WMGMC Tech Group wants to merge two etcd clusters, of which one is currently on Cloud VPS and the others is on our own server. However, etcd supports only TLS-based authentication for cluster traffic. Thus we want to expose the etcd endpoint directly.

Per Help:Exposing_IPv6_services#Important_note this is not allowed, so I am creating this task to discuss about this.

The primary reason of the rule is for privacy reasons. However, for services like etcd server-to-server endpoints, they targets other machines (more specifically, only our own machines) but not human, and a human is never allowed to use the endpoint. Thus I think there shouldn't be significant privacy concerns?

Another reason (I guess) is for anti-spam. Web proxies may block some crawlers while exposing services directly doesn't.

In our case, an alternative solution is to setup a VPN between the two servers.