summaryrefslogtreecommitdiff
path: root/nova/virt/xenapi/fake.py
blob: eabe139aec797d1341a0c0ee285057e0decd7d21 (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
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
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
#    Copyright (c) 2010 Citrix Systems, Inc.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.
#
#============================================================================
#
# Parts of this file are based upon xmlrpclib.py, the XML-RPC client
# interface included in the Python distribution.
#
# Copyright (c) 1999-2002 by Secret Labs AB
# Copyright (c) 1999-2002 by Fredrik Lundh
#
# By obtaining, using, and/or copying this software and/or its
# associated documentation, you agree that you have read, understood,
# and will comply with the following terms and conditions:
#
# Permission to use, copy, modify, and distribute this software and
# its associated documentation for any purpose and without fee is
# hereby granted, provided that the above copyright notice appears in
# all copies, and that both that copyright notice and this permission
# notice appear in supporting documentation, and that the name of
# Secret Labs AB or the author not be used in advertising or publicity
# pertaining to distribution of the software without specific, written
# prior permission.
#
# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
# ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
# OF THIS SOFTWARE.
# --------------------------------------------------------------------


"""
A fake XenAPI SDK.
"""

import base64
import pickle
import pprint
import random
import uuid
from xml.sax import saxutils
import zlib

from nova import exception
from nova.openstack.common.gettextutils import _
from nova.openstack.common import jsonutils
from nova.openstack.common import log as logging
from nova.openstack.common import timeutils
from nova.openstack.common import units
from nova.virt.xenapi.client import session as xenapi_session


_CLASSES = ['host', 'network', 'session', 'pool', 'SR', 'VBD',
            'PBD', 'VDI', 'VIF', 'PIF', 'VM', 'VLAN', 'task']

_db_content = {}

LOG = logging.getLogger(__name__)


def log_db_contents(msg=None):
    text = msg or ""
    content = pprint.pformat(_db_content)
    LOG.debug("%(text)s: _db_content => %(content)s",
              {'text': text, 'content': content})


def reset():
    for c in _CLASSES:
        _db_content[c] = {}
    host = create_host('fake')
    create_vm('fake dom 0',
              'Running',
              is_a_template=False,
              is_control_domain=True,
              resident_on=host)


def reset_table(table):
    if table not in _CLASSES:
        return
    _db_content[table] = {}


def _create_pool(name_label):
    return _create_object('pool',
                          {'name_label': name_label})


def create_host(name_label, hostname='fake_name', address='fake_addr'):
    host_ref = _create_object('host',
                               {'name_label': name_label,
                                'hostname': hostname,
                                'address': address})
    host_default_sr_ref = _create_local_srs(host_ref)
    _create_local_pif(host_ref)

    # Create a pool if we don't have one already
    if len(_db_content['pool']) == 0:
        pool_ref = _create_pool('')
        _db_content['pool'][pool_ref]['master'] = host_ref
        _db_content['pool'][pool_ref]['default-SR'] = host_default_sr_ref
        _db_content['pool'][pool_ref]['suspend-image-SR'] = host_default_sr_ref


def create_network(name_label, bridge):
    return _create_object('network',
                          {'name_label': name_label,
                           'bridge': bridge})


def create_vm(name_label, status, **kwargs):
    if status == 'Running':
        domid = random.randrange(1, 1 << 16)
        resident_on = _db_content['host'].keys()[0]
    else:
        domid = -1
        resident_on = ''

    vm_rec = kwargs.copy()
    vm_rec.update({'name_label': name_label,
                   'domid': domid,
                   'power_state': status,
                   'blocked_operations': {},
                   'resident_on': resident_on})
    vm_ref = _create_object('VM', vm_rec)
    after_VM_create(vm_ref, vm_rec)
    return vm_ref


def destroy_vm(vm_ref):
    vm_rec = _db_content['VM'][vm_ref]

    vbd_refs = vm_rec['VBDs']
    # NOTE(johannes): Shallow copy since destroy_vbd will remove itself
    # from the list
    for vbd_ref in vbd_refs[:]:
        destroy_vbd(vbd_ref)

    del _db_content['VM'][vm_ref]


def destroy_vbd(vbd_ref):
    vbd_rec = _db_content['VBD'][vbd_ref]

    vm_ref = vbd_rec['VM']
    vm_rec = _db_content['VM'][vm_ref]
    vm_rec['VBDs'].remove(vbd_ref)

