forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 3
/
nodecontroller.go
1176 lines (1100 loc) · 45.8 KB
/
nodecontroller.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 2014 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 node
import (
"errors"
"fmt"
"net"
"sync"
"time"
apiequality "k8s.io/apimachinery/pkg/api/equality"
apierrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/fields"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/types"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/util/wait"
v1core "k8s.io/client-go/kubernetes/typed/core/v1"
clientv1 "k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/tools/record"
"k8s.io/client-go/util/flowcontrol"
"k8s.io/kubernetes/pkg/api"
"k8s.io/kubernetes/pkg/api/v1"
"k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
coreinformers "k8s.io/kubernetes/pkg/client/informers/informers_generated/externalversions/core/v1"
extensionsinformers "k8s.io/kubernetes/pkg/client/informers/informers_generated/externalversions/extensions/v1beta1"
corelisters "k8s.io/kubernetes/pkg/client/listers/core/v1"
extensionslisters "k8s.io/kubernetes/pkg/client/listers/extensions/v1beta1"
"k8s.io/kubernetes/pkg/cloudprovider"
"k8s.io/kubernetes/pkg/controller"
"k8s.io/kubernetes/pkg/util/metrics"
utilnode "k8s.io/kubernetes/pkg/util/node"
"k8s.io/kubernetes/pkg/util/system"
utilversion "k8s.io/kubernetes/pkg/util/version"
"github.com/golang/glog"
)
func init() {
// Register prometheus metrics
Register()
}
var (
ErrCloudInstance = errors.New("cloud provider doesn't support instances.")
gracefulDeletionVersion = utilversion.MustParseSemantic("v1.1.0")
// The minimum kubelet version for which the nodecontroller
// can safely flip pod.Status to NotReady.
podStatusReconciliationVersion = utilversion.MustParseSemantic("v1.2.0")
UnreachableTaintTemplate = &v1.Taint{
Key: metav1.TaintNodeUnreachable,
Effect: v1.TaintEffectNoExecute,
}
NotReadyTaintTemplate = &v1.Taint{
Key: metav1.TaintNodeNotReady,
Effect: v1.TaintEffectNoExecute,
}
)
const (
// nodeStatusUpdateRetry controls the number of retries of writing NodeStatus update.
nodeStatusUpdateRetry = 5
// controls how often NodeController will try to evict Pods from non-responsive Nodes.
nodeEvictionPeriod = 100 * time.Millisecond
// Burst value for all eviction rate limiters
evictionRateLimiterBurst = 1
// The amount of time the nodecontroller polls on the list nodes endpoint.
apiserverStartupGracePeriod = 10 * time.Minute
// The amount of time the nodecontroller should sleep between retrying NodeStatus updates
retrySleepTime = 20 * time.Millisecond
)
type zoneState string
const (
stateInitial = zoneState("Initial")
stateNormal = zoneState("Normal")
stateFullDisruption = zoneState("FullDisruption")
statePartialDisruption = zoneState("PartialDisruption")
)
type nodeStatusData struct {
probeTimestamp metav1.Time
readyTransitionTimestamp metav1.Time
status v1.NodeStatus
}
type NodeController struct {
allocateNodeCIDRs bool
cloud cloudprovider.Interface
clusterCIDR *net.IPNet
serviceCIDR *net.IPNet
knownNodeSet map[string]*v1.Node
kubeClient clientset.Interface
// Method for easy mocking in unittest.
lookupIP func(host string) ([]net.IP, error)
// Value used if sync_nodes_status=False. NodeController will not proactively
// sync node status in this case, but will monitor node status updated from kubelet. If
// it doesn't receive update for this amount of time, it will start posting "NodeReady==
// ConditionUnknown". The amount of time before which NodeController start evicting pods
// is controlled via flag 'pod-eviction-timeout'.
// Note: be cautious when changing the constant, it must work with nodeStatusUpdateFrequency
// in kubelet. There are several constraints:
// 1. nodeMonitorGracePeriod must be N times more than nodeStatusUpdateFrequency, where
// N means number of retries allowed for kubelet to post node status. It is pointless
// to make nodeMonitorGracePeriod be less than nodeStatusUpdateFrequency, since there
// will only be fresh values from Kubelet at an interval of nodeStatusUpdateFrequency.
// The constant must be less than podEvictionTimeout.
// 2. nodeMonitorGracePeriod can't be too large for user experience - larger value takes
// longer for user to see up-to-date node status.
nodeMonitorGracePeriod time.Duration
// Value controlling NodeController monitoring period, i.e. how often does NodeController
// check node status posted from kubelet. This value should be lower than nodeMonitorGracePeriod.
// TODO: Change node status monitor to watch based.
nodeMonitorPeriod time.Duration
// Value used if sync_nodes_status=False, only for node startup. When node
// is just created, e.g. cluster bootstrap or node creation, we give a longer grace period.
nodeStartupGracePeriod time.Duration
// per Node map storing last observed Status together with a local time when it was observed.
