CleanupLeftovers removes all iptables rules and chains created by the Proxier It returns true if an error was encountered.

NewProxier returns a new Proxier given an iptables Interface instance.

ShouldUseIptablesProxier returns true if we should use the iptables Proxier instead of the "classic" userspace Proxier.

Proxier is an iptables based proxy for connections between a localhost:lport and services that provide the actual backends.