-
Notifications
You must be signed in to change notification settings - Fork 395
/
etcd3.go
492 lines (437 loc) · 15 KB
/
etcd3.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
/*
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 factory
import (
"context"
"fmt"
"log"
"math/rand"
"net"
"net/url"
"os"
"path"
"strings"
"sync"
"time"
grpcprom "github.com/grpc-ecosystem/go-grpc-prometheus"
"go.etcd.io/etcd/client/pkg/v3/logutil"
"go.etcd.io/etcd/client/pkg/v3/transport"
clientv3 "go.etcd.io/etcd/client/v3"
"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
"go.uber.org/zap"
"go.uber.org/zap/zapcore"
"golang.org/x/time/rate"
"google.golang.org/grpc"
"k8s.io/klog/v2"
"k8s.io/apimachinery/pkg/runtime"
utilnet "k8s.io/apimachinery/pkg/util/net"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/util/wait"
genericfeatures "k8s.io/apiserver/pkg/features"
"k8s.io/apiserver/pkg/server/egressselector"
"k8s.io/apiserver/pkg/storage"
"k8s.io/apiserver/pkg/storage/etcd3"
"k8s.io/apiserver/pkg/storage/etcd3/metrics"
"k8s.io/apiserver/pkg/storage/storagebackend"
"k8s.io/apiserver/pkg/storage/value/encrypt/identity"
utilfeature "k8s.io/apiserver/pkg/util/feature"
"k8s.io/component-base/metrics/legacyregistry"
tracing "k8s.io/component-base/tracing"
)
const (
// The short keepalive timeout and interval have been chosen to aggressively
// detect a failed etcd server without introducing much overhead.
keepaliveTime = 30 * time.Second
keepaliveTimeout = 10 * time.Second
// dialTimeout is the timeout for failing to establish a connection.
// It is set to 20 seconds as times shorter than that will cause TLS connections to fail
// on heavily loaded arm64 CPUs (issue #64649)
dialTimeout = 20 * time.Second
dbMetricsMonitorJitter = 0.5
)
// TODO(negz): Stop using a package scoped logger. At the time of writing we're
// creating an etcd client for each CRD. We need to pass each etcd client a
// logger or each client will create its own, which comes with a significant
// memory cost (around 20% of the API server's memory when hundreds of CRDs are
// present). The correct fix here is to not create a client per CRD. See
// https://github.com/kubernetes/kubernetes/issues/111476 for more.
var etcd3ClientLogger *zap.Logger
func init() {
// grpcprom auto-registers (via an init function) their client metrics, since we are opting out of
// using the global prometheus registry and using our own wrapped global registry,
// we need to explicitly register these metrics to our global registry here.
// For reference: https://github.com/kubernetes/kubernetes/pull/81387
legacyregistry.RawMustRegister(grpcprom.DefaultClientMetrics)
dbMetricsMonitors = make(map[string]struct{})
l, err := logutil.CreateDefaultZapLogger(etcdClientDebugLevel())
if err != nil {
l = zap.NewNop()
}
etcd3ClientLogger = l.Named("etcd-client")
}
// etcdClientDebugLevel translates ETCD_CLIENT_DEBUG into zap log level.
// NOTE(negz): This is a copy of a private etcd client function:
// https://github.com/etcd-io/etcd/blob/v3.5.4/client/v3/logger.go#L47
func etcdClientDebugLevel() zapcore.Level {
envLevel := os.Getenv("ETCD_CLIENT_DEBUG")
if envLevel == "" || envLevel == "true" {
return zapcore.InfoLevel
}
var l zapcore.Level
if err := l.Set(envLevel); err == nil {
log.Printf("Deprecated env ETCD_CLIENT_DEBUG value. Using default level: 'info'")
return zapcore.InfoLevel
}
return l
}
func newETCD3HealthCheck(c storagebackend.Config, stopCh <-chan struct{}) (func() error, error) {
timeout := storagebackend.DefaultHealthcheckTimeout
if c.HealthcheckTimeout != time.Duration(0) {
timeout = c.HealthcheckTimeout
}
return newETCD3Check(c, timeout, stopCh)
}
func newETCD3ReadyCheck(c storagebackend.Config, stopCh <-chan struct{}) (func() error, error) {
timeout := storagebackend.DefaultReadinessTimeout
if c.ReadycheckTimeout != time.Duration(0) {
timeout = c.ReadycheckTimeout
}
return newETCD3Check(c, timeout, stopCh)
}
// atomic error acts as a cache for atomically store an error
// the error is only updated if the timestamp is more recent than
// current stored error.
