luxi.py 14.5 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
#
#

# Copyright (C) 2006, 2007 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.


"""Module for the unix socket protocol

24
This module implements the local unix socket protocol. You only need
25
26
27
this module and the opcodes module in the client program in order to
communicate with the master.

Guido Trotter's avatar
Guido Trotter committed
28
The module is also used by the master daemon.
29
30
31
32
33
34

"""

import socket
import collections
import time
35
import errno
36
import logging
37

38
from ganeti import serializer
Iustin Pop's avatar
Iustin Pop committed
39
from ganeti import constants
40
from ganeti import errors
41
from ganeti import utils
42
43


44
45
KEY_METHOD = "method"
KEY_ARGS = "args"
46
47
KEY_SUCCESS = "success"
KEY_RESULT = "result"
48
KEY_VERSION = "version"
49

50
REQ_SUBMIT_JOB = "SubmitJob"
51
REQ_SUBMIT_MANY_JOBS = "SubmitManyJobs"
52
REQ_WAIT_FOR_JOB_CHANGE = "WaitForJobChange"
53
54
REQ_CANCEL_JOB = "CancelJob"
REQ_ARCHIVE_JOB = "ArchiveJob"
Iustin Pop's avatar
Iustin Pop committed
55
REQ_AUTOARCHIVE_JOBS = "AutoArchiveJobs"
56
REQ_QUERY_JOBS = "QueryJobs"
57
REQ_QUERY_INSTANCES = "QueryInstances"
Michael Hanselmann's avatar
Michael Hanselmann committed
58
REQ_QUERY_NODES = "QueryNodes"
59
REQ_QUERY_GROUPS = "QueryGroups"
60
REQ_QUERY_EXPORTS = "QueryExports"
61
REQ_QUERY_CONFIG_VALUES = "QueryConfigValues"
62
REQ_QUERY_CLUSTER_INFO = "QueryClusterInfo"
Iustin Pop's avatar
Iustin Pop committed
63
REQ_QUERY_TAGS = "QueryTags"
Michael Hanselmann's avatar
Michael Hanselmann committed
64
REQ_QUERY_LOCKS = "QueryLocks"
65
REQ_QUEUE_SET_DRAIN_FLAG = "SetDrainFlag"
66
REQ_SET_WATCHER_PAUSE = "SetWatcherPause"
67
68
69
70

DEF_CTMO = 10
DEF_RWTO = 60

71
72
73
# WaitForJobChange timeout
WFJC_TIMEOUT = (DEF_RWTO - 1) / 2

74

75
class ProtocolError(errors.LuxiError):
76
  """Denotes an error in the LUXI protocol."""
77
78
79


class ConnectionClosedError(ProtocolError):
80
  """Connection closed error."""
81
82
83


class TimeoutError(ProtocolError):
84
  """Operation timeout error."""
85
86


87
class RequestError(ProtocolError):
88
  """Error on request.
89
90
91
92
93
94
95
96
97
98

  This signifies an error in the request format or request handling,
  but not (e.g.) an error in starting up an instance.

  Some common conditions that can trigger this exception:
    - job submission failed because the job data was wrong
    - query failed because required fields were missing

  """

99

100
class NoMasterError(ProtocolError):
101
  """The master cannot be reached.
102
103
104
105
106
107

  This means that the master daemon is not running or the socket has
  been removed.

  """

108

109
110
111
112
113
114
115
116
class PermissionError(ProtocolError):
  """Permission denied while connecting to the master socket.

  This means the user doesn't have the proper rights.

  """


117
118
119
120
121
122
123
124
125
126
127
128
class Transport:
  """Low-level transport class.

  This is used on the client side.

  This could be replace by any other class that provides the same
  semantics to the Client. This means:
    - can send messages and receive messages
    - safe for multithreading

  """

129
  def __init__(self, address, timeouts=None):
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
    """Constructor for the Client class.

    Arguments:
      - address: a valid address the the used transport class
      - timeout: a list of timeouts, to be used on connect and read/write

    There are two timeouts used since we might want to wait for a long
    time for a response, but the connect timeout should be lower.

    If not passed, we use a default of 10 and respectively 60 seconds.

    Note that on reading data, since the timeout applies to an
    invidual receive, it might be that the total duration is longer
    than timeout value passed (we make a hard limit at twice the read
    timeout).

