socket(af, socktype, proto)
if socktype == socket.SOCK_STREAM:
sock.connect(sa)
break
except OSError as exc:
err = exc
if sock is not None:
sock.close()
if err is not None:
raise err
self.socket = sock
self.socktype = socktype
def _connect_unixsocket(self, address):
use_socktype = self.socktype
if use_socktype is None:
use_socktype = socket.SOCK_DGRAM
self.socket = socket.socket(socket.AF_UNIX, use_socktype)
try:
self.socket.connect(address)
# it worked, so set self.socktype to the used type
self.socktype = use_socktype
except OSError:
self.socket.close()
if self.socktype is not None:
# user didn't specify falling back, so fail
raise
use_socktype = socket.SOCK_STREAM
self.socket = socket.socket(socket.AF_UNIX, use_socktype)
try:
self.socket.connect(address)
# it worked, so set self.socktype to the used type
self.socktype = use_socktype
except OSError:
self.socket.close()
raise
[docs] def encodePriority(self, facility, priority):
"""
Encode the facility and priority. You can pass in strings or
integers - if strings are passed, the facility_names and
priority_names mapping dictionaries are used to convert them to
integers.
"""
if isinstance(facility, str):
facility = self.facility_names[facility]
if isinstance(priority, str):
priority = self.priority_names[priority]
return (facility << 3) | priority
[docs] def close(self):
"""
Closes the socket.
"""
self.acquire()
try:
self.socket.close()
logging.Handler.close(self)
finally:
self.release()
[docs] def mapPriority(self, levelName):
"""
Map a logging level name to a key in the priority_names map.
This is useful in two scenarios: when custom levels are being
used, and in the case where you can't do a straightforward
mapping by lowercasing the logging level name because of locale-
specific issues (see SF #1524081).
"""
return self.priority_map.get(levelName, "warning")
ident = '' # prepended to all messages
append_nul = True # some old syslog daemons expect a NUL terminator
[docs] def emit(self, record):
"""
Emit a record.
The record is formatted, and then sent to the syslog server. If
exception information is present, it is NOT sent to the server.
"""
try:
msg = self.format(record)
if self.ident:
msg = self.ident + msg
if self.append_nul:
msg += '\000'
# We need to convert record level to lowercase, maybe this will
# change in the future.
prio = '<%d>' % self.encodePriority(self.facility,
self.mapPriority(record.levelname))
prio = prio.encode('utf-8')
# Message is a string. Convert to bytes as required by RFC 5424
msg = msg.encode('utf-8')
msg = prio + msg
if self.unixsocket:
try:
self.socket.send(msg)
except OSError:
self.socket.close()
self._connect_unixsocket(self.address)
self.socket.send(msg)
elif self.socktype == socket.SOCK_DGRAM:
self.socket.sendto(msg, self.address)
else:
self.socket.sendall(msg)
except Exception:
self.handleError(record)
[docs]class SMTPHandler(logging.Handler):
"""
A handler class which sends an SMTP email for each logging event.
"""
def __init__(self, mailhost, fromaddr, toaddrs, subject,
credentials=None, secure=None, timeout=5.0):
"""
Initialize the handler.
Initialize the instance with the from and to addresses and subject
line of the email. To specify a non-standard SMTP port, use the
(host, port) tuple format for the mailhost argument. To specify
authentication credentials, supply a (username, password) tuple
for the credentials argument. To specify the use of a secure
protocol (TLS), pass in a tuple for the secure argument. This will
only be used when authentication credentials are supplied. The tuple
will be either an empty tuple, or a single-value tuple with the name
of a keyfile, or a 2-value tuple with the names of the keyfile and
certificate file. (This tuple is passed to the `starttls` method).
A timeout in seconds can be specified for the SMTP connection (the
default is one second).
"""
logging.Handler.__init__(self)
if isinstance(mailhost, (list, tuple)):
self.mailhost, self.mailport = mailhost
else:
self.mailhost, self.mailport = mailhost, None
if isinstance(credentials, (list, tuple)):
self.username, self.password = credentials
else:
self.username = None
self.fromaddr = fromaddr
if isinstance(toaddrs, str):
toaddrs = [toaddrs]
self.toaddrs = toaddrs
self.subject = subject
self.secure = secure
self.timeout = timeout
[docs] def getSubject(self, record):
"""
Determine the subject for the email.
If you want to specify a subject line which is record-dependent,
override this method.
"""
return self.subject
[docs] def emit(self, record):
"""
Emit a record.
Format the record and send it to the specified addressees.
