-
Notifications
You must be signed in to change notification settings - Fork 1.1k
/
relabel.go
541 lines (518 loc) · 15.8 KB
/
relabel.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
package promrelabel
import (
"fmt"
"regexp"
"strconv"
"strings"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
xxhash "github.com/cespare/xxhash/v2"
)
// parsedRelabelConfig contains parsed `relabel_config`.
//
// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config
type parsedRelabelConfig struct {
SourceLabels []string
Separator string
TargetLabel string
Regex *regexp.Regexp
Modulus uint64
Replacement string
Action string
If *IfExpression
graphiteMatchTemplate *graphiteMatchTemplate
graphiteLabelRules []graphiteLabelRule
regexOriginal *regexp.Regexp
hasCaptureGroupInTargetLabel bool
hasCaptureGroupInReplacement bool
}
// String returns human-readable representation for prc.
func (prc *parsedRelabelConfig) String() string {
return fmt.Sprintf("SourceLabels=%s, Separator=%s, TargetLabel=%s, Regex=%s, Modulus=%d, Replacement=%s, Action=%s, If=%s, graphiteMatchTemplate=%s, graphiteLabelRules=%s",
prc.SourceLabels, prc.Separator, prc.TargetLabel, prc.Regex, prc.Modulus, prc.Replacement, prc.Action, prc.If, prc.graphiteMatchTemplate, prc.graphiteLabelRules)
}
// Apply applies pcs to labels starting from the labelsOffset.
//
// If isFinalize is set, then FinalizeLabels is called on the labels[labelsOffset:].
//
// The returned labels at labels[labelsOffset:] are sorted.
func (pcs *ParsedConfigs) Apply(labels []prompbmarshal.Label, labelsOffset int, isFinalize bool) []prompbmarshal.Label {
var inStr string
relabelDebug := false
if pcs != nil {
relabelDebug = pcs.relabelDebug
if relabelDebug {
inStr = labelsToString(labels[labelsOffset:])
}
for _, prc := range pcs.prcs {
tmp := prc.apply(labels, labelsOffset)
if len(tmp) == labelsOffset {
// All the labels have been removed.
if pcs.relabelDebug {
logger.Infof("\nRelabel In: %s\nRelabel Out: DROPPED - all labels removed", inStr)
}
return tmp
}
labels = tmp
}
}
labels = removeEmptyLabels(labels, labelsOffset)
if isFinalize {
labels = FinalizeLabels(labels[:labelsOffset], labels[labelsOffset:])
}
SortLabels(labels[labelsOffset:])
if relabelDebug {
if len(labels) == labelsOffset {
logger.Infof("\nRelabel In: %s\nRelabel Out: DROPPED - all labels removed", inStr)
return labels
}
outStr := labelsToString(labels[labelsOffset:])
if inStr == outStr {
logger.Infof("\nRelabel In: %s\nRelabel Out: KEPT AS IS - no change", inStr)
} else {
logger.Infof("\nRelabel In: %s\nRelabel Out: %s", inStr, outStr)
}
// Drop labels
labels = labels[:labelsOffset]
}
return labels
}
func removeEmptyLabels(labels []prompbmarshal.Label, labelsOffset int) []prompbmarshal.Label {
src := labels[labelsOffset:]
needsRemoval := false
for i := range src {
label := &src[i]
if label.Name == "" || label.Value == "" {
needsRemoval = true
break
}
}
if !needsRemoval {
return labels
}
dst := labels[:labelsOffset]
for i := range src {
label := &src[i]
if label.Name != "" && label.Value != "" {
dst = append(dst, *label)
}
}
return dst
}
// RemoveMetaLabels removes all the `__meta_` labels from src and puts the rest of labels to dst.
//
// See https://www.robustperception.io/life-of-a-label fo details.
func RemoveMetaLabels(dst, src []prompbmarshal.Label) []prompbmarshal.Label {
for i := range src {
label := &src[i]
if strings.HasPrefix(label.Name, "__meta_") {
continue
}
dst = append(dst, *label)
}
return dst
}
// FinalizeLabels removes labels with "__" in the beginning (except of "__name__").
func FinalizeLabels(dst, src []prompbmarshal.Label) []prompbmarshal.Label {
for i := range src {
label := &src[i]
name := label.Name
if strings.HasPrefix(name, "__") && name != "__name__" {
continue
}
dst = append(dst, *label)
}
return dst
}
// apply applies relabeling according to prc.
//
// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config
func (prc *parsedRelabelConfig) apply(labels []prompbmarshal.Label, labelsOffset int) []prompbmarshal.Label {
src := labels[labelsOffset:]
if prc.If != nil && !prc.If.Match(labels) {
if prc.Action == "keep" {
// Drop the target on `if` mismatch for `action: keep`
return labels[:labelsOffset]
}
// Do not apply prc actions on `if` mismatch.
return labels
}
switch prc.Action {
case "graphite":
metricName := GetLabelValueByName(src, "__name__")
gm := graphiteMatchesPool.Get().(*graphiteMatches)
var ok bool
gm.a, ok = prc.graphiteMatchTemplate.Match(gm.a[:0], metricName)
if !ok {
// Fast path - name mismatch
graphiteMatchesPool.Put(gm)
return labels
}
// Slow path - extract labels from graphite metric name
bb := relabelBufPool.Get()
for _, gl := range prc.graphiteLabelRules {
bb.B = gl.grt.Expand(bb.B[:0], gm.a)
valueStr := string(bb.B)
labels = setLabelValue(labels, labelsOffset, gl.targetLabel, valueStr)
}
relabelBufPool.Put(bb)
graphiteMatchesPool.Put(gm)
return labels
case "replace":
// Store `replacement` at `target_label` if the `regex` matches `source_labels` joined with `separator`
bb := relabelBufPool.Get()
bb.B = concatLabelValues(bb.B[:0], src, prc.SourceLabels, prc.Separator)
if prc.Regex == defaultRegexForRelabelConfig && !prc.hasCaptureGroupInTargetLabel {
if prc.Replacement == "$1" {
// Fast path for the rule that copies source label values to destination:
// - source_labels: [...]
// target_label: foobar
valueStr := string(bb.B)
relabelBufPool.Put(bb)
return setLabelValue(labels, labelsOffset, prc.TargetLabel, valueStr)
}
if !prc.hasCaptureGroupInReplacement {
// Fast path for the rule that sets label value:
// - target_label: foobar
// replacement: something-here
relabelBufPool.Put(bb)
labels = setLabelValue(labels, labelsOffset, prc.TargetLabel, prc.Replacement)
return labels
}
}
match := prc.Regex.FindSubmatchIndex(bb.B)
if match == nil {
// Fast path - nothing to replace.
relabelBufPool.Put(bb)
return labels
}
sourceStr := bytesutil.ToUnsafeString(bb.B)
nameStr := prc.TargetLabel
if prc.hasCaptureGroupInTargetLabel {
nameStr = prc.expandCaptureGroups(nameStr, sourceStr, match)
}
valueStr := prc.expandCaptureGroups(prc.Replacement, sourceStr, match)
relabelBufPool.Put(bb)
return setLabelValue(labels, labelsOffset, nameStr, valueStr)
case "replace_all":
// Replace all the occurrences of `regex` at `source_labels` joined with `separator` with the `replacement`
// and store the result at `target_label`
bb := relabelBufPool.Get()
bb.B = concatLabelValues(bb.B[:0], src, prc.SourceLabels, prc.Separator)
sourceStr := string(bb.B)
relabelBufPool.Put(bb)
valueStr, ok := prc.replaceStringSubmatches(sourceStr, prc.Replacement, prc.hasCaptureGroupInReplacement)
if ok {
labels = setLabelValue(labels, labelsOffset, prc.TargetLabel, valueStr)
}
return labels
case "keep_if_equal":
// Keep the entry if all the label values in source_labels are equal.
// For example:
//
// - source_labels: [foo, bar]
// action: keep_if_equal
//
// Would leave the entry if `foo` value equals `bar` value
if areEqualLabelValues(src, prc.SourceLabels) {
return labels
}
return labels[:labelsOffset]
case "drop_if_equal":
// Drop the entry if all the label values in source_labels are equal.