type atomicLastError struct {
mu sync.RWMutex
err error
timestamp time.Time
}
func (a *atomicLastError) Store(err error, t time.Time) {
a.mu.Lock()
defer a.mu.Unlock()
if a.timestamp.IsZero() || a.timestamp.Before(t) {
a.err = err
a.timestamp = t
}
}
func (a *atomicLastError) Load() error {
a.mu.RLock()
defer a.mu.RUnlock()
return a.err
}
func newETCD3Check(c storagebackend.Config, timeout time.Duration, stopCh <-chan struct{}) (func() error, error) {
// constructing the etcd v3 client blocks and times out if etcd is not available.
// retry in a loop in the background until we successfully create the client, storing the client or error encountered
lock := sync.RWMutex{}
var prober *etcd3ProberMonitor
clientErr := fmt.Errorf("etcd client connection not yet established")
go wait.PollImmediateUntil(time.Second, func() (bool, error) {
lock.Lock()
defer lock.Unlock()
newProber, err := newETCD3ProberMonitor(c)
// Ensure that server is already not shutting down.
select {
case <-stopCh:
if err == nil {
newProber.Close()
}
return true, nil
default:
}
if err != nil {
clientErr = err
return false, nil
}
prober = newProber
clientErr = nil
return true, nil
}, stopCh)
// Close the client on shutdown.
go func() {
defer utilruntime.HandleCrash()
<-stopCh
lock.Lock()
defer lock.Unlock()
if prober != nil {
prober.Close()
clientErr = fmt.Errorf("server is shutting down")
}
}()
// limit to a request every half of the configured timeout with a maximum burst of one
// rate limited requests will receive the last request sent error (note: not the last received response)
limiter := rate.NewLimiter(rate.Every(timeout/2), 1)
// initial state is the clientErr
lastError := &atomicLastError{err: fmt.Errorf("etcd client connection not yet established")}
return func() error {
// Given that client is closed on shutdown we hold the lock for
// the entire period of healthcheck call to ensure that client will
// not be closed during healthcheck.
// Given that healthchecks has a 2s timeout, worst case of blocking
// shutdown for additional 2s seems acceptable.
lock.RLock()
defer lock.RUnlock()
if clientErr != nil {
return clientErr
}
if limiter.Allow() == false {
return lastError.Load()
}
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
now := time.Now()
err := prober.Probe(ctx)
lastError.Store(err, now)
return err
}, nil
}
func newETCD3ProberMonitor(c storagebackend.Config) (*etcd3ProberMonitor, error) {
client, err := newETCD3Client(c.Transport)
if err != nil {
return nil, err
}
return &etcd3ProberMonitor{
client: client,
prefix: c.Prefix,
endpoints: c.Transport.ServerList,
}, nil
}
type etcd3ProberMonitor struct {
prefix string
endpoints []string
mux sync.RWMutex
client *clientv3.Client
closed bool
}
func (t *etcd3ProberMonitor) Close() error {
t.mux.Lock()
defer t.mux.Unlock()
if !t.closed {
t.closed = true
return t.client.Close()
}
return fmt.Errorf("closed")
}
func (t *etcd3ProberMonitor) Probe(ctx context.Context) error {
t.mux.RLock()
defer t.mux.RUnlock()
if t.closed {
return fmt.Errorf("closed")
}
// See https://github.com/etcd-io/etcd/blob/c57f8b3af865d1b531b979889c602ba14377420e/etcdctl/ctlv3/command/ep_command.go#L118
_, err := t.client.Get(ctx, path.Join("/", t.prefix, "health"))
if err != nil {
return fmt.Errorf("error getting data from etcd: %w", err)
}
return nil
}
func (t *etcd3ProberMonitor) Monitor(ctx context.Context) (metrics.StorageMetrics, error) {
