Change hardcoded host for sensu/graphite/sphinx in nginx

Change-Id: I939da0cc704174a5e453cc9e02ddbafc73a6a503
diff --git a/nginx/server/proxy/graphite_web.yml b/nginx/server/proxy/graphite_web.yml
index 02035cd..2f3e1e8 100644
--- a/nginx/server/proxy/graphite_web.yml
+++ b/nginx/server/proxy/graphite_web.yml
@@ -8,7 +8,7 @@
           type: nginx_proxy
           name: graphite
           proxy:
-            host: mon
+            host: ${_param:stacklight_monitor_hostname}
             port: 80
             protocol: http
           host:
diff --git a/nginx/server/proxy/infra/sphinx.yml b/nginx/server/proxy/infra/sphinx.yml
index 5f733ac..b7bbfc1 100644
--- a/nginx/server/proxy/infra/sphinx.yml
+++ b/nginx/server/proxy/infra/sphinx.yml
@@ -8,7 +8,7 @@
           type: nginx_proxy
           name: sphinx
           proxy:
-            host: prx
+            host: ${_param:openstack_proxy_hostname}
             port: 8090
             protocol: http
           host:
diff --git a/nginx/server/proxy/sensu_web.yml b/nginx/server/proxy/sensu_web.yml
index e06120d..c250a49 100644
--- a/nginx/server/proxy/sensu_web.yml
+++ b/nginx/server/proxy/sensu_web.yml
@@ -8,7 +8,7 @@
           type: nginx_proxy
           name: sensu
           proxy:
-            host: mon
+            host: ${_param:stacklight_monitor_hostname}
             port: 3000
             protocol: http
           host:
diff --git a/nginx/server/proxy/sphinx_web.yml b/nginx/server/proxy/sphinx_web.yml
index 5f733ac..b7bbfc1 100644
--- a/nginx/server/proxy/sphinx_web.yml
+++ b/nginx/server/proxy/sphinx_web.yml
@@ -8,7 +8,7 @@
           type: nginx_proxy
           name: sphinx
           proxy:
-            host: prx
+            host: ${_param:openstack_proxy_hostname}
             port: 8090
             protocol: http
           host: