| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | // Package relabel applies Prometheus-compatible metric-relabeling rules to |
| 4 | // scraped samples (the metric name plus labels, including le/quantile) before |
| 5 | // typed-family assembly. It is collector-local to the prometheus collector. |
| 6 | package relabel |
| 7 | |
| 8 | import ( |
| 9 | "crypto/md5" |
| 10 | "encoding/binary" |
| 11 | "errors" |
| 12 | "fmt" |
| 13 | "strconv" |
| 14 | "strings" |
| 15 | |
| 16 | "github.com/grafana/regexp" |
| 17 | commonmodel "github.com/prometheus/common/model" |
| 18 | "github.com/prometheus/prometheus/model/labels" |
| 19 | |
| 20 | prompkg "github.com/netdata/netdata/go/plugins/pkg/prometheus" |
| 21 | ) |
| 22 | |
| 23 | var ( |
| 24 | relabelTargetLegacy = regexp.MustCompile(`^(?:(?:[a-zA-Z_]|\$(?:\{\w+\}|\w+))+\w*)+$`) |
| 25 | |
| 26 | defaultConfig = Config{ |
| 27 | Action: Replace, |
| 28 | Separator: ";", |
| 29 | Regex: MustNewRegexp("(.*)"), |
| 30 | Replacement: "$1", |
| 31 | } |
| 32 | ) |
| 33 | |
| 34 | // defaultNameValidationScheme is the name-validation scheme applied when a rule |
| 35 | // does not set one. It is UTF-8: relabeling may legitimately produce dotted or |
| 36 | // otherwise non-legacy metric and label names, and only an empty name is |
| 37 | // rejected. A rule may still opt into commonmodel.LegacyValidation via |
| 38 | // Config.NameScheme. |
| 39 | const defaultNameValidationScheme = commonmodel.UTF8Validation |
| 40 | |
| 41 | // Action is the operation a relabel rule performs on a sample's labels and metric |
| 42 | // name. It mirrors Prometheus's relabel actions; New canonicalizes the value, so it |
| 43 | // is case-insensitive. "Joined value" below means the SourceLabels values joined by |
| 44 | // Separator. |
| 45 | type Action string |
| 46 | |
| 47 | const ( |
| 48 | // Replace sets TargetLabel from the regex match of the joined value (Replacement |
| 49 | // is the template; an empty result deletes the target label). |
| 50 | Replace Action = "replace" |
| 51 | // Keep keeps the sample only when Regex matches the joined value. |
| 52 | Keep Action = "keep" |
| 53 | // Drop drops the sample when Regex matches the joined value. |
| 54 | Drop Action = "drop" |
| 55 | // KeepEqual keeps the sample only when TargetLabel equals the joined value. |
| 56 | KeepEqual Action = "keepequal" |
| 57 | // DropEqual drops the sample when TargetLabel equals the joined value. |
| 58 | DropEqual Action = "dropequal" |
| 59 | // HashMod sets TargetLabel to the MD5 of the joined value modulo Modulus. |
| 60 | HashMod Action = "hashmod" |
| 61 | // LabelMap copies each label whose name matches Regex to a new name from Replacement. |
| 62 | LabelMap Action = "labelmap" |
| 63 | // LabelDrop removes every label whose name matches Regex. |
| 64 | LabelDrop Action = "labeldrop" |
| 65 | // LabelKeep removes every label whose name does not match Regex. |
| 66 | LabelKeep Action = "labelkeep" |
| 67 | // Lowercase sets TargetLabel to the lowercased joined value. |
| 68 | Lowercase Action = "lowercase" |
| 69 | // Uppercase sets TargetLabel to the uppercased joined value. |
| 70 | Uppercase Action = "uppercase" |
| 71 | ) |
| 72 | |
