-
Notifications
You must be signed in to change notification settings - Fork 4.2k
/
testhelpers.go
771 lines (665 loc) · 19 KB
/
testhelpers.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
package testhelpers
import (
"context"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"math/rand"
"net/url"
"sync/atomic"
"time"
"github.com/armon/go-metrics"
raftlib "github.com/hashicorp/raft"
"github.com/hashicorp/vault/api"
"github.com/hashicorp/vault/helper/metricsutil"
"github.com/hashicorp/vault/helper/namespace"
"github.com/hashicorp/vault/physical/raft"
"github.com/hashicorp/vault/sdk/helper/xor"
"github.com/hashicorp/vault/vault"
"github.com/mitchellh/go-testing-interface"
)
type GenerateRootKind int
const (
GenerateRootRegular GenerateRootKind = iota
GenerateRootDR
GenerateRecovery
)
// Generates a root token on the target cluster.
func GenerateRoot(t testing.T, cluster *vault.TestCluster, kind GenerateRootKind) string {
t.Helper()
token, err := GenerateRootWithError(t, cluster, kind)
if err != nil {
t.Fatal(err)
}
return token
}
func GenerateRootWithError(t testing.T, cluster *vault.TestCluster, kind GenerateRootKind) (string, error) {
t.Helper()
// If recovery keys supported, use those to perform root token generation instead
var keys [][]byte
if cluster.Cores[0].SealAccess().RecoveryKeySupported() {
keys = cluster.RecoveryKeys
} else {
keys = cluster.BarrierKeys
}
client := cluster.Cores[0].Client
var err error
var status *api.GenerateRootStatusResponse
switch kind {
case GenerateRootRegular:
status, err = client.Sys().GenerateRootInit("", "")
case GenerateRootDR:
status, err = client.Sys().GenerateDROperationTokenInit("", "")
case GenerateRecovery:
status, err = client.Sys().GenerateRecoveryOperationTokenInit("", "")
}
if err != nil {
return "", err
}
if status.Required > len(keys) {
return "", fmt.Errorf("need more keys than have, need %d have %d", status.Required, len(keys))
}
otp := status.OTP
for i, key := range keys {
if i >= status.Required {
break
}
strKey := base64.StdEncoding.EncodeToString(key)
switch kind {
case GenerateRootRegular:
status, err = client.Sys().GenerateRootUpdate(strKey, status.Nonce)
case GenerateRootDR:
status, err = client.Sys().GenerateDROperationTokenUpdate(strKey, status.Nonce)
case GenerateRecovery:
status, err = client.Sys().GenerateRecoveryOperationTokenUpdate(strKey, status.Nonce)
}
if err != nil {
return "", err
}
}
if !status.Complete {
return "", errors.New("generate root operation did not end successfully")
}
tokenBytes, err := base64.RawStdEncoding.DecodeString(status.EncodedToken)
if err != nil {
return "", err
}
tokenBytes, err = xor.XORBytes(tokenBytes, []byte(otp))
if err != nil {
return "", err
}
return string(tokenBytes), nil
}
// RandomWithPrefix is used to generate a unique name with a prefix, for
// randomizing names in acceptance tests
func RandomWithPrefix(name string) string {
return fmt.Sprintf("%s-%d", name, rand.New(rand.NewSource(time.Now().UnixNano())).Int())
}
func EnsureCoresSealed(t testing.T, c *vault.TestCluster) {
t.Helper()
for _, core := range c.Cores {
EnsureCoreSealed(t, core)
}
}
func EnsureCoreSealed(t testing.T, core *vault.TestClusterCore) {
t.Helper()
core.Seal(t)
timeout := time.Now().Add(60 * time.Second)
for {
if time.Now().After(timeout) {
t.Fatal("timeout waiting for core to seal")
}
if core.Core.Sealed() {
break
}
time.Sleep(250 * time.Millisecond)
}
}
func EnsureCoresUnsealed(t testing.T, c *vault.TestCluster) {
t.Helper()
for i, core := range c.Cores {
err := AttemptUnsealCore(c, core)
if err != nil {
t.Fatalf("failed to unseal core %d: %v", i, err)
}
}
}
func EnsureCoreUnsealed(t testing.T, c *vault.TestCluster, core *vault.TestClusterCore) {
