custom response

nginx.conf

error_page 400 403 404 405 =200 @40*_xml;
        location @40*_xml {
            default_type application/xml;
            return 200 '<country  technical_work=\'{"notify_start":1501834800,"work_start":1501835400,"work_end":1501836300}\' server_time=\'1501835409\'>
          <field></field>
          <messages>
            <message code=\'technical_works\' />
          </messages>
        </country>';
        }