fix: relabeling

Author: heliapb

pkg/prometheus/validation/validator.go

@@ -114,7 +114,7 @@ func (lcv *LabelConfigValidator) ValidateRelabelConfig(rc monitoringv1.RelabelCo
 		return fmt.Errorf("'replacement' can not be set for %s action", rc.Action)
 	}
 
-	if action == string(relabel.LabelMap) && (rc.Replacement != nil) && !lcv.isValidLabelName(*rc.Replacement) {
+	if action == string(relabel.LabelMap) && (rc.Replacement != nil) && !varInRegexTemplate(*rc.Replacement) && !lcv.isValidLabelName(*rc.Replacement) {
 		return fmt.Errorf("%q is invalid 'replacement' for %s action", *rc.Replacement, rc.Action)
 	}
 

pkg/prometheus/validation/validator_test.go

@@ -385,6 +385,24 @@ func TestValidateRelabelConfig(t *testing.T) {
 				},
 			},
 		},
+		{
+			scenario: "valid labelmap config with replacement containing template variable",
+			relabelConfig: monitoringv1.RelabelConfig{
+				Action:      "labelmap",
+				Regex:       "^(cluster)$",
+				Replacement: ptr.To("exported_${1}"),
+			},
+			prometheus: defaultPrometheusSpec,
+		},
+		{
+			scenario: "valid labelmap config with replacement",
+			relabelConfig: monitoringv1.RelabelConfig{
+				Action:      "labelmap",
+				Regex:       "__meta_kubernetes_(.*)",
+				Replacement: ptr.To("k8s_${1}"),
+			},
+			prometheus: defaultPrometheusSpec,
+		},
 	} {
 		t.Run(tc.scenario, func(t *testing.T) {
 			lcv, err := NewLabelConfigValidator(&tc.prometheus)