-
Notifications
You must be signed in to change notification settings - Fork 1
/
store.go
788 lines (707 loc) · 24.7 KB
/
store.go
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
/*
Copyright 2016 The Kubernetes Authors.
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.
*/
package etcd3
import (
"bytes"
"context"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"path"
"reflect"
"strings"
"time"
"github.com/coreos/etcd/clientv3"
"k8s.io/klog"
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/conversion"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/watch"
"k8s.io/apiserver/pkg/storage"
"k8s.io/apiserver/pkg/storage/etcd"
"k8s.io/apiserver/pkg/storage/value"
utiltrace "k8s.io/utils/trace"
)
// authenticatedDataString satisfies the value.Context interface. It uses the key to
// authenticate the stored data. This does not defend against reuse of previously
// encrypted values under the same key, but will prevent an attacker from using an
// encrypted value from a different key. A stronger authenticated data segment would
// include the etcd3 Version field (which is incremented on each write to a key and
// reset when the key is deleted), but an attacker with write access to etcd can
// force deletion and recreation of keys to weaken that angle.
type authenticatedDataString string
// AuthenticatedData implements the value.Context interface.
func (d authenticatedDataString) AuthenticatedData() []byte {
return []byte(string(d))
}
var _ value.Context = authenticatedDataString("")
type store struct {
client *clientv3.Client
// getOpts contains additional options that should be passed
// to all Get() calls.
getOps []clientv3.OpOption
codec runtime.Codec
versioner storage.Versioner
transformer value.Transformer
pathPrefix string
watcher *watcher
pagingEnabled bool
leaseManager *leaseManager
}
type objState struct {
obj runtime.Object
meta *storage.ResponseMeta
rev int64
data []byte
stale bool
}
// New returns an etcd3 implementation of storage.Interface.
func New(c *clientv3.Client, codec runtime.Codec, prefix string, transformer value.Transformer, pagingEnabled bool) storage.Interface {
return newStore(c, pagingEnabled, codec, prefix, transformer)
}
func newStore(c *clientv3.Client, pagingEnabled bool, codec runtime.Codec, prefix string, transformer value.Transformer) *store {
versioner := etcd.APIObjectVersioner{}
result := &store{
client: c,
codec: codec,
versioner: versioner,
transformer: transformer,
pagingEnabled: pagingEnabled,
// for compatibility with etcd2 impl.
// no-op for default prefix of '/registry'.
// keeps compatibility with etcd2 impl for custom prefixes that don't start with '/'
pathPrefix: path.Join("/", prefix),
watcher: newWatcher(c, codec, versioner, transformer),
leaseManager: newDefaultLeaseManager(c),
}
return result
}
// Versioner implements storage.Interface.Versioner.
func (s *store) Versioner() storage.Versioner {
return s.versioner
}
// Get implements storage.Interface.Get.
func (s *store) Get(ctx context.Context, key string, resourceVersion string, out runtime.Object, ignoreNotFound bool) error {
key = path.Join(s.pathPrefix, key)
getResp, err := s.client.KV.Get(ctx, key, s.getOps...)
if err != nil {
return err
}
if len(getResp.Kvs) == 0 {
if ignoreNotFound {
return runtime.SetZeroValue(out)
}
return storage.NewKeyNotFoundError(key, 0)
}
kv := getResp.Kvs[0]
data, _, err := s.transformer.TransformFromStorage(kv.Value, authenticatedDataString(key))
if err != nil {
return storage.NewInternalError(err.Error())
}
return decode(s.codec, s.versioner, data, out, kv.ModRevision)
}
// Create implements storage.Interface.Create.
func (s *store) Create(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error {
if version, err := s.versioner.ObjectResourceVersion(obj); err == nil && version != 0 {
return errors.New("resourceVersion should not be set on objects to be created")
}
if err := s.versioner.PrepareObjectForStorage(obj); err != nil {
return fmt.Errorf("PrepareObjectForStorage failed: %v", err)
}
data, err := runtime.Encode(s.codec, obj)
if err != nil {
return err
}
key = path.Join(s.pathPrefix, key)
opts, err := s.ttlOpts(ctx, int64(ttl))
if err != nil {
return err
}
newData, err := s.transformer.TransformToStorage(data, authenticatedDataString(key))
if err != nil {
return storage.NewInternalError(err.Error())
}
txnResp, err := s.client.KV.Txn(ctx).If(
notFound(key),
).Then(
clientv3.OpPut(key, string(newData), opts...),
).Commit()
if err != nil {
return err
}
if !txnResp.Succeeded {
return storage.NewKeyExistsError(key, 0)
}
if out != nil {
putResp := txnResp.Responses[0].GetResponsePut()
return decode(s.codec, s.versioner, data, out, putResp.Header.Revision)
}
return nil
}
// Delete implements storage.Interface.Delete.
