Connection and host liveness checks use only ipv4

[vin01]

Hi,

currently hostname validation (https://github.com/apache/superset/blob/master/superset/utils/network.py#L42) and port check (https://github.com/apache/superset/blob/master/superset/utils/network.py#L25) use only ipv4 addresses (because of gethostbyname and AF_INET respectively)

This results in ipv6 only hostnames being marked as invalid and ports show up as closed.

Both of these can be. fixed by using getaddrinfo.

• https://docs.python.org/3/library/socket.html#socket.gethostbyname
• https://docs.python.org/3/library/socket.html#socket.getaddrinfo

I am creating this single issue to track both these bugs as they are related. Hopefully that is alright with the guidelines ;)

Please review related patches.

Thanks!

[betodealmeida]

Thanks for the PRs!