Protect a site using a dyndns host and htaccess.

gistfile1.sh

#!/bin/bash
##  Crontab Example:
##   #*/3 * * * * /bin/sh ~/htaccessdynamic.sh whatevermydyndnsis.dyndns-remote.com ~/domainiwanttoprotect.com/.htaccess > /dev/null 2>&1


dynDomain="$1"
htaccessLoc="$2"

dynIP=$(/usr/bin/dig +short $dynDomain)

echo "dynip: $dynIP"
# verify dynIP resembles an IP
if ! echo -n $dynIP | grep -Eq "[0-9.]+"; then
    exit 1
fi

# if dynIP has changed
if ! cat $htaccessLoc | /bin/grep -q "$dynIP"; then

        # grab the old IP
        oldIP=`cat ~/htold-ip.txt`

        # output .htaccess file
        echo "order deny,allow" > $htaccessLoc 2>&1
        echo "allow from $dynIP" >> $htaccessLoc 2>&1
        echo "allow from x.x.x.x" >> $htaccessLoc 2>&1
        echo "deny from all" >> $htaccessLoc 2>&1

        # save the new ip to remove next time it changes, overwriting previous old IP
        echo $dynIP > ~/htold-ip.txt
fi