| 73 | // DropReason explains why Apply dropped a sample, for the caller to log. |
| 74 | type DropReason string |
| 75 | |
| 76 | const ( |
| 77 | DropReasonNone DropReason = "" |
| 78 | DropReasonDropRuleMatched DropReason = "drop rule matched" |
| 79 | DropReasonKeepRuleMismatch DropReason = "keep rule did not match" |
| 80 | DropReasonDropEqualMatched DropReason = "dropequal rule matched" |
| 81 | DropReasonKeepEqualMismatch DropReason = "keepequal rule did not match" |
| 82 | DropReasonInvalidMetricName DropReason = "resulting metric name is empty or invalid" |
| 83 | ) |
| 84 | |
| 85 | // DropInfo is the outcome of Apply. Dropped reports whether the sample was |
| 86 | // dropped; when it was, Reason says why and, for a rule-driven drop, RuleIndex |
| 87 | // and Action identify the rule. RuleIndex is -1 when the drop is not tied to a |
| 88 | // single rule (an invalid final metric name). |
| 89 | type DropInfo struct { |
| 90 | Reason DropReason |
| 91 | RuleIndex int |
| 92 | Action Action |
| 93 | } |
| 94 | |
| 95 | // Dropped reports whether the sample was dropped. |
| 96 | func (d DropInfo) Dropped() bool { return d.Reason != DropReasonNone } |
| 97 | |
| 98 | // DropObserver is called by the SampleTransform returned from NewTransform for |
| 99 | // each dropped sample. Implementations SHOULD log the reason/rule/action but |
| 100 | // MUST NOT log label values (cardinality and privacy). |
| 101 | type DropObserver func(sample prompkg.Sample, drop DropInfo) |
| 102 | |
| 103 | // Config is one relabeling rule. Construct it directly using the Action constants |
| 104 | // and exported fields; rules are validated (and the Action canonicalized) by New. |
| 105 | // |
| 106 | // The unexported separatorSet/replacementSet/sourceLabelsSet fields distinguish an |
| 107 | // explicitly-empty field from an unset one (they are read by withDefaults, validate |
| 108 | // and applyReplace). They are settable only within this package; callers outside the |
| 109 | // package cannot express explicit-empty Separator/Replacement/SourceLabels via normal |
| 110 | // struct literals or standard YAML/JSON unmarshaling (unexported fields are ignored), |
| 111 | // so a dedicated config loader must set them when that behavior is needed. |
| 112 | type Config struct { |
| 113 | SourceLabels []string |
| 114 | Separator string |
| 115 | Regex Regexp |
| 116 | Modulus uint64 |
| 117 | TargetLabel string |
| 118 | Replacement string |
| 119 | Action Action |
| 120 | NameScheme commonmodel.ValidationScheme |
| 121 | |
| 122 | separatorSet bool |
| 123 | replacementSet bool |
| 124 | sourceLabelsSet bool |
| 125 | } |
| 126 | |
| 127 | // Regexp is a relabel regular expression: a regexp.Regexp compiled fully anchored |
| 128 | // (see NewRegexp). The zero value has no pattern; build one with NewRegexp or |
| 129 | // MustNewRegexp. String returns the original, un-anchored source. |
| 130 | type Regexp struct { |
| 131 | *regexp.Regexp |
| 132 | original string // un-anchored source passed to NewRegexp; returned by String |
| 133 | } |
| 134 | |
| 135 | // Processor applies an ordered list of rules to samples. It reuses internal |
| 136 | // buffers across calls, so a Processor is single-threaded per scrape and is NOT |