// This timestamp is to be used instead of LastProbeTime stored in Condition. We do this
// to aviod the problem with time skew across the cluster.
nodeStatusMap map[string]nodeStatusData
now func() metav1.Time
// Lock to access evictor workers
evictorLock sync.Mutex
// workers that evicts pods from unresponsive nodes.
zonePodEvictor map[string]*RateLimitedTimedQueue
// workers that are responsible for tainting nodes.
zoneNotReadyOrUnreachableTainer map[string]*RateLimitedTimedQueue
podEvictionTimeout time.Duration
// The maximum duration before a pod evicted from a node can be forcefully terminated.
maximumGracePeriod time.Duration
recorder record.EventRecorder
nodeLister corelisters.NodeLister
nodeInformerSynced cache.InformerSynced
daemonSetStore extensionslisters.DaemonSetLister
daemonSetInformerSynced cache.InformerSynced
podInformerSynced cache.InformerSynced
// allocate/recycle CIDRs for node if allocateNodeCIDRs == true
cidrAllocator CIDRAllocator
// manages taints
taintManager *NoExecuteTaintManager
forcefullyDeletePod func(*v1.Pod) error
nodeExistsInCloudProvider func(types.NodeName) (bool, error)
computeZoneStateFunc func(nodeConditions []*v1.NodeCondition) (int, zoneState)
enterPartialDisruptionFunc func(nodeNum int) float32
enterFullDisruptionFunc func(nodeNum int) float32
zoneStates map[string]zoneState
evictionLimiterQPS float32
secondaryEvictionLimiterQPS float32
largeClusterThreshold int32
unhealthyZoneThreshold float32
// if set to true NodeController will start TaintManager that will evict Pods from
// tainted nodes, if they're not tolerated.
runTaintManager bool
// if set to true NodeController will taint Nodes with 'TaintNodeNotReady' and 'TaintNodeUnreachable'
// taints instead of evicting Pods itself.
useTaintBasedEvictions bool
}
// NewNodeController returns a new node controller to sync instances from cloudprovider.
// This method returns an error if it is unable to initialize the CIDR bitmap with
// podCIDRs it has already allocated to nodes. Since we don't allow podCIDR changes
// currently, this should be handled as a fatal error.
func NewNodeController(
podInformer coreinformers.PodInformer,
nodeInformer coreinformers.NodeInformer,
daemonSetInformer extensionsinformers.DaemonSetInformer,
cloud cloudprovider.Interface,
kubeClient clientset.Interface,
podEvictionTimeout time.Duration,
evictionLimiterQPS float32,
secondaryEvictionLimiterQPS float32,
largeClusterThreshold int32,
unhealthyZoneThreshold float32,
nodeMonitorGracePeriod time.Duration,
nodeStartupGracePeriod time.Duration,
nodeMonitorPeriod time.Duration,
clusterCIDR *net.IPNet,
serviceCIDR *net.IPNet,
nodeCIDRMaskSize int,
allocateNodeCIDRs bool,
runTaintManager bool,
useTaintBasedEvictions bool) (*NodeController, error) {
eventBroadcaster := record.NewBroadcaster()
recorder := eventBroadcaster.NewRecorder(api.Scheme, clientv1.EventSource{Component: "controllermanager"})
eventBroadcaster.StartLogging(glog.Infof)
if kubeClient != nil {
glog.V(0).Infof("Sending events to api server.")
eventBroadcaster.StartRecordingToSink(&v1core.EventSinkImpl{Interface: v1core.New(kubeClient.Core().RESTClient()).Events("")})
} else {
glog.Fatalf("kubeClient is nil when starting NodeController")
}
if kubeClient != nil && kubeClient.Core().RESTClient().GetRateLimiter() != nil {
metrics.RegisterMetricAndTrackRateLimiterUsage("node_controller", kubeClient.Core().RESTClient().GetRateLimiter())
}
if allocateNodeCIDRs {
if clusterCIDR == nil {
glog.Fatal("NodeController: Must specify clusterCIDR if allocateNodeCIDRs == true.")
}
mask := clusterCIDR.Mask
if maskSize, _ := mask.Size(); maskSize > nodeCIDRMaskSize {
glog.Fatal("NodeController: Invalid clusterCIDR, mask size of clusterCIDR must be less than nodeCIDRMaskSize.")
}
}
nc := &NodeController{
cloud: cloud,
knownNodeSet: make(map[string]*v1.Node),
kubeClient: kubeClient,
recorder: recorder,
podEvictionTimeout: podEvictionTimeout,
maximumGracePeriod: 5 * time.Minute,
zonePodEvictor: make(map[string]*RateLimitedTimedQueue),
zoneNotReadyOrUnreachableTainer: make(map[string]*RateLimitedTimedQueue),
nodeStatusMap: make(map[string]nodeStatusData),
nodeMonitorGracePeriod: nodeMonitorGracePeriod,
nodeMonitorPeriod: nodeMonitorPeriod,
nodeStartupGracePeriod: nodeStartupGracePeriod,
lookupIP: net.LookupIP,
now: metav1.Now,
clusterCIDR: clusterCIDR,
serviceCIDR: serviceCIDR,
allocateNodeCIDRs: allocateNodeCIDRs,
forcefullyDeletePod: func(p *v1.Pod) error { return forcefullyDeletePod(kubeClient, p) },
nodeExistsInCloudProvider: func(nodeName types.NodeName) (bool, error) { return nodeExistsInCloudProvider(cloud, nodeName) },
evictionLimiterQPS: evictionLimiterQPS,
secondaryEvictionLimiterQPS: secondaryEvictionLimiterQPS,
largeClusterThreshold: largeClusterThreshold,
unhealthyZoneThreshold: unhealthyZoneThreshold,
zoneStates: make(map[string]zoneState),
runTaintManager: runTaintManager,
useTaintBasedEvictions: useTaintBasedEvictions && runTaintManager,
}
if useTaintBasedEvictions {
glog.Infof("NodeController is using taint based evictions.")
