#!/bin/bash

LOOPBACK="loopback"
ANYCAST="{{ anycast_ipv4 | ipaddr('address') }}"

ANYCAST_PRESENT=false
if ping -c 1 "${ANYCAST}" > /dev/null 2>&1 ; then
   ANYCAST_PRESENT=true
fi

DNS_PRESENT=false
if /sbin/resolvconf -l "${LOOPBACK}" > /dev/null 2>&1 ; then
    DNS_PRESENT=true
fi

if [[ ${ANYCAST_PRESENT} == true && ${DNS_PRESENT} == true ]] ; then
    exit 0
elif [[ ${ANYCAST_PRESENT} == true && ${DNS_PRESENT} == false ]] ; then
    echo "nameserver ${ANYCAST}" | /sbin/resolvconf -a "${LOOPBACK}" -m 1
elif [[ ${ANYCAST_PRESENT} == false && ${DNS_PRESENT} == true ]] ; then
    /sbin/resolvconf -d "${LOOPBACK}"
fi