// For example:
//
// - source_labels: [foo, bar]
// action: drop_if_equal
//
// Would drop the entry if `foo` value equals `bar` value.
if areEqualLabelValues(src, prc.SourceLabels) {
return labels[:labelsOffset]
}
return labels
case "keep":
// Keep the target if `source_labels` joined with `separator` match the `regex`.
if prc.Regex == defaultRegexForRelabelConfig {
// Fast path for the case with `if` and without explicitly set `regex`:
//
// - action: keep
// if: 'some{label=~"filters"}'
//
return labels
}
bb := relabelBufPool.Get()
bb.B = concatLabelValues(bb.B[:0], src, prc.SourceLabels, prc.Separator)
keep := prc.matchString(bytesutil.ToUnsafeString(bb.B))
relabelBufPool.Put(bb)
if !keep {
return labels[:labelsOffset]
}
return labels
case "drop":
// Drop the target if `source_labels` joined with `separator` don't match the `regex`.
if prc.Regex == defaultRegexForRelabelConfig {
// Fast path for the case with `if` and without explicitly set `regex`:
//
// - action: drop
// if: 'some{label=~"filters"}'
//
return labels[:labelsOffset]
}
bb := relabelBufPool.Get()
bb.B = concatLabelValues(bb.B[:0], src, prc.SourceLabels, prc.Separator)
drop := prc.matchString(bytesutil.ToUnsafeString(bb.B))
relabelBufPool.Put(bb)
if drop {
return labels[:labelsOffset]
}
return labels
case "hashmod":
// Calculate the `modulus` from the hash of `source_labels` joined with `separator` and store it at `target_label`
bb := relabelBufPool.Get()
bb.B = concatLabelValues(bb.B[:0], src, prc.SourceLabels, prc.Separator)
h := xxhash.Sum64(bb.B) % prc.Modulus
value := strconv.Itoa(int(h))
relabelBufPool.Put(bb)
return setLabelValue(labels, labelsOffset, prc.TargetLabel, value)
case "labelmap":
// Replace label names with the `replacement` if they match `regex`
for i := range src {
label := &src[i]
labelName, ok := prc.replaceFullString(label.Name, prc.Replacement, prc.hasCaptureGroupInReplacement)
if ok {
labels = setLabelValue(labels, labelsOffset, labelName, label.Value)
}
}
return labels
case "labelmap_all":
// Replace all the occurences of `regex` at label names with `replacement`
for i := range src {
label := &src[i]
label.Name, _ = prc.replaceStringSubmatches(label.Name, prc.Replacement, prc.hasCaptureGroupInReplacement)
}
return labels
case "labeldrop":
// Drop labels with names matching the `regex`
dst := labels[:labelsOffset]
for i := range src {
label := &src[i]
if !prc.matchString(label.Name) {
dst = append(dst, *label)
}
}
return dst
case "labelkeep":
// Keep labels with names matching the `regex`
dst := labels[:labelsOffset]
for i := range src {
label := &src[i]
if prc.matchString(label.Name) {
dst = append(dst, *label)
}
}
return dst
case "uppercase":
bb := relabelBufPool.Get()
bb.B = concatLabelValues(bb.B[:0], src, prc.SourceLabels, prc.Separator)
valueStr := string(bb.B)
relabelBufPool.Put(bb)
valueStr = strings.ToUpper(valueStr)
labels = setLabelValue(labels, labelsOffset, prc.TargetLabel, valueStr)
return labels
case "lowercase":
bb := relabelBufPool.Get()
bb.B = concatLabelValues(bb.B[:0], src, prc.SourceLabels, prc.Separator)
valueStr := string(bb.B)
relabelBufPool.Put(bb)
valueStr = strings.ToLower(valueStr)
labels = setLabelValue(labels, labelsOffset, prc.TargetLabel, valueStr)
return labels
default:
logger.Panicf("BUG: unknown `action`: %q", prc.Action)
return labels
}
}
func (prc *parsedRelabelConfig) replaceFullString(s, replacement string, hasCaptureGroupInReplacement bool) (string, bool) {
prefix, complete := prc.regexOriginal.LiteralPrefix()
if complete && !hasCaptureGroupInReplacement {
if s == prefix {
return replacement, true
}
return s, false
}
if !strings.HasPrefix(s, prefix) {
return s, false
}
if replacement == "$1" {
// Fast path for commonly used rule for deleting label prefixes such as:
//
// - action: labelmap
// regex: __meta_kubernetes_node_label_(.+)
//
reStr := prc.regexOriginal.String()
if strings.HasPrefix(reStr, prefix) {
suffix := s[len(prefix):]
reSuffix := reStr[len(prefix):]
switch reSuffix {
case "(.*)":
return suffix, true
case "(.+)":
