1 # -*- Mode: python; coding:utf-8; indent-tabs-mode: nil -*- */
3 # This file is part of systemd.
5 # Copyright 2012 David Strauss <david@davidstrauss.net>
6 # Copyright 2012 Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
7 # Copyright 2012 Marti Raudsepp <marti@juffo.org>
9 # systemd is free software; you can redistribute it and/or modify it
10 # under the terms of the GNU Lesser General Public License as published by
11 # the Free Software Foundation; either version 2.1 of the License, or
12 # (at your option) any later version.
14 # systemd is distributed in the hope that it will be useful, but
15 # WITHOUT ANY WARRANTY; without even the implied warranty of
16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 # Lesser General Public License for more details.
19 # You should have received a copy of the GNU Lesser General Public License
20 # along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 import traceback as _traceback
24 import logging as _logging
25 from syslog import (LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR,
26 LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG)
27 from ._journal import sendv, stream_fd
28 from ._reader import (Journal, NOP, APPEND, INVALIDATE,
29 LOCAL_ONLY, RUNTIME_ONLY, SYSTEM_ONLY)
31 def _make_line(field, value):
32 if isinstance(value, bytes):
33 return field.encode('utf-8') + b'=' + value
35 return field + '=' + value
37 def send(MESSAGE, MESSAGE_ID=None,
38 CODE_FILE=None, CODE_LINE=None, CODE_FUNC=None,
40 r"""Send a message to the journal.
42 >>> journal.send('Hello world')
43 >>> journal.send('Hello, again, world', FIELD2='Greetings!')
44 >>> journal.send('Binary message', BINARY=b'\xde\xad\xbe\xef')
46 Value of the MESSAGE argument will be used for the MESSAGE=
47 field. MESSAGE must be a string and will be sent as UTF-8 to
50 MESSAGE_ID can be given to uniquely identify the type of
51 message. It must be a string or a uuid.UUID object.
53 CODE_LINE, CODE_FILE, and CODE_FUNC can be specified to
54 identify the caller. Unless at least on of the three is given,
55 values are extracted from the stack frame of the caller of
56 send(). CODE_FILE and CODE_FUNC must be strings, CODE_LINE
59 Additional fields for the journal entry can only be specified
60 as keyword arguments. The payload can be either a string or
61 bytes. A string will be sent as UTF-8, and bytes will be sent
64 Other useful fields include PRIORITY, SYSLOG_FACILITY,
65 SYSLOG_IDENTIFIER, SYSLOG_PID.
68 args = ['MESSAGE=' + MESSAGE]
70 if MESSAGE_ID is not None:
71 id = getattr(MESSAGE_ID, 'hex', MESSAGE_ID)
72 args.append('MESSAGE_ID=' + id)
74 if CODE_LINE == CODE_FILE == CODE_FUNC == None:
75 CODE_FILE, CODE_LINE, CODE_FUNC = \
76 _traceback.extract_stack(limit=2)[0][:3]
77 if CODE_FILE is not None:
78 args.append('CODE_FILE=' + CODE_FILE)
79 if CODE_LINE is not None:
80 args.append('CODE_LINE={:d}'.format(CODE_LINE))
81 if CODE_FUNC is not None:
82 args.append('CODE_FUNC=' + CODE_FUNC)
84 args.extend(_make_line(key, val) for key, val in kwargs.items())
87 def stream(identifier, priority=LOG_DEBUG, level_prefix=False):
88 r"""Return a file object wrapping a stream to journal.
90 Log messages written to this file as simple newline sepearted
91 text strings are written to the journal.
93 The file will be line buffered, so messages are actually sent
94 after a newline character is written.
96 >>> stream = journal.stream('myapp')
98 <open file '<fdopen>', mode 'w' at 0x...>
99 >>> stream.write('message...\n')
101 will produce the following message in the journal::
104 SYSLOG_IDENTIFIER=myapp
107 Using the interface with print might be more convinient:
109 >>> from __future__ import print_function
110 >>> print('message...', file=stream)
112 priority is the syslog priority, one of `LOG_EMERG`,
113 `LOG_ALERT`, `LOG_CRIT`, `LOG_ERR`, `LOG_WARNING`,
114 `LOG_NOTICE`, `LOG_INFO`, `LOG_DEBUG`.
116 level_prefix is a boolean. If true, kernel-style log priority
117 level prefixes (such as '<1>') are interpreted. See
118 sd-daemon(3) for more information.
121 fd = stream_fd(identifier, priority, level_prefix)
122 return _os.fdopen(fd, 'w', 1)
124 class JournalHandler(_logging.Handler):
125 """Journal handler class for the Python logging framework.
127 Please see the Python logging module documentation for an
128 overview: http://docs.python.org/library/logging.html.
130 To create a custom logger whose messages go only to journal:
132 >>> log = logging.getLogger('custom_logger_name')
133 >>> log.propagate = False
134 >>> log.addHandler(journal.JournalHandler())
135 >>> log.warn("Some message: %s", detail)
137 Note that by default, message levels `INFO` and `DEBUG` are
138 ignored by the logging framework. To enable those log levels:
140 >>> log.setLevel(logging.DEBUG)
142 To attach journal MESSAGE_ID, an extra field is supported:
145 >>> mid = uuid.UUID('0123456789ABCDEF0123456789ABCDEF')
146 >>> log.warn("Message with ID", extra={'MESSAGE_ID': mid})
148 To redirect all logging messages to journal regardless of where
149 they come from, attach it to the root logger:
151 >>> logging.root.addHandler(journal.JournalHandler())
153 For more complex configurations when using `dictConfig` or
154 `fileConfig`, specify `systemd.journal.JournalHandler` as the
155 handler class. Only standard handler configuration options
156 are supported: `level`, `formatter`, `filters`.
158 The following journal fields will be sent:
159 `MESSAGE`, `PRIORITY`, `THREAD_NAME`, `CODE_FILE`, `CODE_LINE`,
160 `CODE_FUNC`, `LOGGER` (name as supplied to getLogger call),
161 `MESSAGE_ID` (optional, see above).
164 def emit(self, record):
165 """Write record as journal event.
167 MESSAGE is taken from the message provided by the
168 user, and PRIORITY, LOGGER, THREAD_NAME,
169 CODE_{FILE,LINE,FUNC} fields are appended
170 automatically. In addition, record.MESSAGE_ID will be
174 msg = self.format(record)
175 pri = self.mapPriority(record.levelno)
176 mid = getattr(record, 'MESSAGE_ID', None)
179 PRIORITY=format(pri),
181 THREAD_NAME=record.threadName,
182 CODE_FILE=record.pathname,
183 CODE_LINE=record.lineno,
184 CODE_FUNC=record.funcName)
186 self.handleError(record)
189 def mapPriority(levelno):
190 """Map logging levels to journald priorities.
192 Since Python log level numbers are "sparse", we have
193 to map numbers in between the standard levels too.
195 if levelno <= _logging.DEBUG:
197 elif levelno <= _logging.INFO:
199 elif levelno <= _logging.WARNING:
201 elif levelno <= _logging.ERROR:
203 elif levelno <= _logging.CRITICAL: