added new script update-hosts.sh

refreshes the dyndns ip of realm.mynetgear.com it it changes

update-hosts.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# path to hosts file
+hostsFile="/etc/hosts"
+
+# get old puppet hosts entry
+oldIP=`cat ${hostsFile} | grep puppet | cut -d" " -f1`
+
+# get new ip
+newIP=`dig realm.mynetgear.com +short`
+
+# check if newIP is different and change hosts entry
+if [ ${newIP} != ${oldIP} ]; then
+    echo "Updating hosts file" | logger
+    sed -ie "/${oldIP}/d" "${hostsFile}";
+    echo "${newIP} realm.mynetgear.com realm" >> ${hostsFile}
+    echo "${newIP} puppet.realm.local puppet" >> ${hostsFile}
+else
+  echo "IP still up-to-date. Nothing to do, exiting." | logger
+fi