Revert removal of support for TCP and UDP services

rootfs/etc/nginx/lua/tcp_udp_configuration.lua

@@ -0,0 +1,36 @@
+-- this is the Lua representation of TCP/UDP Configuration
+local tcp_udp_configuration_data = ngx.shared.tcp_udp_configuration_data
+
+local _M = {
+  nameservers = {}
+}
+
+function _M.get_backends_data()
+  return tcp_udp_configuration_data:get("backends")
+end
+
+function _M.call()
+  local sock, err = ngx.req.socket(true)
+  if not sock then
+    ngx.log(ngx.ERR, "failed to get raw req socket: ", err)
+    ngx.say("error: ", err)
+    return
+  end
+
+  local reader = sock:receiveuntil("\r\n")
+  local backends, err_read = reader()
+  if not backends then
+    ngx.log(ngx.ERR, "failed TCP/UDP dynamic-configuration:", err_read)
+    ngx.say("error: ", err_read)
+    return
+  end
+
+  local success, err_conf = tcp_udp_configuration_data:set("backends", backends)
+  if not success then
+    ngx.log(ngx.ERR, "dynamic-configuration: error updating configuration: " .. tostring(err_conf))
+    ngx.say("error: ", err_conf)
+    return
+  end
+end
+
+return _M