    vdi_ref = vbd_rec['VDI']
    vdi_rec = _db_content['VDI'][vdi_ref]
    vdi_rec['VBDs'].remove(vbd_ref)

    del _db_content['VBD'][vbd_ref]


def destroy_vdi(vdi_ref):
    vdi_rec = _db_content['VDI'][vdi_ref]

    vbd_refs = vdi_rec['VBDs']
    # NOTE(johannes): Shallow copy since destroy_vbd will remove itself
    # from the list
    for vbd_ref in vbd_refs[:]:
        destroy_vbd(vbd_ref)

    del _db_content['VDI'][vdi_ref]


def create_vdi(name_label, sr_ref, **kwargs):
    vdi_rec = {
        'SR': sr_ref,
        'read_only': False,
        'type': '',
        'name_label': name_label,
        'name_description': '',
        'sharable': False,
        'other_config': {},
        'location': '',
        'xenstore_data': {},
        'sm_config': {'vhd-parent': None},
        'physical_utilisation': '123',
        'managed': True,
    }
    vdi_rec.update(kwargs)
    vdi_ref = _create_object('VDI', vdi_rec)
    after_VDI_create(vdi_ref, vdi_rec)
    return vdi_ref


def after_VDI_create(vdi_ref, vdi_rec):
    vdi_rec.setdefault('VBDs', [])


def create_vbd(vm_ref, vdi_ref, userdevice=0):
    vbd_rec = {'VM': vm_ref,
               'VDI': vdi_ref,
               'userdevice': str(userdevice),
               'currently_attached': False}
    vbd_ref = _create_object('VBD', vbd_rec)
    after_VBD_create(vbd_ref, vbd_rec)
    return vbd_ref


def after_VBD_create(vbd_ref, vbd_rec):
    """Create read-only fields and backref from VM and VDI to VBD when VBD
    is created.
    """
    vbd_rec['currently_attached'] = False
    vbd_rec['device'] = ''

    vm_ref = vbd_rec['VM']
    vm_rec = _db_content['VM'][vm_ref]
    vm_rec['VBDs'].append(vbd_ref)

    vm_name_label = _db_content['VM'][vm_ref]['name_label']
    vbd_rec['vm_name_label'] = vm_name_label

    vdi_ref = vbd_rec['VDI']
    if vdi_ref and vdi_ref != "OpaqueRef:NULL":
        vdi_rec = _db_content['VDI'][vdi_ref]
        vdi_rec['VBDs'].append(vbd_ref)


def after_VM_create(vm_ref, vm_rec):
    """Create read-only fields in the VM record."""
    vm_rec.setdefault('domid', -1)
    vm_rec.setdefault('is_control_domain', False)
    vm_rec.setdefault('is_a_template', False)
    vm_rec.setdefault('memory_static_max', str(8 * units.Gi))
    vm_rec.setdefault('memory_dynamic_max', str(8 * units.Gi))
    vm_rec.setdefault('VCPUs_max', str(4))
    vm_rec.setdefault('VBDs', [])
    vm_rec.setdefault('resident_on', '')


def create_pbd(host_ref, sr_ref, attached):
    config = {'path': '/var/run/sr-mount/%s' % sr_ref}
    return _create_object('PBD',
                          {'device_config': config,
                           'host': host_ref,
                           'SR': sr_ref,
                           'currently_attached': attached})


def create_task(name_label):
    return _create_object('task',
                          {'name_label': name_label,
                           'status': 'pending'})


def _create_local_srs(host_ref):
    """Create an SR that looks like the one created on the local disk by
    default by the XenServer installer.  Also, fake the installation of
    an ISO SR.
    """
    create_sr(name_label='Local storage ISO',
              type='iso',
              other_config={'i18n-original-value-name_label':
                            'Local storage ISO',
                            'i18n-key': 'local-storage-iso'},
              physical_size=80000,
              physical_utilisation=40000,
              virtual_allocation=80000,
              host_ref=host_ref)
    return create_sr(name_label='Local storage',
                     type='ext',
                     other_config={'i18n-original-value-name_label':
                                   'Local storage',
                                   'i18n-key': 'local-storage'},
                     physical_size=40000,
                     physical_utilisation=20000,
                     virtual_allocation=10000,
                     host_ref=host_ref)


