-
Notifications
You must be signed in to change notification settings - Fork 1.9k
/
feasible.go
1046 lines (891 loc) · 26.8 KB
/
feasible.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
package scheduler
import (
"fmt"
"reflect"
"regexp"
"strconv"
"strings"
"github.com/hashicorp/go-version"
"github.com/hashicorp/nomad/nomad/structs"
psstructs "github.com/hashicorp/nomad/plugins/shared/structs"
)
// FeasibleIterator is used to iteratively yield nodes that
// match feasibility constraints. The iterators may manage
// some state for performance optimizations.
type FeasibleIterator interface {
// Next yields a feasible node or nil if exhausted
Next() *structs.Node
// Reset is invoked when an allocation has been placed
// to reset any stale state.
Reset()
}
// JobContextualIterator is an iterator that can have the job and task group set
// on it.
type ContextualIterator interface {
SetJob(*structs.Job)
SetTaskGroup(*structs.TaskGroup)
}
// FeasibilityChecker is used to check if a single node meets feasibility
// constraints.
type FeasibilityChecker interface {
Feasible(*structs.Node) bool
}
// StaticIterator is a FeasibleIterator which returns nodes
// in a static order. This is used at the base of the iterator
// chain only for testing due to deterministic behavior.
type StaticIterator struct {
ctx Context
nodes []*structs.Node
offset int
seen int
}
// NewStaticIterator constructs a random iterator from a list of nodes
func NewStaticIterator(ctx Context, nodes []*structs.Node) *StaticIterator {
iter := &StaticIterator{
ctx: ctx,
nodes: nodes,
}
return iter
}
func (iter *StaticIterator) Next() *structs.Node {
// Check if exhausted
n := len(iter.nodes)
if iter.offset == n || iter.seen == n {
if iter.seen != n {
iter.offset = 0
} else {
return nil
}
}
// Return the next offset
offset := iter.offset
iter.offset += 1
iter.seen += 1
iter.ctx.Metrics().EvaluateNode()
return iter.nodes[offset]
}
func (iter *StaticIterator) Reset() {
iter.seen = 0
}
func (iter *StaticIterator) SetNodes(nodes []*structs.Node) {
iter.nodes = nodes
iter.offset = 0
iter.seen = 0
}
// NewRandomIterator constructs a static iterator from a list of nodes
// after applying the Fisher-Yates algorithm for a random shuffle. This
// is applied in-place
func NewRandomIterator(ctx Context, nodes []*structs.Node) *StaticIterator {
// shuffle with the Fisher-Yates algorithm
shuffleNodes(nodes)
// Create a static iterator
return NewStaticIterator(ctx, nodes)
}
// DriverChecker is a FeasibilityChecker which returns whether a node has the
// drivers necessary to scheduler a task group.
type DriverChecker struct {
ctx Context
drivers map[string]struct{}
}
// NewDriverChecker creates a DriverChecker from a set of drivers
func NewDriverChecker(ctx Context, drivers map[string]struct{}) *DriverChecker {
return &DriverChecker{
ctx: ctx,
drivers: drivers,
}
}
func (c *DriverChecker) SetDrivers(d map[string]struct{}) {
c.drivers = d
}
func (c *DriverChecker) Feasible(option *structs.Node) bool {
// Use this node if possible
if c.hasDrivers(option) {
return true
}
c.ctx.Metrics().FilterNode(option, "missing drivers")
return false
}
// hasDrivers is used to check if the node has all the appropriate
// drivers for this task group. Drivers are registered as node attribute
// like "driver.docker=1" with their corresponding version.
func (c *DriverChecker) hasDrivers(option *structs.Node) bool {
for driver := range c.drivers {
driverStr := fmt.Sprintf("driver.%s", driver)
// COMPAT: Remove in 0.10: As of Nomad 0.8, nodes have a DriverInfo that
// corresponds with every driver. As a Nomad server might be on a later
// version than a Nomad client, we need to check for compatibility here
// to verify the client supports this.
