From 73c0495f6830ca99c0c6eb15e83c3c7d44096d19 Mon Sep 17 00:00:00 2001 From: Marti Raudsepp Date: Tue, 9 Oct 2012 18:12:02 +0300 Subject: python: add journal backend for the logging framework Supports Python versions 2.6 through 3.3 (tested on 2.7 and 3.2). See JournalHandler docstring for usage details. [zj: - use send() instead of using sendv() directly - do exception handling like in the logging module - bumped min version to python2.6, since the module does not work with python2.5 anyway ] --- src/python-systemd/journal.py | 85 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) (limited to 'src/python-systemd') diff --git a/src/python-systemd/journal.py b/src/python-systemd/journal.py index 760d2db014..516ca1ab56 100644 --- a/src/python-systemd/journal.py +++ b/src/python-systemd/journal.py @@ -19,6 +19,7 @@ import traceback as _traceback import os as _os +import logging as _logging from syslog import (LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG) from ._journal import sendv, stream_fd @@ -114,3 +115,87 @@ def stream(identifier, priority=LOG_DEBUG, level_prefix=False): fd = stream_fd(identifier, priority, level_prefix) return _os.fdopen(fd, 'w', 1) + +class JournalHandler(_logging.Handler): + """Journal handler class for the Python logging framework. + + Please see the Python logging module documentation for an + overview: http://docs.python.org/library/logging.html + + To create a custom logger whose messages go only to journal: + + >>> log = logging.getLogger('custom_logger_name') + >>> log.propagate = False + >>> log.addHandler(journal.JournalHandler()) + >>> log.warn("Some message: %s", detail) + + Note that by default, message levels INFO and DEBUG are ignored + by the logging framework. To enable those log levels: + + >>> log.setLevel(logging.DEBUG) + + To attach journal MESSAGE_ID, an extra field is supported: + + >>> log.warn("Message with ID", + >>> extra={'MESSAGE_ID': '22bb01335f724c959ac4799627d1cb61'}) + + To redirect all logging messages to journal regardless of where + they come from, attach it to the root logger: + + >>> logging.root.addHandler(journal.JournalHandler()) + + For more complex configurations when using dictConfig or + fileConfig, specify 'systemd.journal.JournalHandler' as the + handler class. Only standard handler configuration options + are supported: level, formatter, filters. + + The following journal fields will be sent: + + MESSAGE, PRIORITY, THREAD_NAME, CODE_FILE, CODE_LINE, + CODE_FUNC, LOGGER (name as supplied to getLogger call), + MESSAGE_ID (optional, see above). + """ + + def emit(self, record): + """Write record as journal event. + + MESSAGE is taken from the message provided by the + user, and PRIORITY, LOGGER, THREAD_NAME, + CODE_{FILE,LINE,FUNC} fields are appended + automatically. In addition, record.MESSAGE_ID will be + used if present. + """ + try: + msg = self.format(record) + pri = self.mapPriority(record.levelno) + mid = getattr(record, 'MESSAGE_ID', None) + send(msg, + MESSAGE_ID=mid, + PRIORITY=format(pri), + LOGGER=record.name, + THREAD_NAME=record.threadName, + CODE_FILE=record.pathname, + CODE_LINE=record.lineno, + CODE_FUNC=record.funcName) + except Exception: + self.handleError(record) + + @staticmethod + def mapPriority(levelno): + """Map logging levels to journald priorities. + + Since Python log level numbers are "sparse", we have + to map numbers in between the standard levels too. + """ + if levelno <= _logging.DEBUG: + return LOG_DEBUG + elif levelno <= _logging.INFO: + return LOG_INFO + elif levelno <= _logging.WARNING: + return LOG_WARNING + elif levelno <= _logging.ERROR: + return LOG_ERR + elif levelno <= _logging.CRITICAL: + return LOG_CRIT + else: + return LOG_ALERT -- cgit v1.2.3-54-g00ecf