"""
try:
import smtplib
from email.message import EmailMessage
import email.utils
port = self.mailport
if not port:
port = smtplib.SMTP_PORT
smtp = smtplib.SMTP(self.mailhost, port, timeout=self.timeout)
msg = EmailMessage()
msg['From'] = self.fromaddr
msg['To'] = ','.join(self.toaddrs)
msg['Subject'] = self.getSubject(record)
msg['Date'] = email.utils.localtime()
msg.set_content(self.format(record))
if self.username:
if self.secure is not None:
smtp.ehlo()
smtp.starttls(*self.secure)
smtp.ehlo()
smtp.login(self.username, self.password)
smtp.send_message(msg)
smtp.quit()
except Exception:
self.handleError(record)
[docs]class NTEventLogHandler(logging.Handler):
"""
A handler class which sends events to the NT Event Log. Adds a
registry entry for the specified application name. If no dllname is
provided, win32service.pyd (which contains some basic message
placeholders) is used. Note that use of these placeholders will make
your event logs big, as the entire message source is held in the log.
If you want slimmer logs, you have to pass in the name of your own DLL
which contains the message definitions you want to use in the event log.
"""
def __init__(self, appname, dllname=None, logtype="Application"):
logging.Handler.__init__(self)
try:
import win32evtlogutil, win32evtlog
self.appname = appname
self._welu = win32evtlogutil
if not dllname:
dllname = os.path.split(self._welu.__file__)
dllname = os.path.split(dllname[0])
dllname = os.path.join(dllname[0], r'win32service.pyd')
self.dllname = dllname
self.logtype = logtype
self._welu.AddSourceToRegistry(appname, dllname, logtype)
self.deftype = win32evtlog.EVENTLOG_ERROR_TYPE
self.typemap = {
logging.DEBUG : win32evtlog.EVENTLOG_INFORMATION_TYPE,
logging.INFO : win32evtlog.EVENTLOG_INFORMATION_TYPE,
logging.WARNING : win32evtlog.EVENTLOG_WARNING_TYPE,
logging.ERROR : win32evtlog.EVENTLOG_ERROR_TYPE,
logging.CRITICAL: win32evtlog.EVENTLOG_ERROR_TYPE,
}
except ImportError:
print("The Python Win32 extensions for NT (service, event "\
"logging) appear not to be available.")
self._welu = None
[docs] def getMessageID(self, record):
"""
Return the message ID for the event record. If you are using your
own messages, you could do this by having the msg passed to the
logger being an ID rather than a formatting string. Then, in here,
you could use a dictionary lookup to get the message ID. This
version returns 1, which is the base message ID in win32service.pyd.
"""
return 1
[docs] def getEventCategory(self, record):
"""
Return the event category for the record.
Override this if you want to specify your own categories. This version
returns 0.
"""
return 0
[docs] def getEventType(self, record):
"""
Return the event type for the record.
Override this if you want to specify your own types. This version does
a mapping using the handler's typemap attribute, which is set up in
__init__() to a dictionary which contains mappings for DEBUG, INFO,
WARNING, ERROR and CRITICAL. If you are using your own levels you will
either need to override this method or place a suitable dictionary in
the handler's typemap attribute.
"""
return self.typemap.get(record.levelno, self.deftype)
[docs] def emit(self, record):
"""
Emit a record.
Determine the message ID, event category and event type. Then
log the message in the NT event log.
"""
if self._welu:
try:
id = self.getMessageID(record)
cat = self.getEventCategory(record)
type = self.getEventType(record)
msg = self.format(record)
self._welu.ReportEvent(self.appname, id, cat, type, [msg])
except Exception:
self.handleError(record)
[docs] def close(self):
"""
Clean up this handler.
You can remove the application name from the registry as a
source of event log entries. However, if you do this, you will
not be able to see the events as you intended in the Event Log
Viewer - it needs to be able to access the registry to get the
DLL name.
"""
#self._welu.RemoveSourceFromRegistry(self.appname, self.logtype)
logging.Handler.close(self)
[docs]class HTTPHandler(logging.Handler):
"""
A class which sends records to a Web server, using either GET or
POST semantics.
"""
def __init__(self, host, url, method="GET", secure=False, credentials=None,
context=None):
"""
Initialize the instance with the host, the request URL, and the method
("GET" or "POST")
"""
logging.Handler.__init__(self)
method = method.upper()
if method not in ["GET", "POST"]:
raise ValueError("method must be GET or POST")
if not secure and context is not None:
raise ValueError("context parameter only makes sense "
"with secure=True")
self.host = host
self.url = url
self.method = method
self.secure = secure
self.credentials = credentials
self.context = context
[docs] def mapLogRecord(self, record):
"""
Default implementation of mapping the log record into a dict
that is sent as the CGI data. Overwrite in your class.
