feat: Metrics for Prometheus (#309)

* feat: prometheus metrics

* Added Prometheus resources support to helm chart

deploy/helm/templates/_pod.tpl

@@ -6,11 +6,7 @@ metadata:
     {{- with .Values.podAnnotations }}
     {{- tpl (toYaml .) $ | nindent 4 }}
     {{- end }}
-  labels:
-    {{- include "wg-portal.selectorLabels" . | nindent 4 }}
-    {{- with .Values.podLabels }}
-    {{- toYaml . | nindent 4 }}
-    {{- end }}
+  labels: {{- include "wg-portal.util.merge" (list $ .Values.podLabels "wg-portal.selectorLabels") | nindent 4 }}
 spec:
   {{- with .Values.affinity }}
   affinity: {{- toYaml . | nindent 4 }}
@@ -36,6 +32,9 @@ spec:
       envFrom: {{- tpl (toYaml .) $ | nindent 8 }}
       {{- end }}
       ports:
+        - name: metrics
+          containerPort: {{ .Values.service.metrics.port}}
+          protocol: TCP
         - name: web
           containerPort: {{ .Values.service.web.port }}
           protocol: TCP