Fixes links on Alpine Linux

dns-hack.sh

#!/usr/bin/with-contenv sh
if [ ! -f /etc/dnsmasq-resolv.conf ]
then
    cp -f /etc/resolv.conf /etc/dnsmasq-resolv.conf
    echo "nameserver 127.0.0.1" > /etc/resolv.conf
fi

while ! ps -ef | grep -v grep | grep dnsmasq-resolv.conf
do
    sleep 1
done

while true
do
    env_vars=$(env | grep ".*_NAME=" | cut -d= -f1 | tr '\n' ' ')
    echo "#Auto Generated - DO NOT CHANGE" > /tmp/hosts
    for env_var in $env_vars
    do
      link=${env_var%_NAME}
      domain=$(cat /etc/dnsmasq-resolv.conf | grep search | cut -d' ' -f2)
      nameserver=$(cat /etc/dnsmasq-resolv.conf | grep nameserver | head -1 | cut -d' ' -f2)
      ip=$(nslookup "${link}.${domain}" ${nameserver}  | grep Address | tail -1 | cut -d: -f2  | cut -d' ' -f2)
      if [ -n "$ip" ]
      then
        echo "${ip} ${link}" >> /tmp/hosts
      else
        logger "ip ${link}.${domain} skipped, it didn't resolve."
      fi
    done

     if ! diff /tmp/hosts /etc/hosts.links
     then
        cp -f /tmp/hosts /etc/hosts.links
        killall -HUP dnsmasq
     fi

    sleep 30
done

Should this be used as entrypoint or can be used on build phase?