func (s *store) Delete(ctx context.Context, key string, out runtime.Object, preconditions *storage.Preconditions) error {
v, err := conversion.EnforcePtr(out)
if err != nil {
panic("unable to convert output object to pointer")
}
key = path.Join(s.pathPrefix, key)
if preconditions == nil {
return s.unconditionalDelete(ctx, key, out)
}
return s.conditionalDelete(ctx, key, out, v, preconditions)
}
func (s *store) unconditionalDelete(ctx context.Context, key string, out runtime.Object) error {
// We need to do get and delete in single transaction in order to
// know the value and revision before deleting it.
txnResp, err := s.client.KV.Txn(ctx).If().Then(
clientv3.OpGet(key),
clientv3.OpDelete(key),
).Commit()
if err != nil {
return err
}
getResp := txnResp.Responses[0].GetResponseRange()
if len(getResp.Kvs) == 0 {
return storage.NewKeyNotFoundError(key, 0)
}
kv := getResp.Kvs[0]
data, _, err := s.transformer.TransformFromStorage(kv.Value, authenticatedDataString(key))
if err != nil {
return storage.NewInternalError(err.Error())
}
return decode(s.codec, s.versioner, data, out, kv.ModRevision)
}
func (s *store) conditionalDelete(ctx context.Context, key string, out runtime.Object, v reflect.Value, preconditions *storage.Preconditions) error {
getResp, err := s.client.KV.Get(ctx, key)
if err != nil {
return err
}
for {
origState, err := s.getState(getResp, key, v, false)
if err != nil {
return err
}
if err := preconditions.Check(key, origState.obj); err != nil {
return err
}
txnResp, err := s.client.KV.Txn(ctx).If(
clientv3.Compare(clientv3.ModRevision(key), "=", origState.rev),
).Then(
clientv3.OpDelete(key),
).Else(
clientv3.OpGet(key),
).Commit()
if err != nil {
return err
}
if !txnResp.Succeeded {
getResp = (*clientv3.GetResponse)(txnResp.Responses[0].GetResponseRange())
klog.V(4).Infof("deletion of %s failed because of a conflict, going to retry", key)
continue
}
return decode(s.codec, s.versioner, origState.data, out, origState.rev)
}
}
// GuaranteedUpdate implements storage.Interface.GuaranteedUpdate.
func (s *store) GuaranteedUpdate(
ctx context.Context, key string, out runtime.Object, ignoreNotFound bool,
preconditions *storage.Preconditions, tryUpdate storage.UpdateFunc, suggestion ...runtime.Object) error {
trace := utiltrace.New(fmt.Sprintf("GuaranteedUpdate etcd3: %s", reflect.TypeOf(out).String()))
defer trace.LogIfLong(500 * time.Millisecond)
v, err := conversion.EnforcePtr(out)
if err != nil {
panic("unable to convert output object to pointer")
}
key = path.Join(s.pathPrefix, key)
getCurrentState := func() (*objState, error) {
getResp, err := s.client.KV.Get(ctx, key, s.getOps...)