def create_sr(**kwargs):
    sr_ref = _create_object(
             'SR',
             {'name_label': kwargs.get('name_label'),
              'type': kwargs.get('type'),
              'content_type': kwargs.get('type', 'user'),
              'shared': kwargs.get('shared', False),
              'physical_size': kwargs.get('physical_size', str(1 << 30)),
              'physical_utilisation': str(
                                        kwargs.get('physical_utilisation', 0)),
              'virtual_allocation': str(kwargs.get('virtual_allocation', 0)),
              'other_config': kwargs.get('other_config', {}),
              'VDIs': kwargs.get('VDIs', [])})
    pbd_ref = create_pbd(kwargs.get('host_ref'), sr_ref, True)
    _db_content['SR'][sr_ref]['PBDs'] = [pbd_ref]
    return sr_ref


def _create_local_pif(host_ref):
    pif_ref = _create_object('PIF',
                             {'name-label': 'Fake PIF',
                              'MAC': '00:11:22:33:44:55',
                              'physical': True,
                              'VLAN': -1,
                              'device': 'fake0',
                              'host_uuid': host_ref,
                              'network': '',
                              'IP': '10.1.1.1',
                              'IPv6': '',
                              'uuid': '',
                              'management': 'true'})
    _db_content['PIF'][pif_ref]['uuid'] = pif_ref
    return pif_ref


def _create_object(table, obj):
    ref = str(uuid.uuid4())
    obj['uuid'] = str(uuid.uuid4())
    _db_content[table][ref] = obj
    return ref


def _create_sr(table, obj):
    sr_type = obj[6]
    # Forces fake to support iscsi only
    if sr_type != 'iscsi' and sr_type != 'nfs':
        raise Failure(['SR_UNKNOWN_DRIVER', sr_type])
    host_ref = _db_content['host'].keys()[0]
    sr_ref = _create_object(table, obj[2])
    if sr_type == 'iscsi':
        vdi_ref = create_vdi('', sr_ref)
        pbd_ref = create_pbd(host_ref, sr_ref, True)
        _db_content['SR'][sr_ref]['VDIs'] = [vdi_ref]
        _db_content['SR'][sr_ref]['PBDs'] = [pbd_ref]
        _db_content['VDI'][vdi_ref]['SR'] = sr_ref
        _db_content['PBD'][pbd_ref]['SR'] = sr_ref
    return sr_ref


def _create_vlan(pif_ref, vlan_num, network_ref):
    pif_rec = get_record('PIF', pif_ref)
    vlan_pif_ref = _create_object('PIF',
                                  {'name-label': 'Fake VLAN PIF',
                                   'MAC': '00:11:22:33:44:55',
                                   'physical': True,
                                   'VLAN': vlan_num,
                                   'device': pif_rec['device'],
                                   'host_uuid': pif_rec['host_uuid']})
    return _create_object('VLAN',
                          {'tagged-pif': pif_ref,
                           'untagged-pif': vlan_pif_ref,
                           'tag': vlan_num})


def get_all(table):
    return _db_content[table].keys()


def get_all_records(table):
    return _db_content[table]


def _query_matches(record, query):
    # Simple support for the XenServer query language:
    # 'field "host"="<uuid>" and field "SR"="<sr uuid>"'
    # Tested through existing tests (e.g. calls to find_network_with_bridge)

    and_clauses = query.split(" and ")
    if len(and_clauses) > 1:
        matches = True
        for clause in and_clauses:
            matches = matches and _query_matches(record, clause)
        return matches

    or_clauses = query.split(" or ")
    if len(or_clauses) > 1:
        matches = False
        for clause in or_clauses:
            matches = matches or _query_matches(record, clause)
        return matches

    if query[:4] == 'not ':
        return not _query_matches(record, query[4:])

    # Now it must be a single field - bad queries never match
    if query[:5] != 'field':
        return False
    (field, value) = query[6:].split('=', 1)

    # Some fields (e.g. name_label, memory_overhead) have double
    # underscores in the DB, but only single underscores when querying

    field = field.replace("__", "_").strip(" \"'")
    value = value.strip(" \"'")

