8b5fa408e0
kube-proxy sets the sysctl net.ipv4.conf.all.route_localnet=1 so NodePort services can be accessed on the loopback addresses in IPv4, but this may present security issues. Leverage the --nodeport-addresses flag to opt-out of this feature, if the list is not empty and none of the IP ranges contains an IPv4 loopback address this sysctl is not set. In addition, add a warning to inform users about this behavior.