t.mux.RLock()
defer t.mux.RUnlock()
if t.closed {
return metrics.StorageMetrics{}, fmt.Errorf("closed")
}
status, err := t.client.Status(ctx, t.endpoints[rand.Int()%len(t.endpoints)])
if err != nil {
return metrics.StorageMetrics{}, err
}
return metrics.StorageMetrics{
Size: status.DbSize,
}, nil
}
var newETCD3Client = func(c storagebackend.TransportConfig) (*clientv3.Client, error) {
tlsInfo := transport.TLSInfo{
CertFile: c.CertFile,
KeyFile: c.KeyFile,
TrustedCAFile: c.TrustedCAFile,
}
tlsConfig, err := tlsInfo.ClientConfig()
if err != nil {
return nil, err
}
// NOTE: Client relies on nil tlsConfig
// for non-secure connections, update the implicit variable
if len(c.CertFile) == 0 && len(c.KeyFile) == 0 && len(c.TrustedCAFile) == 0 {
tlsConfig = nil
}
networkContext := egressselector.Etcd.AsNetworkContext()
var egressDialer utilnet.DialFunc
if c.EgressLookup != nil {
egressDialer, err = c.EgressLookup(networkContext)
if err != nil {
return nil, err
}
}
dialOptions := []grpc.DialOption{
grpc.WithBlock(), // block until the underlying connection is up
// use chained interceptors so that the default (retry and backoff) interceptors are added.
// otherwise they will be overwritten by the metric interceptor.
//
// these optional interceptors will be placed after the default ones.
// which seems to be what we want as the metrics will be collected on each attempt (retry)
grpc.WithChainUnaryInterceptor(grpcprom.UnaryClientInterceptor),
grpc.WithChainStreamInterceptor(grpcprom.StreamClientInterceptor),
}
if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.APIServerTracing) {
tracingOpts := []otelgrpc.Option{
otelgrpc.WithPropagators(tracing.Propagators()),
otelgrpc.WithTracerProvider(c.TracerProvider),
}
// Even with Noop TracerProvider, the otelgrpc still handles context propagation.
// See https://github.com/open-telemetry/opentelemetry-go/tree/main/example/passthrough
dialOptions = append(dialOptions,
grpc.WithUnaryInterceptor(otelgrpc.UnaryClientInterceptor(tracingOpts...)),
grpc.WithStreamInterceptor(otelgrpc.StreamClientInterceptor(tracingOpts...)))
}
if egressDialer != nil {
dialer := func(ctx context.Context, addr string) (net.Conn, error) {
if strings.Contains(addr, "//") {
// etcd client prior to 3.5 passed URLs to dialer, normalize to address
u, err := url.Parse(addr)
if err != nil {
return nil, err
}
addr = u.Host
}
return egressDialer(ctx, "tcp", addr)
}
dialOptions = append(dialOptions, grpc.WithContextDialer(dialer))
}
cfg := clientv3.Config{
DialTimeout: dialTimeout,
DialKeepAliveTime: keepaliveTime,
DialKeepAliveTimeout: keepaliveTimeout,
DialOptions: dialOptions,
Endpoints: c.ServerList,
TLS: tlsConfig,
Logger: etcd3ClientLogger,
}
return clientv3.New(cfg)
}
type runningCompactor struct {
interval time.Duration
cancel context.CancelFunc
client *clientv3.Client
refs int
}
var (
// compactorsMu guards access to compactors map
compactorsMu sync.Mutex
compactors = map[string]*runningCompactor{}
// dbMetricsMonitorsMu guards access to dbMetricsMonitors map
dbMetricsMonitorsMu sync.Mutex
dbMetricsMonitors map[string]struct{}
)
// startCompactorOnce start one compactor per transport. If the interval get smaller on repeated calls, the
// compactor is replaced. A destroy func is returned. If all destroy funcs with the same transport are called,
// the compactor is stopped.