    # Strings should be directly compared
    if isinstance(record[field], str):
        return record[field] == value

    # But for all other value-checks, convert to a string first
    # (Notably used for booleans - which can be lower or camel
    # case and are interpreted/sanitised by XAPI)
    return str(record[field]).lower() == value.lower()


def get_all_records_where(table_name, query):
    matching_records = {}
    table = _db_content[table_name]
    for record in table:
        if _query_matches(table[record], query):
            matching_records[record] = table[record]
    return matching_records


def get_record(table, ref):
    if ref in _db_content[table]:
        return _db_content[table].get(ref)
    else:
        raise Failure(['HANDLE_INVALID', table, ref])


def check_for_session_leaks():
    if len(_db_content['session']) > 0:
        raise exception.NovaException('Sessions have leaked: %s' %
                              _db_content['session'])


def as_value(s):
    """Helper function for simulating XenAPI plugin responses.  It
    escapes and wraps the given argument.
    """
    return '<value>%s</value>' % saxutils.escape(s)


def as_json(*args, **kwargs):
    """Helper function for simulating XenAPI plugin responses for those
    that are returning JSON.  If this function is given plain arguments,
    then these are rendered as a JSON list.  If it's given keyword
    arguments then these are rendered as a JSON dict.
    """
    arg = args or kwargs
    return jsonutils.dumps(arg)


class Failure(Exception):
    def __init__(self, details):
        self.details = details

    def __str__(self):
        try:
            return str(self.details)
        except Exception:
            return "XenAPI Fake Failure: %s" % str(self.details)

    def _details_map(self):
        return dict([(str(i), self.details[i])
                     for i in range(len(self.details))])


class SessionBase(object):
    """Base class for Fake Sessions."""

    def __init__(self, uri):
        self._session = None
        xenapi_session.apply_session_helpers(self)

    def pool_get_default_SR(self, _1, pool_ref):
        return _db_content['pool'].values()[0]['default-SR']

    def VBD_insert(self, _1, vbd_ref, vdi_ref):
        vbd_rec = get_record('VBD', vbd_ref)
        get_record('VDI', vdi_ref)
        vbd_rec['empty'] = False
        vbd_rec['VDI'] = vdi_ref

    def VBD_plug(self, _1, ref):
        rec = get_record('VBD', ref)
        if rec['currently_attached']:
            raise Failure(['DEVICE_ALREADY_ATTACHED', ref])
        rec['currently_attached'] = True
        rec['device'] = rec['userdevice']

    def VBD_unplug(self, _1, ref):
        rec = get_record('VBD', ref)
        if not rec['currently_attached']:
            raise Failure(['DEVICE_ALREADY_DETACHED', ref])
        rec['currently_attached'] = False
        rec['device'] = ''

    def VBD_add_to_other_config(self, _1, vbd_ref, key, value):
        db_ref = _db_content['VBD'][vbd_ref]
        if 'other_config' not in db_ref:
            db_ref['other_config'] = {}
        if key in db_ref['other_config']:
            raise Failure(['MAP_DUPLICATE_KEY', 'VBD', 'other_config',
                           vbd_ref, key])
        db_ref['other_config'][key] = value

    def VBD_get_other_config(self, _1, vbd_ref):
        db_ref = _db_content['VBD'][vbd_ref]
        if 'other_config' not in db_ref:
            return {}
        return db_ref['other_config']

    def PBD_create(self, _1, pbd_rec):
        pbd_ref = _create_object('PBD', pbd_rec)
        _db_content['PBD'][pbd_ref]['currently_attached'] = False
        return pbd_ref

    def PBD_plug(self, _1, pbd_ref):
        rec = get_record('PBD', pbd_ref)
        if rec['currently_attached']:
            raise Failure(['DEVICE_ALREADY_ATTACHED', rec])
        rec['currently_attached'] = True
        sr_ref = rec['SR']
        _db_content['SR'][sr_ref]['PBDs'] = [pbd_ref]

    def PBD_unplug(self, _1, pbd_ref):
        rec = get_record('PBD', pbd_ref)
        if not rec['currently_attached']:
            raise Failure(['DEVICE_ALREADY_DETACHED', rec])
        rec['currently_attached'] = False
        sr_ref = rec['SR']
        _db_content['SR'][sr_ref]['PBDs'].remove(pbd_ref)

