forked from msazurestackworkloads/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 0
/
proxier.go
1450 lines (1307 loc) · 54.3 KB
/
proxier.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
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
/*
Copyright 2015 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 iptables
//
// NOTE: this needs to be tested in e2e since it uses iptables for everything.
//
import (
"bytes"
"crypto/sha256"
"encoding/base32"
"fmt"
"net"
"reflect"
"strconv"
"strings"
"sync"
"time"
"github.com/davecgh/go-spew/spew"
"github.com/golang/glog"
"k8s.io/apimachinery/pkg/types"
"k8s.io/apimachinery/pkg/util/sets"
utilfeature "k8s.io/apiserver/pkg/util/feature"
clientv1 "k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/record"
"k8s.io/client-go/util/flowcontrol"
"k8s.io/kubernetes/pkg/api"
apiservice "k8s.io/kubernetes/pkg/api/service"
"k8s.io/kubernetes/pkg/features"
"k8s.io/kubernetes/pkg/proxy"
"k8s.io/kubernetes/pkg/proxy/healthcheck"
utilproxy "k8s.io/kubernetes/pkg/proxy/util"
utilexec "k8s.io/kubernetes/pkg/util/exec"
utiliptables "k8s.io/kubernetes/pkg/util/iptables"
utilsysctl "k8s.io/kubernetes/pkg/util/sysctl"
utilversion "k8s.io/kubernetes/pkg/util/version"
)
const (
// iptablesMinVersion is the minimum version of iptables for which we will use the Proxier
// from this package instead of the userspace Proxier. While most of the
// features we need were available earlier, the '-C' flag was added more
// recently. We use that indirectly in Ensure* functions, and if we don't
// have it, we have to be extra careful about the exact args we feed in being
// the same as the args we read back (iptables itself normalizes some args).
// This is the "new" Proxier, so we require "new" versions of tools.
iptablesMinVersion = utiliptables.MinCheckVersion
// the services chain
kubeServicesChain utiliptables.Chain = "KUBE-SERVICES"
// the nodeports chain
kubeNodePortsChain utiliptables.Chain = "KUBE-NODEPORTS"
// the kubernetes postrouting chain
kubePostroutingChain utiliptables.Chain = "KUBE-POSTROUTING"
// the mark-for-masquerade chain
KubeMarkMasqChain utiliptables.Chain = "KUBE-MARK-MASQ"
// the mark-for-drop chain
KubeMarkDropChain utiliptables.Chain = "KUBE-MARK-DROP"
)
// IPTablesVersioner can query the current iptables version.
type IPTablesVersioner interface {
// returns "X.Y.Z"
GetVersion() (string, error)
}
// KernelCompatTester tests whether the required kernel capabilities are
// present to run the iptables proxier.
type KernelCompatTester interface {
IsCompatible() error
}
// CanUseIPTablesProxier returns true if we should use the iptables Proxier
// instead of the "classic" userspace Proxier. This is determined by checking
// the iptables version and for the existence of kernel features. It may return
// an error if it fails to get the iptables version without error, in which
// case it will also return false.
func CanUseIPTablesProxier(iptver IPTablesVersioner, kcompat KernelCompatTester) (bool, error) {
minVersion, err := utilversion.ParseGeneric(iptablesMinVersion)
if err != nil {
return false, err
}
versionString, err := iptver.GetVersion()
if err != nil {
return false, err
}
version, err := utilversion.ParseGeneric(versionString)
if err != nil {
return false, err
}
if version.LessThan(minVersion) {
return false, nil
}
// Check that the kernel supports what we need.
if err := kcompat.IsCompatible(); err != nil {
return false, err
}
return true, nil
}
type LinuxKernelCompatTester struct{}
func (lkct LinuxKernelCompatTester) IsCompatible() error {
// Check for the required sysctls. We don't care about the value, just
// that it exists. If this Proxier is chosen, we'll initialize it as we
// need.
_, err := utilsysctl.New().GetSysctl(sysctlRouteLocalnet)
return err
}
const sysctlRouteLocalnet = "net/ipv4/conf/all/route_localnet"
const sysctlBridgeCallIPTables = "net/bridge/bridge-nf-call-iptables"
// internal struct for string service information
type serviceInfo struct {
clusterIP net.IP
port int
protocol api.Protocol
nodePort int
loadBalancerStatus api.LoadBalancerStatus
sessionAffinityType api.ServiceAffinity
stickyMaxAgeMinutes int
externalIPs []string
loadBalancerSourceRanges []string
onlyNodeLocalEndpoints bool
healthCheckNodePort int
}
// internal struct for endpoints information
type endpointsInfo struct {
endpoint string // TODO: should be an endpointString type
isLocal bool
}
// returns a new serviceInfo struct
func newServiceInfo(serviceName proxy.ServicePortName, port *api.ServicePort, service *api.Service) *serviceInfo {
onlyNodeLocalEndpoints := apiservice.NeedsHealthCheck(service) && utilfeature.DefaultFeatureGate.Enabled(features.ExternalTrafficLocalOnly) && (service.Spec.Type == api.ServiceTypeLoadBalancer || service.Spec.Type == api.ServiceTypeNodePort)
info := &serviceInfo{
clusterIP: net.ParseIP(service.Spec.ClusterIP),
port: int(port.Port),
protocol: port.Protocol,
nodePort: int(port.NodePort),
// Deep-copy in case the service instance changes
loadBalancerStatus: *api.LoadBalancerStatusDeepCopy(&service.Status.LoadBalancer),
sessionAffinityType: service.Spec.SessionAffinity,
stickyMaxAgeMinutes: 180, // TODO: paramaterize this in the API.