    """
    self.address = address
    if timeouts is None:
      self._ctimeout, self._rwtimeout = DEF_CTMO, DEF_RWTO
    else:
      self._ctimeout, self._rwtimeout = timeouts

    self.socket = None
    self._buffer = ""
    self._msgs = collections.deque()

    try:
      self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
159
160

      # Try to connect
161
      try:
162
163
164
165
166
        utils.Retry(self._Connect, 1.0, self._ctimeout,
                    args=(self.socket, address, self._ctimeout))
      except utils.RetryTimeout:
        raise TimeoutError("Connect timed out")

167
      self.socket.settimeout(self._rwtimeout)
168
    except (socket.error, NoMasterError):
169
170
171
172
173
      if self.socket is not None:
        self.socket.close()
      self.socket = None
      raise

174
175
176
177
178
179
180
181
  @staticmethod
  def _Connect(sock, address, timeout):
    sock.settimeout(timeout)
    try:
      sock.connect(address)
    except socket.timeout, err:
      raise TimeoutError("Connect timed out: %s" % str(err))
    except socket.error, err:
182
183
      error_code = err.args[0]
      if error_code in (errno.ENOENT, errno.ECONNREFUSED):
184
        raise NoMasterError(address)
185
186
187
      elif error_code in (errno.EPERM, errno.EACCES):
        raise PermissionError(address)
      elif error_code == errno.EAGAIN:
188
189
190
191
        # Server's socket backlog is full at the moment
        raise utils.RetryAgain()
      raise

192
193
194
195
196
197
198
199
200
201
202
203
204
  def _CheckSocket(self):
    """Make sure we are connected.

    """
    if self.socket is None:
      raise ProtocolError("Connection is closed")

  def Send(self, msg):
    """Send a message.

    This just sends a message and doesn't wait for the response.

    """
205
    if constants.LUXI_EOM in msg:
Michael Hanselmann's avatar
Michael Hanselmann committed
206
207
      raise ProtocolError("Message terminator found in payload")

208
209
    self._CheckSocket()
    try:
210
      # TODO: sendall is not guaranteed to send everything
211
      self.socket.sendall(msg + constants.LUXI_EOM)
212
213
214
215
    except socket.timeout, err:
      raise TimeoutError("Sending timeout: %s" % str(err))

  def Recv(self):
Michael Hanselmann's avatar
Michael Hanselmann committed
216
    """Try to receive a message from the socket.
217
218
219
220
221
222
223
224
225
226
227
228

    In case we already have messages queued, we just return from the
    queue. Otherwise, we try to read data with a _rwtimeout network
    timeout, and making sure we don't go over 2x_rwtimeout as a global
    limit.

    """
    self._CheckSocket()
    etime = time.time() + self._rwtimeout
    while not self._msgs:
      if time.time() > etime:
        raise TimeoutError("Extended receive timeout")
229
230
231
232
233
234
235
236
237
238
      while True:
        try:
          data = self.socket.recv(4096)
        except socket.error, err:
          if err.args and err.args[0] == errno.EAGAIN:
            continue
          raise
        except socket.timeout, err:
          raise TimeoutError("Receive timeout: %s" % str(err))
        break
239
240
      if not data:
        raise ConnectionClosedError("Connection closed while reading")
241
      new_msgs = (self._buffer + data).split(constants.LUXI_EOM)
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
      self._buffer = new_msgs.pop()
      self._msgs.extend(new_msgs)
    return self._msgs.popleft()

  def Call(self, msg):
    """Send a message and wait for the response.

    This is just a wrapper over Send and Recv.

    """
    self.Send(msg)
    return self.Recv()

  def Close(self):
    """Close the socket"""
    if self.socket is not None:
      self.socket.close()
      self.socket = None


262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
def ParseRequest(msg):
  """Parses a LUXI request message.

  """
  try:
    request = serializer.LoadJson(msg)
  except ValueError, err:
    raise ProtocolError("Invalid LUXI request (parsing error): %s" % err)

  logging.debug("LUXI request: %s", request)

  if not isinstance(request, dict):
    logging.error("LUXI request not a dict: %r", msg)
    raise ProtocolError("Invalid LUXI request (not a dict)")

Guido Trotter's avatar
Guido Trotter committed
277
278
  method = request.get(KEY_METHOD, None) # pylint: disable-msg=E1103
  args = request.get(KEY_ARGS, None) # pylint: disable-msg=E1103
Guido Trotter's avatar
Guido Trotter committed
279
  version = request.get(KEY_VERSION, None) # pylint: disable-msg=E1103
Guido Trotter's avatar
Guido Trotter committed
280

281
282
283
284
285
  if method is None or args is None:
    logging.error("LUXI request missing method or arguments: %r", msg)
    raise ProtocolError(("Invalid LUXI request (no method or arguments"
                         " in request): %r") % msg)

286
  return (method, args, version)
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304


def ParseResponse(msg):
  """Parses a LUXI response message.

  """
  # Parse the result
  try:
    data = serializer.LoadJson(msg)
  except Exception, err:
    raise ProtocolError("Error while deserializing response: %s" % str(err))

  # Validate response
  if not (isinstance(data, dict) and
          KEY_SUCCESS in data and
          KEY_RESULT in data):
    raise ProtocolError("Invalid response from server: %r" % data)

Guido Trotter's avatar
Guido Trotter committed
305
306
  return (data[KEY_SUCCESS], data[KEY_RESULT],
          data.get(KEY_VERSION, None)) # pylint: disable-msg=E1103
307
308


309
def FormatResponse(success, result, version=None):
310
311
312
313
314
315
316
317
  """Formats a LUXI response message.

  """
  response = {
    KEY_SUCCESS: success,
    KEY_RESULT: result,
    }

318
319
320
  if version is not None:
    response[KEY_VERSION] = version

321
322
323
324
325
  logging.debug("LUXI response: %s", response)

  return serializer.DumpJson(response)


326
def FormatRequest(method, args, version=None):
327
328
329
330
331
332
333
334
335
  """Formats a LUXI request message.

  """
  # Build request
  request = {
    KEY_METHOD: method,
    KEY_ARGS: args,
    }

336
337
338
  if version is not None:
    request[KEY_VERSION] = version

339
340
341
342
  # Serialize the request
  return serializer.DumpJson(request, indent=False)


343
def CallLuxiMethod(transport_cb, method, args, version=None):
344
345
346
347
348
  """Send a LUXI request via a transport and return the response.

  """
  assert callable(transport_cb)

349
  request_msg = FormatRequest(method, args, version=version)
350
351
352
353

  # Send request and wait for response
  response_msg = transport_cb(request_msg)

354
355
356
357
358
359
  (success, result, resp_version) = ParseResponse(response_msg)

  # Verify version if there was one in the response
  if resp_version is not None and resp_version != version:
    raise errors.LuxiError("LUXI version mismatch, client %s, response %s" %
                           (version, resp_version))
360
361
362
363
364
365
366
367

  if success:
    return result

  errors.MaybeRaise(result)
  raise RequestError(result)


368
369
370
371
372
373
374
class Client(object):
  """High-level client implementation.

  This uses a backing Transport-like class on top of which it
  implements data serialization/deserialization.

  """
Iustin Pop's avatar
Iustin Pop committed
375
  def __init__(self, address=None, timeouts=None, transport=Transport):
376
377
378
379
380
381
382
383
384
385
386
387
    """Constructor for the Client class.

    Arguments:
      - address: a valid address the the used transport class
      - timeout: a list of timeouts, to be used on connect and read/write
      - transport: a Transport-like class


    If timeout is not passed, the default timeouts of the transport
    class are used.

    """
Iustin Pop's avatar
Iustin Pop committed
388
389
    if address is None:
      address = constants.MASTER_SOCKET
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
    self.address = address
    self.timeouts = timeouts
    self.transport_class = transport
    self.transport = None
    self._InitTransport()

  def _InitTransport(self):
    """(Re)initialize the transport if needed.

    """
    if self.transport is None:
      self.transport = self.transport_class(self.address,
                                            timeouts=self.timeouts)

  def _CloseTransport(self):
    """Close the transport, ignoring errors.