}
nc.enterPartialDisruptionFunc = nc.ReducedQPSFunc
nc.enterFullDisruptionFunc = nc.HealthyQPSFunc
nc.computeZoneStateFunc = nc.ComputeZoneState
podInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
nc.maybeDeleteTerminatingPod(obj)
pod := obj.(*v1.Pod)
if nc.taintManager != nil {
nc.taintManager.PodUpdated(nil, pod)
}
},
UpdateFunc: func(prev, obj interface{}) {
nc.maybeDeleteTerminatingPod(obj)
prevPod := prev.(*v1.Pod)
newPod := obj.(*v1.Pod)
if nc.taintManager != nil {
nc.taintManager.PodUpdated(prevPod, newPod)
}
},
DeleteFunc: func(obj interface{}) {
pod, isPod := obj.(*v1.Pod)
// We can get DeletedFinalStateUnknown instead of *v1.Node here and we need to handle that correctly. #34692
if !isPod {
deletedState, ok := obj.(cache.DeletedFinalStateUnknown)
if !ok {
glog.Errorf("Received unexpected object: %v", obj)
return
}
pod, ok = deletedState.Obj.(*v1.Pod)
if !ok {
glog.Errorf("DeletedFinalStateUnknown contained non-Node object: %v", deletedState.Obj)
return
}
}
if nc.taintManager != nil {
nc.taintManager.PodUpdated(pod, nil)
}
},
})
nc.podInformerSynced = podInformer.Informer().HasSynced
nodeEventHandlerFuncs := cache.ResourceEventHandlerFuncs{}
if nc.allocateNodeCIDRs {
var nodeList *v1.NodeList
var err error
// We must poll because apiserver might not be up. This error causes
// controller manager to restart.
if pollErr := wait.Poll(10*time.Second, apiserverStartupGracePeriod, func() (bool, error) {
nodeList, err = kubeClient.Core().Nodes().List(metav1.ListOptions{
FieldSelector: fields.Everything().String(),
LabelSelector: labels.Everything().String(),
})
if err != nil {
glog.Errorf("Failed to list all nodes: %v", err)
return false, nil
}
return true, nil
}); pollErr != nil {
return nil, fmt.Errorf("Failed to list all nodes in %v, cannot proceed without updating CIDR map", apiserverStartupGracePeriod)
}
nc.cidrAllocator, err = NewCIDRRangeAllocator(kubeClient, clusterCIDR, serviceCIDR, nodeCIDRMaskSize, nodeList)
if err != nil {
return nil, err
}
nodeEventHandlerFuncs = cache.ResourceEventHandlerFuncs{
AddFunc: func(originalObj interface{}) {
obj, err := api.Scheme.DeepCopy(originalObj)
if err != nil {
utilruntime.HandleError(err)
return
}
node := obj.(*v1.Node)
if err := nc.cidrAllocator.AllocateOrOccupyCIDR(node); err != nil {
utilruntime.HandleError(fmt.Errorf("Error allocating CIDR: %v", err))
}
if nc.taintManager != nil {
nc.taintManager.NodeUpdated(nil, node)
}
},
UpdateFunc: func(oldNode, newNode interface{}) {
node := newNode.(*v1.Node)
prevNode := oldNode.(*v1.Node)
// If the PodCIDR is not empty we either:
// - already processed a Node that already had a CIDR after NC restarted
// (cidr is marked as used),
// - already processed a Node successfully and allocated a CIDR for it
// (cidr is marked as used),
// - already processed a Node but we did saw a "timeout" response and
// request eventually got through in this case we haven't released
// the allocated CIDR (cidr is still marked as used).
// There's a possible error here:
// - NC sees a new Node and assigns a CIDR X to it,
// - Update Node call fails with a timeout,
// - Node is updated by some other component, NC sees an update and
// assigns CIDR Y to the Node,
// - Both CIDR X and CIDR Y are marked as used in the local cache,
// even though Node sees only CIDR Y
// The problem here is that in in-memory cache we see CIDR X as marked,
// which prevents it from being assigned to any new node. The cluster
// state is correct.