externalIPs: make([]string, len(service.Spec.ExternalIPs)),
loadBalancerSourceRanges: make([]string, len(service.Spec.LoadBalancerSourceRanges)),
onlyNodeLocalEndpoints: onlyNodeLocalEndpoints,
}
copy(info.loadBalancerSourceRanges, service.Spec.LoadBalancerSourceRanges)
copy(info.externalIPs, service.Spec.ExternalIPs)
if info.onlyNodeLocalEndpoints {
p := apiservice.GetServiceHealthCheckNodePort(service)
if p == 0 {
glog.Errorf("Service does not contain necessary annotation %v",
apiservice.BetaAnnotationHealthCheckNodePort)
} else {
info.healthCheckNodePort = int(p)
}
}
return info
}
type proxyServiceMap map[proxy.ServicePortName]*serviceInfo
// Proxier is an iptables based proxy for connections between a localhost:lport
// and services that provide the actual backends.
type Proxier struct {
mu sync.Mutex // protects the following fields
serviceMap proxyServiceMap
endpointsMap map[proxy.ServicePortName][]*endpointsInfo
portsMap map[localPort]closeable
haveReceivedServiceUpdate bool // true once we've seen an OnServiceUpdate event
allEndpoints []api.Endpoints // nil until we have seen an OnEndpointsUpdate event
throttle flowcontrol.RateLimiter
// These are effectively const and do not need the mutex to be held.
syncPeriod time.Duration
minSyncPeriod time.Duration
iptables utiliptables.Interface
masqueradeAll bool
masqueradeMark string
exec utilexec.Interface
clusterCIDR string
hostname string
nodeIP net.IP
portMapper portOpener
recorder record.EventRecorder
healthChecker healthChecker
}
type localPort struct {
desc string
ip string
port int
protocol string
}
func (lp *localPort) String() string {
return fmt.Sprintf("%q (%s:%d/%s)", lp.desc, lp.ip, lp.port, lp.protocol)
}
type closeable interface {
Close() error
}
// portOpener is an interface around port opening/closing.
// Abstracted out for testing.
type portOpener interface {
OpenLocalPort(lp *localPort) (closeable, error)
}
// listenPortOpener opens ports by calling bind() and listen().
type listenPortOpener struct{}
// OpenLocalPort holds the given local port open.
func (l *listenPortOpener) OpenLocalPort(lp *localPort) (closeable, error) {
return openLocalPort(lp)
}
type healthChecker interface {
UpdateEndpoints(serviceName types.NamespacedName, endpointUIDs sets.String)
}
// TODO: the healthcheck pkg should offer a type
type globalHealthChecker struct{}
func (globalHealthChecker) UpdateEndpoints(serviceName types.NamespacedName, endpointUIDs sets.String) {
healthcheck.UpdateEndpoints(serviceName, endpointUIDs)
}
// Proxier implements ProxyProvider
var _ proxy.ProxyProvider = &Proxier{}
// NewProxier returns a new Proxier given an iptables Interface instance.
// Because of the iptables logic, it is assumed that there is only a single Proxier active on a machine.
// An error will be returned if iptables fails to update or acquire the initial lock.
// Once a proxier is created, it will keep iptables up to date in the background and
// will not terminate if a particular iptables call fails.
func NewProxier(ipt utiliptables.Interface,
sysctl utilsysctl.Interface,
exec utilexec.Interface,
syncPeriod time.Duration,
minSyncPeriod time.Duration,
masqueradeAll bool,
masqueradeBit int,
clusterCIDR string,
hostname string,
nodeIP net.IP,
recorder record.EventRecorder,
) (*Proxier, error) {
// check valid user input
if minSyncPeriod > syncPeriod {
return nil, fmt.Errorf("min-sync (%v) must be < sync(%v)", minSyncPeriod, syncPeriod)
}
// Set the route_localnet sysctl we need for
if err := sysctl.SetSysctl(sysctlRouteLocalnet, 1); err != nil {
return nil, fmt.Errorf("can't set sysctl %s: %v", sysctlRouteLocalnet, err)
}
// Proxy needs br_netfilter and bridge-nf-call-iptables=1 when containers
// are connected to a Linux bridge (but not SDN bridges). Until most
// plugins handle this, log when config is missing
if val, err := sysctl.GetSysctl(sysctlBridgeCallIPTables); err == nil && val != 1 {
glog.Infof("missing br-netfilter module or unset sysctl br-nf-call-iptables; proxy may not work as intended")
}
// Generate the masquerade mark to use for SNAT rules.