if err != nil {
return nil, err
}
return s.getState(getResp, key, v, ignoreNotFound)
}
var origState *objState
var mustCheckData bool
if len(suggestion) == 1 && suggestion[0] != nil {
origState, err = s.getStateFromObject(suggestion[0])
if err != nil {
return err
}
mustCheckData = true
} else {
origState, err = getCurrentState()
if err != nil {
return err
}
}
trace.Step("initial value restored")
transformContext := authenticatedDataString(key)
for {
if err := preconditions.Check(key, origState.obj); err != nil {
return err
}
ret, ttl, err := s.updateState(origState, tryUpdate)
if err != nil {
// It's possible we were working with stale data
if mustCheckData && apierrors.IsConflict(err) {
// Actually fetch
origState, err = getCurrentState()
if err != nil {
return err
}
mustCheckData = false
// Retry
continue
}
return err
}
data, err := runtime.Encode(s.codec, ret)
if err != nil {
return err
}
if !origState.stale && bytes.Equal(data, origState.data) {
// if we skipped the original Get in this loop, we must refresh from
// etcd in order to be sure the data in the store is equivalent to
// our desired serialization
if mustCheckData {
origState, err = getCurrentState()
if err != nil {
return err
}
mustCheckData = false
if !bytes.Equal(data, origState.data) {
// original data changed, restart loop
continue
}
}
// recheck that the data from etcd is not stale before short-circuiting a write
if !origState.stale {
return decode(s.codec, s.versioner, origState.data, out, origState.rev)
}
}
newData, err := s.transformer.TransformToStorage(data, transformContext)
if err != nil {
return storage.NewInternalError(err.Error())
}
opts, err := s.ttlOpts(ctx, int64(ttl))
if err != nil {
return err
}
trace.Step("Transaction prepared")
txnResp, err := s.client.KV.Txn(ctx).If(
clientv3.Compare(clientv3.ModRevision(key), "=", origState.rev),
).Then(
clientv3.OpPut(key, string(newData), opts...),
).Else(
clientv3.OpGet(key),
).Commit()
if err != nil {
return err
}
trace.Step("Transaction committed")
if !txnResp.Succeeded {
getResp := (*clientv3.GetResponse)(txnResp.Responses[0].GetResponseRange())
klog.V(4).Infof("GuaranteedUpdate of %s failed because of a conflict, going to retry", key)
origState, err = s.getState(getResp, key, v, ignoreNotFound)
if err != nil {
return err
}
trace.Step("Retry value restored")
mustCheckData = false
continue
}
putResp := txnResp.Responses[0].GetResponsePut()
return decode(s.codec, s.versioner, data, out, putResp.Header.Revision)
}
}
// GetToList implements storage.Interface.GetToList.
func (s *store) GetToList(ctx context.Context, key string, resourceVersion string, pred storage.SelectionPredicate, listObj runtime.Object) error {
listPtr, err := meta.GetItemsPtr(listObj)
if err != nil {
return err
}
v, err := conversion.EnforcePtr(listPtr)
if err != nil || v.Kind() != reflect.Slice {
panic("need ptr to slice")
}
key = path.Join(s.pathPrefix, key)
getResp, err := s.client.KV.Get(ctx, key, s.getOps...)
if err != nil {
return err
}
if len(getResp.Kvs) > 0 {
data, _, err := s.transformer.TransformFromStorage(getResp.Kvs[0].Value, authenticatedDataString(key))
if err != nil {
return storage.NewInternalError(err.Error())
}
if err := appendListItem(v, data, uint64(getResp.Kvs[0].ModRevision), pred, s.codec, s.versioner); err != nil {
return err
}
}
// update version with cluster level revision
return s.versioner.UpdateList(listObj, uint64(getResp.Header.Revision), "")
}
func (s *store) Count(key string) (int64, error) {
key = path.Join(s.pathPrefix, key)
getResp, err := s.client.KV.Get(context.Background(), key, clientv3.WithRange(clientv3.GetPrefixRangeEnd(key)), clientv3.WithCountOnly())
if err != nil {
return 0, err
}
return getResp.Count, nil
}
// continueToken is a simple structured object for encoding the state of a continue token.
// TODO: if we change the version of the encoded from, we can't start encoding the new version
// until all other servers are upgraded (i.e. we need to support rolling schema)
// This is a public API struct and cannot change.
type continueToken struct {
APIVersion string `json:"v"`
ResourceVersion int64 `json:"rv"`
StartKey string `json:"start"`
}
// parseFrom transforms an encoded predicate from into a versioned struct.
