Use proxy to scrape Prometheus datasource

tmpl/grafana-datasources.yml

@@ -3,7 +3,7 @@ apiVersion: 1
 datasources:
 - name: Prometheus
   type: prometheus
-  access: direct
+  access: proxy
   orgId: 1
   url: http://%%adresse_ip_eth0:9090
   isDefault: true