| 137 | // goroutine-safe. |
| 138 | type Processor struct { |
| 139 | cfgs []Config |
| 140 | |
| 141 | builder *labels.Builder |
| 142 | join strings.Builder |
| 143 | buf []byte |
| 144 | rangeBuf []labels.Label |
| 145 | |
| 146 | currentName string |
| 147 | currentNameScheme commonmodel.ValidationScheme |
| 148 | labelsChanged bool |
| 149 | nameChanged bool |
| 150 | } |
| 151 | |
| 152 | // New validates and compiles the rules into a Processor. |
| 153 | func New(cfgs []Config) (*Processor, error) { |
| 154 | compiled, err := normalizeAndValidateConfigs(cfgs) |
| 155 | if err != nil { |
| 156 | return nil, err |
| 157 | } |
| 158 | |
| 159 | return &Processor{ |
| 160 | cfgs: compiled, |
| 161 | builder: labels.NewBuilder(nil), |
| 162 | }, nil |
| 163 | } |
| 164 | |
| 165 | // NewTransform builds a prompkg.SampleTransform from the rules. It returns a nil |
| 166 | // transform when there are no rules, so the scraper keeps its no-transform fast |
| 167 | // path. onDrop, if non-nil, is called for each dropped sample. The returned |
| 168 | // transform closes over a single reusable Processor, so it is NOT goroutine-safe; |
| 169 | // use one transform per scrape goroutine. |
| 170 | func NewTransform(cfgs []Config, onDrop DropObserver) (prompkg.SampleTransform, error) { |
| 171 | p, err := New(cfgs) |
| 172 | if err != nil { |
| 173 | return nil, err |
| 174 | } |
| 175 | if len(p.cfgs) == 0 { |
| 176 | return nil, nil |
| 177 | } |
| 178 | |
| 179 | return func(s prompkg.Sample) (prompkg.Sample, bool, error) { |
| 180 | out, drop := p.Apply(s) |
| 181 | if drop.Dropped() { |
| 182 | if onDrop != nil { |
| 183 | onDrop(out, drop) |
| 184 | } |
| 185 | return prompkg.Sample{}, false, nil |
| 186 | } |
| 187 | return out, true, nil |
| 188 | }, nil |
| 189 | } |
| 190 | |
| 191 | func normalizeAndValidateConfigs(cfgs []Config) ([]Config, error) { |
| 192 | compiled := make([]Config, 0, len(cfgs)) |
| 193 | for i, cfg := range cfgs { |
| 194 | cfg = withDefaults(cfg) |
| 195 | if err := cfg.validate(); err != nil { |
| 196 | return nil, fmt.Errorf("rule %d: %w", i, err) |
| 197 | } |
| 198 | compiled = append(compiled, cfg) |
| 199 | } |
| 200 | return compiled, nil |
| 201 | } |
| 202 | |
| 203 | func (c Config) validate() error { |
| 204 | c = withDefaults(c) |
| 205 | |
| 206 | if _, err := parseAction(string(c.Action)); err != nil { |
| 207 | return err |
| 208 | } |
| 209 | |
| 210 | if err := validateNameScheme(c.NameScheme); err != nil { |
| 211 | return err |
| 212 | } |
| 213 | |
| 214 | scheme := c.NameScheme |
| 215 | if scheme == commonmodel.UnsetValidation { |
| 216 | scheme = defaultNameValidationScheme |
| 217 | } |
| 218 | |
| 219 | if c.Modulus == 0 && c.Action == HashMod { |
| 220 | return errors.New("relabel configuration for hashmod requires non-zero modulus") |
| 221 | } |
| 222 | if needsTargetLabel(c.Action) && c.TargetLabel == "" { |
| 223 | return fmt.Errorf("relabel configuration for %s action requires 'target_label' value", c.Action) |
| 224 | } |
| 225 | |
| 226 | if c.Action == Replace && !varInRegexTemplate(c.TargetLabel) && !scheme.IsValidLabelName(c.TargetLabel) { |
| 227 | return fmt.Errorf("%q is invalid 'target_label' for %s action", c.TargetLabel, c.Action) |
