cf-ddns

#!/usr/bin/env bash
# modified by jfro from http://www.cnysupport.com/index.php/linode-dynamic-dns-ddns-update-script
# Update: changed because the old IP-service wasn't working anymore
# Uses curl to be compatible with machines that don't have wget by default
# modified by Ross Hosman for use with cloudflare.
#
# Place at:
# /usr/local/bin/cf-ddns.sh
# if you're lazy (like me): curl -L https://gist.githubusercontent.com/Mkaysi/15719ff29b1ba29b5bd0/raw/cf-ddns > /usr/local/bin/cf-ddns && nano /usr/local/bin/cf-ddns && chmod 700 /usr/local/bin/cf-ddns
# run `crontab -e` and add next line:
# */5 * * * * /usr/local/bin/cf-ddns >/dev/null 2>&1

cfkey=API-key
cfuser=email-address
cfhost=host-you-want-to-change

WAN_IP=$(dig +short myip.opendns.com @resolver1.opendns.com)
if [ -f $HOME/.wan_ip-cf.txt ]; then
    OLD_WAN_IP=$(cat $HOME/.wan_ip-cf.txt)
else
    echo "No file, need IP"
    OLD_WAN_IP=""
fi

if [ "$WAN_IP" = "$OLD_WAN_IP" ]; then
    echo "IP Unchanged"
else
    echo $WAN_IP > $HOME/.wan_ip-cf.txt
    echo "Updating DNS to $WAN_IP"
  curl -s https://www.cloudflare.com/api.html?a=DIUP\&hosts="$cfhost"\&u="$cfuser"\&tkn="$cfkey"\&ip="$WAN_IP" > /dev/null
fi