feat(shoot-grafter): introduce metrics (#1455)

* add metrics Service and ServiceMonitor to shoot-grafter chart

On-behalf-of: @SAP [email protected]

* bump the version of shoot-grafter chart and plugin definition

On-behalf-of: @SAP [email protected]

* add capabilities check for ServiceMonitor

On-behalf-of: @SAP [email protected]

* separate metrics service and service monitor

On-behalf-of: @SAP [email protected]

Author: Zaggy21

shoot-grafter/charts/Chart.yaml

@@ -5,7 +5,7 @@ apiVersion: v2
 description: Automatic onboarding of Gardener Shoots to Greenhouse
 type: application
 name: shoot-grafter
-version: 0.2.1
+version: 0.2.2
 appVersion: "v0.2.0"
 keywords:
 - operator

shoot-grafter/charts/templates/metrics-service.yaml

@@ -0,0 +1,21 @@
+{{/* 
+SPDX-FileCopyrightText: 2026 SAP SE or an SAP affiliate company and Greenhouse contributors
+SPDX-License-Identifier: Apache-2.0
+*/}}
+
+apiVersion: v1
+kind: Service
+metadata:
+  name: shoot-grafter-metrics
+  namespace: {{ .Release.Namespace }}
+  labels:
+    app: shoot-grafter
+spec:
+  type: ClusterIP
+  selector:
+    app: shoot-grafter
+  ports:
+  - name: metrics
+    port: 8080
+    targetPort: 8080
+    protocol: TCP

shoot-grafter/charts/templates/servicemonitor.yaml

@@ -0,0 +1,30 @@
+{{/* 
+SPDX-FileCopyrightText: 2026 SAP SE or an SAP affiliate company and Greenhouse contributors
+SPDX-License-Identifier: Apache-2.0
+*/}}
+
+{{- if .Capabilities.APIVersions.Has "monitoring.coreos.com/v1" }}
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: shoot-grafter
+  namespace: {{ .Release.Namespace }}
+  labels:
+    app: shoot-grafter
+    {{- with .Values.monitoring.labels }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
+spec:
+  endpoints:
+    - honorLabels: true
+      interval: 30s
+      port: metrics
+      scheme: http
+      path: /metrics
+  namespaceSelector:
+    matchNames:
+      - {{ .Release.Namespace }}
+  selector:
+    matchLabels:
+      app: shoot-grafter
+{{- end }}

shoot-grafter/charts/values.yaml

@@ -2,7 +2,12 @@
 # SPDX-License-Identifier: Apache-2.0
 
 replicaCount: 1
+
 image:
   registry: ghcr.io/cloudoperators
   repository: shoot-grafter
   pullPolicy: IfNotPresent
+
+monitoring:
+  labels:
+    plugin: kube-monitoring

shoot-grafter/plugindefinition.yaml

@@ -7,9 +7,9 @@ metadata:
   name: shoot-grafter
 spec:
   description: Automatic onboarding of Gardener Shoots to Greenhouse
-  version: 0.2.1
+  version: 0.2.2
   helmChart:
     name: shoot-grafter
     repository: oci://ghcr.io/cloudoperators/greenhouse-extensions/charts
-    version: 0.2.1
+    version: 0.2.2