summaryrefslogtreecommitdiff
path: root/src/python-systemd/journal.py
blob: 80299e6b98c180fd4cb63f939aced72e3996e105 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
#  -*- Mode: python; coding:utf-8; indent-tabs-mode: nil -*- */
#
#  This file is part of systemd.
#
#  Copyright 2012 David Strauss <david@davidstrauss.net>
#  Copyright 2012 Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
#  Copyright 2012 Marti Raudsepp <marti@juffo.org>
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.
#
#  systemd is distributed in the hope that it will be useful, but
#  WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
#  Lesser General Public License for more details.
#
#  You should have received a copy of the GNU Lesser General Public License
#  along with systemd; If not, see <http://www.gnu.org/licenses/>.

from __future__ import division

import sys as _sys
import datetime as _datetime
import functools as _functools
import uuid as _uuid
import traceback as _traceback
import os as _os
from os import SEEK_SET, SEEK_CUR, SEEK_END
import logging as _logging
if _sys.version_info >= (3,):
    from collections import ChainMap as _ChainMap
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
from ._reader import (_Reader, NOP, APPEND, INVALIDATE,
                      LOCAL_ONLY, RUNTIME_ONLY, SYSTEM_ONLY)
from . import id128 as _id128

if _sys.version_info >= (3,):
    from ._reader import Monotonic
else:
    Monotonic = tuple

def _convert_monotonic(m):
    return Monotonic((_datetime.timedelta(microseconds=m[0]),
                      _uuid.UUID(bytes=m[1])))

def _convert_source_monotonic(s):
    return _datetime.timedelta(microseconds=int(s))

def _convert_realtime(t):
    return _datetime.datetime.fromtimestamp(t / 1E6)

def _convert_timestamp(s):
    return _datetime.datetime.fromtimestamp(int(s) / 1E6)

if _sys.version_info >= (3,):
    def _convert_uuid(s):
        return _uuid.UUID(s.decode())
else:
    _convert_uuid = _uuid.UUID

DEFAULT_CONVERTERS = {
    'MESSAGE_ID': _convert_uuid,
    '_MACHINE_ID': _convert_uuid,
    '_BOOT_ID': _convert_uuid,
    'PRIORITY': int,
    'LEADER': int,
    'SESSION_ID': int,
    'USERSPACE_USEC': int,
    'INITRD_USEC': int,
    'KERNEL_USEC': int,
    '_UID': int,
    '_GID': int,
    '_PID': int,
    'SYSLOG_FACILITY': int,
    'SYSLOG_PID': int,
    '_AUDIT_SESSION': int,
    '_AUDIT_LOGINUID': int,
    '_SYSTEMD_SESSION': int,
    '_SYSTEMD_OWNER_UID': int,
    'CODE_LINE': int,
    'ERRNO': int,
    'EXIT_STATUS': int,
    '_SOURCE_REALTIME_TIMESTAMP': _convert_timestamp,
    '__REALTIME_TIMESTAMP': _convert_realtime,
    '_SOURCE_MONOTONIC_TIMESTAMP': _convert_source_monotonic,
    '__MONOTONIC_TIMESTAMP': _convert_monotonic,
    'COREDUMP': bytes,
    'COREDUMP_PID': int,
    'COREDUMP_UID': int,
    'COREDUMP_GID': int,
    'COREDUMP_SESSION': int,
    'COREDUMP_SIGNAL': int,
    'COREDUMP_TIMESTAMP': _convert_timestamp,
}

class Reader(_Reader):
    """Reader allows the access and filtering of systemd journal
    entries. Note that in order to access the system journal, a
    non-root user must be in the `adm` group.

    Example usage to print out all informational or higher level
    messages for systemd-udevd for this boot:

    >>> j = journal.Reader()
    >>> j.this_boot()
    >>> j.log_level(journal.LOG_INFO)
    >>> j.add_match(_SYSTEMD_UNIT="systemd-udevd.service")
    >>> for entry in j:
    ...    print(entry['MESSAGE'])

    See systemd.journal-fields(7) for more info on typical fields
    found in the journal.
    """
    def __init__(self, flags=LOCAL_ONLY, path=None, converters=None):
        """Create an instance of Reader, which allows filtering and
        return of journal entries.

        Argument `flags` sets open flags of the journal, which can be one
        of, or ORed combination of constants: LOCAL_ONLY (default) opens
        journal on local machine only; RUNTIME_ONLY opens only
        volatile journal files; and SYSTEM_ONLY opens only
        journal files of system services and the kernel.

        Argument `path` is the directory of journal files. Note that
        currently flags are ignored when `path` is present as they are
        currently not relevant.

        Argument `converters` is a dictionary which updates the
        DEFAULT_CONVERTERS to convert journal field values. Field
        names are used as keys into this dictionary. The values must
        be single argument functions, which take a `bytes` object and
        return a converted value. When there's no entry for a field
        name, then the default UTF-8 decoding will be attempted. If
        the conversion fails with a ValueError, unconverted bytes
        object will be returned. (Note that ValueEror is a superclass
        of UnicodeDecodeError).
        """
        super(Reader, self).__init__(flags, path)
        if _sys.version_info >= (3,3):
            self.converters = _ChainMap()
            if converters is not None:
                self.converters.maps.append(converters)
            self.converters.maps.append(DEFAULT_CONVERTERS)
        else:
            self.converters = DEFAULT_CONVERTERS.copy()
            if converters is not None:
                self.converters.update(converters)

    def _convert_field(self, key, value):
        """Convert value using self.converters[key]

        If `key` is not present in self.converters, a standard unicode
        decoding will be attempted.  If the conversion (either
        key-specific or the default one) fails with a ValueError, the
        original bytes object will be returned.
        """
        convert = self.converters.get(key, bytes.decode)
        try:
            return convert(value)
        except ValueError:
            # Leave in default bytes
            return value

    def _convert_entry(self, entry):
        """Convert entire journal entry utilising _covert_field"""
        result = {}
        for key, value in entry.items():
            if isinstance(value, list):
                result[key] = [self._convert_field(key, val) for val in value]
            else:
                result[key] = self._convert_field(key, value)
        return result

    def add_match(self, *args, **kwargs):
        """Add one or more matches to the filter journal log entries.
        All matches of different field are combined in a logical AND,
        and matches of the same field are automatically combined in a
        logical OR.
        Matches can be passed as strings of form "FIELD=value", or
        keyword arguments FIELD="value".
        """
        args = list(args)
        args.extend(_make_line(key, val) for key, val in kwargs.items())
        for arg in args:
            super(Reader, self).add_match(arg)

    def get_next(self, skip=1):
        """Return the next log entry as a dictionary of fields.

        Optional skip value will return the `skip`\-th log entry.

        Entries will be processed with converters specified during
        Reader creation.
        """
        return self._convert_entry(
            super(Reader, self).get_next(skip))

    def query_unique(self, field):
        """Return unique values appearing in the journal for given `field`.

        Note this does not respect any journal matches.

        Entries will be processed with converters specified during
        Reader creation.
        """
        return set(self._convert_field(field, value)
            for value in super(Reader, self).query_unique(field))

    def seek_realtime(self, realtime):
        """Seek to a matching journal entry nearest to `realtime` time.

        Argument `realtime` must be either an integer unix timestamp
        or datetime.datetime instance.
        """
        if isinstance(realtime, _datetime.datetime):
            realtime = float(realtime.strftime("%s.%f"))
        return super(Reader, self).seek_realtime(realtime)

    def seek_monotonic(self, monotonic, bootid=None):
        """Seek to a matching journal entry nearest to `monotonic` time.

        Argument `monotonic` is a timestamp from boot in either
        seconds or a datetime.timedelta instance. Argument `bootid`
        is a string or UUID representing which boot the monotonic time
        is reference to. Defaults to current bootid.
        """
        if isinstance(monotonic, _datetime.timedelta):
            monotonic = monotonic.totalseconds()
        if isinstance(bootid, _uuid.UUID):
            bootid = bootid.get_hex()
        return super(Reader, self).seek_monotonic(monotonic, bootid)

    def log_level(self, level):
        """Set maximum log `level` by setting matches for PRIORITY.
        """
        if 0 <= level <= 7:
            for i in range(level+1):
                self.add_match(PRIORITY="%d" % i)
        else:
            raise ValueError("Log level must be 0 <= level <= 7")

    def messageid_match(self, messageid):
        """Add match for log entries with specified `messageid`.