if driverInfo, ok := option.Drivers[driver]; ok {
if driverInfo == nil {
c.ctx.Logger().Named("driver_checker").Warn("node has no driver info set", "node_id", option.ID, "driver", driver)
return false
}
return driverInfo.Detected && driverInfo.Healthy
}
value, ok := option.Attributes[driverStr]
if !ok {
return false
}
enabled, err := strconv.ParseBool(value)
if err != nil {
c.ctx.Logger().Named("driver_checker").Warn("node has invalid driver setting", "node_id", option.ID, "driver", driver, "val", value)
return false
}
if !enabled {
return false
}
}
return true
}
// DistinctHostsIterator is a FeasibleIterator which returns nodes that pass the
// distinct_hosts constraint. The constraint ensures that multiple allocations
// do not exist on the same node.
type DistinctHostsIterator struct {
ctx Context
source FeasibleIterator
tg *structs.TaskGroup
job *structs.Job
// Store whether the Job or TaskGroup has a distinct_hosts constraints so
// they don't have to be calculated every time Next() is called.
tgDistinctHosts bool
jobDistinctHosts bool
}
// NewDistinctHostsIterator creates a DistinctHostsIterator from a source.
func NewDistinctHostsIterator(ctx Context, source FeasibleIterator) *DistinctHostsIterator {
return &DistinctHostsIterator{
ctx: ctx,
source: source,
}
}
func (iter *DistinctHostsIterator) SetTaskGroup(tg *structs.TaskGroup) {
iter.tg = tg
iter.tgDistinctHosts = iter.hasDistinctHostsConstraint(tg.Constraints)
}
func (iter *DistinctHostsIterator) SetJob(job *structs.Job) {
iter.job = job
iter.jobDistinctHosts = iter.hasDistinctHostsConstraint(job.Constraints)
}
func (iter *DistinctHostsIterator) hasDistinctHostsConstraint(constraints []*structs.Constraint) bool {
for _, con := range constraints {
if con.Operand == structs.ConstraintDistinctHosts {
return true
}
}
return false
}
func (iter *DistinctHostsIterator) Next() *structs.Node {
for {
// Get the next option from the source
option := iter.source.Next()
// Hot-path if the option is nil or there are no distinct_hosts or
// distinct_property constraints.
hosts := iter.jobDistinctHosts || iter.tgDistinctHosts
if option == nil || !hosts {
return option
}
// Check if the host constraints are satisfied
if !iter.satisfiesDistinctHosts(option) {
iter.ctx.Metrics().FilterNode(option, structs.ConstraintDistinctHosts)
continue
}
return option
}
}
// satisfiesDistinctHosts checks if the node satisfies a distinct_hosts
// constraint either specified at the job level or the TaskGroup level.
func (iter *DistinctHostsIterator) satisfiesDistinctHosts(option *structs.Node) bool {
// Check if there is no constraint set.
if !(iter.jobDistinctHosts || iter.tgDistinctHosts) {
return true
}
// Get the proposed allocations
proposed, err := iter.ctx.ProposedAllocs(option.ID)
if err != nil {
iter.ctx.Logger().Named("distinct_hosts").Error("failed to get proposed allocations", "error", err)
return false
}
// Skip the node if the task group has already been allocated on it.
for _, alloc := range proposed {
// If the job has a distinct_hosts constraint we only need an alloc
// collision on the JobID but if the constraint is on the TaskGroup then
// we need both a job and TaskGroup collision.
jobCollision := alloc.JobID == iter.job.ID
taskCollision := alloc.TaskGroup == iter.tg.Name
if iter.jobDistinctHosts && jobCollision || jobCollision && taskCollision {
return false
}
}
return true
}
func (iter *DistinctHostsIterator) Reset() {
iter.source.Reset()
}
// DistinctPropertyIterator is a FeasibleIterator which returns nodes that pass the
// distinct_property constraint. The constraint ensures that multiple allocations
// do not use the same value of the given property.