    def SR_introduce(self, _1, sr_uuid, label, desc, type, content_type,
                     shared, sm_config):
        ref = None
        rec = None
        for ref, rec in _db_content['SR'].iteritems():
            if rec.get('uuid') == sr_uuid:
                # make forgotten = 0 and return ref
                _db_content['SR'][ref]['forgotten'] = 0
                return ref
        # SR not found in db, so we create one
        params = {'sr_uuid': sr_uuid,
                  'label': label,
                  'desc': desc,
                  'type': type,
                  'content_type': content_type,
                  'shared': shared,
                  'sm_config': sm_config}
        sr_ref = _create_object('SR', params)
        _db_content['SR'][sr_ref]['uuid'] = sr_uuid
        _db_content['SR'][sr_ref]['forgotten'] = 0
        vdi_per_lun = False
        if type == 'iscsi':
            # Just to be clear
            vdi_per_lun = True
        if vdi_per_lun:
            # we need to create a vdi because this introduce
            # is likely meant for a single vdi
            vdi_ref = create_vdi('', sr_ref)
            _db_content['SR'][sr_ref]['VDIs'] = [vdi_ref]
            _db_content['VDI'][vdi_ref]['SR'] = sr_ref
        return sr_ref

    def SR_forget(self, _1, sr_ref):
        _db_content['SR'][sr_ref]['forgotten'] = 1

    def SR_scan(self, _1, sr_ref):
        return

    def VM_get_xenstore_data(self, _1, vm_ref):
        return _db_content['VM'][vm_ref].get('xenstore_data', {})

    def VM_remove_from_xenstore_data(self, _1, vm_ref, key):
        db_ref = _db_content['VM'][vm_ref]
        if 'xenstore_data' not in db_ref:
            return
        if key in db_ref['xenstore_data']:
            del db_ref['xenstore_data'][key]

    def VM_add_to_xenstore_data(self, _1, vm_ref, key, value):
        db_ref = _db_content['VM'][vm_ref]
        if 'xenstore_data' not in db_ref:
            db_ref['xenstore_data'] = {}
        db_ref['xenstore_data'][key] = value

    def VM_pool_migrate(self, _1, vm_ref, host_ref, options):
        pass

    def VDI_remove_from_other_config(self, _1, vdi_ref, key):
        db_ref = _db_content['VDI'][vdi_ref]
        if 'other_config' not in db_ref:
            return
        if key in db_ref['other_config']:
            del db_ref['other_config'][key]

    def VDI_add_to_other_config(self, _1, vdi_ref, key, value):
        db_ref = _db_content['VDI'][vdi_ref]
        if 'other_config' not in db_ref:
            db_ref['other_config'] = {}
        if key in db_ref['other_config']:
            raise Failure(['MAP_DUPLICATE_KEY', 'VDI', 'other_config',
                           vdi_ref, key])
        db_ref['other_config'][key] = value

    def VDI_copy(self, _1, vdi_to_copy_ref, sr_ref):
        db_ref = _db_content['VDI'][vdi_to_copy_ref]
        name_label = db_ref['name_label']
        read_only = db_ref['read_only']
        sharable = db_ref['sharable']
        other_config = db_ref['other_config'].copy()
        return create_vdi(name_label, sr_ref, sharable=sharable,
                          read_only=read_only, other_config=other_config)

    def VDI_clone(self, _1, vdi_to_clone_ref):
        db_ref = _db_content['VDI'][vdi_to_clone_ref]
        sr_ref = db_ref['SR']
        return self.VDI_copy(_1, vdi_to_clone_ref, sr_ref)

    def host_compute_free_memory(self, _1, ref):
        #Always return 12GB available
        return 12 * units.Gi

    def _plugin_agent_version(self, method, args):
        return as_json(returncode='0', message='1.0\\r\\n')

    def _plugin_agent_key_init(self, method, args):
        return as_json(returncode='D0', message='1')

    def _plugin_agent_password(self, method, args):
        return as_json(returncode='0', message='success')

    def _plugin_agent_inject_file(self, method, args):
        return as_json(returncode='0', message='success')

    def _plugin_agent_resetnetwork(self, method, args):
        return as_json(returncode='0', message='success')

    def _plugin_agent_agentupdate(self, method, args):
        url = args["url"]
        md5 = args["md5sum"]
        message = "success with %(url)s and hash:%(md5)s" % dict(url=url,
                                                                 md5=md5)
        return as_json(returncode='0', message=message)

    def _plugin_noop(self, method, args):
        return ''

    def _plugin_pickle_noop(self, method, args):
        return pickle.dumps(None)

    def _plugin_migration_transfer_vhd(self, method, args):
        kwargs = pickle.loads(args['params'])['kwargs']
        vdi_ref = self.xenapi_request('VDI.get_by_uuid',
                (kwargs['vdi_uuid'], ))
        assert vdi_ref
        return pickle.dumps(None)