// TODO: return a typed error that instructs clients that they must relist
func decodeContinue(continueValue, keyPrefix string) (fromKey string, rv int64, err error) {
data, err := base64.RawURLEncoding.DecodeString(continueValue)
if err != nil {
return "", 0, fmt.Errorf("continue key is not valid: %v", err)
}
var c continueToken
if err := json.Unmarshal(data, &c); err != nil {
return "", 0, fmt.Errorf("continue key is not valid: %v", err)
}
switch c.APIVersion {
case "meta.k8s.io/v1":
if c.ResourceVersion == 0 {
return "", 0, fmt.Errorf("continue key is not valid: incorrect encoded start resourceVersion (version meta.k8s.io/v1)")
}
if len(c.StartKey) == 0 {
return "", 0, fmt.Errorf("continue key is not valid: encoded start key empty (version meta.k8s.io/v1)")
}
// defend against path traversal attacks by clients - path.Clean will ensure that startKey cannot
// be at a higher level of the hierarchy, and so when we append the key prefix we will end up with
// continue start key that is fully qualified and cannot range over anything less specific than
// keyPrefix.
key := c.StartKey
if !strings.HasPrefix(key, "/") {
key = "/" + key
}
cleaned := path.Clean(key)
if cleaned != key {
return "", 0, fmt.Errorf("continue key is not valid: %s", c.StartKey)
}
return keyPrefix + cleaned[1:], c.ResourceVersion, nil
default:
return "", 0, fmt.Errorf("continue key is not valid: server does not recognize this encoded version %q", c.APIVersion)
}
}
// encodeContinue returns a string representing the encoded continuation of the current query.
func encodeContinue(key, keyPrefix string, resourceVersion int64) (string, error) {
nextKey := strings.TrimPrefix(key, keyPrefix)
if nextKey == key {
return "", fmt.Errorf("unable to encode next field: the key and key prefix do not match")
}
out, err := json.Marshal(&continueToken{APIVersion: "meta.k8s.io/v1", ResourceVersion: resourceVersion, StartKey: nextKey})
if err != nil {
return "", err
}
return base64.RawURLEncoding.EncodeToString(out), nil
}
// List implements storage.Interface.List.
func (s *store) List(ctx context.Context, key, resourceVersion string, pred storage.SelectionPredicate, listObj runtime.Object) error {
listPtr, err := meta.GetItemsPtr(listObj)
if err != nil {
return err
}
v, err := conversion.EnforcePtr(listPtr)
if err != nil || v.Kind() != reflect.Slice {
panic("need ptr to slice")
}
if s.pathPrefix != "" {
key = path.Join(s.pathPrefix, key)
}
// We need to make sure the key ended with "/" so that we only get children "directories".
// e.g. if we have key "/a", "/a/b", "/ab", getting keys with prefix "/a" will return all three,
// while with prefix "/a/" will return only "/a/b" which is the correct answer.
if !strings.HasSuffix(key, "/") {
key += "/"
}
keyPrefix := key
// set the appropriate clientv3 options to filter the returned data set
var paging bool
options := make([]clientv3.OpOption, 0, 4)
if s.pagingEnabled && pred.Limit > 0 {
paging = true
options = append(options, clientv3.WithLimit(pred.Limit))
}
var returnedRV, continueRV int64
var continueKey string
switch {
case s.pagingEnabled && len(pred.Continue) > 0:
continueKey, continueRV, err = decodeContinue(pred.Continue, keyPrefix)
if err != nil {
return apierrors.NewBadRequest(fmt.Sprintf("invalid continue token: %v", err))
}
if len(resourceVersion) > 0 && resourceVersion != "0" {
return apierrors.NewBadRequest("specifying resource version is not allowed when using continue")
}
rangeEnd := clientv3.GetPrefixRangeEnd(keyPrefix)
options = append(options, clientv3.WithRange(rangeEnd))
key = continueKey
// If continueRV > 0, the LIST request needs a specific resource version.
// continueRV==0 is invalid.
// If continueRV < 0, the request is for the latest resource version.
if continueRV > 0 {
options = append(options, clientv3.WithRev(continueRV))
returnedRV = continueRV
}
case s.pagingEnabled && pred.Limit > 0:
if len(resourceVersion) > 0 {
fromRV, err := s.versioner.ParseResourceVersion(resourceVersion)
if err != nil {
return apierrors.NewBadRequest(fmt.Sprintf("invalid resource version: %v", err))
}
if fromRV > 0 {
options = append(options, clientv3.WithRev(int64(fromRV)))
}
returnedRV = int64(fromRV)
}
rangeEnd := clientv3.GetPrefixRangeEnd(keyPrefix)
options = append(options, clientv3.WithRange(rangeEnd))
default:
if len(resourceVersion) > 0 {
fromRV, err := s.versioner.ParseResourceVersion(resourceVersion)
if err != nil {
return apierrors.NewBadRequest(fmt.Sprintf("invalid resource version: %v", err))
}
if fromRV > 0 {
options = append(options, clientv3.WithRev(int64(fromRV)))
}
returnedRV = int64(fromRV)
}
options = append(options, clientv3.WithPrefix())
}
// loop until we have filled the requested limit from etcd or there are no more results
var lastKey []byte
var hasMore bool
for {
getResp, err := s.client.KV.Get(ctx, key, options...)