// Restart of NC fixes the issue.
if node.Spec.PodCIDR == "" {
nodeCopy, err := api.Scheme.Copy(node)
if err != nil {
utilruntime.HandleError(err)
return
}
if err := nc.cidrAllocator.AllocateOrOccupyCIDR(nodeCopy.(*v1.Node)); err != nil {
utilruntime.HandleError(fmt.Errorf("Error allocating CIDR: %v", err))
}
}
if nc.taintManager != nil {
nc.taintManager.NodeUpdated(prevNode, node)
}
},
DeleteFunc: func(originalObj interface{}) {
obj, err := api.Scheme.DeepCopy(originalObj)
if err != nil {
utilruntime.HandleError(err)
return
}
node, isNode := obj.(*v1.Node)
// We can get DeletedFinalStateUnknown instead of *v1.Node here and we need to handle that correctly. #34692
if !isNode {
deletedState, ok := obj.(cache.DeletedFinalStateUnknown)
if !ok {
glog.Errorf("Received unexpected object: %v", obj)
return
}
node, ok = deletedState.Obj.(*v1.Node)
if !ok {
glog.Errorf("DeletedFinalStateUnknown contained non-Node object: %v", deletedState.Obj)
return
}
}
if nc.taintManager != nil {
nc.taintManager.NodeUpdated(node, nil)
}
if err := nc.cidrAllocator.ReleaseCIDR(node); err != nil {
glog.Errorf("Error releasing CIDR: %v", err)
}
},
}
} else {
nodeEventHandlerFuncs = cache.ResourceEventHandlerFuncs{
AddFunc: func(originalObj interface{}) {
obj, err := api.Scheme.DeepCopy(originalObj)
if err != nil {
utilruntime.HandleError(err)
return
}
node := obj.(*v1.Node)
if nc.taintManager != nil {
nc.taintManager.NodeUpdated(nil, node)
}
},
UpdateFunc: func(oldNode, newNode interface{}) {
node := newNode.(*v1.Node)
prevNode := oldNode.(*v1.Node)
if nc.taintManager != nil {
nc.taintManager.NodeUpdated(prevNode, node)
}
},
DeleteFunc: func(originalObj interface{}) {
obj, err := api.Scheme.DeepCopy(originalObj)
if err != nil {
utilruntime.HandleError(err)
return
}
node, isNode := obj.(*v1.Node)
// We can get DeletedFinalStateUnknown instead of *v1.Node here and we need to handle that correctly. #34692
if !isNode {
deletedState, ok := obj.(cache.DeletedFinalStateUnknown)
if !ok {
glog.Errorf("Received unexpected object: %v", obj)
return
}
node, ok = deletedState.Obj.(*v1.Node)
if !ok {
glog.Errorf("DeletedFinalStateUnknown contained non-Node object: %v", deletedState.Obj)
return
}
}
if nc.taintManager != nil {
nc.taintManager.NodeUpdated(node, nil)
}
},
}
}
if nc.runTaintManager {
nc.taintManager = NewNoExecuteTaintManager(kubeClient)
}
nodeInformer.Informer().AddEventHandler(nodeEventHandlerFuncs)
nc.nodeLister = nodeInformer.Lister()
nc.nodeInformerSynced = nodeInformer.Informer().HasSynced
nc.daemonSetStore = daemonSetInformer.Lister()
nc.daemonSetInformerSynced = daemonSetInformer.Informer().HasSynced
return nc, nil
}
// Run starts an asynchronous loop that monitors the status of cluster nodes.
func (nc *NodeController) Run() {
go func() {
defer utilruntime.HandleCrash()
if !cache.WaitForCacheSync(wait.NeverStop, nc.nodeInformerSynced, nc.podInformerSynced, nc.daemonSetInformerSynced) {
utilruntime.HandleError(fmt.Errorf("timed out waiting for caches to sync"))
return
}
// Incorporate the results of node status pushed from kubelet to master.
go wait.Until(func() {
if err := nc.monitorNodeStatus(); err != nil {
glog.Errorf("Error monitoring node status: %v", err)
}
}, nc.nodeMonitorPeriod, wait.NeverStop)
if nc.runTaintManager {
go nc.taintManager.Run(wait.NeverStop)
}
if nc.useTaintBasedEvictions {
// Handling taint based evictions. Because we don't want a dedicated logic in TaintManager for NC-originated
// taints and we normally don't rate limit evictions caused by taints, we need to rate limit adding taints.
go wait.Until(func() {
nc.evictorLock.Lock()
defer nc.evictorLock.Unlock()
for k := range nc.zoneNotReadyOrUnreachableTainer {
// Function should return 'false' and a time after which it should be retried, or 'true' if it shouldn't (it succeeded).
nc.zoneNotReadyOrUnreachableTainer[k].Try(func(value TimedValue) (bool, time.Duration) {
node, err := nc.nodeLister.Get(value.Value)
if apierrors.IsNotFound(err) {
glog.Warningf("Node %v no longer present in nodeLister!", value.Value)
return true, 0
} else if err != nil {
glog.Warningf("Failed to get Node %v from the nodeLister: %v", value.Value, err)
// retry in 50 millisecond
return false, 50 * time.Millisecond
} else {
zone := utilnode.GetZoneKey(node)
EvictionsNumber.WithLabelValues(zone).Inc()
}
_, condition := v1.GetNodeCondition(&node.Status, v1.NodeReady)
// Because we want to mimic NodeStatus.Condition["Ready"] we make "unreachable" and "not ready" taints mutually exclusive.
