ddnss update script

99_ddnss_update

#!/bin/sh
# derived from https://www.ddnss.de/info.php
# To be stored in /etc/dhcp/dhclient-exit-hooks.d/99_ddnss_update
# Updates the specified subdomain $HOSTNAME with the current IP address.

UPDATE_KEY="<your update key displayed in the dashboard"
HOSTNAME="*.ddnss.*"
DDNSS_PATH="/var/run/ddnss"
ALLHOST="" # 'all' for updating all hosts in the account

TS="$(date +%Y-%m-%d\ %H:%M:%S)"
IP="$(curl -s www.ddnss.de/jsonip.php | jq -r '.IP')"
OLDIP="$([ -f "$DDNSS_PATH/oldip.txt" ] && cat "$DDNSS_PATH/oldip.txt")"

mkdir -p "$DDNSS_PATH"
echo "Current IP: $OLDIP"

if [ x"$IP"x = x"$OLDIP"x ]; then
  echo "$TS - Same IP - NOT UPDATING" >> $DDNSS_PATH/log.txt
else
  echo "$TS - New IP: $IP / Old IP: $OLDIP - UPDATING!" >> $DDNSS_PATH/log.txt
  echo $IP > $DDNSS_PATH/oldip.txt
  URL="https://www.ddnss.de/upd.php?key=$UPDATE_KEY&host=$HOSTNAME"
  [ -z "$ALLHOST" ] || URL="$URL&host=$ALLHOST"
  curl -s "$URL" >> $DDNSS_PATH/log.txt
  echo " " >> $DDNSS_PATH/log.txt
  echo "Updating ..."
fi