Updater for Hurricane Electric for their Dynamic dns service. IPv6 updates are NOT enable at the moment.

he-ddns.sh

#!/bin/bash

# HOSTS
HOSTS="example.com foo.example.com"

# HOSTS PASSWORD
# Because I'm lazy, it needs to be the same for all hosts
HOST_KEY="YOUR_PASSWORD"

# Get Current IPs
current4=`curl -4 -s http://checkip.dns.he.net | grep -o -E '([0-9]{1,3}\.){3}[0-9]{1,3}'`
#current6=`curl -6 -s http://checkip.dns.he.net | grep -o -E '([A-Fa-f0-9]{1,4}:){7}[A-Fa-f0-9]{1,4}'`

for h in $HOSTS; do
        dns4=`host -t A $h | grep -o -E '([0-9]{1,3}\.){3}[0-9]{1,3}'`
        if [ "$current4" != "$dns4" ]; then
                if [ ! -z $update ]; then
                        update=x;
                else
                        update="x$update";
                fi
                r4=$(curl -s -4 "http://$h:$HOST_KEY@dyn.dns.he.net/nic/update?hostname=$h")
                if ! [[ "$r4" =~ "good" || "$r4" =~ "nochg" ]]; then
                        logger -p local0.err -t HE-DDNS  "DNS update failed for $h: $r4"
                fi
        fi

        # For IPv6
#       dns6=`host -t AAAA $h | grep -o -E '([A-Fa-f0-9]{1,4}:){7}[A-Fa-f0-9]{1,4}'`
#       if [ "$current6" != "$dns6" ]; then
#               if [ ! -z $update ]; then
#                       update=x;
#               else
#                       update="x$update";
#               fi
#               r6=$(curl -s -6 "http://$h:$HOST_KEY@dyn.dns.he.net/nic/update?hostname=$h")
#               if ! [[ "$r6" =~ "good" || "$r6" =~ "nochg" ]]; then
#                       logger -p local0.err -t HE-DDNS  "DNS update failed for $h: $r6"
#               fi
#       fi
done

if [ -z "$update" ]; then
        WC=`echo $HOSTS | wc -w`
        logger -p local0.notice -t HE-DDNS "No DNS update needed ($WC hosts)"
else
        WC=`echo $update | wc -c`
        logger -p local0.info -t HE-DDNS "DNS changed for $WC entries to $current4"
fi