helm: ServiceMonitor: sane default namespaceSelector (#7998)

* helm: service-monitor: sane default namespaceSelector

* chart version bump (4.0.16)

charts/ingress-nginx/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: ingress-nginx
 # When the version is modified, make sure the artifacthub.io/changes list is updated
 # Also update CHANGELOG.md
-version: 4.0.15
+version: 4.0.16
 appVersion: 1.1.1
 home: https://github.com/kubernetes/ingress-nginx
 description: Ingress controller for Kubernetes using NGINX as a reverse proxy and load balancer

charts/ingress-nginx/templates/controller-servicemonitor.yaml

@@ -30,6 +30,10 @@ spec:
 {{- end }}
 {{- if .Values.controller.metrics.serviceMonitor.namespaceSelector }}
   namespaceSelector: {{ toYaml .Values.controller.metrics.serviceMonitor.namespaceSelector | nindent 4 }}
+{{- else }}
+  namespaceSelector:
+    matchNames:
+      - {{ .Release.Namespace }}
 {{- end }}
 {{- if .Values.controller.metrics.serviceMonitor.targetLabels }}
   targetLabels: