File: redis.py

package info (click to toggle)
celery 4.2.1-3
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 6,136 kB
  • sloc: python: 47,677; sh: 772; makefile: 226
file content (487 lines) | stat: -rw-r--r-- 17,236 bytes parent folder | download
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
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
# -*- coding: utf-8 -*-
"""Redis result store backend."""
from __future__ import absolute_import, unicode_literals

from functools import partial
from ssl import CERT_NONE, CERT_OPTIONAL, CERT_REQUIRED

from kombu.utils.functional import retry_over_time
from kombu.utils.objects import cached_property
from kombu.utils.url import _parse_url

from celery import states
from celery._state import task_join_will_block
from celery.canvas import maybe_signature
from celery.exceptions import ChordError, ImproperlyConfigured
from celery.five import string_t, text_t
from celery.utils import deprecated
from celery.utils.functional import dictfilter
from celery.utils.log import get_logger
from celery.utils.time import humanize_seconds

from .asynchronous import AsyncBackendMixin, BaseResultConsumer
from .base import BaseKeyValueStoreBackend

try:
    from urllib.parse import unquote
except ImportError:
    # Python 2
    from urlparse import unquote

try:
    import redis
    import redis.connection
    from kombu.transport.redis import get_redis_error_classes
except ImportError:  # pragma: no cover
    redis = None  # noqa
    get_redis_error_classes = None  # noqa

try:
    from redis import sentinel
except ImportError:
    sentinel = None

__all__ = ('RedisBackend', 'SentinelBackend')

E_REDIS_MISSING = """
You need to install the redis library in order to use \
the Redis result store backend.
"""

E_REDIS_SENTINEL_MISSING = """
You need to install the redis library with support of \
sentinel in order to use the Redis result store backend.
"""

W_REDIS_SSL_CERT_OPTIONAL = """
Setting ssl_cert_reqs=CERT_OPTIONAL when connecting to redis means that \
celery might not valdate the identity of the redis broker when connecting. \
This leaves you vulnerable to man in the middle attacks.
"""

W_REDIS_SSL_CERT_NONE = """
Setting ssl_cert_reqs=CERT_NONE when connecting to redis means that celery \
will not valdate the identity of the redis broker when connecting. This \
leaves you vulnerable to man in the middle attacks.
"""

E_REDIS_SSL_CERT_REQS_MISSING = """
A rediss:// URL must have parameter ssl_cert_reqs be CERT_REQUIRED, \
CERT_OPTIONAL, or CERT_NONE
"""

E_LOST = 'Connection to Redis lost: Retry (%s/%s) %s.'

logger = get_logger(__name__)


class ResultConsumer(BaseResultConsumer):
    _pubsub = None

    def __init__(self, *args, **kwargs):
        super(ResultConsumer, self).__init__(*args, **kwargs)
        self._get_key_for_task = self.backend.get_key_for_task
        self._decode_result = self.backend.decode_result
        self.subscribed_to = set()

    def on_after_fork(self):
        try:
            self.backend.client.connection_pool.reset()
            if self._pubsub is not None:
                self._pubsub.close()
        except KeyError as e:
            logger.warn(text_t(e))
        super(ResultConsumer, self).on_after_fork()

    def _maybe_cancel_ready_task(self, meta):
        if meta['status'] in states.READY_STATES:
            self.cancel_for(meta['task_id'])

    def on_state_change(self, meta, message):
        super(ResultConsumer, self).on_state_change(meta, message)
        self._maybe_cancel_ready_task(meta)

    def start(self, initial_task_id, **kwargs):
        self._pubsub = self.backend.client.pubsub(
            ignore_subscribe_messages=True,
        )
        self._consume_from(initial_task_id)

    def on_wait_for_pending(self, result, **kwargs):
        for meta in result._iter_meta():
            if meta is not None:
                self.on_state_change(meta, None)

    def stop(self):
        if self._pubsub is not None:
            self._pubsub.close()

    def drain_events(self, timeout=None):
        m = self._pubsub.get_message(timeout=timeout)
        if m and m['type'] == 'message':
            self.on_state_change(self._decode_result(m['data']), m)