if err != nil {
return interpretListError(err, len(pred.Continue) > 0, continueKey, keyPrefix)
}
hasMore = getResp.More
if len(getResp.Kvs) == 0 && getResp.More {
return fmt.Errorf("no results were found, but etcd indicated there were more values remaining")
}
// avoid small allocations for the result slice, since this can be called in many
// different contexts and we don't know how significantly the result will be filtered
if pred.Empty() {
growSlice(v, len(getResp.Kvs))
} else {
growSlice(v, 2048, len(getResp.Kvs))
}
// take items from the response until the bucket is full, filtering as we go
for _, kv := range getResp.Kvs {
if paging && int64(v.Len()) >= pred.Limit {
hasMore = true
break
}
lastKey = kv.Key
data, _, err := s.transformer.TransformFromStorage(kv.Value, authenticatedDataString(kv.Key))
if err != nil {
return storage.NewInternalErrorf("unable to transform key %q: %v", kv.Key, err)
}
if err := appendListItem(v, data, uint64(kv.ModRevision), pred, s.codec, s.versioner); err != nil {
return err
}
}
// indicate to the client which resource version was returned
if returnedRV == 0 {
returnedRV = getResp.Header.Revision
}
// no more results remain or we didn't request paging
if !hasMore || !paging {
break
}
// we're paging but we have filled our bucket
if int64(v.Len()) >= pred.Limit {
break
}
key = string(lastKey) + "\x00"
}
// instruct the client to begin querying from immediately after the last key we returned
// we never return a key that the client wouldn't be allowed to see
if hasMore {
// we want to start immediately after the last key
next, err := encodeContinue(string(lastKey)+"\x00", keyPrefix, returnedRV)
if err != nil {
return err
}
return s.versioner.UpdateList(listObj, uint64(returnedRV), next)
}
// no continuation
return s.versioner.UpdateList(listObj, uint64(returnedRV), "")
}
// growSlice takes a slice value and grows its capacity up
// to the maximum of the passed sizes or maxCapacity, whichever
// is smaller. Above maxCapacity decisions about allocation are left
// to the Go runtime on append. This allows a caller to make an
// educated guess about the potential size of the total list while
// still avoiding overly aggressive initial allocation. If sizes
// is empty maxCapacity will be used as the size to grow.
func growSlice(v reflect.Value, maxCapacity int, sizes ...int) {
cap := v.Cap()
max := cap
for _, size := range sizes {
if size > max {
max = size
}
}
if len(sizes) == 0 || max > maxCapacity {
max = maxCapacity
}
if max <= cap {
return
}
if v.Len() > 0 {
extra := reflect.MakeSlice(v.Type(), 0, max)
reflect.Copy(extra, v)
v.Set(extra)
} else {
extra := reflect.MakeSlice(v.Type(), 0, max)
v.Set(extra)
}
}
// Watch implements storage.Interface.Watch.
func (s *store) Watch(ctx context.Context, key string, resourceVersion string, pred storage.SelectionPredicate) (watch.Interface, error) {
return s.watch(ctx, key, resourceVersion, pred, false)
}
// WatchList implements storage.Interface.WatchList.
