remove host-cache-size=0/skip-name-resolve

[grooverdan]

Container environment can depend on a HOSTNAME of
the source container being resolvable. The resolution is cached so shouldn't be an impact.

@mmontes11 thoughts?

[mmontes11]

thanks for bringing this up. It shouldn't be an issue for the Kubernetes DNS resolution perspective

[grooverdan]

Is it actually useful? MARIADB_ROOT_HOST of a hostname like 'monitor' would enable the monitor container access to the server as root, regardless of IP of the 'monitor' container (with this merged).

Speed of DNS resolution, is cited as the reason for this setting, however I think container environment will only have a limited number of hosts connecting, well within the default host_cache_size. These values are cached. Resolution is through getnameinfo, consulting the /etc/hosts before DNS (per /etc/nsswitch.conf). From what I've seen container runtimes implement the reverse DNS ok, so this should be ok.

Part of the goal here is just returning the container to the default configuration of the server as much as possible.

[grooverdan]

Server task to reduce possible impacts of this, particularly on users with IP or wildcard to not required DNS lookups - https://jira.mariadb.org/browse/MDEV-31323. So I'm going to treat this as a pre-req.