From 997893284bdf1351a954e8fb9341aa805f77858a Mon Sep 17 00:00:00 2001
From: Mayne0213 <bluemayne0213@icloud.com>
Date: Sun, 4 Jan 2026 14:35:08 +0900
Subject: [PATCH] FEAT(alertmanager): add ServiceMonitor

- Create servicemonitor.yaml for Prometheus to scrape Alertmanager
- alertmanager chart does not include ServiceMonitor, must be added separately
- Enables Grafana Alertmanager dashboard to display data
---
 alertmanager/helm-values.yaml    |  7 -------
 alertmanager/kustomization.yaml  |  1 +
 alertmanager/servicemonitor.yaml | 27 +++++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 7 deletions(-)
 create mode 100644 alertmanager/servicemonitor.yaml

diff --git a/alertmanager/helm-values.yaml b/alertmanager/helm-values.yaml
index 76a978c..a0d8c66 100644
--- a/alertmanager/helm-values.yaml
+++ b/alertmanager/helm-values.yaml
@@ -13,13 +13,6 @@ resources:
     cpu: 10m
     memory: 32Mi
 
-# Prometheus ServiceMonitor 설정
-serviceMonitor:
-  enabled: true
-  additionalLabels:
-    release: prometheus
-  namespace: prometheus
-
 # Disable default config - use secret instead
 config:
   enabled: false
diff --git a/alertmanager/kustomization.yaml b/alertmanager/kustomization.yaml
index 7d7a3be..31e0fad 100644
--- a/alertmanager/kustomization.yaml
+++ b/alertmanager/kustomization.yaml
@@ -2,4 +2,5 @@ apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 resources:
   - ingress.yaml
+  - servicemonitor.yaml
   - vault/alertmanager-secrets.yaml
diff --git a/alertmanager/servicemonitor.yaml b/alertmanager/servicemonitor.yaml
new file mode 100644
index 0000000..8d6ec84
--- /dev/null
+++ b/alertmanager/servicemonitor.yaml
@@ -0,0 +1,27 @@
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: alertmanager
+  namespace: prometheus
+  labels:
+    release: prometheus
+spec:
+  endpoints:
+    - port: http
+      path: /metrics
+      scheme: http
+      interval: 60s
+      relabelings:
+        - targetLabel: cluster
+          replacement: "mayne-cluster"
+        # Drop alertmanager-headless to avoid duplicate metrics
+        - sourceLabels: [__meta_kubernetes_service_name]
+          regex: alertmanager-headless
+          action: drop
+  namespaceSelector:
+    matchNames:
+      - alertmanager
+  selector:
+    matchLabels:
+      app.kubernetes.io/instance: alertmanager
+      app.kubernetes.io/name: alertmanager