func startCompactorOnce(c storagebackend.TransportConfig, interval time.Duration) (func(), error) {
compactorsMu.Lock()
defer compactorsMu.Unlock()
key := fmt.Sprintf("%v", c) // gives: {[server1 server2] keyFile certFile caFile}
if compactor, foundBefore := compactors[key]; !foundBefore || compactor.interval > interval {
compactorClient, err := newETCD3Client(c)
if err != nil {
return nil, err
}
if foundBefore {
// replace compactor
compactor.cancel()
compactor.client.Close()
} else {
// start new compactor
compactor = &runningCompactor{}
compactors[key] = compactor
}
ctx, cancel := context.WithCancel(context.Background())
compactor.interval = interval
compactor.cancel = cancel
compactor.client = compactorClient
etcd3.StartCompactor(ctx, compactorClient, interval)
}
compactors[key].refs++
return func() {
compactorsMu.Lock()
defer compactorsMu.Unlock()
compactor := compactors[key]
compactor.refs--
if compactor.refs == 0 {
compactor.cancel()
compactor.client.Close()
delete(compactors, key)
}
}, nil
}
func newETCD3Storage(c storagebackend.ConfigForResource, newFunc, newListFunc func() runtime.Object, resourcePrefix string) (storage.Interface, DestroyFunc, error) {
stopCompactor, err := startCompactorOnce(c.Transport, c.CompactionInterval)
if err != nil {
return nil, nil, err
}
client, err := newETCD3Client(c.Transport)
if err != nil {
stopCompactor()
return nil, nil, err
}
// decorate the KV instance so we can track etcd latency per request.
client.KV = etcd3.NewETCDLatencyTracker(client.KV)
stopDBSizeMonitor, err := startDBSizeMonitorPerEndpoint(client, c.DBMetricPollInterval)
if err != nil {
return nil, nil, err
}
var once sync.Once
destroyFunc := func() {
// we know that storage destroy funcs are called multiple times (due to reuse in subresources).
// Hence, we only destroy once.
// TODO: fix duplicated storage destroy calls higher level
once.Do(func() {
stopCompactor()
stopDBSizeMonitor()
client.Close()
})
}
transformer := c.Transformer
if transformer == nil {
transformer = identity.NewEncryptCheckTransformer()
}
return etcd3.New(client, c.Codec, newFunc, newListFunc, c.Prefix, resourcePrefix, c.GroupResource, transformer, c.LeaseManagerConfig), destroyFunc, nil
}
// startDBSizeMonitorPerEndpoint starts a loop to monitor etcd database size and update the
// corresponding metric etcd_db_total_size_in_bytes for each etcd server endpoint.
// Deprecated: Will be replaced with newETCD3ProberMonitor
func startDBSizeMonitorPerEndpoint(client *clientv3.Client, interval time.Duration) (func(), error) {
if interval == 0 {
return func() {}, nil
}
dbMetricsMonitorsMu.Lock()
defer dbMetricsMonitorsMu.Unlock()
ctx, cancel := context.WithCancel(context.Background())
for _, ep := range client.Endpoints() {
if _, found := dbMetricsMonitors[ep]; found {
continue
}
dbMetricsMonitors[ep] = struct{}{}
endpoint := ep
klog.V(4).Infof("Start monitoring storage db size metric for endpoint %s with polling interval %v", endpoint, interval)
go wait.JitterUntilWithContext(ctx, func(context.Context) {
epStatus, err := client.Maintenance.Status(ctx, endpoint)
if err != nil {
klog.V(4).Infof("Failed to get storage db size for ep %s: %v", endpoint, err)
metrics.UpdateEtcdDbSize(endpoint, -1)
} else {
metrics.UpdateEtcdDbSize(endpoint, epStatus.DbSize)
}
}, interval, dbMetricsMonitorJitter, true)
}
return func() {
cancel()
}, nil
}