feat(monitoring): stamp EC2-compat labels on ServiceMonitor

internal/controller/nodedeployment/monitoring.go

@@ -109,9 +109,22 @@ func endpointSpec(group *seiv1alpha1.SeiNodeDeployment, interval string) map[str
 			"targetLabel": "chain_id",
 		})
 	}
-	if len(relabelings) > 0 {
-		ep["metricRelabelings"] = relabelings
-	}
+	// EC2-compat shim: stamp legacy labels from `pod` so dashboards that
+	// filter on instance_name / public_dns work for both EC2 and k8s scrapes.
+	// TODO(sei-protocol/sei-k8s-controller#122): remove after EC2 scrape decommission.
+	relabelings = append(relabelings,
+		map[string]any{
+			"action":       "replace",
+			"sourceLabels": []any{"pod"},
+			"targetLabel":  "instance_name",
+		},
+		map[string]any{
+			"action":       "replace",
+			"sourceLabels": []any{"pod"},
+			"targetLabel":  "public_dns",
+		},
+	)
+	ep["metricRelabelings"] = relabelings
 	return ep
 }
 

internal/controller/nodedeployment/monitoring_test.go

@@ -122,7 +122,7 @@ func TestGenerateServiceMonitor_ChainIDRelabeling(t *testing.T) {
 	g.Expect(findRelabeling(relabelings, "chain_id")).To(Equal("pacific-1"))
 }
 
-func TestGenerateServiceMonitor_NoRelabelingsWhenNothingDerivable(t *testing.T) {
+func TestGenerateServiceMonitor_OnlyEC2CompatWhenNothingDerivable(t *testing.T) {
 	g := NewWithT(t)
 	group := newTestGroup("role-test", "sei")
 	group.Spec.Monitoring = &seiv1alpha1.MonitoringConfig{
@@ -134,18 +134,58 @@ func TestGenerateServiceMonitor_NoRelabelingsWhenNothingDerivable(t *testing.T)
 	sm := generateServiceMonitor(group)
 	spec := sm.Object["spec"].(map[string]any)
 	ep := spec["endpoints"].([]any)[0].(map[string]any)
-	_, has := ep["metricRelabelings"]
-	g.Expect(has).To(BeFalse())
+	relabelings := ep["metricRelabelings"].([]any)
+	g.Expect(findRelabeling(relabelings, "component")).To(Equal(""))
+	g.Expect(findRelabeling(relabelings, "chain_id")).To(Equal(""))
+	g.Expect(findSourceRelabeling(relabelings, "instance_name")).To(Equal("pod"))
+	g.Expect(findSourceRelabeling(relabelings, "public_dns")).To(Equal("pod"))
+}
+
+func TestGenerateServiceMonitor_EC2CompatLabels(t *testing.T) {
+	g := NewWithT(t)
+	group := newTestGroup("role-test", "sei")
+	group.Spec.Monitoring = &seiv1alpha1.MonitoringConfig{
+		ServiceMonitor: &seiv1alpha1.ServiceMonitorConfig{},
+	}
+
+	sm := generateServiceMonitor(group)
+	spec := sm.Object["spec"].(map[string]any)
+	ep := spec["endpoints"].([]any)[0].(map[string]any)
+	relabelings := ep["metricRelabelings"].([]any)
+	g.Expect(findSourceRelabeling(relabelings, "instance_name")).To(Equal("pod"))
+	g.Expect(findSourceRelabeling(relabelings, "public_dns")).To(Equal("pod"))
 }
 
 // findRelabeling returns the `replacement` string for a metricRelabeling
 // targeting the given label, or "" if no such rule exists.
 func findRelabeling(relabelings []any, targetLabel string) string {
 	for _, r := range relabelings {
 		rule := r.(map[string]any)
-		if rule["targetLabel"] == targetLabel {
-			return rule["replacement"].(string)
+		if rule["targetLabel"] != targetLabel {
+			continue
+		}
+		repl, ok := rule["replacement"].(string)
+		if !ok {
+			continue
+		}
+		return repl
+	}
+	return ""
+}
+
+// findSourceRelabeling returns the first sourceLabels entry for a metricRelabeling
+// targeting the given label, or "" if no such rule exists.
+func findSourceRelabeling(relabelings []any, targetLabel string) string {
+	for _, r := range relabelings {
+		rule := r.(map[string]any)
+		if rule["targetLabel"] != targetLabel {
+			continue
+		}
+		src, ok := rule["sourceLabels"].([]any)
+		if !ok || len(src) == 0 {
+			continue
 		}
+		return src[0].(string)
 	}
 	return ""
 }