    def consume_from(self, task_id):
        if self._pubsub is None:
            return self.start(task_id)
        self._consume_from(task_id)

    def _consume_from(self, task_id):
        key = self._get_key_for_task(task_id)
        if key not in self.subscribed_to:
            self.subscribed_to.add(key)
            self._pubsub.subscribe(key)

    def cancel_for(self, task_id):
        if self._pubsub:
            key = self._get_key_for_task(task_id)
            self.subscribed_to.discard(key)
            self._pubsub.unsubscribe(key)


class RedisBackend(BaseKeyValueStoreBackend, AsyncBackendMixin):
    """Redis task result store."""

    ResultConsumer = ResultConsumer

    #: :pypi:`redis` client module.
    redis = redis

    #: Maximum number of connections in the pool.
    max_connections = None

    supports_autoexpire = True
    supports_native_join = True

    def __init__(self, host=None, port=None, db=None, password=None,
                 max_connections=None, url=None,
                 connection_pool=None, **kwargs):
        super(RedisBackend, self).__init__(expires_type=int, **kwargs)
        _get = self.app.conf.get
        if self.redis is None:
            raise ImproperlyConfigured(E_REDIS_MISSING.strip())

        if host and '://' in host:
            url, host = host, None

        self.max_connections = (
            max_connections or
            _get('redis_max_connections') or
            self.max_connections)
        self._ConnectionPool = connection_pool

        socket_timeout = _get('redis_socket_timeout')
        socket_connect_timeout = _get('redis_socket_connect_timeout')

        self.connparams = {
            'host': _get('redis_host') or 'localhost',
            'port': _get('redis_port') or 6379,
            'db': _get('redis_db') or 0,
            'password': _get('redis_password'),
            'max_connections': self.max_connections,
            'socket_timeout': socket_timeout and float(socket_timeout),
            'socket_connect_timeout':
                socket_connect_timeout and float(socket_connect_timeout),
        }

        # "redis_backend_use_ssl" must be a dict with the keys:
        # 'ssl_cert_reqs', 'ssl_ca_certs', 'ssl_certfile', 'ssl_keyfile'
        # (the same as "broker_use_ssl")
        ssl = _get('redis_backend_use_ssl')
        if ssl:
            self.connparams.update(ssl)
            self.connparams['connection_class'] = redis.SSLConnection

        if url:
            self.connparams = self._params_from_url(url, self.connparams)
        self.url = url

        self.connection_errors, self.channel_errors = (
            get_redis_error_classes() if get_redis_error_classes
            else ((), ()))
        self.result_consumer = self.ResultConsumer(
            self, self.app, self.accept,
            self._pending_results, self._pending_messages,
        )

    def _params_from_url(self, url, defaults):
        scheme, host, port, _, password, path, query = _parse_url(url)
        connparams = dict(
            defaults, **dictfilter({
                'host': host, 'port': port, 'password': password,
                'db': query.pop('virtual_host', None)})
        )

        if scheme == 'socket':
            # use 'path' as path to the socket… in this case
            # the database number should be given in 'query'
            connparams.update({
                'connection_class': self.redis.UnixDomainSocketConnection,
                'path': '/' + path,
            })
            # host+port are invalid options when using this connection type.
            connparams.pop('host', None)
            connparams.pop('port', None)
            connparams.pop('socket_connect_timeout')
        else:
            connparams['db'] = path

        if scheme == 'rediss':
            connparams['connection_class'] = redis.SSLConnection
            # The following parameters, if present in the URL, are encoded. We
            # must add the decoded values to connparams.
            for ssl_setting in ['ssl_ca_certs', 'ssl_certfile', 'ssl_keyfile']:
                ssl_val = query.pop(ssl_setting, None)
                if ssl_val:
                    connparams[ssl_setting] = unquote(ssl_val)
            ssl_cert_reqs = query.pop('ssl_cert_reqs', 'MISSING')
            if ssl_cert_reqs == 'CERT_REQUIRED':
                connparams['ssl_cert_reqs'] = CERT_REQUIRED
            elif ssl_cert_reqs == 'CERT_OPTIONAL':
                logger.warn(W_REDIS_SSL_CERT_OPTIONAL)
                connparams['ssl_cert_reqs'] = CERT_OPTIONAL
            elif ssl_cert_reqs == 'CERT_NONE':
                logger.warn(W_REDIS_SSL_CERT_NONE)
                connparams['ssl_cert_reqs'] = CERT_NONE
            else:
                raise ValueError(E_REDIS_SSL_CERT_REQS_MISSING)

