Add alert for unreachable rgw endpoints

Change-Id: I38198e454e43309ae8b2507e0c57dfcaedf0da98
Related-Prod: PROD-35124
diff --git a/ceph/meta/prometheus.yml b/ceph/meta/prometheus.yml
index d2ef410..86c1aff 100644
--- a/ceph/meta/prometheus.yml
+++ b/ceph/meta/prometheus.yml
@@ -172,6 +172,26 @@
       query: >-
         rate(diskio_read_time[5m])
   alert:
+    RadosGWOutage:
+      if: >-
+        max(openstack_api_check_status{name=~"radosgw.*"}) == 0
+      labels:
+        severity: critical
+        service: ceph
+      annotations:
+        summary: "RadosGW outage"
+        description: >-
+          RadosGW is not accessible for all available RadosGW endpoints in the OpenStack service catalog.
+    RadosGWDown:
+      if: >-
+        openstack_api_check_status{name=~"radosgw.*"} == 0
+      labels:
+        severity: major
+        service: ceph
+      annotations:
+        summary: "{{ $labels.name }} endpoint is not accessible"
+        description: >-
+          RadosGW is not accessible for the {{ $labels.name }} endpoint.
     CephClusterHealthMinor:
       if: >-
         ceph_health_status == 1