type DistinctPropertyIterator struct {
ctx Context
source FeasibleIterator
tg *structs.TaskGroup
job *structs.Job
hasDistinctPropertyConstraints bool
jobPropertySets []*propertySet
groupPropertySets map[string][]*propertySet
}
// NewDistinctPropertyIterator creates a DistinctPropertyIterator from a source.
func NewDistinctPropertyIterator(ctx Context, source FeasibleIterator) *DistinctPropertyIterator {
return &DistinctPropertyIterator{
ctx: ctx,
source: source,
groupPropertySets: make(map[string][]*propertySet),
}
}
func (iter *DistinctPropertyIterator) SetTaskGroup(tg *structs.TaskGroup) {
iter.tg = tg
// Build the property set at the taskgroup level
if _, ok := iter.groupPropertySets[tg.Name]; !ok {
for _, c := range tg.Constraints {
if c.Operand != structs.ConstraintDistinctProperty {
continue
}
pset := NewPropertySet(iter.ctx, iter.job)
pset.SetTGConstraint(c, tg.Name)
iter.groupPropertySets[tg.Name] = append(iter.groupPropertySets[tg.Name], pset)
}
}
// Check if there is a distinct property
iter.hasDistinctPropertyConstraints = len(iter.jobPropertySets) != 0 || len(iter.groupPropertySets[tg.Name]) != 0
}
func (iter *DistinctPropertyIterator) SetJob(job *structs.Job) {
iter.job = job
// Build the property set at the job level
for _, c := range job.Constraints {
if c.Operand != structs.ConstraintDistinctProperty {
continue
}
pset := NewPropertySet(iter.ctx, job)
pset.SetJobConstraint(c)
iter.jobPropertySets = append(iter.jobPropertySets, pset)
}
}
func (iter *DistinctPropertyIterator) Next() *structs.Node {
for {
// Get the next option from the source
option := iter.source.Next()
// Hot path if there is nothing to check
if option == nil || !iter.hasDistinctPropertyConstraints {
return option
}
// Check if the constraints are met
if !iter.satisfiesProperties(option, iter.jobPropertySets) ||
!iter.satisfiesProperties(option, iter.groupPropertySets[iter.tg.Name]) {
continue
}
return option
}
}
// satisfiesProperties returns whether the option satisfies the set of
// properties. If not it will be filtered.
func (iter *DistinctPropertyIterator) satisfiesProperties(option *structs.Node, set []*propertySet) bool {
for _, ps := range set {
if satisfies, reason := ps.SatisfiesDistinctProperties(option, iter.tg.Name); !satisfies {
iter.ctx.Metrics().FilterNode(option, reason)
return false
}
}
return true
}
func (iter *DistinctPropertyIterator) Reset() {
iter.source.Reset()
for _, ps := range iter.jobPropertySets {
ps.PopulateProposed()
}
for _, sets := range iter.groupPropertySets {
for _, ps := range sets {
ps.PopulateProposed()
}
}
}
// ConstraintChecker is a FeasibilityChecker which returns nodes that match a
// given set of constraints. This is used to filter on job, task group, and task
// constraints.
type ConstraintChecker struct {
ctx Context
constraints []*structs.Constraint
}
// NewConstraintChecker creates a ConstraintChecker for a set of constraints
func NewConstraintChecker(ctx Context, constraints []*structs.Constraint) *ConstraintChecker {
return &ConstraintChecker{
ctx: ctx,
constraints: constraints,
}
}
func (c *ConstraintChecker) SetConstraints(constraints []*structs.Constraint) {
c.constraints = constraints
}
func (c *ConstraintChecker) Feasible(option *structs.Node) bool {
// Use this node if possible
for _, constraint := range c.constraints {
if !c.meetsConstraint(constraint, option) {
c.ctx.Metrics().FilterNode(option, constraint.String())
return false
}
}
return true
}
func (c *ConstraintChecker) meetsConstraint(constraint *structs.Constraint, option *structs.Node) bool {
// Resolve the targets. Targets that are not present are treated as `nil`.