| 228 | } |
| 229 | if c.Action == Replace && varInRegexTemplate(c.TargetLabel) && !isValidLabelNameWithRegexVar(c.TargetLabel, scheme) { |
| 230 | return fmt.Errorf("%q is invalid 'target_label' for %s action", c.TargetLabel, c.Action) |
| 231 | } |
| 232 | if (c.Action == Lowercase || c.Action == Uppercase || c.Action == KeepEqual || c.Action == DropEqual) && |
| 233 | !scheme.IsValidLabelName(c.TargetLabel) { |
| 234 | return fmt.Errorf("%q is invalid 'target_label' for %s action", c.TargetLabel, c.Action) |
| 235 | } |
| 236 | if (c.Action == Lowercase || c.Action == Uppercase || c.Action == KeepEqual || c.Action == DropEqual) && |
| 237 | c.Replacement != defaultConfig.Replacement { |
| 238 | return fmt.Errorf("'replacement' can not be set for %s action", c.Action) |
| 239 | } |
| 240 | if c.Action == LabelMap && !isValidLabelNameWithRegexVar(c.Replacement, scheme) { |
| 241 | return fmt.Errorf("%q is invalid 'replacement' for %s action", c.Replacement, c.Action) |
| 242 | } |
| 243 | if c.Action == HashMod && !scheme.IsValidLabelName(c.TargetLabel) { |
| 244 | return fmt.Errorf("%q is invalid 'target_label' for %s action", c.TargetLabel, c.Action) |
| 245 | } |
| 246 | if c.Action == DropEqual || c.Action == KeepEqual { |
| 247 | if c.Regex.String() != defaultConfig.Regex.String() || |
| 248 | c.Modulus != defaultConfig.Modulus || |
| 249 | c.Separator != defaultConfig.Separator || |
| 250 | c.Replacement != defaultConfig.Replacement { |
| 251 | return fmt.Errorf("%s action requires only 'source_labels' and 'target_label', and no other fields", c.Action) |
| 252 | } |
| 253 | } |
| 254 | if c.Action == LabelDrop || c.Action == LabelKeep { |
| 255 | if c.sourceLabelsSet || |
| 256 | len(c.SourceLabels) > 0 || |
| 257 | c.TargetLabel != defaultConfig.TargetLabel || |
| 258 | c.Modulus != defaultConfig.Modulus || |
| 259 | c.Separator != defaultConfig.Separator || |
| 260 | c.Replacement != defaultConfig.Replacement { |
| 261 | return fmt.Errorf("%s action requires only 'regex', and no other fields", c.Action) |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | return nil |
| 266 | } |
| 267 | |
| 268 | func NewRegexp(s string) (Regexp, error) { |
| 269 | re, err := regexp.Compile("^(?s:" + s + ")$") |
| 270 | return Regexp{Regexp: re, original: s}, err |
| 271 | } |
| 272 | |
| 273 | func MustNewRegexp(s string) Regexp { |
| 274 | re, err := NewRegexp(s) |
| 275 | if err != nil { |
| 276 | panic(err) |
| 277 | } |
| 278 | return re |
| 279 | } |
| 280 | |
| 281 | // String returns the original, un-anchored pattern passed to NewRegexp. It returns |
| 282 | // "" for the zero value or any Regexp not built via NewRegexp, and never inspects the |
| 283 | // compiled form, so it is safe on a Regexp wrapping an arbitrary *regexp.Regexp. |
| 284 | func (re Regexp) String() string { |
| 285 | return re.original |
| 286 | } |
| 287 | |
| 288 | // Apply runs the rules against one sample. It returns the (possibly mutated) |
| 289 | // sample and a DropInfo. When DropInfo.Dropped() is true the sample must be |
| 290 | // discarded; the returned sample is the original (unmutated) so the caller can |
| 291 | // log its name. Value, Kind and FamilyType are passed through unchanged — a |
