poor man's dyndns for host europe

update_dns_hosteurope.sh

#!/bin/sh

KUNDENNR=XXXXXX
PASSWORD=XXXXXX

IP=$(wget -qO- ifconfig.me/ip)

UPDATEIP=false

 if [ -f /var/run/current.ip ]
 then
   oldIP=$(cat /var/run/current.ip)
   if [ $oldIP != $IP ]
   then
     UPDATEIP=true
   fi
 else
   echo $IP > /var/run/current.ip
   UPDATEIP=true
 fi

if $UPDATEIP ; then

  curl -k --url "https://kis.hosteurope.de/?kdnummer=$KUNDENNR&passwd=$PASSWORD"

  DOMAIN="mydomain.tld"
  HOSTID=XXXXXX
  curl -k --url "https://kis.hosteurope.de/administration/domainservices/index.php?record=A&pointer=$IP&menu=1&mode=autodns&domain=$DOMAIN&submode=edit&truemode=host&hostid=$HOSTID&submit=Update" -c /dev/null >/dev/null 2>1
  
  DOMAIN="mydomain2.tld"
  HOSTID=XXXXXX
  curl -k --url "https://kis.hosteurope.de/administration/domainservices/index.php?record=A&pointer=$IP&menu=1&mode=autodns&domain=$DOMAIN&submode=edit&truemode=host&hostid=$HOSTID&submit=Update" -c /dev/null >/dev/null 2>1
  
  
fi

I have this running as cronjob every 30 minutes on my Synology Diskstation:

/etc/crontab

0,30    *       *       *       *       root    /path/to/script/update_dns_hosteurope.sh