Contributed by Franz Glasner.
"""
return record.__dict__
def getConnection(self, host, secure):
"""
get a HTTP[S]Connection.
Override when a custom connection is required, for example if
there is a proxy.
"""
import http.client
if secure:
connection = http.client.HTTPSConnection(host, context=self.context)
else:
connection = http.client.HTTPConnection(host)
return connection
[docs] def emit(self, record):
"""
Emit a record.
Send the record to the Web server as a percent-encoded dictionary
"""
try:
import urllib.parse
host = self.host
h = self.getConnection(host, self.secure)
url = self.url
data = urllib.parse.urlencode(self.mapLogRecord(record))
if self.method == "GET":
if (url.find('?') >= 0):
sep = '&'
else:
sep = '?'
url = url + "%c%s" % (sep, data)
h.putrequest(self.method, url)
# support multiple hosts on one IP address...
# need to strip optional :port from host, if present
i = host.find(":")
if i >= 0:
host = host[:i]
# See issue #30904: putrequest call above already adds this header
# on Python 3.x.
# h.putheader("Host", host)
if self.method == "POST":
h.putheader("Content-type",
"application/x-www-form-urlencoded")
h.putheader("Content-length", str(len(data)))
if self.credentials:
import base64
s = ('%s:%s' % self.credentials).encode('utf-8')
s = 'Basic ' + base64.b64encode(s).strip().decode('ascii')
h.putheader('Authorization', s)
h.endheaders()
if self.method == "POST":
h.send(data.encode('utf-8'))
h.getresponse() #can't do anything with the result
except Exception:
self.handleError(record)
[docs]class BufferingHandler(logging.Handler):
"""
A handler class which buffers logging records in memory. Whenever each
record is added to the buffer, a check is made to see if the buffer should
be flushed. If it should, then flush() is expected to do what's needed.
"""
def __init__(self, capacity):
"""
Initialize the handler with the buffer size.
"""
logging.Handler.__init__(self)
self.capacity = capacity
self.buffer = []
[docs] def shouldFlush(self, record):
"""
Should the handler flush its buffer?
Returns true if the buffer is up to capacity. This method can be
overridden to implement custom flushing strategies.
"""
return (len(self.buffer) >= self.capacity)
[docs] def emit(self, record):
"""
Emit a record.
Append the record. If shouldFlush() tells us to, call flush() to process
the buffer.
"""
self.buffer.append(record)
if self.shouldFlush(record):
self.flush()
[docs] def flush(self):
"""
Override to implement custom flushing behaviour.
This version just zaps the buffer to empty.
"""
self.acquire()
try:
self.buffer.clear()
finally:
self.release()
def close(self):
"""
Close the handler.
This version just flushes and chains to the parent class' close().
"""
try:
self.flush()
finally:
logging.Handler.close(self)
[docs]class MemoryHandler(BufferingHandler):
"""
A handler class which buffers logging records in memory, periodically
flushing them to a target handler. Flushing occurs whenever the buffer
is full, or when an event of a certain severity or greater is seen.
"""
def __init__(self, capacity, flushLevel=logging.ERROR, target=None,
flushOnClose=True):
"""
Initialize the handler with the buffer size, the level at which
flushing should occur and an optional target.
Note that without a target being set either here or via setTarget(),
a MemoryHandler is no use to anyone!
The ``flushOnClose`` argument is ``True`` for backward compatibility
reasons - the old behaviour is that when the handler is closed, the
buffer is flushed, even if the flush level hasn't been exceeded nor the
capacity exceeded. To prevent this, set ``flushOnClose`` to ``False``.
"""
BufferingHandler.__init__(self, capacity)
self.flushLevel = flushLevel
self.target = target
# See Issue #26559 for why this has been added
self.flushOnClose = flushOnClose
[docs] def shouldFlush(self, record):
"""
Check for buffer full or a record at the flushLevel or higher.
"""
return (len(self.buffer) >= self.capacity) or \
(record.levelno >= self.flushLevel)
[docs] def setTarget(self, target):
"""
Set the target handler for this handler.
"""
self.acquire()
try:
self.target = target
finally:
self.release()
[docs] def flush(self):
"""
For a MemoryHandler, flushing means just sending the buffered
records to the target, if there is one. Override if you want
different behaviour.
