Change the SSH port on RedHat/Cent Os

Changing the SSH port of RedHat or Cent Os is not a tough job. Any administrator can change it by just editing sshd_config file and then reloading the service.

Step 1. Edit the sshd_config

vi /etc/ssh/sshd_config

Step 2. Change the Port No
You will find something like

#Port 22

Simply change this like

Port 2222

Step 3. Save and Exit
Step 4. Reload the New Configuration
service sshd reload
You are done and now you can test your new configuration using this command

ssh username@myhostnaname.com -p 2222

Precaution: Before logging out make sure your 2222 or the port you have set is open. Otherwise you will no be able to log in using that port. Check your firewall settings for this.

How to install Red5 on Cent Os 5.4

Red5 is open source flash server written in java supports streaming audio/video, recording client streams, shared objects, live stream publishing etc. Here I will describe in details how you can install Red5 on your CentOS. For this you will also need to install Java and Apache Ant.

Step 1. Install Java

RED5 server depends on Java. CentOS 5.3 comes with OpenJDK 1.6 and install it using yum.

yum -y install java-1.6.0-openjdk java-1.6.0-openjdk-devel

Step 2. Install Ant

Ant will need to compile RED5 server code. Ant comes in binary form, so just download and install it in /usr/local directory.

cd /usr/src
wget http://opensource.become.com/apache/ant/binaries/apache-ant-1.7.1-bin.tar.gz
tar zxvf apache-ant-1.7.1-bin.tar.gz
mv apache-ant-1.7.1/ /usr/local/ant

Step 3. Export Variables for Ant and Java

export ANT_HOME=/usr/local/ant
export JAVA_HOME=/usr/lib/jvm/java
export PATH=$PATH:/usr/local/ant/bin
export CLASSPATH=.:$JAVA_HOME/lib/classes.zip

Also export these variables in /etc/bashrc to become available for every user login or for any terminal opens.

echo ‘export ANT_HOME=/usr/local/ant’ >> /etc/bashrc
echo ‘export JAVA_HOME=/usr/lib/jvm/java’ >> /etc/bashrc
echo ‘export PATH=$PATH:/usr/local/ant/bin’ >> /etc/bashrc
echo ‘export CLASSPATH=.:$JAVA_HOME/lib/classes.zip’ >> /etc/bashrc

Step 4. Download and Install RED5 Server

Here the latest version available for RED5 is 0.7 on site but download from google code using svn as the tarball of 0.7 on site is missing some of the files.

cd /usr/src
svn checkout http://red5.googlecode.com/svn/java/server/trunk/ red5
mv red5 /usr/local/
cd /usr/local/red5
ant prepare
ant dist

you will see a ton of lines, but you should get at last

BUILD SUCCESSFUL

that’s mean its install and now copy the conf directory from dist/ and test the red5 installation.

cp -r dist/conf .
./red5.sh

If it shows Installer service created in the last then everything is fine here, press ctrl+c and move to next step to create init script.

Step 5. Init Script

Now we will create init script for red5 to start, stop and restart easily.

vi /etc/init.d/red5

The init script code is below.

#!/bin/sh
# For RedHat and cousins:
# chkconfig: 2345 85 85
# description: Red5 flash streaming server
# processname: red5

PROG=red5
RED5_HOME=/usr/local/red5
DAEMON=$RED5_HOME/$PROG.sh
PIDFILE=/var/run/$PROG.pid

# Source function library
. /etc/rc.d/init.d/functions

[ -r /etc/sysconfig/red5 ] && . /etc/sysconfig/red5

RETVAL=0

case “$1″ in
start)
echo -n $”Starting $PROG: ”
cd $RED5_HOME
$DAEMON >/dev/null 2>/dev/null &
RETVAL=$?
if [ $RETVAL -eq 0 ]; then
echo $! > $PIDFILE
touch /var/lock/subsys/$PROG

fi
[ $RETVAL -eq 0 ] && success $”$PROG startup” || failure $”$PROG startup”
echo
;;
stop)
echo -n $”Shutting down $PROG: ”
killproc -p $PIDFILE
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && rm -f /var/lock/subsys/$PROG
;;
restart)
$0 stop
$0 start
;;
status)
status $PROG -p $PIDFILE
RETVAL=$?
;;
*)
echo $”Usage: $0 {start|stop|restart|status}”
RETVAL=1
esac

exit $RETVAL

Now start the service

/etc/init.d/red5 start

check status

/etc/init.d/red5 status
red5 (pid XXXXX) is running…

again you can do stop, restart.

Step 6. Test

Now test the RED5 installation by opening following URL in browser

http://yourip:5080/

You will see Red5 test page.

How to set a cron job using PHP in webmin

I have a CentOS server to test my all projects. According to clients requirement webmin is installed as admin panel. Today I had tried to use a cron PHP script in that server and succeeded. This is how I have setup the cron job.

In the webmin panel ther is a menu group named ‘Cluster’;
So from that menu group -> Cluster Cron Job.
Then I have added a new cron job.
1. Selected user ‘apache’.
2. in the command box:
/usr/bin/php -q /full/path/to/the/cronjob.php
3. Then selected the time which I want the cron job should be done.

Wow… It’s working. Please feel free to ask if you need any further help regarding this.