CHRONY_SOURCEDIR=/run/chrony-dhcp
SERVERFILE=$CHRONY_SOURCEDIR/$interface.sources

chrony_config() {
    rm -f "$SERVERFILE"
    mkdir -p "$CHRONY_SOURCEDIR"
    for server in $new_ntp_servers; do
        echo "server $server iburst" >> "$SERVERFILE"
    done
    /usr/bin/chronyc reload sources > /dev/null 2>&1 || :
}

chrony_restore() {
    if [ -f "$SERVERFILE" ]; then
        rm -f "$SERVERFILE"
        /usr/bin/chronyc reload sources > /dev/null 2>&1 || :
    fi
}

case $reason in
    BOUND|RENEW|REBIND|REBOOT)
        chrony_config
        ;;
    EXPIRE|FAIL|RELEASE|STOP)
        chrony_restore
        ;;
esac