| 292 | // relabeled sample is never re-typed. |
| 293 | func (p *Processor) Apply(sample prompkg.Sample) (prompkg.Sample, DropInfo) { |
| 294 | if len(p.cfgs) == 0 { |
| 295 | return sample, DropInfo{} |
| 296 | } |
| 297 | |
| 298 | p.builder.Reset(sample.Labels) |
| 299 | p.currentName = sample.Name |
| 300 | p.currentNameScheme = defaultNameValidationScheme |
| 301 | p.labelsChanged = false |
| 302 | p.nameChanged = false |
| 303 | |
| 304 | for i := range p.cfgs { |
| 305 | if keep, drop := p.applyConfig(&p.cfgs[i], i); !keep { |
| 306 | return sample, drop |
| 307 | } |
| 308 | } |
| 309 | |
| 310 | if !p.currentNameScheme.IsValidMetricName(p.currentName) { |
| 311 | return sample, DropInfo{Reason: DropReasonInvalidMetricName, RuleIndex: -1} |
| 312 | } |
| 313 | |
| 314 | if !p.nameChanged && !p.labelsChanged { |
| 315 | return sample, DropInfo{} |
| 316 | } |
| 317 | |
| 318 | sample.Name = p.currentName |
| 319 | if p.labelsChanged { |
| 320 | sample.Labels = p.builder.Labels() |
| 321 | } |
| 322 | return sample, DropInfo{} |
| 323 | } |
| 324 | |
| 325 | func (p *Processor) applyConfig(cfg *Config, idx int) (bool, DropInfo) { |
| 326 | val := p.joinSourceLabels(cfg.SourceLabels, cfg.Separator) |
| 327 | |
| 328 | switch cfg.Action { |
| 329 | case Drop: |
| 330 | if cfg.Regex.MatchString(val) { |
| 331 | return false, DropInfo{Reason: DropReasonDropRuleMatched, RuleIndex: idx, Action: Drop} |
| 332 | } |
| 333 | case Keep: |
| 334 | if !cfg.Regex.MatchString(val) { |
| 335 | return false, DropInfo{Reason: DropReasonKeepRuleMismatch, RuleIndex: idx, Action: Keep} |
| 336 | } |
| 337 | case DropEqual: |
| 338 | if p.getLabel(cfg.TargetLabel) == val { |
| 339 | return false, DropInfo{Reason: DropReasonDropEqualMatched, RuleIndex: idx, Action: DropEqual} |
| 340 | } |
| 341 | case KeepEqual: |
| 342 | if p.getLabel(cfg.TargetLabel) != val { |
| 343 | return false, DropInfo{Reason: DropReasonKeepEqualMismatch, RuleIndex: idx, Action: KeepEqual} |
| 344 | } |
| 345 | case Replace: |
| 346 | p.applyReplace(cfg, val) |
| 347 | case Lowercase: |
| 348 | p.setLabel(cfg.TargetLabel, strings.ToLower(val), cfg.NameScheme) |
| 349 | case Uppercase: |
| 350 | p.setLabel(cfg.TargetLabel, strings.ToUpper(val), cfg.NameScheme) |
| 351 | case HashMod: |
| 352 | hash := md5.Sum([]byte(val)) |
| 353 | mod := binary.BigEndian.Uint64(hash[8:]) % cfg.Modulus |
| 354 | p.setLabel(cfg.TargetLabel, strconv.FormatUint(mod, 10), cfg.NameScheme) |
| 355 | case LabelMap: |
| 356 | p.rangeLabels(func(l labels.Label) { |
| 357 | if cfg.Regex.MatchString(l.Name) { |
| 358 | p.setLabel(cfg.Regex.ReplaceAllString(l.Name, cfg.Replacement), l.Value, cfg.NameScheme) |
| 359 | } |
| 360 | }) |
| 361 | case LabelDrop: |
| 362 | p.rangeLabels(func(l labels.Label) { |
| 363 | if cfg.Regex.MatchString(l.Name) { |
| 364 | p.delLabel(l.Name) |
| 365 | } |
| 366 | }) |
| 367 | case LabelKeep: |
| 368 | p.rangeLabels(func(l labels.Label) { |
| 369 | if !cfg.Regex.MatchString(l.Name) { |
| 370 | p.delLabel(l.Name) |
| 371 | } |
| 372 | }) |
| 373 | default: |
| 374 | panic(fmt.Errorf("unknown relabel action %q", cfg.Action)) |
| 375 | } |
| 376 | |
| 377 | return true, DropInfo{} |
| 378 | } |
| 379 | |
| 380 | func (p *Processor) applyReplace(cfg *Config, val string) { |
| 381 | if val == "" && |
| 382 | cfg.Regex.String() == defaultConfig.Regex.String() && |
| 383 | !varInRegexTemplate(cfg.TargetLabel) && |
| 384 | !varInRegexTemplate(cfg.Replacement) { |
| 385 | p.setLabel(cfg.TargetLabel, cfg.Replacement, cfg.NameScheme) |
| 386 | return |
| 387 | } |
| 388 | |
| 389 | indexes := cfg.Regex.FindStringSubmatchIndex(val) |
| 390 | if indexes == nil { |
| 391 | return |
| 392 | } |
| 393 | |
| 394 | p.buf = cfg.Regex.ExpandString(p.buf[:0], cfg.TargetLabel, val, indexes) |
| 395 | target := string(p.buf) |
| 396 | if !cfg.NameScheme.IsValidLabelName(target) { |
| 397 | return |
| 398 | } |
| 399 | |
| 400 | p.buf = cfg.Regex.ExpandString(p.buf[:0], cfg.Replacement, val, indexes) |
| 401 | if len(p.buf) == 0 { |
| 402 | p.delLabel(target) |
| 403 | return |
| 404 | } |
| 405 | |
| 406 | p.setLabel(target, string(p.buf), cfg.NameScheme) |
| 407 | } |
| 408 | |
| 409 | func (p *Processor) joinSourceLabels(sourceLabels []string, separator string) string { |
| 410 | switch len(sourceLabels) { |
| 411 | case 0: |
| 412 | return "" |
| 413 | case 1: |
| 414 | return p.getLabel(sourceLabels[0]) |
| 415 | } |
| 416 | |
| 417 | p.join.Reset() |
| 418 | for i, name := range sourceLabels { |
| 419 | if i > 0 { |
| 420 | p.join.WriteString(separator) |
| 421 | } |
| 422 | p.join.WriteString(p.getLabel(name)) |
| 423 | } |
| 424 | |
| 425 | return p.join.String() |
| 426 | } |
| 427 | |
| 428 | func (p *Processor) getLabel(name string) string { |
| 429 | if name == commonmodel.MetricNameLabel { |
| 430 | return p.currentName |
| 431 | } |
| 432 | return p.builder.Get(name) |
| 433 | } |
| 434 | |
| 435 | func (p *Processor) setLabel(name, value string, scheme commonmodel.ValidationScheme) { |
| 436 | if name == commonmodel.MetricNameLabel { |
| 437 | p.currentNameScheme = scheme |
| 438 | if p.currentName != value { |
| 439 | p.currentName = value |
| 440 | p.nameChanged = true |
| 441 | } |
| 442 | return |
| 443 | } |
| 444 | |
| 445 | if current, ok := p.lookupLabel(name); ok && current == value { |
| 446 | return |
| 447 | } |
| 448 | |
| 449 | p.builder.Set(name, value) |
| 450 | p.labelsChanged = true |
| 451 | } |
| 452 | |
| 453 | func (p *Processor) delLabel(name string) { |
| 454 | if name == commonmodel.MetricNameLabel { |
| 455 | if p.currentName != "" { |
| 456 | p.currentName = "" |
| 457 | p.nameChanged = true |
| 458 | } |
| 459 | return |
| 460 | } |
| 461 | |
| 462 | if _, ok := p.lookupLabel(name); !ok { |
| 463 | return |
| 464 | } |
| 465 | |
| 466 | p.builder.Del(name) |
| 467 | p.labelsChanged = true |
| 468 | } |
| 469 | |
| 470 | func (p *Processor) rangeLabels(fn func(labels.Label)) { |
| 471 | // Snapshot the current label set (including __name__) before invoking fn, so a |
| 472 | // callback that adds labels (labelmap) does not re-process labels it creates in |
| 473 | // the same rule — matching Prometheus, which ranges one snapshot per rule. The |
| 474 | // scratch buffer is reused across calls. |
| 475 | p.rangeBuf = p.rangeBuf[:0] |
| 476 | if p.currentName != "" { |
| 477 | p.rangeBuf = append(p.rangeBuf, labels.Label{Name: commonmodel.MetricNameLabel, Value: p.currentName}) |
| 478 | } |
