invalid UDP DNS response 51279 fl:81A3

k8s servicename.namespace can not be resolved in lua scripts

Hi team
we are using openresty to connect redis with k8s service name,but redis address can not be resolved inside lua script

nginx version: openresty/1.13.6.2
built by gcc 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.11)
built with OpenSSL 1.1.0i 14 Aug 2018
TLS SNI support enabled
configure arguments: --prefix=/usr/local/openresty/nginx --with-cc-opt=-O2 --add-module=../ngx_devel_kit-0.3.0 --add-module=../echo-nginx-module-0.61 --add-module=../xss-nginx-module-0.06 --add-module=../ngx_coolkit-0.2rc3 --add-module=../set-misc-nginx-module-0.32 --add-module=../form-input-nginx-module-0.12 --add-module=../encrypted-session-nginx-module-0.08 --add-module=../srcache-nginx-module-0.31 --add-module=../ngx_lua-0.10.13 --add-module=../ngx_lua_upstream-0.07 --add-module=../headers-more-nginx-module-0.33 --add-module=../array-var-nginx-module-0.05 --add-module=../memc-nginx-module-0.19 --add-module=../redis2-nginx-module-0.15 --add-module=../redis-nginx-module-0.3.7 --add-module=../rds-json-nginx-module-0.15 --add-module=../rds-csv-nginx-module-0.09 --add-module=../ngx_stream_lua-0.0.5 --with-ld-opt=-Wl,-rpath,/usr/local/openresty/luajit/lib --with-openssl=/tmp/openssl-1.1.0i --with-pcre=/tmp/pcre-8.42 --with-file-aio --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_geoip_module=dynamic --with-http_gunzip_module --with-http_gzip_static_module --with-http_image_filter_module=dynamic --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-http_xslt_module=dynamic --with-ipv6 --with-mail --with-mail_ssl_module --with-md5-asm --with-pcre-jit --with-sha1-asm --with-stream --with-stream_ssl_module --with-threads --add-module=/tmp/nginx-dav-ext-module --with-stream --with-stream_ssl_module

Start with the reported OpenResty 1.13.6.2 configuration and the Kubernetes service-name lookup from a Lua script. Reproduce the Redis resolution failure and inspect the invalid UDP DNS response noted in the title. Done requires a minimal reproduction and a confirmed resolution behavior, but the issue does not name a source file or test.