taintToAdd := v1.Taint{}
oppositeTaint := v1.Taint{}
if condition.Status == v1.ConditionFalse {
taintToAdd = *NotReadyTaintTemplate
oppositeTaint = *UnreachableTaintTemplate
} else if condition.Status == v1.ConditionUnknown {
taintToAdd = *UnreachableTaintTemplate
oppositeTaint = *NotReadyTaintTemplate
} else {
// It seems that the Node is ready again, so there's no need to taint it.
glog.V(4).Infof("Node %v was in a taint queue, but it's ready now. Ignoring taint request.", value.Value)
return true, 0
}
taintToAdd.TimeAdded = metav1.Now()
err = controller.AddOrUpdateTaintOnNode(nc.kubeClient, value.Value, &taintToAdd)
if err != nil {
utilruntime.HandleError(
fmt.Errorf(
"unable to taint %v unresponsive Node %q: %v",
taintToAdd.Key,
value.Value,
err))
return false, 0
} else {
glog.V(4).Info("Added %v Taint to Node %v", taintToAdd, value.Value)
}
err = controller.RemoveTaintOffNode(nc.kubeClient, value.Value, &oppositeTaint, node)
if err != nil {
utilruntime.HandleError(
fmt.Errorf(
"unable to remove %v unneeded taint from unresponsive Node %q: %v",
oppositeTaint.Key,
value.Value,
err))
return false, 0
} else {
glog.V(4).Info("Made sure that Node %v has no %v Taint", value.Value, oppositeTaint)
}
return true, 0
})
}
}, nodeEvictionPeriod, wait.NeverStop)
} else {
// Managing eviction of nodes:
// When we delete pods off a node, if the node was not empty at the time we then
// queue an eviction watcher. If we hit an error, retry deletion.
go wait.Until(func() {
nc.evictorLock.Lock()
defer nc.evictorLock.Unlock()
for k := range nc.zonePodEvictor {
// Function should return 'false' and a time after which it should be retried, or 'true' if it shouldn't (it succeeded).
nc.zonePodEvictor[k].Try(func(value TimedValue) (bool, time.Duration) {
node, err := nc.nodeLister.Get(value.Value)
if apierrors.IsNotFound(err) {
glog.Warningf("Node %v no longer present in nodeLister!", value.Value)
} else if err != nil {
glog.Warningf("Failed to get Node %v from the nodeLister: %v", value.Value, err)
} else {
zone := utilnode.GetZoneKey(node)
EvictionsNumber.WithLabelValues(zone).Inc()
}
nodeUid, _ := value.UID.(string)
remaining, err := deletePods(nc.kubeClient, nc.recorder, value.Value, nodeUid, nc.daemonSetStore)
if err != nil {
utilruntime.HandleError(fmt.Errorf("unable to evict node %q: %v", value.Value, err))
return false, 0
}
if remaining {
glog.Infof("Pods awaiting deletion due to NodeController eviction")
}
return true, 0
})
}
}, nodeEvictionPeriod, wait.NeverStop)
}
}()
}
// monitorNodeStatus verifies node status are constantly updated by kubelet, and if not,
// post "NodeReady==ConditionUnknown". It also evicts all pods if node is not ready or
// not reachable for a long period of time.
func (nc *NodeController) monitorNodeStatus() error {
// We are listing nodes from local cache as we can tolerate some small delays
// comparing to state from etcd and there is eventual consistency anyway.
nodes, err := nc.nodeLister.List(labels.Everything())
if err != nil {
return err
}
added, deleted := nc.checkForNodeAddedDeleted(nodes)
for i := range added {
glog.V(1).Infof("NodeController observed a new Node: %#v", added[i].Name)
recordNodeEvent(nc.recorder, added[i].Name, string(added[i].UID), v1.EventTypeNormal, "RegisteredNode", fmt.Sprintf("Registered Node %v in NodeController", added[i].Name))
nc.knownNodeSet[added[i].Name] = added[i]
// When adding new Nodes we need to check if new zone appeared, and if so add new evictor.
zone := utilnode.GetZoneKey(added[i])
if _, found := nc.zoneStates[zone]; !found {
nc.zoneStates[zone] = stateInitial
if !nc.useTaintBasedEvictions {
nc.zonePodEvictor[zone] =
NewRateLimitedTimedQueue(
flowcontrol.NewTokenBucketRateLimiter(nc.evictionLimiterQPS, evictionRateLimiterBurst))
} else {
nc.zoneNotReadyOrUnreachableTainer[zone] =
NewRateLimitedTimedQueue(
flowcontrol.NewTokenBucketRateLimiter(nc.evictionLimiterQPS, evictionRateLimiterBurst))
}
// Init the metric for the new zone.
