Add prometheus main dashboard

Change-Id: Ic4a16eb4d512f2378850dc99a37d6b6e46ffebc7
diff --git a/nginx/meta/grafana.yml b/nginx/meta/grafana.yml
index 69d5fac..c7e2606 100644
--- a/nginx/meta/grafana.yml
+++ b/nginx/meta/grafana.yml
@@ -7,7 +7,7 @@
     datasource: prometheus
     format: json
     template: nginx/files/grafana_dashboards/nginx_prometheus.json
-  main:
+  main_infludb:
     datasource: influxdb
     row:
       ost-middleware:
@@ -23,3 +23,18 @@
               cluster_status:
                 rawQuery: true
                 query: SELECT last(value) FROM cluster_status WHERE cluster_name = 'nginx' AND environment_label = '$environment' AND $timeFilter GROUP BY time($interval) fill(null)
+  main_prometheus:
+    datasource: prometheus
+    row:
+      ost-middleware:
+        title: Middleware
+        panel:
+          nginx:
+            title: Nginx
+            links:
+            - dashboard: Nginx
+              title: Nginx
+              type: dashboard
+            target:
+              cluster_status:
+                expr: avg(nginx_up) by (name)