chore: add metrics service to prometheus component

Include metrics_service.yaml in the prometheus kustomize Component
so that deploying with the prometheus component provides both the
ServiceMonitor and the matching Service for metrics scraping.

Add app.kubernetes.io/name selector to Service and ServiceMonitor
to uniquely target this operator's pods in shared namespaces.

Author: scotwells

config/default/metrics_service.yaml

@@ -15,3 +15,4 @@ spec:
     targetPort: 8443
   selector:
     control-plane: controller-manager
+    app.kubernetes.io/name: network-services-operator

config/prometheus/kustomization.yaml

@@ -2,3 +2,4 @@ apiVersion: kustomize.config.k8s.io/v1alpha1
 kind: Component
 resources:
   - monitor.yaml
+  - metrics_service.yaml

config/prometheus/metrics_service.yaml

@@ -0,0 +1,18 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    control-plane: controller-manager
+    app.kubernetes.io/name: network-services-operator
+    app.kubernetes.io/managed-by: kustomize
+  name: controller-manager-metrics-service
+  namespace: system
+spec:
+  ports:
+  - name: https
+    port: 8443
+    protocol: TCP
+    targetPort: 8443
+  selector:
+    control-plane: controller-manager
+    app.kubernetes.io/name: network-services-operator

config/prometheus/monitor.yaml

@@ -28,3 +28,4 @@ spec:
   selector:
     matchLabels:
       control-plane: controller-manager
+      app.kubernetes.io/name: network-services-operator