if masqueradeBit < 0 || masqueradeBit > 31 {
return nil, fmt.Errorf("invalid iptables-masquerade-bit %v not in [0, 31]", masqueradeBit)
}
masqueradeValue := 1 << uint(masqueradeBit)
masqueradeMark := fmt.Sprintf("%#08x/%#08x", masqueradeValue, masqueradeValue)
if nodeIP == nil {
glog.Warningf("invalid nodeIP, initializing kube-proxy with 127.0.0.1 as nodeIP")
nodeIP = net.ParseIP("127.0.0.1")
}
if len(clusterCIDR) == 0 {
glog.Warningf("clusterCIDR not specified, unable to distinguish between internal and external traffic")
}
healthChecker := globalHealthChecker{}
go healthcheck.Run()
var throttle flowcontrol.RateLimiter
// Defaulting back to not limit sync rate when minSyncPeriod is 0.
if minSyncPeriod != 0 {
syncsPerSecond := float32(time.Second) / float32(minSyncPeriod)
// The average use case will process 2 updates in short succession
throttle = flowcontrol.NewTokenBucketRateLimiter(syncsPerSecond, 2)
}
return &Proxier{
serviceMap: make(proxyServiceMap),
endpointsMap: make(map[proxy.ServicePortName][]*endpointsInfo),
portsMap: make(map[localPort]closeable),
syncPeriod: syncPeriod,
minSyncPeriod: minSyncPeriod,
throttle: throttle,
iptables: ipt,
masqueradeAll: masqueradeAll,
masqueradeMark: masqueradeMark,
exec: exec,
clusterCIDR: clusterCIDR,
hostname: hostname,
nodeIP: nodeIP,
portMapper: &listenPortOpener{},
recorder: recorder,
healthChecker: healthChecker,
}, nil
}
// CleanupLeftovers removes all iptables rules and chains created by the Proxier
// It returns true if an error was encountered. Errors are logged.
func CleanupLeftovers(ipt utiliptables.Interface) (encounteredError bool) {
// Unlink the services chain.
args := []string{
"-m", "comment", "--comment", "kubernetes service portals",
"-j", string(kubeServicesChain),
}
tableChainsWithJumpServices := []struct {
table utiliptables.Table
chain utiliptables.Chain
}{
{utiliptables.TableFilter, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainPrerouting},
}
for _, tc := range tableChainsWithJumpServices {
if err := ipt.DeleteRule(tc.table, tc.chain, args...); err != nil {
if !utiliptables.IsNotFoundError(err) {
glog.Errorf("Error removing pure-iptables proxy rule: %v", err)
encounteredError = true
}
}
}
// Unlink the postrouting chain.
args = []string{
"-m", "comment", "--comment", "kubernetes postrouting rules",
"-j", string(kubePostroutingChain),
}
if err := ipt.DeleteRule(utiliptables.TableNAT, utiliptables.ChainPostrouting, args...); err != nil {
if !utiliptables.IsNotFoundError(err) {
glog.Errorf("Error removing pure-iptables proxy rule: %v", err)
encounteredError = true
}
}
// Flush and remove all of our chains.
if iptablesSaveRaw, err := ipt.Save(utiliptables.TableNAT); err != nil {
glog.Errorf("Failed to execute iptables-save for %s: %v", utiliptables.TableNAT, err)
encounteredError = true
} else {
existingNATChains := utiliptables.GetChainLines(utiliptables.TableNAT, iptablesSaveRaw)
natChains := bytes.NewBuffer(nil)
natRules := bytes.NewBuffer(nil)
writeLine(natChains, "*nat")
// Start with chains we know we need to remove.
for _, chain := range []utiliptables.Chain{kubeServicesChain, kubeNodePortsChain, kubePostroutingChain, KubeMarkMasqChain} {
if _, found := existingNATChains[chain]; found {
chainString := string(chain)
writeLine(natChains, existingNATChains[chain]) // flush
writeLine(natRules, "-X", chainString) // delete
}
}
// Hunt for service and endpoint chains.
for chain := range existingNATChains {
chainString := string(chain)
if strings.HasPrefix(chainString, "KUBE-SVC-") || strings.HasPrefix(chainString, "KUBE-SEP-") || strings.HasPrefix(chainString, "KUBE-FW-") || strings.HasPrefix(chainString, "KUBE-XLB-") {
writeLine(natChains, existingNATChains[chain]) // flush
writeLine(natRules, "-X", chainString) // delete
}
}
writeLine(natRules, "COMMIT")
natLines := append(natChains.Bytes(), natRules.Bytes()...)
