The following guide will show how to do a basic install and configuration of lsync for a master-slave configuration.
With this configuration lsync will sync the files every 20 milliseconds.
Quick Links:
Configuring ssh keys
Master server installations
Configuring /etc/init.d/lsyncd
Configuring sync directories and slave servers in lsyncd.lua
Slave server = x.x.x.x
Key Configuration
There are two parts to the key configuring, one part for Master and one step for the Slave.
Key config Master server (step 1)
From the master server you will need to run the following:
ssh-keygen -t rsa
This should then create two new files in ~/.ssh/ id_rsa and id_rsa.pub.
You should secure copy the id_rsa.pub to /root/.ssh/ directory on each of the slave servers. You can do this via scp with the following command:
scp .ssh/id_rsa.pub [email protected]:~/.ssh/master.pub
Key config Slave server (step 2)
Once you have copied the files over to /.ssh/master.pub on the slave server you will now need to run the following command on the slave:
cat ~/.ssh/master.pub >> ~/.ssh/authorized_keys
Once this has been performed you should test the keys by logging in.
From the MASTER server run the following command:
Note: you should not be prompted for a password if the keys have been configured correctly
Master Installation
You should install the dependencies with:
yum -y install lua lua-devel pkgconfig gcc asciidoc
You should then make an lsync directory and get the tar file for lsync with the following command:
mkdir lsync_src; cd lsync_src; wget http://lsyncd.googlecode.com/files/lsyncd-2.1.4.tar.gz
Extract with:
tar zxf lsyncd-2.1.4.tar.gz; cd lsyncd-2.1.4
Then run the following to install:
export CFLAGS=”-march=native -O2″
./configure && make && make install
To run lsync you will need to create a log directory with the following command:
Lsync init.d configuration
You will need to create the following location /etc/init.d/lsyncd and then enter the following information into the file
#!/bin/bash
#
# lsyncd: Starts the lsync Daemon
#
# chkconfig: 345 99 90
# description: Lsyncd uses rsync to synchronize local directories with a remote
# machine running rsyncd. Lsyncd watches multiple directories
# trees through inotify. The first step after adding the watches
# is to, rsync all directories with the remote host, and then sync
# single file buy collecting the inotify events.
# processname: lsyncd
. /etc/rc.d/init.d/functions
config="/etc/lsyncd.lua"
lsyncd="/usr/local/bin/lsyncd"
lockfile="/var/lock/subsys/lsyncd"
pidfile="/var/run/lsyncd.pid"
prog="lsyncd"
RETVAL=0
start() {
if [ -f $lockfile ]; then
echo -n $"$prog is already running: "
echo
else
echo -n $"Starting $prog: "
daemon $lsyncd -pidfile $pidfile $config
RETVAL=$?
echo
[ $RETVAL = 0 ] && touch $lockfile
return $RETVAL
fi
}
stop() {
echo -n $"Stopping $prog: "
killproc $lsyncd
RETVAL=$?
echo
[ $RETVAL = 0 ] && rm -f $lockfile
return $RETVAL
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
status)
status $lsyncd
;;
*)
echo "Usage: lsyncd {start|stop|restart|status}"
exit 1
esac
exit $?
You will then need to run the following commands to make sure it has the right permissions:
chmod 775 /etc/init.d/lsyncd
chown root:root /etc/init.d/lsyncd
Configuring sync directories
You should create the following location /etc/lsyncd.lua and paste the following:
settings {
logfile = "/var/log/lsyncd/lsyncd.log",
statusFile = "/var/log/lsyncd/lsyncd-status.log",
statusInterval = 20
}
--FIRST SLAVE
sync {
default.rsync,
source="/var/www/",
target="x.x.x.x:/var/www/",
rsync = {
compress = true,
acls = true,
verbose = true,
rsh = "/usr/bin/ssh -p 22 -o StrictHostKeyChecking=no"
}
}
You should change ‘source‘ to the directory you wish to sync and ‘target‘ to the ip address of the slave server configured above and the sync target.
You should now start lsyncd with the following command and then installation should be complete:
service lsyncd start
Done! You can now test the configuration by creating a file on the master and then checking the location on the slave.