nfs export ip sync (use provider ptr)

exports.default

/dir *(rw,no_root_squash,no_subtree_check)

ip-sync

#!/bin/bash

ip=`dig +short nslookup.domain.tld @ns.provider.com`

if /bin/ping -qc 3 $ip > /dev/null 2>&1; then
 if [ ! -f /tmp/.ip-sync ]; then
  logger "ip-sync: create ip rule to $ip"
  sed -e "s/\*/$ip/" /etc/exports.default > /etc/exports
  echo $ip > /tmp/.ip-sync
  /usr/sbin/exportfs -r
 else
  if [ `cat /tmp/.ip-sync` != $ip ]; then
   logger "ip-sync: update ip rule to $ip"
   sed -e "s/\*/$ip/" /etc/exports.default > /etc/exports
   echo $ip > /tmp/.ip-sync
   /usr/sbin/exportfs -r
  fi
 fi
fi