    _plugin_glance_upload_vhd = _plugin_pickle_noop
    _plugin_kernel_copy_vdi = _plugin_noop
    _plugin_kernel_create_kernel_ramdisk = _plugin_noop
    _plugin_kernel_remove_kernel_ramdisk = _plugin_noop
    _plugin_migration_move_vhds_into_sr = _plugin_noop

    def _plugin_xenhost_host_data(self, method, args):
            return jsonutils.dumps({'host_memory': {'total': 10,
                                                    'overhead': 20,
                                                    'free': 30,
                                                    'free-computed': 40},
                                    'host_hostname': 'fake-xenhost',
                                    'host_cpu_info': {'cpu_count': 50},
                                    })

    def _plugin_poweraction(self, method, args):
        return jsonutils.dumps({"power_action": method[5:]})

    _plugin_xenhost_host_reboot = _plugin_poweraction
    _plugin_xenhost_host_startup = _plugin_poweraction
    _plugin_xenhost_host_shutdown = _plugin_poweraction

    def _plugin_xenhost_set_host_enabled(self, method, args):
        enabled = 'enabled' if args.get('enabled') == 'true' else 'disabled'
        return jsonutils.dumps({"status": enabled})

    def _plugin_xenhost_host_uptime(self, method, args):
        return jsonutils.dumps({"uptime": "fake uptime"})

    def _plugin_xenhost_get_pci_device_details(self, method, args):
        """Simulate the ouput of three pci devices.

        Both of those devices are available for pci passtrough but
        only one will match with the pci whitelist used in the
        method test_pci_passthrough_devices_*().
        Return a single list.

        """
        # Driver is not pciback
        dev_bad1 = ["Slot:\t86:10.0", "Class:\t0604", "Vendor:\t10b5",
                    "Device:\t8747", "Rev:\tba", "Driver:\tpcieport", "\n"]
        # Driver is pciback but vendor and device are bad
        dev_bad2 = ["Slot:\t88:00.0", "Class:\t0300", "Vendor:\t0bad",
                    "Device:\tcafe", "SVendor:\t10de", "SDevice:\t100d",
                    "Rev:\ta1", "Driver:\tpciback", "\n"]
        # Driver is pciback and vendor, device are used for matching
        dev_good = ["Slot:\t87:00.0", "Class:\t0300", "Vendor:\t10de",
                    "Device:\t11bf", "SVendor:\t10de", "SDevice:\t100d",
                    "Rev:\ta1", "Driver:\tpciback", "\n"]

        lspci_output = "\n".join(dev_bad1 + dev_bad2 + dev_good)
        return pickle.dumps(lspci_output)

    def _plugin_xenhost_get_pci_type(self, method, args):
        return pickle.dumps("type-PCI")

    def _plugin_console_get_console_log(self, method, args):
        dom_id = args["dom_id"]
        if dom_id == 0:
            raise Failure('Guest does not have a console')
        return base64.b64encode(zlib.compress("dom_id: %s" % dom_id))

    def _plugin_nova_plugin_version_get_version(self, method, args):
        return pickle.dumps("1.2")

    def _plugin_xenhost_query_gc(self, method, args):
        return pickle.dumps("False")

    def host_call_plugin(self, _1, _2, plugin, method, args):
        func = getattr(self, '_plugin_%s_%s' % (plugin, method), None)
        if not func:
            raise Exception('No simulation in host_call_plugin for %s,%s' %
                            (plugin, method))

        return func(method, args)

    def VDI_get_virtual_size(self, *args):
        return 1 * units.Gi

    def VDI_resize_online(self, *args):
        return 'derp'

    VDI_resize = VDI_resize_online

    def _VM_reboot(self, session, vm_ref):
        db_ref = _db_content['VM'][vm_ref]
        if db_ref['power_state'] != 'Running':
            raise Failure(['VM_BAD_POWER_STATE',
                'fake-opaque-ref', db_ref['power_state'].lower(), 'halted'])
        db_ref['power_state'] = 'Running'
        db_ref['domid'] = random.randrange(1, 1 << 16)

    def VM_clean_reboot(self, session, vm_ref):
        return self._VM_reboot(session, vm_ref)

    def VM_hard_reboot(self, session, vm_ref):
        return self._VM_reboot(session, vm_ref)

    def VM_hard_shutdown(self, session, vm_ref):
        db_ref = _db_content['VM'][vm_ref]
        db_ref['power_state'] = 'Halted'
        db_ref['domid'] = -1
    VM_clean_shutdown = VM_hard_shutdown

