Un-hardcoding horizon server address

The patch makes a possible to change horizon address
which could be used  by horizon by soft param.

Change-Id: Ib4794406612fdb61377ac341314268494b07ee66
Related-PROD: PROD-25528
diff --git a/defaults/init.yml b/defaults/init.yml
index 2a595b4..e98e3ae 100644
--- a/defaults/init.yml
+++ b/defaults/init.yml
@@ -38,3 +38,4 @@
     salt_minion_ca_host: cfg01.${_param:cluster_domain}
     # Make sure this global variable is defined everywhere, where used it is already set on cluster level
     cluster_public_host: '127.0.0.1'
+    single_address: '127.0.0.1'
diff --git a/defaults/openstack/init.yml b/defaults/openstack/init.yml
index 69ff618..2f6d807 100644
--- a/defaults/openstack/init.yml
+++ b/defaults/openstack/init.yml
@@ -59,6 +59,7 @@
     horizon_public_host: ${_param:cluster_public_host}
     horizon_public_port: 443
     horizon_public_protocol: https
+    horizon_server_bind_address: ${_param:single_address}
     # HAproxy
     haproxy_openstack_web_bind_port: ${_param:horizon_public_port}
     #
diff --git a/horizon/server/single.yml b/horizon/server/single.yml
index e1ceb2d..73fbcc3 100644
--- a/horizon/server/single.yml
+++ b/horizon/server/single.yml
@@ -11,7 +11,7 @@
     server:
       branding: ${_param:horizon_site_branding}
       bind:
-        address: 0.0.0.0
+        address: ${_param:horizon_server_bind_address}
         port: 8078
       plugin: {}
       session: