Comment 5 for bug 824167

Avahi is nothing more than a multicast-dns implementation. if avahi-daemon is installed in the container and libnss-mdns (IIRC) in the host, then the container will broadcast it's hostname through mdns and the host would be able to resolve it. It might be overkill however, specially since the dhclient/resolv.conf option works fine as you pointed out.