The record buffer is also cleared by this operation.
"""
self.acquire()
try:
if self.target:
for record in self.buffer:
self.target.handle(record)
self.buffer.clear()
finally:
self.release()
[docs] def close(self):
"""
Flush, if appropriately configured, set the target to None and lose the
buffer.
"""
try:
if self.flushOnClose:
self.flush()
finally:
self.acquire()
try:
self.target = None
BufferingHandler.close(self)
finally:
self.release()
class QueueHandler(logging.Handler):
"""
This handler sends events to a queue. Typically, it would be used together
with a multiprocessing Queue to centralise logging to file in one process
(in a multi-process application), so as to avoid file write contention
between processes.
This code is new in Python 3.2, but this class can be copy pasted into
user code for use with earlier Python versions.
"""
def __init__(self, queue):
"""
Initialise an instance, using the passed queue.
"""
logging.Handler.__init__(self)
self.queue = queue
def enqueue(self, record):
"""
Enqueue a record.
The base implementation uses put_nowait. You may want to override
this method if you want to use blocking, timeouts or custom queue
implementations.
"""
self.queue.put_nowait(record)
def prepare(self, record):
"""
Prepares a record for queuing. The object returned by this method is
enqueued.
The base implementation formats the record to merge the message
and arguments, and removes unpickleable items from the record
in-place.
You might want to override this method if you want to convert
the record to a dict or JSON string, or send a modified copy
of the record while leaving the original intact.
"""
# The format operation gets traceback text into record.exc_text
# (if there's exception data), and also returns the formatted
# message. We can then use this to replace the original
# msg + args, as these might be unpickleable. We also zap the
# exc_info and exc_text attributes, as they are no longer
# needed and, if not None, will typically not be pickleable.
msg = self.format(record)
# bpo-35726: make copy of record to avoid affecting other handlers in the chain.
record = copy.copy(record)
record.message = msg
record.msg = msg
record.args = None
record.exc_info = None
record.exc_text = None
return record
def emit(self, record):
"""
Emit a record.
Writes the LogRecord to the queue, preparing it for pickling first.
"""
try:
self.enqueue(self.prepare(record))
except Exception:
self.handleError(record)
class QueueListener(object):
"""
This class implements an internal threaded listener which watches for
LogRecords being added to a queue, removes them and passes them to a
list of handlers for processing.
"""
_sentinel = None
def __init__(self, queue, *handlers, respect_handler_level=False):
"""
Initialise an instance with the specified queue and
handlers.
"""
self.queue = queue
self.handlers = handlers
self._thread = None
self.respect_handler_level = respect_handler_level
def dequeue(self, block):
"""
Dequeue a record and return it, optionally blocking.
The base implementation uses get. You may want to override this method
if you want to use timeouts or work with custom queue implementations.
"""
return self.queue.get(block)
def start(self):
"""
Start the listener.
This starts up a background thread to monitor the queue for
LogRecords to process.
"""
self._thread = t = threading.Thread(target=self._monitor)
t.daemon = True
t.start()
def prepare(self, record):
"""
Prepare a record for handling.
This method just returns the passed-in record. You may want to
override this method if you need to do any custom marshalling or
manipulation of the record before passing it to the handlers.
"""
return record
def handle(self, record):
"""
Handle a record.
This just loops through the handlers offering them the record
to handle.
"""
record = self.prepare(record)
for handler in self.handlers:
if not self.respect_handler_level:
process = True
else:
process = record.levelno >= handler.level
if process:
handler.handle(record)
def _monitor(self):
"""
Monitor the queue for records, and ask the handler
to deal with them.
This method runs on a separate, internal thread.
The thread will terminate if it sees a sentinel object in the queue.
"""
q = self.queue
has_task_done = hasattr(q, 'task_done')
while True:
try:
record = self.dequeue(True)
if record is self._sentinel:
if has_task_done:
q.task_done()
break
self.handle(record)
if has_task_done:
q.task_done()
except queue.Empty:
break
def enqueue_sentinel(self):
"""
This is used to enqueue the sentinel record.
The base implementation uses put_nowait. You may want to override this
method if you want to use timeouts or work with custom queue
implementations.
"""
self.queue.put_nowait(self._sentinel)
def stop(self):
"""
Stop the listener.
This asks the thread to terminate, and then waits for it to do so.
Note that if you don't call this before your application exits, there
may be some records still left on the queue, which won't be processed.
"""
self.enqueue_sentinel()
self._thread.join()
self._thread = None