// This is to allow for matching constraints where a target is not present.
lVal, lOk := resolveTarget(constraint.LTarget, option)
rVal, rOk := resolveTarget(constraint.RTarget, option)
// Check if satisfied
return checkConstraint(c.ctx, constraint.Operand, lVal, rVal, lOk, rOk)
}
// resolveTarget is used to resolve the LTarget and RTarget of a Constraint.
func resolveTarget(target string, node *structs.Node) (interface{}, bool) {
// If no prefix, this must be a literal value
if !strings.HasPrefix(target, "${") {
return target, true
}
// Handle the interpolations
switch {
case "${node.unique.id}" == target:
return node.ID, true
case "${node.datacenter}" == target:
return node.Datacenter, true
case "${node.unique.name}" == target:
return node.Name, true
case "${node.class}" == target:
return node.NodeClass, true
case strings.HasPrefix(target, "${attr."):
attr := strings.TrimSuffix(strings.TrimPrefix(target, "${attr."), "}")
val, ok := node.Attributes[attr]
return val, ok
case strings.HasPrefix(target, "${meta."):
meta := strings.TrimSuffix(strings.TrimPrefix(target, "${meta."), "}")
val, ok := node.Meta[meta]
return val, ok
default:
return nil, false
}
}
// checkConstraint checks if a constraint is satisfied. The lVal and rVal
// interfaces may be nil.
func checkConstraint(ctx Context, operand string, lVal, rVal interface{}, lFound, rFound bool) bool {
// Check for constraints not handled by this checker.
switch operand {
case structs.ConstraintDistinctHosts, structs.ConstraintDistinctProperty:
return true
default:
break
}
switch operand {
case "=", "==", "is":
return reflect.DeepEqual(lVal, rVal)
case "!=", "not":
return !reflect.DeepEqual(lVal, rVal)
case "<", "<=", ">", ">=":
return checkLexicalOrder(operand, lVal, rVal)
case structs.ConstraintAttributeIsSet:
return lFound
case structs.ConstraintAttributeIsNotSet:
return !lFound
case structs.ConstraintVersion:
return checkVersionMatch(ctx, lVal, rVal)
case structs.ConstraintRegex:
return checkRegexpMatch(ctx, lVal, rVal)
case structs.ConstraintSetContains, structs.ConstraintSetContainsAll:
return checkSetContainsAll(ctx, lVal, rVal)
case structs.ConstraintSetContainsAny:
return checkSetContainsAny(lVal, rVal)
default:
return false
}
}
// checkAffinity checks if a specific affinity is satisfied
func checkAffinity(ctx Context, operand string, lVal, rVal interface{}) bool {
// We pass ok here for both values, because matchesAffinity prevalidates these
return checkConstraint(ctx, operand, lVal, rVal, true, true)
}
// checkAttributeAffinity checks if an affinity is satisfied
func checkAttributeAffinity(ctx Context, operand string, lVal, rVal *psstructs.Attribute) bool {
return checkAttributeConstraint(ctx, operand, lVal, rVal)
}
// checkLexicalOrder is used to check for lexical ordering
func checkLexicalOrder(op string, lVal, rVal interface{}) bool {
// Ensure the values are strings
lStr, ok := lVal.(string)
if !ok {
return false
}
rStr, ok := rVal.(string)
if !ok {
return false
}
switch op {
case "<":
return lStr < rStr
case "<=":
return lStr <= rStr
case ">":
return lStr > rStr
case ">=":
return lStr >= rStr
default:
return false
}
}
// checkVersionMatch is used to compare a version on the
// left hand side with a set of constraints on the right hand side
func checkVersionMatch(ctx Context, lVal, rVal interface{}) bool {
// Parse the version
var versionStr string
switch v := lVal.(type) {
case string:
versionStr = v
case int:
versionStr = fmt.Sprintf("%d", v)
default:
return false
}
// Parse the version
vers, err := version.NewVersion(versionStr)