glog.Infof("Initializing eviction metric for zone: %v", zone)
EvictionsNumber.WithLabelValues(zone).Add(0)
}
if nc.useTaintBasedEvictions {
nc.markNodeAsHealthy(added[i])
} else {
nc.cancelPodEviction(added[i])
}
}
for i := range deleted {
glog.V(1).Infof("NodeController observed a Node deletion: %v", deleted[i].Name)
recordNodeEvent(nc.recorder, deleted[i].Name, string(deleted[i].UID), v1.EventTypeNormal, "RemovingNode", fmt.Sprintf("Removing Node %v from NodeController", deleted[i].Name))
delete(nc.knownNodeSet, deleted[i].Name)
}
zoneToNodeConditions := map[string][]*v1.NodeCondition{}
for i := range nodes {
var gracePeriod time.Duration
var observedReadyCondition v1.NodeCondition
var currentReadyCondition *v1.NodeCondition
nodeCopy, err := api.Scheme.DeepCopy(nodes[i])
if err != nil {
utilruntime.HandleError(err)
continue
}
node := nodeCopy.(*v1.Node)
if err := wait.PollImmediate(retrySleepTime, retrySleepTime*nodeStatusUpdateRetry, func() (bool, error) {
gracePeriod, observedReadyCondition, currentReadyCondition, err = nc.tryUpdateNodeStatus(node)
if err == nil {
return true, nil
}
name := node.Name
node, err = nc.kubeClient.Core().Nodes().Get(name, metav1.GetOptions{})
if err != nil {
glog.Errorf("Failed while getting a Node to retry updating NodeStatus. Probably Node %s was deleted.", name)
return false, err
}
return false, nil
}); err != nil {
glog.Errorf("Update status of Node %v from NodeController error : %v. "+
"Skipping - no pods will be evicted.", node.Name, err)
continue
}
// We do not treat a master node as a part of the cluster for network disruption checking.
if !system.IsMasterNode(node.Name) {
zoneToNodeConditions[utilnode.GetZoneKey(node)] = append(zoneToNodeConditions[utilnode.GetZoneKey(node)], currentReadyCondition)
}
decisionTimestamp := nc.now()
if currentReadyCondition != nil {
// Check eviction timeout against decisionTimestamp
if observedReadyCondition.Status == v1.ConditionFalse {
if nc.useTaintBasedEvictions {
if nc.markNodeForTainting(node) {
glog.V(2).Infof("Node %v is NotReady as of %v. Adding it to the Taint queue.",
node.Name,
decisionTimestamp,
)
}
} else {
if decisionTimestamp.After(nc.nodeStatusMap[node.Name].readyTransitionTimestamp.Add(nc.podEvictionTimeout)) {
if nc.evictPods(node) {
glog.V(2).Infof("Node is NotReady. Adding Pods on Node %s to eviction queue: %v is later than %v + %v",
node.Name,
decisionTimestamp,
nc.nodeStatusMap[node.Name].readyTransitionTimestamp,
nc.podEvictionTimeout,
)
}
}
}
}
if observedReadyCondition.Status == v1.ConditionUnknown {
if nc.useTaintBasedEvictions {
if nc.markNodeForTainting(node) {
glog.V(2).Infof("Node %v is unresponsive as of %v. Adding it to the Taint queue.",
node.Name,
decisionTimestamp,
)
}
} else {
if decisionTimestamp.After(nc.nodeStatusMap[node.Name].probeTimestamp.Add(nc.podEvictionTimeout)) {
if nc.evictPods(node) {
glog.V(2).Infof("Node is unresponsive. Adding Pods on Node %s to eviction queues: %v is later than %v + %v",
node.Name,
decisionTimestamp,
nc.nodeStatusMap[node.Name].readyTransitionTimestamp,
nc.podEvictionTimeout-gracePeriod,
)
}
}
}
}
if observedReadyCondition.Status == v1.ConditionTrue {
if nc.useTaintBasedEvictions {
removed, err := nc.markNodeAsHealthy(node)
if err != nil {
glog.Errorf("Failed to remove taints from node %v. Will retry in next iteration.", node.Name)
}
if removed {
glog.V(2).Infof("Node %s is healthy again, removing all taints", node.Name)
}
} else {
if nc.cancelPodEviction(node) {
glog.V(2).Infof("Node %s is ready again, cancelled pod eviction", node.Name)
}
}
}
// Report node event.
if currentReadyCondition.Status != v1.ConditionTrue && observedReadyCondition.Status == v1.ConditionTrue {
recordNodeStatusChange(nc.recorder, node, "NodeNotReady")
if err = markAllPodsNotReady(nc.kubeClient, node); err != nil {
utilruntime.HandleError(fmt.Errorf("Unable to mark all pods NotReady on node %v: %v", node.Name, err))
}
}
// Check with the cloud provider to see if the node still exists. If it
// doesn't, delete the node immediately.
if currentReadyCondition.Status != v1.ConditionTrue && nc.cloud != nil {
exists, err := nc.nodeExistsInCloudProvider(types.NodeName(node.Name))
if err != nil {
glog.Errorf("Error determining if node %v exists in cloud: %v", node.Name, err)
continue
}
if !exists {
glog.V(2).Infof("Deleting node (no longer present in cloud provider): %s", node.Name)
recordNodeEvent(nc.recorder, node.Name, string(node.UID), v1.EventTypeNormal, "DeletingNode", fmt.Sprintf("Deleting Node %v because it's not present according to cloud provider", node.Name))
go func(nodeName string) {
defer utilruntime.HandleCrash()
// Kubelet is not reporting and Cloud Provider says node
// is gone. Delete it without worrying about grace
// periods.
