Only proxy app roles since mongrel may be used by non-app roles.

generators/vulcanize/templates/complete_mongrel_mysql/config/rubber/role/haproxy/haproxy-mongrel.conf

@@ -8,14 +8,14 @@ listen mongrel_proxy 0.0.0.0:<%= rubber_env.haproxy_listen_port %>
     # Since we do "fair" load balancing to the mongrels, we don't want to share mongrels
     # between haproxy instances otherwise we still end up with requests getting queued behind
     # slow ones.
-    mongrel_hosts = rubber_instances.for_role('mongrel').collect { |i| i.name }
+    app_hosts = rubber_instances.for_role('app').collect { |i| i.name }
     haproxy_hosts = rubber_instances.for_role('haproxy').collect { |i| i.name }
     ports = (rubber_env.mongrel_base_port.to_i ... rubber_env.mongrel_base_port.to_i + rubber_env.mongrel_count.to_i).to_a
     host_count = haproxy_hosts.size
     host_mod = haproxy_hosts.sort.index(rubber_env.host) rescue 0
     ports = ports.find_all {|x| x % host_count == host_mod}
   %>
-  <% mongrel_hosts.each do |server| %>
+  <% app_hosts.each do |server| %>
     <% ports.each do |port| %>
       server <%= server %>_<%= port %> <%= server %>:<%= port %> maxconn 1 check
     <% end %>