        # db may be string and start with / like in kombu.
        db = connparams.get('db') or 0
        db = db.strip('/') if isinstance(db, string_t) else db
        connparams['db'] = int(db)

        for key, value in query.items():
            if key in redis.connection.URL_QUERY_ARGUMENT_PARSERS:
                query[key] = redis.connection.URL_QUERY_ARGUMENT_PARSERS[key](
                    value
                )

        # Query parameters override other parameters
        connparams.update(query)
        return connparams

    def on_task_call(self, producer, task_id):
        if not task_join_will_block():
            self.result_consumer.consume_from(task_id)

    def get(self, key):
        return self.client.get(key)

    def mget(self, keys):
        return self.client.mget(keys)

    def ensure(self, fun, args, **policy):
        retry_policy = dict(self.retry_policy, **policy)
        max_retries = retry_policy.get('max_retries')
        return retry_over_time(
            fun, self.connection_errors, args, {},
            partial(self.on_connection_error, max_retries),
            **retry_policy)

    def on_connection_error(self, max_retries, exc, intervals, retries):
        tts = next(intervals)
        logger.error(
            E_LOST.strip(),
            retries, max_retries or 'Inf', humanize_seconds(tts, 'in '))
        return tts

    def set(self, key, value, **retry_policy):
        return self.ensure(self._set, (key, value), **retry_policy)

    def _set(self, key, value):
        with self.client.pipeline() as pipe:
            if self.expires:
                pipe.setex(key, self.expires, value)
            else:
                pipe.set(key, value)
            pipe.publish(key, value)
            pipe.execute()

    def forget(self, task_id):
        super(RedisBackend, self).forget(task_id)
        self.result_consumer.cancel_for(task_id)

    def delete(self, key):
        self.client.delete(key)

    def incr(self, key):
        return self.client.incr(key)

    def expire(self, key, value):
        return self.client.expire(key, value)

    def add_to_chord(self, group_id, result):
        self.client.incr(self.get_key_for_group(group_id, '.t'), 1)

    def _unpack_chord_result(self, tup, decode,
                             EXCEPTION_STATES=states.EXCEPTION_STATES,
                             PROPAGATE_STATES=states.PROPAGATE_STATES):
        _, tid, state, retval = decode(tup)
        if state in EXCEPTION_STATES:
            retval = self.exception_to_python(retval)
        if state in PROPAGATE_STATES:
            raise ChordError('Dependency {0} raised {1!r}'.format(tid, retval))
        return retval

    def apply_chord(self, header_result, body, **kwargs):
        # Overrides this to avoid calling GroupResult.save
        # pylint: disable=method-hidden
        # Note that KeyValueStoreBackend.__init__ sets self.apply_chord
        # if the implements_incr attr is set.  Redis backend doesn't set
        # this flag.
        pass

    def on_chord_part_return(self, request, state, result,
                             propagate=None, **kwargs):
        app = self.app
        tid, gid = request.id, request.group
        if not gid or not tid:
            return

        client = self.client
        jkey = self.get_key_for_group(gid, '.j')
        tkey = self.get_key_for_group(gid, '.t')
        result = self.encode_result(result, state)
        with client.pipeline() as pipe:
            _, readycount, totaldiff, _, _ = pipe \
                .rpush(jkey, self.encode([1, tid, state, result])) \
                .llen(jkey) \
                .get(tkey) \
                .expire(jkey, self.expires) \
                .expire(tkey, self.expires) \
                .execute()

        totaldiff = int(totaldiff or 0)

        try:
            callback = maybe_signature(request.chord, app=app)
            total = callback['chord_size'] + totaldiff
            if readycount == total:
                decode, unpack = self.decode, self._unpack_chord_result
                with client.pipeline() as pipe:
                    resl, _, _ = pipe \
                        .lrange(jkey, 0, total) \
                        .delete(jkey) \
                        .delete(tkey) \
                        .execute()
                try:
                    callback.delay([unpack(tup, decode) for tup in resl])
                except Exception as exc:  # pylint: disable=broad-except
                    logger.exception(
                        'Chord callback for %r raised: %r', request.group, exc)
                    return self.chord_error_from_stack(
                        callback,
                        ChordError('Callback error: {0!r}'.format(exc)),
                    )
        except ChordError as exc:
            logger.exception('Chord %r raised: %r', request.group, exc)
            return self.chord_error_from_stack(callback, exc)
        except Exception as exc:  # pylint: disable=broad-except
            logger.exception('Chord %r raised: %r', request.group, exc)
            return self.chord_error_from_stack(
                callback,
                ChordError('Join error: {0!r}'.format(exc)),
            )

    def _create_client(self, **params):
        return self._get_client()(
            connection_pool=self._get_pool(**params),
        )

    def _get_client(self):
        return self.redis.StrictRedis

    def _get_pool(self, **params):
        return self.ConnectionPool(**params)

    @property
    def ConnectionPool(self):
        if self._ConnectionPool is None:
            self._ConnectionPool = self.redis.ConnectionPool
        return self._ConnectionPool

    @cached_property
    def client(self):
        return self._create_client(**self.connparams)

    def __reduce__(self, args=(), kwargs={}):
        return super(RedisBackend, self).__reduce__(
            (self.url,), {'expires': self.expires},
        )

    @deprecated.Property(4.0, 5.0)
    def host(self):
        return self.connparams['host']

    @deprecated.Property(4.0, 5.0)
    def port(self):
        return self.connparams['port']

    @deprecated.Property(4.0, 5.0)
    def db(self):
        return self.connparams['db']

    @deprecated.Property(4.0, 5.0)
    def password(self):
        return self.connparams['password']


class SentinelBackend(RedisBackend):
    """Redis sentinel task result store."""

    sentinel = sentinel

    def __init__(self, *args, **kwargs):
        if self.sentinel is None:
            raise ImproperlyConfigured(E_REDIS_SENTINEL_MISSING.strip())

        super(SentinelBackend, self).__init__(*args, **kwargs)

    def _params_from_url(self, url, defaults):
        # URL looks like sentinel://0.0.0.0:26347/3;sentinel://0.0.0.0:26348/3.
        chunks = url.split(";")
        connparams = dict(defaults, hosts=[])
        for chunk in chunks:
            data = super(SentinelBackend, self)._params_from_url(
                url=chunk, defaults=defaults)
            connparams['hosts'].append(data)
        for p in ("host", "port", "db", "password"):
            connparams.pop(p)

        # Adding db/password in connparams to connect to the correct instance
        for p in ("db", "password"):
            if connparams['hosts'] and p in connparams['hosts'][0]:
                connparams[p] = connparams['hosts'][0].get(p)
        return connparams

    def _get_sentinel_instance(self, **params):
        connparams = params.copy()

        hosts = connparams.pop("hosts")
        result_backend_transport_opts = self.app.conf.get(
            "result_backend_transport_options", {})
        min_other_sentinels = result_backend_transport_opts.get(
            "min_other_sentinels", 0)
        sentinel_kwargs = result_backend_transport_opts.get(
            "sentinel_kwargs", {})

        sentinel_instance = self.sentinel.Sentinel(
            [(cp['host'], cp['port']) for cp in hosts],
            min_other_sentinels=min_other_sentinels,
            sentinel_kwargs=sentinel_kwargs,
            **connparams)

        return sentinel_instance

    def _get_pool(self, **params):
        sentinel_instance = self._get_sentinel_instance(**params)

        result_backend_transport_opts = self.app.conf.get(
            "result_backend_transport_options", {})
        master_name = result_backend_transport_opts.get("master_name", None)

        return sentinel_instance.master_for(
            service_name=master_name,
            redis_class=self._get_client(),
        ).connection_pool