MoinQ:

DNS/返答/NoData/cloudflare/返事について、ここに記述してください。

https://github.com/kubernetes/dns/issues/119#issuecomment-318749314

Cloudflare has responded to this issue after investigating it for almost a month.

They're not going to fix their DNS anytime soon:
 it appears that they rely on this kind of functionality internally (!),
 and they've determined it too risky to change.

I've since put in place a workaround whereby I do not use Cloudflare hosted domains 
in my DNS search list as circulated by DHCP.
It's an inconvenience to specify FQDN where appropriate but one I can live with.

too risky! こういう判断をするところには任せたくない。@sig@