// Write it.
err = ipt.Restore(utiliptables.TableNAT, natLines, utiliptables.NoFlushTables, utiliptables.RestoreCounters)
if err != nil {
glog.Errorf("Failed to execute iptables-restore for %s: %v", utiliptables.TableNAT, err)
encounteredError = true
}
}
{
filterBuf := bytes.NewBuffer(nil)
writeLine(filterBuf, "*filter")
writeLine(filterBuf, fmt.Sprintf(":%s - [0:0]", kubeServicesChain))
writeLine(filterBuf, fmt.Sprintf("-X %s", kubeServicesChain))
writeLine(filterBuf, "COMMIT")
// Write it.
if err := ipt.Restore(utiliptables.TableFilter, filterBuf.Bytes(), utiliptables.NoFlushTables, utiliptables.RestoreCounters); err != nil {
glog.Errorf("Failed to execute iptables-restore for %s: %v", utiliptables.TableFilter, err)
encounteredError = true
}
}
return encounteredError
}
// Sync is called to immediately synchronize the proxier state to iptables
func (proxier *Proxier) Sync() {
proxier.mu.Lock()
defer proxier.mu.Unlock()
proxier.syncProxyRules()
}
// SyncLoop runs periodic work. This is expected to run as a goroutine or as the main loop of the app. It does not return.
func (proxier *Proxier) SyncLoop() {
t := time.NewTicker(proxier.syncPeriod)
defer t.Stop()
for {
<-t.C
glog.V(6).Infof("Periodic sync")
proxier.Sync()
}
}
type healthCheckPort struct {
namespace types.NamespacedName
nodeport int
}
// Accepts a list of Services and the existing service map. Returns the new
// service map, a list of healthcheck ports to add to or remove from the health
// checking listener service, and a set of stale UDP services.
func buildServiceMap(allServices []api.Service, oldServiceMap proxyServiceMap) (proxyServiceMap, []healthCheckPort, []healthCheckPort, sets.String) {
newServiceMap := make(proxyServiceMap)
healthCheckAdd := make([]healthCheckPort, 0)
healthCheckDel := make([]healthCheckPort, 0)
for i := range allServices {
service := &allServices[i]
svcName := types.NamespacedName{
Namespace: service.Namespace,
Name: service.Name,
}
// if ClusterIP is "None" or empty, skip proxying
if !api.IsServiceIPSet(service) {
glog.V(3).Infof("Skipping service %s due to clusterIP = %q", svcName, service.Spec.ClusterIP)
continue
}
// Even if ClusterIP is set, ServiceTypeExternalName services don't get proxied
if service.Spec.Type == api.ServiceTypeExternalName {
glog.V(3).Infof("Skipping service %s due to Type=ExternalName", svcName)
continue
}
for i := range service.Spec.Ports {
servicePort := &service.Spec.Ports[i]
serviceName := proxy.ServicePortName{
NamespacedName: svcName,
Port: servicePort.Name,
}
info := newServiceInfo(serviceName, servicePort, service)
oldInfo, exists := oldServiceMap[serviceName]
equal := reflect.DeepEqual(info, oldInfo)
if !exists {
glog.V(1).Infof("Adding new service %q at %s:%d/%s", serviceName, info.clusterIP, servicePort.Port, servicePort.Protocol)
} else if !equal {
glog.V(1).Infof("Updating existing service %q at %s:%d/%s", serviceName, info.clusterIP, servicePort.Port, servicePort.Protocol)
}
if !exists || !equal {
if info.onlyNodeLocalEndpoints && info.healthCheckNodePort > 0 {
healthCheckAdd = append(healthCheckAdd, healthCheckPort{serviceName.NamespacedName, info.healthCheckNodePort})
} else {
healthCheckDel = append(healthCheckDel, healthCheckPort{serviceName.NamespacedName, 0})
}
}
newServiceMap[serviceName] = info
glog.V(4).Infof("added serviceInfo(%s): %s", serviceName, spew.Sdump(info))
}
}
staleUDPServices := sets.NewString()
// Remove serviceports missing from the update.
for name, info := range oldServiceMap {
if _, exists := newServiceMap[name]; !exists {
glog.V(1).Infof("Removing service %q", name)
if info.protocol == api.ProtocolUDP {
staleUDPServices.Insert(info.clusterIP.String())
}
if info.onlyNodeLocalEndpoints && info.healthCheckNodePort > 0 {
healthCheckDel = append(healthCheckDel, healthCheckPort{name.NamespacedName, info.healthCheckNodePort})
}
}
}
return newServiceMap, healthCheckAdd, healthCheckDel, staleUDPServices
}
// OnServiceUpdate tracks the active set of service proxies.
// They will be synchronized using syncProxyRules()
func (proxier *Proxier) OnServiceUpdate(allServices []api.Service) {
start := time.Now()
defer func() {
glog.V(4).Infof("OnServiceUpdate took %v for %d services", time.Since(start), len(allServices))
}()
proxier.mu.Lock()
defer proxier.mu.Unlock()
proxier.haveReceivedServiceUpdate = true
newServiceMap, hcAdd, hcDel, staleUDPServices := buildServiceMap(allServices, proxier.serviceMap)
for _, hc := range hcAdd {
glog.V(4).Infof("Adding health check for %+v, port %v", hc.namespace, hc.nodeport)
// Turn on healthcheck responder to listen on the health check nodePort
// FIXME: handle failures from adding the service
healthcheck.AddServiceListener(hc.namespace, hc.nodeport)
}
for _, hc := range hcDel {
// Remove ServiceListener health check nodePorts from the health checker
// TODO - Stats
glog.V(4).Infof("Deleting health check for %+v, port %v", hc.namespace, hc.nodeport)
// FIXME: handle failures from deleting the service
healthcheck.DeleteServiceListener(hc.namespace, hc.nodeport)
}
if len(newServiceMap) != len(proxier.serviceMap) || !reflect.DeepEqual(newServiceMap, proxier.serviceMap) {
proxier.serviceMap = newServiceMap
proxier.syncProxyRules()
} else {
glog.V(4).Infof("Skipping proxy iptables rule sync on service update because nothing changed")
}
utilproxy.DeleteServiceConnections(proxier.exec, staleUDPServices.List())
}
// Reconstruct the list of endpoint infos from the endpointIP list
// Use the slice of endpointIPs to rebuild a slice of corresponding {endpointIP, localEndpointOnly} infos
// from the full []hostPortInfo slice.
//
// For e.g. if input is
// endpoints = []hostPortInfo{ {host="1.1.1.1", port=22, localEndpointOnly=<bool>}, {host="2.2.2.2", port=80, localEndpointOnly=<bool>} }
// endpointIPs = []string{ "2.2.2.2:80" }
//
// then output will be
//
// []endpointsInfo{ {"2.2.2.2:80", localEndpointOnly=<bool>} }
func buildEndpointInfoList(endPoints []hostPortInfo, endpointIPs []string) []*endpointsInfo {
lookupSet := sets.NewString()
for _, ip := range endpointIPs {
lookupSet.Insert(ip)
}
var filteredEndpoints []*endpointsInfo
for _, hpp := range endPoints {
key := net.JoinHostPort(hpp.host, strconv.Itoa(hpp.port))
if lookupSet.Has(key) {
filteredEndpoints = append(filteredEndpoints, &endpointsInfo{endpoint: key, isLocal: hpp.isLocal})
}
}
return filteredEndpoints
}
// OnEndpointsUpdate takes in a slice of updated endpoints.
func (proxier *Proxier) OnEndpointsUpdate(allEndpoints []api.Endpoints) {
proxier.mu.Lock()
defer proxier.mu.Unlock()
if proxier.allEndpoints == nil {
glog.V(2).Info("Received first Endpoints update")
}
proxier.allEndpoints = allEndpoints
// TODO: once service has made this same transform, move this into proxier.syncProxyRules()
newMap, staleConnections := updateEndpoints(proxier.allEndpoints, proxier.endpointsMap, proxier.hostname, proxier.healthChecker)
if len(newMap) != len(proxier.endpointsMap) || !reflect.DeepEqual(newMap, proxier.endpointsMap) {
proxier.endpointsMap = newMap
proxier.syncProxyRules()
} else {
glog.V(4).Infof("Skipping proxy iptables rule sync on endpoint update because nothing changed")
}
proxier.deleteEndpointConnections(staleConnections)
}
// Convert a slice of api.Endpoints objects into a map of service-port -> endpoints.
func updateEndpoints(allEndpoints []api.Endpoints, curMap map[proxy.ServicePortName][]*endpointsInfo, hostname string,
healthChecker healthChecker) (newMap map[proxy.ServicePortName][]*endpointsInfo, staleSet map[endpointServicePair]bool) {
// return values
newMap = make(map[proxy.ServicePortName][]*endpointsInfo)
staleSet = make(map[endpointServicePair]bool)
// local
svcPortToInfoMap := make(map[proxy.ServicePortName][]hostPortInfo)
// Update endpoints for services.
for i := range allEndpoints {
accumulateEndpointsMap(&allEndpoints[i], hostname, curMap, &newMap, &svcPortToInfoMap)
}
// Check stale connections against endpoints missing from the update.
// TODO: we should really only mark a connection stale if the proto was UDP
// and the (ip, port, proto) was removed from the endpoints.
for svcPort, epList := range curMap {
for _, ep := range epList {
stale := true
for i := range newMap[svcPort] {
if *newMap[svcPort][i] == *ep {
stale = false
break
}
}
if stale {
glog.V(4).Infof("Stale endpoint %v -> %v", svcPort, ep.endpoint)
staleSet[endpointServicePair{endpoint: ep.endpoint, servicePortName: svcPort}] = true
}
}
}
// Update service health check
allSvcPorts := make(map[proxy.ServicePortName]bool)
for svcPort := range curMap {
allSvcPorts[svcPort] = true
}
for svcPort := range newMap {
allSvcPorts[svcPort] = true
}
for svcPort := range allSvcPorts {
updateHealthCheckEntries(svcPort.NamespacedName, svcPortToInfoMap[svcPort], healthChecker)
}
return newMap, staleSet
}
// Gather information about all the endpoint state for a given api.Endpoints.
// This can not report complete info on stale connections because it has limited
// scope - it only knows one Endpoints, but sees the whole current map. That
// cleanup has to be done above.
//
// TODO: this could be simplified:
// - hostPortInfo and endpointsInfo overlap too much
// - the test for this is overlapped by the test for updateEndpoints
// - naming is poor and responsibilities are muddled
func accumulateEndpointsMap(endpoints *api.Endpoints, hostname string,
curEndpoints map[proxy.ServicePortName][]*endpointsInfo,
newEndpoints *map[proxy.ServicePortName][]*endpointsInfo,
svcPortToInfoMap *map[proxy.ServicePortName][]hostPortInfo) {
// We need to build a map of portname -> all ip:ports for that
// portname. Explode Endpoints.Subsets[*] into this structure.
for i := range endpoints.Subsets {
ss := &endpoints.Subsets[i]
for i := range ss.Ports {
port := &ss.Ports[i]
svcPort := proxy.ServicePortName{
NamespacedName: types.NamespacedName{Namespace: endpoints.Namespace, Name: endpoints.Name},
Port: port.Name,
}
for i := range ss.Addresses {
addr := &ss.Addresses[i]
hostPortObject := hostPortInfo{
host: addr.IP,
port: int(port.Port),
isLocal: addr.NodeName != nil && *addr.NodeName == hostname,
}
(*svcPortToInfoMap)[svcPort] = append((*svcPortToInfoMap)[svcPort], hostPortObject)
}
}
}
// Decompose the lists of endpoints into details of what was changed for the caller.
for svcPort, hostPortInfos := range *svcPortToInfoMap {
newEPList := flattenValidEndpoints(hostPortInfos)
glog.V(3).Infof("Setting endpoints for %q to %+v", svcPort, newEPList)
// Once the set operations using the list of ips are complete, build the list of endpoint infos
(*newEndpoints)[svcPort] = buildEndpointInfoList(hostPortInfos, newEPList)
}
}
// updateHealthCheckEntries - send the new set of local endpoints to the health checker
func updateHealthCheckEntries(name types.NamespacedName, hostPorts []hostPortInfo, healthChecker healthChecker) {
if !utilfeature.DefaultFeatureGate.Enabled(features.ExternalTrafficLocalOnly) {
return
}
// Use a set instead of a slice to provide deduplication
endpoints := sets.NewString()
for _, portInfo := range hostPorts {
if portInfo.isLocal {
// kube-proxy health check only needs local endpoints
endpoints.Insert(fmt.Sprintf("%s/%s", name.Namespace, name.Name))
}
}
healthChecker.UpdateEndpoints(name, endpoints)
}
// used in OnEndpointsUpdate
type hostPortInfo struct {
host string
port int
isLocal bool
}
func isValidEndpoint(hpp *hostPortInfo) bool {
return hpp.host != "" && hpp.port > 0
}
func flattenValidEndpoints(endpoints []hostPortInfo) []string {
// Convert Endpoint objects into strings for easier use later.
var result []string
for i := range endpoints {
hpp := &endpoints[i]
if isValidEndpoint(hpp) {
result = append(result, net.JoinHostPort(hpp.host, strconv.Itoa(hpp.port)))
} else {
glog.Warningf("got invalid endpoint: %+v", *hpp)
}
}
return result
}
// portProtoHash takes the ServicePortName and protocol for a service
// returns the associated 16 character hash. This is computed by hashing (sha256)
// then encoding to base32 and truncating to 16 chars. We do this because IPTables
// Chain Names must be <= 28 chars long, and the longer they are the harder they are to read.
func portProtoHash(s proxy.ServicePortName, protocol string) string {
hash := sha256.Sum256([]byte(s.String() + protocol))
encoded := base32.StdEncoding.EncodeToString(hash[:])
return encoded[:16]
}
// servicePortChainName takes the ServicePortName for a service and
// returns the associated iptables chain. This is computed by hashing (sha256)
// then encoding to base32 and truncating with the prefix "KUBE-SVC-".
func servicePortChainName(s proxy.ServicePortName, protocol string) utiliptables.Chain {
return utiliptables.Chain("KUBE-SVC-" + portProtoHash(s, protocol))
}
// serviceFirewallChainName takes the ServicePortName for a service and
// returns the associated iptables chain. This is computed by hashing (sha256)
// then encoding to base32 and truncating with the prefix "KUBE-FW-".
