Merge pull request #17372 from roidelapluie/roidelapluie/relabeling

relabeling: Fix labelmap action validation with legacy metric name scheme

model/relabel/relabel.go

@@ -145,7 +145,13 @@ func (c *Config) Validate(nameValidationScheme model.ValidationScheme) error {
 		// UTF-8 allows ${} characters, so standard validation allow $variables by default.
 		// TODO(bwplotka): Relabelling users cannot put $ and ${<...>} characters in metric names or values.
 		// Design escaping mechanism to allow that, once valid use case appears.
-		return c.NameValidationScheme.IsValidLabelName(value)
+		switch c.NameValidationScheme {
+		case model.UTF8Validation:
+			return c.NameValidationScheme.IsValidLabelName(value)
+		default:
+			// For legacy validation, use the legacy regex that allows $variables.
+			return relabelTargetLegacy.MatchString(value)
+		}
 	}
 	if c.Action == Replace && varInRegexTemplate(c.TargetLabel) && !isValidLabelNameWithRegexVarFn(c.TargetLabel) {
 		return fmt.Errorf("%q is invalid 'target_label' for %s action", c.TargetLabel, c.Action)

model/relabel/relabel_test.go

@@ -831,6 +831,22 @@ func TestRelabelValidate(t *testing.T) {
 				NameValidationScheme: model.UTF8Validation,
 			},
 		},
+		{
+			config: Config{
+				Regex:                MustNewRegexp("__meta_kubernetes_pod_label_(strimzi_io_.+)"),
+				Action:               LabelMap,
+				Replacement:          "$1",
+				NameValidationScheme: model.LegacyValidation,
+			},
+		},
+		{
+			config: Config{
+				Regex:                MustNewRegexp("__meta_(.+)"),
+				Action:               LabelMap,
+				Replacement:          "${1}",
+				NameValidationScheme: model.LegacyValidation,
+			},
+		},
 	}
 	for i, test := range tests {
 		t.Run(strconv.Itoa(i), func(t *testing.T) {