Ubuntu.GNU/Linux

A simple script to sync remote hosts, steps to achieve it :
 
1.Avoid SCP prompting for password [ local host ] =>
ssh-keygen -t dsa -b 2048 -f ~/key.pub
 
2.SCP the key for the first time to the [ remote host ] =>
 
scp ~/key.pub remoteuser@remotehost:/home/remoteuser/
 
3. In remote host : 
[ Authorize the Host from which key was received ]
 
if [ ! -d .ssh ]; then 
     mkdir .ssh 
     chmod 700 .ssh 
fi
mv key.pub .ssh/
cd .ssh/
if [ ! -f authorized_keys ]; then 
     touch authorized_keys 
     chmod 600 authorized_keys ; 
fi
cat key.pub >> authorized_keys
 
"rsync + Cron jobs" to keep both the hosts in sync :
 
##################################################################
#!/bin/sh
 
RSYNC=/usr/bin/rsync
SSH=/usr/bin/ssh
KEY=/home/`whoami`/key.pub
LOCAL_PATH=/sync/dir
REMOTE_USER=remote-user
REMOTE_HOST=remote-host
REMOTE_PATH=/remote/dir
 
$RSYNC -az -e "$SSH -i $KEY" \
$REMOTE_USER@$REMOTE_HOST:$REMOTE_PATH $LOCAL_PATH 
 
##################################################################
 
# Setting up cron 
mv syncScp.sh /etc/cron.daily/
 
or
# crontab -e 
0 5 * * 5 /home/you/syncScp.sh