allow override balance mode
diff --git a/haproxy/files/haproxy.cfg b/haproxy/files/haproxy.cfg
index ab865d9..c9b7688 100644
--- a/haproxy/files/haproxy.cfg
+++ b/haproxy/files/haproxy.cfg
@@ -67,10 +67,10 @@
   {%- endfor %}
   {%- if listen.get('type', None) == 'http' %}
   mode http
-  balance  roundrobin
+  balance {{ listen.get('balance', 'roundrobin') }}
   option  httplog
   {%- elif listen.get('type', None) == 'rabbitmq' %}
-  balance roundrobin
+  balance {{ listen.get('balance', 'roundrobin') }}
   mode tcp
   option tcpka
   timeout client 48h
@@ -97,7 +97,7 @@
   rspidel ^Set-cookie:\ IP=
   {%- elif listen.get('type', None) == 'general-service' %}
   mode http
-  balance  roundrobin
+  balance {{ listen.get('balance', 'roundrobin') }}
   option  httplog
   {%- elif listen.get('type', None) == 'openstack-service' %}
   option  httpchk
@@ -115,10 +115,10 @@
   stats auth {{ listen.user }}:{{ listen.password }}
   {%- elif listen.get('type', None) == 'contrail-api' %}
   option nolinger
-  balance roundrobin
+  balance {{ listen.get('balance', 'roundrobin') }}
   {%- elif listen.get('type', None) == 'contrail-analytics' %}
   option nolinger
-  balance roundrobin
+  balance {{ listen.get('balance', 'roundrobin') }}
   option tcp-check
   tcp-check connect port 6379
   default-server error-limit 1 on-error mark-down
@@ -185,7 +185,7 @@
 
 backend {{ listen_name }}-backend
   {%- if listen.get('type', None) == 'http' %}
-  balance roundrobin
+  balance {{ listen.get('balance', 'roundrobin') }}
   {%- endif %}
   {%- for server in listen.get('servers', []) %}
   server {{ server.get('name', server.host) }} {{ server.host }}:{{ server.port }} {{ server.get('params', '') }}
@@ -193,7 +193,7 @@
 {%- for acl in listen.get('acls', []) %}
 
 backend {{ acl.name }}-backend
-  balance     roundrobin
+  balance {{ listen.get('balance', 'roundrobin') }}
   {%- for server in acl.get('servers', []) %}
   server {{ server.get('name', server.host) }} {{ server.host }}:{{ server.port }} {{ server.get('params', '') }}
   {%- endfor %}