Add oxia_cluster label to all the pods (#345)

Depending on the Prometheus/VictoriaMetrics scraper, the labels attached
to the "service" are attached to the metrics scraped from the pods. It's
safer to also have the labels on the pods, so that they will be present
on the metrics

deploy/charts/oxia-cluster/templates/coordinator-deployment.yaml

@@ -29,6 +29,7 @@ spec:
         prometheus.io/port: "{{ .Values.coordinator.ports.metrics }}"
         prometheus.io/scrape: "{{ .Values.monitoringEnabled }}"
       labels:
+        oxia_cluster: {{ .Release.Name }}
         {{- include "oxia-cluster.coordinator.labels" . | nindent 8 }}
       name: {{ .Release.Name }}-coordinator
     spec:

deploy/charts/oxia-cluster/templates/server-statefulset.yaml

@@ -31,6 +31,7 @@ spec:
         prometheus.io/port: "{{ .Values.server.ports.metrics }}"
         prometheus.io/scrape: "{{ .Values.monitoringEnabled }}"
       labels:
+        oxia_cluster: {{ .Release.Name }}
         {{- include "oxia-cluster.server.labels" . | nindent 8 }}
       name: {{ .Release.Name }}
     spec:

kubernetes/resources.go

@@ -66,6 +66,7 @@ func selectorLabels(component Component, name string) map[string]string {
 		"app.kubernetes.io/name":      "oxia-cluster",
 		"app.kubernetes.io/Component": string(component),
 		"app.kubernetes.io/instance":  _resourceName,
+		"oxia_cluster":                name,
 	}
 }
 func additionalLabels(version string) map[string]string {