t.Helper()
err := AttemptUnsealCore(c, core)
if err != nil {
t.Fatalf("failed to unseal core: %v", err)
}
}
func AttemptUnsealCores(c *vault.TestCluster) error {
for i, core := range c.Cores {
err := AttemptUnsealCore(c, core)
if err != nil {
return fmt.Errorf("failed to unseal core %d: %v", i, err)
}
}
return nil
}
func AttemptUnsealCore(c *vault.TestCluster, core *vault.TestClusterCore) error {
if !core.Sealed() {
return nil
}
core.SealAccess().ClearCaches(context.Background())
if err := core.UnsealWithStoredKeys(context.Background()); err != nil {
return err
}
client := core.Client
client.Sys().ResetUnsealProcess()
for j := 0; j < len(c.BarrierKeys); j++ {
statusResp, err := client.Sys().Unseal(base64.StdEncoding.EncodeToString(c.BarrierKeys[j]))
if err != nil {
// Sometimes when we get here it's already unsealed on its own
// and then this fails for DR secondaries so check again
if core.Sealed() {
return err
} else {
return nil
}
}
if statusResp == nil {
return fmt.Errorf("nil status response during unseal")
}
if !statusResp.Sealed {
break
}
}
if core.Sealed() {
return fmt.Errorf("core is still sealed")
}
return nil
}
func EnsureStableActiveNode(t testing.T, cluster *vault.TestCluster) {
t.Helper()
deriveStableActiveCore(t, cluster)
}
func DeriveStableActiveCore(t testing.T, cluster *vault.TestCluster) *vault.TestClusterCore {
t.Helper()
return deriveStableActiveCore(t, cluster)
}
func deriveStableActiveCore(t testing.T, cluster *vault.TestCluster) *vault.TestClusterCore {
t.Helper()
activeCore := DeriveActiveCore(t, cluster)
minDuration := time.NewTimer(3 * time.Second)
for i := 0; i < 60; i++ {
leaderResp, err := activeCore.Client.Sys().Leader()
if err != nil {
t.Fatal(err)
}
if !leaderResp.IsSelf {
minDuration.Reset(3 * time.Second)
}
time.Sleep(200 * time.Millisecond)
}
select {
case <-minDuration.C:
default:
if stopped := minDuration.Stop(); stopped {
t.Fatal("unstable active node")
}
// Drain the value
<-minDuration.C
}
return activeCore
}
func DeriveActiveCore(t testing.T, cluster *vault.TestCluster) *vault.TestClusterCore {
t.Helper()
for i := 0; i < 60; i++ {
for _, core := range cluster.Cores {
leaderResp, err := core.Client.Sys().Leader()
if err != nil {
t.Fatal(err)
}
if leaderResp.IsSelf {
return core
}
}
time.Sleep(1 * time.Second)
}
t.Fatal("could not derive the active core")
return nil
}
func DeriveStandbyCores(t testing.T, cluster *vault.TestCluster) []*vault.TestClusterCore {
t.Helper()
cores := make([]*vault.TestClusterCore, 0, 2)
for _, core := range cluster.Cores {
leaderResp, err := core.Client.Sys().Leader()
if err != nil {
t.Fatal(err)
}
if !leaderResp.IsSelf {
cores = append(cores, core)
}
}
return cores
}
func WaitForNCoresUnsealed(t testing.T, cluster *vault.TestCluster, n int) {
t.Helper()
for i := 0; i < 30; i++ {
unsealed := 0
for _, core := range cluster.Cores {
if !core.Core.Sealed() {
unsealed++
}
}
if unsealed >= n {
return
}
time.Sleep(time.Second)
}
t.Fatalf("%d cores were not unsealed", n)
}
func SealCores(t testing.T, cluster *vault.TestCluster) {
t.Helper()
for _, core := range cluster.Cores {
if err := core.Shutdown(); err != nil {
t.Fatal(err)
}
timeout := time.Now().Add(3 * time.Second)
for {
if time.Now().After(timeout) {
t.Fatal("timeout waiting for core to seal")
}
if core.Sealed() {
break
}
time.Sleep(100 * time.Millisecond)
}
}
}
func WaitForNCoresSealed(t testing.T, cluster *vault.TestCluster, n int) {
t.Helper()
for i := 0; i < 60; i++ {
sealed := 0
for _, core := range cluster.Cores {
if core.Core.Sealed() {
sealed++
}
}
if sealed >= n {
return
}
time.Sleep(time.Second)
}
t.Fatalf("%d cores were not sealed", n)
}
func WaitForActiveNode(t testing.T, cluster *vault.TestCluster) *vault.TestClusterCore {
t.Helper()
for i := 0; i < 60; i++ {
for _, core := range cluster.Cores {
if standby, _ := core.Core.Standby(); !standby {
return core
}
}
time.Sleep(time.Second)
}
t.Fatalf("node did not become active")
return nil
}
func WaitForStandbyNode(t testing.T, core *vault.TestClusterCore) {
t.Helper()
for i := 0; i < 30; i++ {
if isLeader, _, clusterAddr, _ := core.Core.Leader(); isLeader != true && clusterAddr != "" {
return
}
time.Sleep(time.Second)
}
t.Fatalf("node did not become standby")
}
func RekeyCluster(t testing.T, cluster *vault.TestCluster, recovery bool) [][]byte {
t.Helper()
cluster.Logger.Info("rekeying cluster", "recovery", recovery)
client := cluster.Cores[0].Client
initFunc := client.Sys().RekeyInit
if recovery {
initFunc = client.Sys().RekeyRecoveryKeyInit
}
init, err := initFunc(&api.RekeyInitRequest{
SecretShares: 5,
SecretThreshold: 3,
})
if err != nil {
t.Fatal(err)
}
var statusResp *api.RekeyUpdateResponse
keys := cluster.BarrierKeys
if cluster.Cores[0].Core.SealAccess().RecoveryKeySupported() {
keys = cluster.RecoveryKeys
}
updateFunc := client.Sys().RekeyUpdate
if recovery {
updateFunc = client.Sys().RekeyRecoveryKeyUpdate
}
for j := 0; j < len(keys); j++ {
statusResp, err = updateFunc(base64.StdEncoding.EncodeToString(keys[j]), init.Nonce)
if err != nil {
t.Fatal(err)
}
if statusResp == nil {
t.Fatal("nil status response during unseal")
}
if statusResp.Complete {
break
}
}
cluster.Logger.Info("cluster rekeyed", "recovery", recovery)
if cluster.Cores[0].Core.SealAccess().RecoveryKeySupported() && !recovery {
return nil
}
if len(statusResp.KeysB64) != 5 {
t.Fatal("wrong number of keys")
}
newKeys := make([][]byte, 5)
for i, key := range statusResp.KeysB64 {
newKeys[i], err = base64.StdEncoding.DecodeString(key)
if err != nil {
t.Fatal(err)
}
}
return newKeys
}
// TestRaftServerAddressProvider is a ServerAddressProvider that uses the
// ClusterAddr() of each node to provide raft addresses.
//
// Note that TestRaftServerAddressProvider should only be used in cases where
// cores that are part of a raft configuration have already had
// startClusterListener() called (via either unsealing or raft joining).
type TestRaftServerAddressProvider struct {
Cluster *vault.TestCluster
}
func (p *TestRaftServerAddressProvider) ServerAddr(id raftlib.ServerID) (raftlib.ServerAddress, error) {
for _, core := range p.Cluster.Cores {
if core.NodeID == string(id) {
parsed, err := url.Parse(core.ClusterAddr())
if err != nil {
return "", err
}
return raftlib.ServerAddress(parsed.Host), nil
}
}
return "", errors.New("could not find cluster addr")
}
func RaftClusterJoinNodes(t testing.T, cluster *vault.TestCluster) {
addressProvider := &TestRaftServerAddressProvider{Cluster: cluster}
atomic.StoreUint32(&vault.TestingUpdateClusterAddr, 1)
leader := cluster.Cores[0]
// Seal the leader so we can install an address provider
{
EnsureCoreSealed(t, leader)
leader.UnderlyingRawStorage.(*raft.RaftBackend).SetServerAddressProvider(addressProvider)
cluster.UnsealCore(t, leader)
vault.TestWaitActive(t, leader.Core)
}
leaderInfos := []*raft.LeaderJoinInfo{
{
LeaderAPIAddr: leader.Client.Address(),
TLSConfig: leader.TLSConfig,
},
}
// Join followers
for i := 1; i < len(cluster.Cores); i++ {
core := cluster.Cores[i]
core.UnderlyingRawStorage.(*raft.RaftBackend).SetServerAddressProvider(addressProvider)
_, err := core.JoinRaftCluster(namespace.RootContext(context.Background()), leaderInfos, false)
if err != nil {
t.Fatal(err)
}
cluster.UnsealCore(t, core)
}
WaitForNCoresUnsealed(t, cluster, len(cluster.Cores))
}
// HardcodedServerAddressProvider is a ServerAddressProvider that uses
// a hardcoded map of raft node addresses.
