+ The file will be line buffered, so messages are actually sent
+ after a newline character is written.
+
+ >>> stream = journal.stream('myapp')
+ >>> stream
+ <open file '<fdopen>', mode 'w' at 0x...>
+ >>> stream.write('message...\n')
+
+ will produce the following message in the journal::
+
+ PRIORITY=7
+ SYSLOG_IDENTIFIER=myapp
+ MESSAGE=message...
+
+ Using the interface with print might be more convinient:
+
+ >>> from __future__ import print_function
+ >>> print('message...', file=stream)
+
+ priority is the syslog priority, one of `LOG_EMERG`,
+ `LOG_ALERT`, `LOG_CRIT`, `LOG_ERR`, `LOG_WARNING`,
+ `LOG_NOTICE`, `LOG_INFO`, `LOG_DEBUG`.
+
+ level_prefix is a boolean. If true, kernel-style log priority
+ level prefixes (such as '<1>') are interpreted. See
+ sd-daemon(3) for more information.
+ """
+
+ 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:
+
+ >>> import uuid
+ >>> mid = uuid.UUID('0123456789ABCDEF0123456789ABCDEF')
+ >>> log.warn("Message with ID", extra={'MESSAGE_ID': mid})
+
+ 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