func (s *store) WatchList(ctx context.Context, key string, resourceVersion string, pred storage.SelectionPredicate) (watch.Interface, error) {
return s.watch(ctx, key, resourceVersion, pred, true)
}
func (s *store) watch(ctx context.Context, key string, rv string, pred storage.SelectionPredicate, recursive bool) (watch.Interface, error) {
rev, err := s.versioner.ParseResourceVersion(rv)
if err != nil {
return nil, err
}
key = path.Join(s.pathPrefix, key)
return s.watcher.Watch(ctx, key, int64(rev), recursive, pred)
}
func (s *store) getState(getResp *clientv3.GetResponse, key string, v reflect.Value, ignoreNotFound bool) (*objState, error) {
state := &objState{
obj: reflect.New(v.Type()).Interface().(runtime.Object),
meta: &storage.ResponseMeta{},
}
if len(getResp.Kvs) == 0 {
if !ignoreNotFound {
return nil, storage.NewKeyNotFoundError(key, 0)
}
if err := runtime.SetZeroValue(state.obj); err != nil {
return nil, err
}
} else {
data, stale, err := s.transformer.TransformFromStorage(getResp.Kvs[0].Value, authenticatedDataString(key))
if err != nil {
return nil, storage.NewInternalError(err.Error())
}
state.rev = getResp.Kvs[0].ModRevision
state.meta.ResourceVersion = uint64(state.rev)
state.data = data
state.stale = stale
if err := decode(s.codec, s.versioner, state.data, state.obj, state.rev); err != nil {
return nil, err
}
}
return state, nil
}
func (s *store) getStateFromObject(obj runtime.Object) (*objState, error) {
state := &objState{
obj: obj,
meta: &storage.ResponseMeta{},
}
rv, err := s.versioner.ObjectResourceVersion(obj)
if err != nil {
return nil, fmt.Errorf("couldn't get resource version: %v", err)
}
state.rev = int64(rv)
state.meta.ResourceVersion = uint64(state.rev)
// Compute the serialized form - for that we need to temporarily clean
// its resource version field (those are not stored in etcd).
if err := s.versioner.PrepareObjectForStorage(obj); err != nil {
return nil, fmt.Errorf("PrepareObjectForStorage failed: %v", err)
}
state.data, err = runtime.Encode(s.codec, obj)
if err != nil {
return nil, err
}
s.versioner.UpdateObject(state.obj, uint64(rv))
return state, nil
}
func (s *store) updateState(st *objState, userUpdate storage.UpdateFunc) (runtime.Object, uint64, error) {
ret, ttlPtr, err := userUpdate(st.obj, *st.meta)
if err != nil {
return nil, 0, err
}
if err := s.versioner.PrepareObjectForStorage(ret); err != nil {
return nil, 0, fmt.Errorf("PrepareObjectForStorage failed: %v", err)
}
var ttl uint64
if ttlPtr != nil {
ttl = *ttlPtr
}
return ret, ttl, nil
}
// ttlOpts returns client options based on given ttl.
// ttl: if ttl is non-zero, it will attach the key to a lease with ttl of roughly the same length
func (s *store) ttlOpts(ctx context.Context, ttl int64) ([]clientv3.OpOption, error) {
if ttl == 0 {
return nil, nil
}
id, err := s.leaseManager.GetLease(ctx, ttl)
if err != nil {
return nil, err
}
return []clientv3.OpOption{clientv3.WithLease(id)}, nil
}
// decode decodes value of bytes into object. It will also set the object resource version to rev.
// On success, objPtr would be set to the object.
func decode(codec runtime.Codec, versioner storage.Versioner, value []byte, objPtr runtime.Object, rev int64) error {
if _, err := conversion.EnforcePtr(objPtr); err != nil {
panic("unable to convert output object to pointer")
}
_, _, err := codec.Decode(value, nil, objPtr)
if err != nil {
return err
}
// being unable to set the version does not prevent the object from being extracted
versioner.UpdateObject(objPtr, uint64(rev))
return nil
}
// appendListItem decodes and appends the object (if it passes filter) to v, which must be a slice.
func appendListItem(v reflect.Value, data []byte, rev uint64, pred storage.SelectionPredicate, codec runtime.Codec, versioner storage.Versioner) error {
obj, _, err := codec.Decode(data, nil, reflect.New(v.Type().Elem()).Interface().(runtime.Object))
if err != nil {
return err
}
// being unable to set the version does not prevent the object from being extracted
versioner.UpdateObject(obj, rev)
if matched, err := pred.Matches(obj); err == nil && matched {
v.Set(reflect.Append(v, reflect.ValueOf(obj).Elem()))
}
return nil
}
func notFound(key string) clientv3.Cmp {
return clientv3.Compare(clientv3.ModRevision(key), "=", 0)
}