if len(suffix) > 0 {
return suffix, true
}
return s, false
}
}
}
// Slow path - regexp processing
match := prc.Regex.FindStringSubmatchIndex(s)
if match == nil {
return s, false
}
bb := relabelBufPool.Get()
bb.B = prc.Regex.ExpandString(bb.B[:0], replacement, s, match)
result := string(bb.B)
relabelBufPool.Put(bb)
return result, true
}
func (prc *parsedRelabelConfig) replaceStringSubmatches(s, replacement string, hasCaptureGroupInReplacement bool) (string, bool) {
re := prc.regexOriginal
prefix, complete := re.LiteralPrefix()
if complete && !hasCaptureGroupInReplacement {
if !strings.Contains(s, prefix) {
return s, false
}
return strings.ReplaceAll(s, prefix, replacement), true
}
if !re.MatchString(s) {
return s, false
}
return re.ReplaceAllString(s, replacement), true
}
func (prc *parsedRelabelConfig) matchString(s string) bool {
prefix, complete := prc.regexOriginal.LiteralPrefix()
if complete {
return prefix == s
}
if !strings.HasPrefix(s, prefix) {
return false
}
reStr := prc.regexOriginal.String()
if strings.HasPrefix(reStr, prefix) {
// Fast path for `foo.*` and `bar.+` regexps
reSuffix := reStr[len(prefix):]
switch reSuffix {
case ".+", "(.+)":
return len(s) > len(prefix)
case ".*", "(.*)":
return true
}
}
return prc.Regex.MatchString(s)
}
func (prc *parsedRelabelConfig) expandCaptureGroups(template, source string, match []int) string {
bb := relabelBufPool.Get()
bb.B = prc.Regex.ExpandString(bb.B[:0], template, source, match)
s := string(bb.B)
relabelBufPool.Put(bb)
return s
}
var relabelBufPool bytesutil.ByteBufferPool
func areEqualLabelValues(labels []prompbmarshal.Label, labelNames []string) bool {
if len(labelNames) < 2 {
logger.Panicf("BUG: expecting at least 2 labelNames; got %d", len(labelNames))
return false
}
labelValue := GetLabelValueByName(labels, labelNames[0])
for _, labelName := range labelNames[1:] {
v := GetLabelValueByName(labels, labelName)
if v != labelValue {
return false
}
}
return true
}
func concatLabelValues(dst []byte, labels []prompbmarshal.Label, labelNames []string, separator string) []byte {
if len(labelNames) == 0 {
return dst
}
for _, labelName := range labelNames {
label := GetLabelByName(labels, labelName)
if label != nil {
dst = append(dst, label.Value...)
}
dst = append(dst, separator...)
}
return dst[:len(dst)-len(separator)]
}
func setLabelValue(labels []prompbmarshal.Label, labelsOffset int, name, value string) []prompbmarshal.Label {
if label := GetLabelByName(labels[labelsOffset:], name); label != nil {
label.Value = value
return labels
}
labels = append(labels, prompbmarshal.Label{
Name: name,
Value: value,
})
return labels
}
// GetLabelByName returns label with the given name from labels.
func GetLabelByName(labels []prompbmarshal.Label, name string) *prompbmarshal.Label {
for i := range labels {
label := &labels[i]
if label.Name == name {
return label
}
}
return nil
}
// GetLabelValueByName returns value for label with the given name from labels.
//
// It returns empty string for non-existing label.
func GetLabelValueByName(labels []prompbmarshal.Label, name string) string {
label := GetLabelByName(labels, name)
if label == nil {
return ""
}
return label.Value
}
// CleanLabels sets label.Name and label.Value to an empty string for all the labels.
//
// This should help GC cleaning up label.Name and label.Value strings.
func CleanLabels(labels []prompbmarshal.Label) {
for i := range labels {
label := &labels[i]
label.Name = ""
label.Value = ""
}
}
func labelsToString(labels []prompbmarshal.Label) string {
labelsCopy := append([]prompbmarshal.Label{}, labels...)
SortLabels(labelsCopy)
mname := ""
for _, label := range labelsCopy {
if label.Name == "__name__" {
mname = label.Value
break
}
}
if mname != "" && len(labelsCopy) <= 1 {
return mname
}
b := []byte(mname)
b = append(b, '{')
for i, label := range labelsCopy {
if label.Name == "__name__" {
continue
}
b = append(b, label.Name...)
b = append(b, '=')
b = strconv.AppendQuote(b, label.Value)
if i+1 < len(labelsCopy) {
b = append(b, ',')
}
}
b = append(b, '}')
return string(b)
}