add headless service for statefulset (#17747)

Signed-off-by: afirth <afirth@users.noreply.github.com>

stable/grafana/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 name: grafana
-version: 3.8.18
+version: 3.8.19
 appVersion: 6.3.5
 kubeVersion: "^1.8.0-0"
 description: The leading tool for querying and visualizing time series and metrics.

stable/grafana/templates/headless-service.yaml

@@ -0,0 +1,22 @@
+{{- if and .Values.persistence.enabled (not .Values.persistence.existingClaim) (eq .Values.persistence.type "statefulset")}}
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ template "grafana.fullname" . }}-headless
+  namespace: {{ .Release.Namespace }}
+  labels:
+    app: {{ template "grafana.name" . }}
+    chart: {{ template "grafana.chart" . }}
+    release: {{ .Release.Name }}
+    heritage: {{ .Release.Service }}
+{{- with .Values.annotations }}
+  annotations:
+{{ toYaml . | indent 4 }}
+{{- end }}
+spec:
+  clusterIP: None
+  selector:
+    app: {{ template "grafana.name" . }}
+    release: {{ .Release.Name }}
+  type: ClusterIP
+{{- end }}

stable/grafana/templates/statefulset.yaml

@@ -19,6 +19,7 @@ spec:
     matchLabels:
       app: {{ template "grafana.name" . }}
       release: {{ .Release.Name }}
+  serviceName: {{ template "grafana.fullname" . }}-headless
   template:
     metadata:
       labels:
@@ -45,4 +46,4 @@ spec:
       resources:
         requests:
           storage: {{ .Values.persistence.size }} 
-{{- end }}
+{{- end }}