    def VM_suspend(self, session, vm_ref):
        db_ref = _db_content['VM'][vm_ref]
        db_ref['power_state'] = 'Suspended'

    def VM_pause(self, session, vm_ref):
        db_ref = _db_content['VM'][vm_ref]
        db_ref['power_state'] = 'Paused'

    def pool_eject(self, session, host_ref):
        pass

    def pool_join(self, session, hostname, username, password):
        pass

    def pool_set_name_label(self, session, pool_ref, name):
        pass

    def host_migrate_receive(self, session, destref, nwref, options):
        return "fake_migrate_data"

    def VM_assert_can_migrate(self, session, vmref, migrate_data, live,
                              vdi_map, vif_map, options):
        pass

    def VM_migrate_send(self, session, mref, migrate_data, live, vdi_map,
                        vif_map, options):
        pass

    def VM_remove_from_blocked_operations(self, session, vm_ref, key):
        # operation is idempotent, XenServer doesn't care if the key exists
        _db_content['VM'][vm_ref]['blocked_operations'].pop(key, None)

    def xenapi_request(self, methodname, params):
        if methodname.startswith('login'):
            self._login(methodname, params)
            return None
        elif methodname == 'logout' or methodname == 'session.logout':
            self._logout()
            return None
        else:
            full_params = (self._session,) + params
            meth = getattr(self, methodname, None)
            if meth is None:
                LOG.debug('Raising NotImplemented')
                raise NotImplementedError(
                    _('xenapi.fake does not have an implementation for %s') %
                    methodname)
            return meth(*full_params)

    def _login(self, method, params):
        self._session = str(uuid.uuid4())
        _session_info = {'uuid': str(uuid.uuid4()),
                         'this_host': _db_content['host'].keys()[0]}
        _db_content['session'][self._session] = _session_info

    def _logout(self):
        s = self._session
        self._session = None
        if s not in _db_content['session']:
            raise exception.NovaException(
                "Logging out a session that is invalid or already logged "
                "out: %s" % s)
        del _db_content['session'][s]

    def __getattr__(self, name):
        if name == 'handle':
            return self._session
        elif name == 'xenapi':
            return _Dispatcher(self.xenapi_request, None)
        elif name.startswith('login') or name.startswith('slave_local'):
            return lambda *params: self._login(name, params)
        elif name.startswith('Async'):
            return lambda *params: self._async(name, params)
        elif '.' in name:
            impl = getattr(self, name.replace('.', '_'))
            if impl is not None:

                def callit(*params):
                    LOG.debug('Calling %(name)s %(impl)s',
                              {'name': name, 'impl': impl})
                    self._check_session(params)
                    return impl(*params)
                return callit
        if self._is_gettersetter(name, True):
            LOG.debug('Calling getter %s', name)
            return lambda *params: self._getter(name, params)
        elif self._is_gettersetter(name, False):
            LOG.debug('Calling setter %s', name)
            return lambda *params: self._setter(name, params)
        elif self._is_create(name):
            return lambda *params: self._create(name, params)
        elif self._is_destroy(name):
            return lambda *params: self._destroy(name, params)
        elif name == 'XenAPI':
            return FakeXenAPI()
        else:
            return None

    def _is_gettersetter(self, name, getter):
        bits = name.split('.')
        return (len(bits) == 2 and
                bits[0] in _CLASSES and
                bits[1].startswith(getter and 'get_' or 'set_'))

    def _is_create(self, name):
        return self._is_method(name, 'create')

    def _is_destroy(self, name):
        return self._is_method(name, 'destroy')

    def _is_method(self, name, meth):
        bits = name.split('.')
        return (len(bits) == 2 and
                bits[0] in _CLASSES and
                bits[1] == meth)

    def _getter(self, name, params):
        self._check_session(params)
        (cls, func) = name.split('.')
        if func == 'get_all':
            self._check_arg_count(params, 1)
            return get_all(cls)

        if func == 'get_all_records':
            self._check_arg_count(params, 1)
            return get_all_records(cls)

        if func == 'get_all_records_where':
            self._check_arg_count(params, 2)
            return get_all_records_where(cls, params[1])

        if func == 'get_record':
            self._check_arg_count(params, 2)
            return get_record(cls, params[1])

        if func in ('get_by_name_label', 'get_by_uuid'):
            self._check_arg_count(params, 2)
            return_singleton = (func == 'get_by_uuid')
            return self._get_by_field(
                _db_content[cls], func[len('get_by_'):], params[1],
                return_singleton=return_singleton)

        if len(params) == 2:
            field = func[len('get_'):]
            ref = params[1]
            if (ref in _db_content[cls]):
                if (field in _db_content[cls][ref]):
                    return _db_content[cls][ref][field]
            else:
                raise Failure(['HANDLE_INVALID', cls, ref])

