stack/erp5/haproxy: open ipv6 port (frontend) for opcua server

stack/erp5/haproxy.cfg.in

@@ -224,3 +224,17 @@ backend backend_{{ group_name }}_{{ name }}
   server {{ name }} {{ urllib_parse.urlparse(url).netloc }}
 {%-  endfor %}
 {% endfor %}
+
+# <<<<<<
+# Adhoc added opcua server listener
+{% set opcua_port = 2262 }
+
+frontend opcuaFrontend
+  mode tcp
+  bind {{ parameter_dict['ipv6'] }}:{{ opcua_port }}
+  default_backend opcuaBackend
+
+backend opcuaBackend
+  mode tcp
+  server server1 {{ parameter_dict['ipv4'] }}:{{ opcua_port }}
+# >>>>>>