func serviceFirewallChainName(s proxy.ServicePortName, protocol string) utiliptables.Chain {
return utiliptables.Chain("KUBE-FW-" + portProtoHash(s, protocol))
}
// serviceLBPortChainName takes the ServicePortName for a service and
// returns the associated iptables chain. This is computed by hashing (sha256)
// then encoding to base32 and truncating with the prefix "KUBE-XLB-". We do
// this because IPTables Chain Names must be <= 28 chars long, and the longer
// they are the harder they are to read.
func serviceLBChainName(s proxy.ServicePortName, protocol string) utiliptables.Chain {
return utiliptables.Chain("KUBE-XLB-" + portProtoHash(s, protocol))
}
// This is the same as servicePortChainName but with the endpoint included.
func servicePortEndpointChainName(s proxy.ServicePortName, protocol string, endpoint string) utiliptables.Chain {
hash := sha256.Sum256([]byte(s.String() + protocol + endpoint))
encoded := base32.StdEncoding.EncodeToString(hash[:])
return utiliptables.Chain("KUBE-SEP-" + encoded[:16])
}
type endpointServicePair struct {
endpoint string
servicePortName proxy.ServicePortName
}
const noConnectionToDelete = "0 flow entries have been deleted"
// After a UDP endpoint has been removed, we must flush any pending conntrack entries to it, or else we
// risk sending more traffic to it, all of which will be lost (because UDP).
// This assumes the proxier mutex is held
func (proxier *Proxier) deleteEndpointConnections(connectionMap map[endpointServicePair]bool) {
for epSvcPair := range connectionMap {
if svcInfo, ok := proxier.serviceMap[epSvcPair.servicePortName]; ok && svcInfo.protocol == api.ProtocolUDP {
endpointIP := strings.Split(epSvcPair.endpoint, ":")[0]
glog.V(2).Infof("Deleting connection tracking state for service IP %s, endpoint IP %s", svcInfo.clusterIP.String(), endpointIP)
err := utilproxy.ExecConntrackTool(proxier.exec, "-D", "--orig-dst", svcInfo.clusterIP.String(), "--dst-nat", endpointIP, "-p", "udp")
if err != nil && !strings.Contains(err.Error(), noConnectionToDelete) {
// TODO: Better handling for deletion failure. When failure occur, stale udp connection may not get flushed.
// These stale udp connection will keep black hole traffic. Making this a best effort operation for now, since it
// is expensive to baby sit all udp connections to kubernetes services.
glog.Errorf("conntrack return with error: %v", err)
}
}
}
}
// This is where all of the iptables-save/restore calls happen.
// The only other iptables rules are those that are setup in iptablesInit()
// assumes proxier.mu is held
func (proxier *Proxier) syncProxyRules() {
if proxier.throttle != nil {
proxier.throttle.Accept()
}
start := time.Now()
defer func() {
glog.V(4).Infof("syncProxyRules took %v", time.Since(start))
}()
// don't sync rules till we've received services and endpoints
if proxier.allEndpoints == nil || !proxier.haveReceivedServiceUpdate {
glog.V(2).Info("Not syncing iptables until Services and Endpoints have been received from master")
return
}
glog.V(3).Infof("Syncing iptables rules")
// Create and link the kube services chain.
{
tablesNeedServicesChain := []utiliptables.Table{utiliptables.TableFilter, utiliptables.TableNAT}
for _, table := range tablesNeedServicesChain {
if _, err := proxier.iptables.EnsureChain(table, kubeServicesChain); err != nil {
glog.Errorf("Failed to ensure that %s chain %s exists: %v", table, kubeServicesChain, err)
return
}
}
tableChainsNeedJumpServices := []struct {
table utiliptables.Table
chain utiliptables.Chain
}{
{utiliptables.TableFilter, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainOutput},
{utiliptables.TableNAT, utiliptables.ChainPrerouting},
}
comment := "kubernetes service portals"
args := []string{"-m", "comment", "--comment", comment, "-j", string(kubeServicesChain)}
for _, tc := range tableChainsNeedJumpServices {
if _, err := proxier.iptables.EnsureRule(utiliptables.Prepend, tc.table, tc.chain, args...); err != nil {
glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", tc.table, tc.chain, kubeServicesChain, err)
return
}
}
}
// Create and link the kube postrouting chain.
{
if _, err := proxier.iptables.EnsureChain(utiliptables.TableNAT, kubePostroutingChain); err != nil {
glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, kubePostroutingChain, err)
return
}
comment := "kubernetes postrouting rules"
args := []string{"-m", "comment", "--comment", comment, "-j", string(kubePostroutingChain)}
if _, err := proxier.iptables.EnsureRule(utiliptables.Prepend, utiliptables.TableNAT, utiliptables.ChainPostrouting, args...); err != nil {
glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableNAT, utiliptables.ChainPostrouting, kubePostroutingChain, err)
return
}
}
//
// Below this point we will not return until we try to write the iptables rules.
//
// Get iptables-save output so we can check for existing chains and rules.