if err != nil {
return false
}
// Constraint must be a string
constraintStr, ok := rVal.(string)
if !ok {
return false
}
// Check the cache for a match
cache := ctx.VersionConstraintCache()
constraints := cache[constraintStr]
// Parse the constraints
if constraints == nil {
constraints, err = version.NewConstraint(constraintStr)
if err != nil {
return false
}
cache[constraintStr] = constraints
}
// Check the constraints against the version
return constraints.Check(vers)
}
// checkAttributeVersionMatch is used to compare a version on the
// left hand side with a set of constraints on the right hand side
func checkAttributeVersionMatch(ctx Context, lVal, rVal *psstructs.Attribute) bool {
// Parse the version
var versionStr string
if s, ok := lVal.GetString(); ok {
versionStr = s
} else if i, ok := lVal.GetInt(); ok {
versionStr = fmt.Sprintf("%d", i)
} else {
return false
}
// Parse the version
vers, err := version.NewVersion(versionStr)
if err != nil {
return false
}
// Constraint must be a string
constraintStr, ok := rVal.GetString()
if !ok {
return false
}
// Check the cache for a match
cache := ctx.VersionConstraintCache()
constraints := cache[constraintStr]
// Parse the constraints
if constraints == nil {
constraints, err = version.NewConstraint(constraintStr)
if err != nil {
return false
}
cache[constraintStr] = constraints
}
// Check the constraints against the version
return constraints.Check(vers)
}
// checkRegexpMatch is used to compare a value on the
// left hand side with a regexp on the right hand side
func checkRegexpMatch(ctx Context, lVal, rVal interface{}) bool {
// Ensure left-hand is string
lStr, ok := lVal.(string)
if !ok {
return false
}
// Regexp must be a string
regexpStr, ok := rVal.(string)
if !ok {
return false
}
// Check the cache
cache := ctx.RegexpCache()
re := cache[regexpStr]
// Parse the regexp
if re == nil {
var err error
re, err = regexp.Compile(regexpStr)
if err != nil {
return false
}
cache[regexpStr] = re
}
// Look for a match
return re.MatchString(lStr)
}
// checkSetContainsAll is used to see if the left hand side contains the
// string on the right hand side
func checkSetContainsAll(ctx Context, lVal, rVal interface{}) bool {
// Ensure left-hand is string
lStr, ok := lVal.(string)
if !ok {
return false
}
// Regexp must be a string
rStr, ok := rVal.(string)
if !ok {
return false
}
input := strings.Split(lStr, ",")
lookup := make(map[string]struct{}, len(input))
for _, in := range input {
cleaned := strings.TrimSpace(in)
lookup[cleaned] = struct{}{}
}
for _, r := range strings.Split(rStr, ",") {
cleaned := strings.TrimSpace(r)
if _, ok := lookup[cleaned]; !ok {
return false
}
}
return true
}
// checkSetContainsAny is used to see if the left hand side contains any
// values on the right hand side
func checkSetContainsAny(lVal, rVal interface{}) bool {
// Ensure left-hand is string
lStr, ok := lVal.(string)
if !ok {
return false
}
// RHS must be a string
rStr, ok := rVal.(string)
if !ok {
return false
}
input := strings.Split(lStr, ",")
lookup := make(map[string]struct{}, len(input))
for _, in := range input {
cleaned := strings.TrimSpace(in)
lookup[cleaned] = struct{}{}
}
for _, r := range strings.Split(rStr, ",") {
cleaned := strings.TrimSpace(r)
if _, ok := lookup[cleaned]; ok {
return true
}
}
return false
}
// FeasibilityWrapper is a FeasibleIterator which wraps both job and task group
// FeasibilityCheckers in which feasibility checking can be skipped if the
// computed node class has previously been marked as eligible or ineligible.
type FeasibilityWrapper struct {
ctx Context
source FeasibleIterator
jobCheckers []FeasibilityChecker
tgCheckers []FeasibilityChecker
tg string
}
// NewFeasibilityWrapper returns a FeasibleIterator based on the passed source
// and FeasibilityCheckers.
func NewFeasibilityWrapper(ctx Context, source FeasibleIterator,
jobCheckers, tgCheckers []FeasibilityChecker) *FeasibilityWrapper {
return &FeasibilityWrapper{
ctx: ctx,
source: source,
jobCheckers: jobCheckers,
tgCheckers: tgCheckers,
}
}
func (w *FeasibilityWrapper) SetTaskGroup(tg string) {
w.tg = tg
}
func (w *FeasibilityWrapper) Reset() {
w.source.Reset()
}
// Next returns an eligible node, only running the FeasibilityCheckers as needed
// based on the sources computed node class.
func (w *FeasibilityWrapper) Next() *structs.Node {
evalElig := w.ctx.Eligibility()
metrics := w.ctx.Metrics()
OUTER:
for {
// Get the next option from the source
option := w.source.Next()
if option == nil {
return nil
}
// Check if the job has been marked as eligible or ineligible.
jobEscaped, jobUnknown := false, false
switch evalElig.JobStatus(option.ComputedClass) {
case EvalComputedClassIneligible:
// Fast path the ineligible case
metrics.FilterNode(option, "computed class ineligible")
continue
case EvalComputedClassEscaped:
jobEscaped = true
case EvalComputedClassUnknown:
jobUnknown = true
}
// Run the job feasibility checks.
for _, check := range w.jobCheckers {
feasible := check.Feasible(option)
if !feasible {
// If the job hasn't escaped, set it to be ineligible since it
// failed a job check.
if !jobEscaped {
evalElig.SetJobEligibility(false, option.ComputedClass)
}
continue OUTER
}
}
// Set the job eligibility if the constraints weren't escaped and it
// hasn't been set before.
if !jobEscaped && jobUnknown {
evalElig.SetJobEligibility(true, option.ComputedClass)
}
// Check if the task group has been marked as eligible or ineligible.
tgEscaped, tgUnknown := false, false
switch evalElig.TaskGroupStatus(w.tg, option.ComputedClass) {
case EvalComputedClassIneligible:
// Fast path the ineligible case
metrics.FilterNode(option, "computed class ineligible")
continue
case EvalComputedClassEligible:
// Fast path the eligible case
return option
case EvalComputedClassEscaped:
tgEscaped = true
case EvalComputedClassUnknown:
tgUnknown = true
}
// Run the task group feasibility checks.
for _, check := range w.tgCheckers {
feasible := check.Feasible(option)
if !feasible {
// If the task group hasn't escaped, set it to be ineligible
// since it failed a check.
if !tgEscaped {
evalElig.SetTaskGroupEligibility(false, w.tg, option.ComputedClass)
}
continue OUTER
}
}
// Set the task group eligibility if the constraints weren't escaped and
// it hasn't been set before.
if !tgEscaped && tgUnknown {
evalElig.SetTaskGroupEligibility(true, w.tg, option.ComputedClass)
}
return option
}
}
// DeviceChecker is a FeasibilityChecker which returns whether a node has the
// devices necessary to scheduler a task group.
type DeviceChecker struct {
ctx Context
// required is the set of requested devices that must exist on the node
required []*structs.RequestedDevice
// requiresDevices indicates if the task group requires devices
requiresDevices bool
}
// NewDeviceChecker creates a DeviceChecker
func NewDeviceChecker(ctx Context) *DeviceChecker {
return &DeviceChecker{
ctx: ctx,
}
}
func (c *DeviceChecker) SetTaskGroup(tg *structs.TaskGroup) {
c.required = nil
for _, task := range tg.Tasks {
c.required = append(c.required, task.Resources.Devices...)
}
c.requiresDevices = len(c.required) != 0
}
func (c *DeviceChecker) Feasible(option *structs.Node) bool {
if c.hasDevices(option) {
return true
}
c.ctx.Metrics().FilterNode(option, "missing devices")
return false
}
func (c *DeviceChecker) hasDevices(option *structs.Node) bool {
if !c.requiresDevices {
return true
}
// COMPAT(0.11): Remove in 0.11
// The node does not have the new resources object so it can not have any
// devices
if option.NodeResources == nil {
return false
}
// Check if the node has any devices
nodeDevs := option.NodeResources.Devices
if len(nodeDevs) == 0 {
return false
}
// Create a mapping of node devices to the remaining count
available := make(map[*structs.NodeDeviceResource]uint64, len(nodeDevs))
for _, d := range nodeDevs {
var healthy uint64 = 0
for _, instance := range d.Instances {
if instance.Healthy {
healthy++
}
}
if healthy != 0 {
available[d] = healthy
}
}
// Go through the required devices trying to find matches
OUTER:
for _, req := range c.required {
// Determine how many there are to place
desiredCount := req.Count
// Go through the device resources and see if we have a match
for d, unused := range available {
if unused == 0 {
// Depleted
continue
}
// First check we have enough instances of the device since this is
// cheaper than checking the constraints
if unused < desiredCount {
continue
}
// Check the constraints
if nodeDeviceMatches(c.ctx, d, req) {
// Consume the instances
available[d] -= desiredCount
// Move on to the next request
continue OUTER
}
}
// We couldn't match the request for the device
return false
}
// Only satisfied if there are no more devices to place
return true
}
// nodeDeviceMatches checks if the device matches the request and its
// constraints. It doesn't check the count.
func nodeDeviceMatches(ctx Context, d *structs.NodeDeviceResource, req *structs.RequestedDevice) bool {
if !d.ID().Matches(req.ID()) {
return false
}
// There are no constraints to consider
if len(req.Constraints) == 0 {
return true
}
for _, c := range req.Constraints {
// Resolve the targets
lVal, ok := resolveDeviceTarget(c.LTarget, d)
if !ok {
return false
}
rVal, ok := resolveDeviceTarget(c.RTarget, d)
if !ok {
return false
}
// Check if satisfied
if !checkAttributeConstraint(ctx, c.Operand, lVal, rVal) {
return false
}
}
return true
}
// resolveDeviceTarget is used to resolve the LTarget and RTarget of a Constraint
// when used on a device
func resolveDeviceTarget(target string, d *structs.NodeDeviceResource) (*psstructs.Attribute, bool) {
// If no prefix, this must be a literal value
if !strings.HasPrefix(target, "${") {
return psstructs.ParseAttribute(target), true
}
// Handle the interpolations
switch {
case "${driver.model}" == target:
return psstructs.NewStringAttribute(d.Name), true
case "${driver.vendor}" == target:
return psstructs.NewStringAttribute(d.Vendor), true
case "${driver.type}" == target:
return psstructs.NewStringAttribute(d.Type), true
case strings.HasPrefix(target, "${driver.attr."):
attr := strings.TrimPrefix(target, "${driver.attr.")
attr = strings.TrimSuffix(attr, "}")
val, ok := d.Attributes[attr]
return val, ok
default:
return nil, false
}
}
// checkAttributeConstraint checks if a constraint is satisfied
func checkAttributeConstraint(ctx Context, operand string, lVal, rVal *psstructs.Attribute) bool {
// Check for constraints not handled by this checker.
switch operand {
case structs.ConstraintDistinctHosts, structs.ConstraintDistinctProperty:
return true
default:
break
}
switch operand {
case "<", "<=", ">", ">=", "=", "==", "is", "!=", "not":
v, ok := lVal.Compare(rVal)
if !ok {
return false
}
switch operand {