//
// It is useful in cases where the raft configuration is known ahead of time,
// but some of the cores have not yet had startClusterListener() called (via
// either unsealing or raft joining), and thus do not yet have a ClusterAddr()
// assigned.
type HardcodedServerAddressProvider struct {
Entries map[raftlib.ServerID]raftlib.ServerAddress
}
func (p *HardcodedServerAddressProvider) ServerAddr(id raftlib.ServerID) (raftlib.ServerAddress, error) {
if addr, ok := p.Entries[id]; ok {
return addr, nil
}
return "", errors.New("could not find cluster addr")
}
// NewHardcodedServerAddressProvider is a convenience function that makes a
// ServerAddressProvider from a given cluster address base port.
func NewHardcodedServerAddressProvider(numCores, baseClusterPort int) raftlib.ServerAddressProvider {
entries := make(map[raftlib.ServerID]raftlib.ServerAddress)
for i := 0; i < numCores; i++ {
id := fmt.Sprintf("core-%d", i)
addr := fmt.Sprintf("127.0.0.1:%d", baseClusterPort+i)
entries[raftlib.ServerID(id)] = raftlib.ServerAddress(addr)
}
return &HardcodedServerAddressProvider{
entries,
}
}
// VerifyRaftConfiguration checks that we have a valid raft configuration, i.e.
// the correct number of servers, having the correct NodeIDs, and exactly one
// leader.
func VerifyRaftConfiguration(core *vault.TestClusterCore, numCores int) error {
backend := core.UnderlyingRawStorage.(*raft.RaftBackend)
ctx := namespace.RootContext(context.Background())
config, err := backend.GetConfiguration(ctx)
if err != nil {
return err
}
servers := config.Servers
if len(servers) != numCores {
return fmt.Errorf("Found %d servers, not %d", len(servers), numCores)
}
leaders := 0
for i, s := range servers {
if s.NodeID != fmt.Sprintf("core-%d", i) {
return fmt.Errorf("Found unexpected node ID %q", s.NodeID)
}
if s.Leader {
leaders++
}
}
if leaders != 1 {
return fmt.Errorf("Found %d leaders", leaders)
}
return nil
}
func RaftAppliedIndex(core *vault.TestClusterCore) uint64 {
return core.UnderlyingRawStorage.(*raft.RaftBackend).AppliedIndex()
}
func WaitForRaftApply(t testing.T, core *vault.TestClusterCore, index uint64) {
t.Helper()
backend := core.UnderlyingRawStorage.(*raft.RaftBackend)
for i := 0; i < 30; i++ {
if backend.AppliedIndex() >= index {
return
}
time.Sleep(time.Second)
}
t.Fatalf("node did not apply index")
}
// AwaitLeader waits for one of the cluster's nodes to become leader.
func AwaitLeader(t testing.T, cluster *vault.TestCluster) (int, error) {
timeout := time.Now().Add(60 * time.Second)
for {
if time.Now().After(timeout) {
break
}
for i, core := range cluster.Cores {
if core.Core.Sealed() {
continue
}
isLeader, _, _, _ := core.Leader()
if isLeader {
return i, nil
}
}
time.Sleep(time.Second)
}
return 0, fmt.Errorf("timeout waiting leader")
}
func GenerateDebugLogs(t testing.T, client *api.Client) chan struct{} {
t.Helper()
stopCh := make(chan struct{})
ticker := time.NewTicker(time.Second)
var err error
go func() {
for {
select {
case <-stopCh:
ticker.Stop()
stopCh <- struct{}{}
return
case <-ticker.C:
err = client.Sys().Mount("foo", &api.MountInput{
Type: "kv",
Options: map[string]string{
"version": "1",
},
})
if err != nil {
t.Fatal(err)
}
err = client.Sys().Unmount("foo")
if err != nil {
t.Fatal(err)
}
}
}
}()
return stopCh
}
func VerifyRaftPeers(t testing.T, client *api.Client, expected map[string]bool) {
t.Helper()
resp, err := client.Logical().Read("sys/storage/raft/configuration")
if err != nil {
t.Fatalf("error reading raft config: %v", err)
}
if resp == nil || resp.Data == nil {
t.Fatal("missing response data")
}
config, ok := resp.Data["config"].(map[string]interface{})
if !ok {
t.Fatal("missing config in response data")
}
servers, ok := config["servers"].([]interface{})
if !ok {
t.Fatal("missing servers in response data config")
}
// Iterate through the servers and remove the node found in the response
// from the expected collection
for _, s := range servers {
server := s.(map[string]interface{})
delete(expected, server["node_id"].(string))
}
// If the collection is non-empty, it means that the peer was not found in
// the response.
if len(expected) != 0 {
t.Fatalf("failed to read configuration successfully, expected peers not found in configuration list: %v", expected)
}
}
func TestMetricSinkProvider(gaugeInterval time.Duration) func(string) (*metricsutil.ClusterMetricSink, *metricsutil.MetricsHelper) {
return func(clusterName string) (*metricsutil.ClusterMetricSink, *metricsutil.MetricsHelper) {
inm := metrics.NewInmemSink(1000000*time.Hour, 2000000*time.Hour)
clusterSink := metricsutil.NewClusterMetricSink(clusterName, inm)
clusterSink.GaugeInterval = gaugeInterval
return clusterSink, metricsutil.NewMetricsHelper(inm, false)
}
}
func SysMetricsReq(client *api.Client, cluster *vault.TestCluster, unauth bool) (*SysMetricsJSON, error) {
r := client.NewRequest("GET", "/v1/sys/metrics")
if !unauth {
r.Headers.Set("X-Vault-Token", cluster.RootToken)
}
var data SysMetricsJSON
resp, err := client.RawRequestWithContext(context.Background(), r)
if err != nil {
return nil, err
}
bodyBytes, err := ioutil.ReadAll(resp.Response.Body)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if err := json.Unmarshal(bodyBytes, &data); err != nil {
return nil, errors.New("failed to unmarshal:" + err.Error())
}
return &data, nil
}
type SysMetricsJSON struct {
Gauges []gaugeJSON `json:"Gauges"`
Counters []counterJSON `json:"Counters"`
// note: this is referred to as a "Summary" type in our telemetry docs, but
// the field name in the JSON is "Samples"
Summaries []summaryJSON `json:"Samples"`
}
type baseInfoJSON struct {
Name string `json:"Name"`
Labels map[string]interface{} `json:"Labels"`
}
type gaugeJSON struct {
baseInfoJSON
Value int `json:"Value"`
}
type counterJSON struct {
baseInfoJSON
Count int `json:"Count"`
Rate float64 `json:"Rate"`
Sum int `json:"Sum"`
Min int `json:"Min"`
Max int `json:"Max"`
Mean float64 `json:"Mean"`
Stddev float64 `json:"Stddev"`
}
type summaryJSON struct {
baseInfoJSON
Count int `json:"Count"`
Rate float64 `json:"Rate"`
Sum float64 `json:"Sum"`
Min float64 `json:"Min"`
Max float64 `json:"Max"`
Mean float64 `json:"Mean"`
Stddev float64 `json:"Stddev"`
}
// SetNonRootToken sets a token on :client: with a fairly generic policy.
// This is useful if a test needs to examine differing behavior based on if a
// root token is passed with the request.
func SetNonRootToken(client *api.Client) error {
policy := `path "*" { capabilities = ["create", "update", "read"] }`
if err := client.Sys().PutPolicy("policy", policy); err != nil {
return fmt.Errorf("error putting policy: %v", err)
}
secret, err := client.Auth().Token().Create(&api.TokenCreateRequest{
Policies: []string{"policy"},
TTL: "30m",
})
if err != nil {
return fmt.Errorf("error creating token secret: %v", err)
}
if secret == nil || secret.Auth == nil || secret.Auth.ClientToken == "" {
return fmt.Errorf("missing token auth data")
}
client.SetToken(secret.Auth.ClientToken)
return nil
}
// RetryUntil runs f until it returns a nil result or the timeout is reached.
// If a nil result hasn't been obtained by timeout, calls t.Fatal.
func RetryUntil(t testing.T, timeout time.Duration, f func() error) {
t.Helper()
deadline := time.Now().Add(timeout)
var err error
for time.Now().Before(deadline) {
if err = f(); err == nil {
return
}
time.Sleep(100 * time.Millisecond)
}
t.Fatalf("did not complete before deadline, err: %v", err)
}