        `messageid` can be string of hexadicimal digits or a UUID
        instance. Standard message IDs can be found in systemd.id128.

        Equivalent to add_match(MESSAGE_ID=`messageid`).
        """
        if isinstance(messageid, _uuid.UUID):
            messageid = messageid.get_hex()
        self.add_match(MESSAGE_ID=messageid)

    def this_boot(self, bootid=None):
        """Add match for _BOOT_ID equal to current boot ID or the specified boot ID.

        If specified, bootid should be either a UUID or a 32 digit hex number.

        Equivalent to add_match(_BOOT_ID='bootid').
        """
        if bootid is None:
            bootid = _id128.get_boot().hex
        else:
            bootid = getattr(bootid, 'hex', bootid)
        self.add_match(_BOOT_ID=bootid)

    def this_machine(self, machineid=None):
        """Add match for _MACHINE_ID equal to the ID of this machine.

        If specified, machineid should be either a UUID or a 32 digit hex number.

        Equivalent to add_match(_MACHINE_ID='machineid').
        """
        if machineid is None:
            machineid = _id128.get_machine().hex
        else:
            machineid = getattr(machineid, 'hex', machineid)
        self.add_match(_MACHINE_ID=machineid)


def _make_line(field, value):
        if isinstance(value, bytes):
                return field.encode('utf-8') + b'=' + value
        else:
                return field + '=' + value

def send(MESSAGE, MESSAGE_ID=None,
         CODE_FILE=None, CODE_LINE=None, CODE_FUNC=None,
         **kwargs):
        r"""Send a message to the journal.

        >>> journal.send('Hello world')
        >>> journal.send('Hello, again, world', FIELD2='Greetings!')
        >>> journal.send('Binary message', BINARY=b'\xde\xad\xbe\xef')

        Value of the MESSAGE argument will be used for the MESSAGE=
        field. MESSAGE must be a string and will be sent as UTF-8 to
        the journal.

        MESSAGE_ID can be given to uniquely identify the type of
        message. It must be a string or a uuid.UUID object.

        CODE_LINE, CODE_FILE, and CODE_FUNC can be specified to
        identify the caller. Unless at least on of the three is given,
        values are extracted from the stack frame of the caller of
        send(). CODE_FILE and CODE_FUNC must be strings, CODE_LINE
        must be an integer.

        Additional fields for the journal entry can only be specified
        as keyword arguments. The payload can be either a string or
        bytes. A string will be sent as UTF-8, and bytes will be sent
        as-is to the journal.

        Other useful fields include PRIORITY, SYSLOG_FACILITY,
        SYSLOG_IDENTIFIER, SYSLOG_PID.
        """

        args = ['MESSAGE=' + MESSAGE]

        if MESSAGE_ID is not None:
                id = getattr(MESSAGE_ID, 'hex', MESSAGE_ID)
                args.append('MESSAGE_ID=' + id)

        if CODE_LINE == CODE_FILE == CODE_FUNC == None:
                CODE_FILE, CODE_LINE, CODE_FUNC = \
                        _traceback.extract_stack(limit=2)[0][:3]
        if CODE_FILE is not None:
                args.append('CODE_FILE=' + CODE_FILE)
        if CODE_LINE is not None:
                args.append('CODE_LINE={:d}'.format(CODE_LINE))
        if CODE_FUNC is not None:
                args.append('CODE_FUNC=' + CODE_FUNC)

        args.extend(_make_line(key, val) for key, val in kwargs.items())
        return sendv(*args)

def stream(identifier, priority=LOG_DEBUG, level_prefix=False):
        r"""Return a file object wrapping a stream to journal.

        Log messages written to this file as simple newline sepearted
        text strings are written to the journal.

        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