if err := forcefullyDeleteNode(nc.kubeClient, nodeName); err != nil {
glog.Errorf("Unable to forcefully delete node %q: %v", nodeName, err)
}
}(node.Name)
}
}
}
}
nc.handleDisruption(zoneToNodeConditions, nodes)
return nil
}
func (nc *NodeController) handleDisruption(zoneToNodeConditions map[string][]*v1.NodeCondition, nodes []*v1.Node) {
newZoneStates := map[string]zoneState{}
allAreFullyDisrupted := true
for k, v := range zoneToNodeConditions {
ZoneSize.WithLabelValues(k).Set(float64(len(v)))
unhealthy, newState := nc.computeZoneStateFunc(v)
ZoneHealth.WithLabelValues(k).Set(float64(100*(len(v)-unhealthy)) / float64(len(v)))
UnhealthyNodes.WithLabelValues(k).Set(float64(unhealthy))
if newState != stateFullDisruption {
allAreFullyDisrupted = false
}
newZoneStates[k] = newState
if _, had := nc.zoneStates[k]; !had {
glog.Errorf("Setting initial state for unseen zone: %v", k)
nc.zoneStates[k] = stateInitial
}
}
allWasFullyDisrupted := true
for k, v := range nc.zoneStates {
if _, have := zoneToNodeConditions[k]; !have {
ZoneSize.WithLabelValues(k).Set(0)
ZoneHealth.WithLabelValues(k).Set(100)
UnhealthyNodes.WithLabelValues(k).Set(0)
delete(nc.zoneStates, k)
continue
}
if v != stateFullDisruption {
allWasFullyDisrupted = false
break
}
}
// At least one node was responding in previous pass or in the current pass. Semantics is as follows:
// - if the new state is "partialDisruption" we call a user defined function that returns a new limiter to use,
// - if the new state is "normal" we resume normal operation (go back to default limiter settings),
// - if new state is "fullDisruption" we restore normal eviction rate,
// - unless all zones in the cluster are in "fullDisruption" - in that case we stop all evictions.
if !allAreFullyDisrupted || !allWasFullyDisrupted {
// We're switching to full disruption mode
if allAreFullyDisrupted {
glog.V(0).Info("NodeController detected that all Nodes are not-Ready. Entering master disruption mode.")
for i := range nodes {
if nc.useTaintBasedEvictions {
_, err := nc.markNodeAsHealthy(nodes[i])
if err != nil {
glog.Errorf("Failed to remove taints from Node %v", nodes[i].Name)
}
} else {
nc.cancelPodEviction(nodes[i])
}
}
// We stop all evictions.
for k := range nc.zoneStates {
if nc.useTaintBasedEvictions {
nc.zoneNotReadyOrUnreachableTainer[k].SwapLimiter(0)
} else {
nc.zonePodEvictor[k].SwapLimiter(0)
}
}
for k := range nc.zoneStates {
nc.zoneStates[k] = stateFullDisruption
}
// All rate limiters are updated, so we can return early here.
return
}
// We're exiting full disruption mode
if allWasFullyDisrupted {
glog.V(0).Info("NodeController detected that some Nodes are Ready. Exiting master disruption mode.")
// When exiting disruption mode update probe timestamps on all Nodes.
now := nc.now()
for i := range nodes {
v := nc.nodeStatusMap[nodes[i].Name]
v.probeTimestamp = now
v.readyTransitionTimestamp = now
nc.nodeStatusMap[nodes[i].Name] = v
}
// We reset all rate limiters to settings appropriate for the given state.
for k := range nc.zoneStates {
nc.setLimiterInZone(k, len(zoneToNodeConditions[k]), newZoneStates[k])
nc.zoneStates[k] = newZoneStates[k]
}
return
}
// We know that there's at least one not-fully disrupted so,
// we can use default behavior for rate limiters
for k, v := range nc.zoneStates {
newState := newZoneStates[k]
if v == newState {
continue
}
glog.V(0).Infof("NodeController detected that zone %v is now in state %v.", k, newState)
nc.setLimiterInZone(k, len(zoneToNodeConditions[k]), newState)
nc.zoneStates[k] = newState
}
}
}
func (nc *NodeController) setLimiterInZone(zone string, zoneSize int, state zoneState) {
switch state {
case stateNormal:
if nc.useTaintBasedEvictions {
nc.zoneNotReadyOrUnreachableTainer[zone].SwapLimiter(nc.evictionLimiterQPS)
} else {
nc.zonePodEvictor[zone].SwapLimiter(nc.evictionLimiterQPS)
}
case statePartialDisruption:
if nc.useTaintBasedEvictions {
nc.zoneNotReadyOrUnreachableTainer[zone].SwapLimiter(
nc.enterPartialDisruptionFunc(zoneSize))
} else {
nc.zonePodEvictor[zone].SwapLimiter(
nc.enterPartialDisruptionFunc(zoneSize))
}
case stateFullDisruption:
if nc.useTaintBasedEvictions {
nc.zoneNotReadyOrUnreachableTainer[zone].SwapLimiter(
nc.enterFullDisruptionFunc(zoneSize))
} else {
nc.zonePodEvictor[zone].SwapLimiter(
nc.enterFullDisruptionFunc(zoneSize))
}
}
}
// For a given node checks its conditions and tries to update it. Returns grace period to which given node
// is entitled, state of current and last observed Ready Condition, and an error if it occurred.
