Reverse Proxy Similar to nginx

[emil191995]

I want to make reverse proxy with pingora where from Ui user can make server whic is equivalent of nginx sites-enabled config file.
when user adds from it saves in etcd and etcd notifies my pingora gateway app about config changes and the config will be loaded from etcd and pingora server will be reloaded with new servers. we can think of each server as one background service with listener. my question is how can we reload the pingora server gracefuly with ne config. eg it should load config and reload servers if some ports has been changed or removed after reload it should drop that ports.