        LOG.debug('Raising NotImplemented')
        raise NotImplementedError(
            _('xenapi.fake does not have an implementation for %s or it has '
            'been called with the wrong number of arguments') % name)

    def _setter(self, name, params):
        self._check_session(params)
        (cls, func) = name.split('.')

        if len(params) == 3:
            field = func[len('set_'):]
            ref = params[1]
            val = params[2]

            if (ref in _db_content[cls] and
                    field in _db_content[cls][ref]):
                _db_content[cls][ref][field] = val
                return

        LOG.debug('Raising NotImplemented')
        raise NotImplementedError(
            'xenapi.fake does not have an implementation for %s or it has '
            'been called with the wrong number of arguments or the database '
            'is missing that field' % name)

    def _create(self, name, params):
        self._check_session(params)
        is_sr_create = name == 'SR.create'
        is_vlan_create = name == 'VLAN.create'
        # Storage Repositories have a different API
        expected = is_sr_create and 10 or is_vlan_create and 4 or 2
        self._check_arg_count(params, expected)
        (cls, _) = name.split('.')
        ref = (is_sr_create and
               _create_sr(cls, params) or
               is_vlan_create and
               _create_vlan(params[1], params[2], params[3]) or
               _create_object(cls, params[1]))

        # Call hook to provide any fixups needed (ex. creating backrefs)
        after_hook = 'after_%s_create' % cls
        if after_hook in globals():
            globals()[after_hook](ref, params[1])

        obj = get_record(cls, ref)

        # Add RO fields
        if cls == 'VM':
            obj['power_state'] = 'Halted'
        return ref

    def _destroy(self, name, params):
        self._check_session(params)
        self._check_arg_count(params, 2)
        table = name.split('.')[0]
        ref = params[1]
        if ref not in _db_content[table]:
            raise Failure(['HANDLE_INVALID', table, ref])

        # Call destroy function (if exists)
        destroy_func = globals().get('destroy_%s' % table.lower())
        if destroy_func:
            destroy_func(ref)
        else:
            del _db_content[table][ref]

    def _async(self, name, params):
        task_ref = create_task(name)
        task = _db_content['task'][task_ref]
        func = name[len('Async.'):]
        try:
            result = self.xenapi_request(func, params[1:])
            if result:
                result = as_value(result)
            task['result'] = result
            task['status'] = 'success'
        except Failure as exc:
            task['error_info'] = exc.details
            task['status'] = 'failed'
        task['finished'] = timeutils.utcnow()
        return task_ref

    def _check_session(self, params):
        if (self._session is None or
                self._session not in _db_content['session']):
            raise Failure(['HANDLE_INVALID', 'session', self._session])
        if len(params) == 0 or params[0] != self._session:
            LOG.debug('Raising NotImplemented')
            raise NotImplementedError('Call to XenAPI without using .xenapi')

    def _check_arg_count(self, params, expected):
        actual = len(params)
        if actual != expected:
            raise Failure(['MESSAGE_PARAMETER_COUNT_MISMATCH',
                                  expected, actual])

    def _get_by_field(self, recs, k, v, return_singleton):
        result = []
        for ref, rec in recs.iteritems():
            if rec.get(k) == v:
                result.append(ref)

        if return_singleton:
            try:
                return result[0]
            except IndexError:
                raise Failure(['UUID_INVALID', v, result, recs, k])

        return result


class FakeXenAPI(object):
    def __init__(self):
        self.Failure = Failure


# Based upon _Method from xmlrpclib.
class _Dispatcher:
    def __init__(self, send, name):
        self.__send = send
        self.__name = name

    def __repr__(self):
        if self.__name:
            return '<xenapi.fake._Dispatcher for %s>' % self.__name
        else:
            return '<xenapi.fake._Dispatcher>'

    def __getattr__(self, name):
        if self.__name is None:
            return _Dispatcher(self.__send, name)
        else:
            return _Dispatcher(self.__send, "%s.%s" % (self.__name, name))

    def __call__(self, *args):
        return self.__send(self.__name, args)