func (nc *NodeController) tryUpdateNodeStatus(node *v1.Node) (time.Duration, v1.NodeCondition, *v1.NodeCondition, error) {
var err error
var gracePeriod time.Duration
var observedReadyCondition v1.NodeCondition
_, currentReadyCondition := v1.GetNodeCondition(&node.Status, v1.NodeReady)
if currentReadyCondition == nil {
// If ready condition is nil, then kubelet (or nodecontroller) never posted node status.
// A fake ready condition is created, where LastProbeTime and LastTransitionTime is set
// to node.CreationTimestamp to avoid handle the corner case.
observedReadyCondition = v1.NodeCondition{
Type: v1.NodeReady,
Status: v1.ConditionUnknown,
LastHeartbeatTime: node.CreationTimestamp,
LastTransitionTime: node.CreationTimestamp,
}
gracePeriod = nc.nodeStartupGracePeriod
nc.nodeStatusMap[node.Name] = nodeStatusData{
status: node.Status,
probeTimestamp: node.CreationTimestamp,
readyTransitionTimestamp: node.CreationTimestamp,
}
} else {
// If ready condition is not nil, make a copy of it, since we may modify it in place later.
observedReadyCondition = *currentReadyCondition
gracePeriod = nc.nodeMonitorGracePeriod
}
savedNodeStatus, found := nc.nodeStatusMap[node.Name]
// There are following cases to check:
// - both saved and new status have no Ready Condition set - we leave everything as it is,
// - saved status have no Ready Condition, but current one does - NodeController was restarted with Node data already present in etcd,
// - saved status have some Ready Condition, but current one does not - it's an error, but we fill it up because that's probably a good thing to do,
// - both saved and current statuses have Ready Conditions and they have the same LastProbeTime - nothing happened on that Node, it may be
// unresponsive, so we leave it as it is,
// - both saved and current statuses have Ready Conditions, they have different LastProbeTimes, but the same Ready Condition State -
// everything's in order, no transition occurred, we update only probeTimestamp,
// - both saved and current statuses have Ready Conditions, different LastProbeTimes and different Ready Condition State -
// Ready Condition changed it state since we last seen it, so we update both probeTimestamp and readyTransitionTimestamp.
// TODO: things to consider:
// - if 'LastProbeTime' have gone back in time its probably an error, currently we ignore it,
// - currently only correct Ready State transition outside of Node Controller is marking it ready by Kubelet, we don't check
// if that's the case, but it does not seem necessary.
var savedCondition *v1.NodeCondition
if found {
_, savedCondition = v1.GetNodeCondition(&savedNodeStatus.status, v1.NodeReady)
}
_, observedCondition := v1.GetNodeCondition(&node.Status, v1.NodeReady)
if !found {
glog.Warningf("Missing timestamp for Node %s. Assuming now as a timestamp.", node.Name)
savedNodeStatus = nodeStatusData{
status: node.Status,
probeTimestamp: nc.now(),
readyTransitionTimestamp: nc.now(),
}
} else if savedCondition == nil && observedCondition != nil {
glog.V(1).Infof("Creating timestamp entry for newly observed Node %s", node.Name)
savedNodeStatus = nodeStatusData{
status: node.Status,
probeTimestamp: nc.now(),
readyTransitionTimestamp: nc.now(),
}
} else if savedCondition != nil && observedCondition == nil {
glog.Errorf("ReadyCondition was removed from Status of Node %s", node.Name)
// TODO: figure out what to do in this case. For now we do the same thing as above.
savedNodeStatus = nodeStatusData{
status: node.Status,
probeTimestamp: nc.now(),
readyTransitionTimestamp: nc.now(),
}
} else if savedCondition != nil && observedCondition != nil && savedCondition.LastHeartbeatTime != observedCondition.LastHeartbeatTime {
var transitionTime metav1.Time
// If ReadyCondition changed since the last time we checked, we update the transition timestamp to "now",
// otherwise we leave it as it is.
if savedCondition.LastTransitionTime != observedCondition.LastTransitionTime {
glog.V(3).Infof("ReadyCondition for Node %s transitioned from %v to %v", node.Name, savedCondition.Status, observedCondition)
transitionTime = nc.now()
} else {
transitionTime = savedNodeStatus.readyTransitionTimestamp
}
if glog.V(5) {
glog.V(5).Infof("Node %s ReadyCondition updated. Updating timestamp: %+v vs %+v.", node.Name, savedNodeStatus.status, node.Status)
} else {
glog.V(3).Infof("Node %s ReadyCondition updated. Updating timestamp.", node.Name)
}
savedNodeStatus = nodeStatusData{
status: node.Status,
probeTimestamp: nc.now(),
readyTransitionTimestamp: transitionTime,
}
}
nc.nodeStatusMap[node.Name] = savedNodeStatus