// This will be a map of chain name to chain with rules as stored in iptables-save/iptables-restore
existingFilterChains := make(map[utiliptables.Chain]string)
iptablesSaveRaw, err := proxier.iptables.Save(utiliptables.TableFilter)
if err != nil { // if we failed to get any rules
glog.Errorf("Failed to execute iptables-save, syncing all rules: %v", err)
} else { // otherwise parse the output
existingFilterChains = utiliptables.GetChainLines(utiliptables.TableFilter, iptablesSaveRaw)
}
existingNATChains := make(map[utiliptables.Chain]string)
iptablesSaveRaw, err = proxier.iptables.Save(utiliptables.TableNAT)
if err != nil { // if we failed to get any rules
glog.Errorf("Failed to execute iptables-save, syncing all rules: %v", err)
} else { // otherwise parse the output
existingNATChains = utiliptables.GetChainLines(utiliptables.TableNAT, iptablesSaveRaw)
}
filterChains := bytes.NewBuffer(nil)
filterRules := bytes.NewBuffer(nil)
natChains := bytes.NewBuffer(nil)
natRules := bytes.NewBuffer(nil)
// Write table headers.
writeLine(filterChains, "*filter")
writeLine(natChains, "*nat")
// Make sure we keep stats for the top-level chains, if they existed
// (which most should have because we created them above).
if chain, ok := existingFilterChains[kubeServicesChain]; ok {
writeLine(filterChains, chain)
} else {
writeLine(filterChains, utiliptables.MakeChainLine(kubeServicesChain))
}
if chain, ok := existingNATChains[kubeServicesChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(kubeServicesChain))
}
if chain, ok := existingNATChains[kubeNodePortsChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(kubeNodePortsChain))
}
if chain, ok := existingNATChains[kubePostroutingChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(kubePostroutingChain))
}
if chain, ok := existingNATChains[KubeMarkMasqChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(KubeMarkMasqChain))
}
// Install the kubernetes-specific postrouting rules. We use a whole chain for
// this so that it is easier to flush and change, for example if the mark
// value should ever change.
writeLine(natRules, []string{
"-A", string(kubePostroutingChain),
"-m", "comment", "--comment", `"kubernetes service traffic requiring SNAT"`,
"-m", "mark", "--mark", proxier.masqueradeMark,
"-j", "MASQUERADE",
}...)
// Install the kubernetes-specific masquerade mark rule. We use a whole chain for
// this so that it is easier to flush and change, for example if the mark
// value should ever change.
writeLine(natRules, []string{
"-A", string(KubeMarkMasqChain),
"-j", "MARK", "--set-xmark", proxier.masqueradeMark,
}...)
// Accumulate NAT chains to keep.
activeNATChains := map[utiliptables.Chain]bool{} // use a map as a set
// Accumulate the set of local ports that we will be holding open once this update is complete
replacementPortsMap := map[localPort]closeable{}
// Build rules for each service.
for svcName, svcInfo := range proxier.serviceMap {
protocol := strings.ToLower(string(svcInfo.protocol))
// Create the per-service chain, retaining counters if possible.
svcChain := servicePortChainName(svcName, protocol)
if chain, ok := existingNATChains[svcChain]; ok {
writeLine(natChains, chain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(svcChain))
}
activeNATChains[svcChain] = true
svcXlbChain := serviceLBChainName(svcName, protocol)
if svcInfo.onlyNodeLocalEndpoints {
// Only for services with the externalTraffic annotation set to OnlyLocal
// create the per-service LB chain, retaining counters if possible.
if lbChain, ok := existingNATChains[svcXlbChain]; ok {
writeLine(natChains, lbChain)
} else {
writeLine(natChains, utiliptables.MakeChainLine(svcXlbChain))
}
activeNATChains[svcXlbChain] = true
} else if activeNATChains[svcXlbChain] {
// Cleanup the previously created XLB chain for this service
delete(activeNATChains, svcXlbChain)
}
// Capture the clusterIP.
args := []string{
"-A", string(kubeServicesChain),
"-m", "comment", "--comment", fmt.Sprintf(`"%s cluster IP"`, svcName.String()),
"-m", protocol, "-p", protocol,
"-d", fmt.Sprintf("%s/32", svcInfo.clusterIP.String()),
"--dport", fmt.Sprintf("%d", svcInfo.port),
}
if proxier.masqueradeAll {
writeLine(natRules, append(args, "-j", string(KubeMarkMasqChain))...)
}
if len(proxier.clusterCIDR) > 0 {
writeLine(natRules, append(args, "! -s", proxier.clusterCIDR, "-j", string(KubeMarkMasqChain))...)
}
writeLine(natRules, append(args, "-j", string(svcChain))...)
// Capture externalIPs.
for _, externalIP := range svcInfo.externalIPs {
// If the "external" IP happens to be an IP that is local to this
// machine, hold the local port open so no other process can open it
// (because the socket might open but it would never work).
if local, err := isLocalIP(externalIP); err != nil {