Fix.

partials/proxy.erb

@@ -14,6 +14,8 @@ server {
 	include /etc/nginx/snippets/includes.conf;
 
     location / {
+		resolver 127.0.0.1 valid=30s;
+
 		set $upstream___UPSTREAM__ __HOST__;
 
         proxy_pass http://$upstream___UPSTREAM__;