| 479 | p.builder.Range(func(l labels.Label) { |
| 480 | p.rangeBuf = append(p.rangeBuf, l) |
| 481 | }) |
| 482 | for _, l := range p.rangeBuf { |
| 483 | fn(l) |
| 484 | } |
| 485 | } |
| 486 | |
| 487 | func (p *Processor) lookupLabel(name string) (string, bool) { |
| 488 | if name == commonmodel.MetricNameLabel { |
| 489 | if p.currentName == "" { |
| 490 | return "", false |
| 491 | } |
| 492 | return p.currentName, true |
| 493 | } |
| 494 | |
| 495 | var ( |
| 496 | value string |
| 497 | ok bool |
| 498 | ) |
| 499 | p.builder.Range(func(l labels.Label) { |
| 500 | if l.Name == name { |
| 501 | value = l.Value |
| 502 | ok = true |
| 503 | } |
| 504 | }) |
| 505 | return value, ok |
| 506 | } |
| 507 | |
| 508 | func parseAction(s string) (Action, error) { |
| 509 | switch act := Action(strings.ToLower(s)); act { |
| 510 | case Replace, Keep, Drop, KeepEqual, DropEqual, HashMod, LabelMap, LabelDrop, LabelKeep, Lowercase, Uppercase: |
| 511 | return act, nil |
| 512 | default: |
| 513 | return "", fmt.Errorf("unknown relabel action %q", s) |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | func withDefaults(cfg Config) Config { |
| 518 | cfg.NameScheme = withNameScheme(cfg.NameScheme) |
| 519 | if cfg.Action == "" { |
| 520 | cfg.Action = defaultConfig.Action |
| 521 | } else if act, err := parseAction(string(cfg.Action)); err == nil { |
| 522 | // Canonicalize a valid action (e.g. "KEEP" -> "keep") so Apply's switch |
| 523 | // matches; an invalid action is left for validate to reject. |
| 524 | cfg.Action = act |
| 525 | } |
| 526 | if !cfg.separatorSet && cfg.Separator == "" { |
| 527 | cfg.Separator = defaultConfig.Separator |
| 528 | } |
| 529 | if cfg.Regex.Regexp == nil { |
| 530 | cfg.Regex = defaultConfig.Regex |
| 531 | } |
| 532 | if !cfg.replacementSet && cfg.Replacement == "" { |
| 533 | cfg.Replacement = defaultConfig.Replacement |
| 534 | } |
| 535 | return cfg |
| 536 | } |
| 537 | |
| 538 | func withNameScheme(scheme commonmodel.ValidationScheme) commonmodel.ValidationScheme { |
| 539 | if scheme == commonmodel.UnsetValidation { |
| 540 | return defaultNameValidationScheme |
| 541 | } |
| 542 | return scheme |
| 543 | } |
| 544 | |
| 545 | func validateNameScheme(scheme commonmodel.ValidationScheme) error { |
| 546 | switch scheme { |
| 547 | case commonmodel.UnsetValidation, commonmodel.LegacyValidation, commonmodel.UTF8Validation: |
| 548 | return nil |
| 549 | default: |
| 550 | return fmt.Errorf("unknown relabel config name validation method specified, must be either '', 'legacy' or 'utf8', got %s", scheme) |
| 551 | } |
| 552 | } |
| 553 | |
| 554 | func needsTargetLabel(action Action) bool { |
| 555 | return action == Replace || action == HashMod || action == Lowercase || action == Uppercase || action == KeepEqual || action == DropEqual |
| 556 | } |
| 557 | |
| 558 | func isValidLabelNameWithRegexVar(value string, scheme commonmodel.ValidationScheme) bool { |
| 559 | if scheme == commonmodel.UTF8Validation { |
| 560 | return scheme.IsValidLabelName(value) |
| 561 | } |
| 562 | return relabelTargetLegacy.MatchString(value) |
| 563 | } |
| 564 | |
| 565 | func varInRegexTemplate(template string) bool { |
| 566 | return strings.Contains(template, "$") |
| 567 | } |