    """
    if self.transport is None:
      return
    try:
      old_transp = self.transport
      self.transport = None
      old_transp.Close()
Iustin Pop's avatar
Iustin Pop committed
414
    except Exception: # pylint: disable-msg=W0703
415
      pass
416

417
  def _SendMethodCall(self, data):
418
    # Send request and wait for response
419
420
    try:
      self._InitTransport()
421
      return self.transport.Call(data)
422
423
424
425
    except Exception:
      self._CloseTransport()
      raise

426
427
  def CallMethod(self, method, args):
    """Send a generic request and return the response.
428

429
    """
430
431
    return CallLuxiMethod(self._SendMethodCall, method, args,
                          version=constants.LUXI_VERSION)
432

433
434
435
  def SetQueueDrainFlag(self, drain_flag):
    return self.CallMethod(REQ_QUEUE_SET_DRAIN_FLAG, drain_flag)

436
437
438
  def SetWatcherPause(self, until):
    return self.CallMethod(REQ_SET_WATCHER_PAUSE, [until])

439
440
441
442
  def SubmitJob(self, ops):
    ops_state = map(lambda op: op.__getstate__(), ops)
    return self.CallMethod(REQ_SUBMIT_JOB, ops_state)

443
444
445
446
447
448
  def SubmitManyJobs(self, jobs):
    jobs_state = []
    for ops in jobs:
      jobs_state.append([op.__getstate__() for op in ops])
    return self.CallMethod(REQ_SUBMIT_MANY_JOBS, jobs_state)

449
450
451
452
453
454
  def CancelJob(self, job_id):
    return self.CallMethod(REQ_CANCEL_JOB, job_id)

  def ArchiveJob(self, job_id):
    return self.CallMethod(REQ_ARCHIVE_JOB, job_id)

Iustin Pop's avatar
Iustin Pop committed
455
  def AutoArchiveJobs(self, age):
456
457
    timeout = (DEF_RWTO - 1) / 2
    return self.CallMethod(REQ_AUTOARCHIVE_JOBS, (age, timeout))
Iustin Pop's avatar
Iustin Pop committed
458

459
  def WaitForJobChangeOnce(self, job_id, fields,
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
                           prev_job_info, prev_log_serial,
                           timeout=WFJC_TIMEOUT):
    """Waits for changes on a job.

    @param job_id: Job ID
    @type fields: list
    @param fields: List of field names to be observed
    @type prev_job_info: None or list
    @param prev_job_info: Previously received job information
    @type prev_log_serial: None or int/long
    @param prev_log_serial: Highest log serial number previously received
    @type timeout: int/float
    @param timeout: Timeout in seconds (values larger than L{WFJC_TIMEOUT} will
                    be capped to that value)

    """
    assert timeout >= 0, "Timeout can not be negative"
477
478
    return self.CallMethod(REQ_WAIT_FOR_JOB_CHANGE,
                           (job_id, fields, prev_job_info,
479
480
                            prev_log_serial,
                            min(WFJC_TIMEOUT, timeout)))
481
482

  def WaitForJobChange(self, job_id, fields, prev_job_info, prev_log_serial):
483
    while True:
484
485
      result = self.WaitForJobChangeOnce(job_id, fields,
                                         prev_job_info, prev_log_serial)
486
487
488
      if result != constants.JOB_NOTCHANGED:
        break
    return result
489

490
491
  def QueryJobs(self, job_ids, fields):
    return self.CallMethod(REQ_QUERY_JOBS, (job_ids, fields))
492

493
494
  def QueryInstances(self, names, fields, use_locking):
    return self.CallMethod(REQ_QUERY_INSTANCES, (names, fields, use_locking))
495

496
497
  def QueryNodes(self, names, fields, use_locking):
    return self.CallMethod(REQ_QUERY_NODES, (names, fields, use_locking))
Michael Hanselmann's avatar
Michael Hanselmann committed
498

499
500
501
  def QueryGroups(self, names, fields, use_locking):
    return self.CallMethod(REQ_QUERY_GROUPS, (names, fields, use_locking))

502
503
  def QueryExports(self, nodes, use_locking):
    return self.CallMethod(REQ_QUERY_EXPORTS, (nodes, use_locking))
504

505
506
507
  def QueryClusterInfo(self):
    return self.CallMethod(REQ_QUERY_CLUSTER_INFO, ())

508
509
510
  def QueryConfigValues(self, fields):
    return self.CallMethod(REQ_QUERY_CONFIG_VALUES, fields)

Iustin Pop's avatar
Iustin Pop committed
511
512
  def QueryTags(self, kind, name):
    return self.CallMethod(REQ_QUERY_TAGS, (kind, name))
Michael Hanselmann's avatar
Michael Hanselmann committed
513
514
515

  def QueryLocks(self, fields, sync):
    return self.CallMethod(REQ_QUERY_LOCKS, (fields, sync))