====== Install Nagios Plugin and NRPE on Redhat ======
Prerequisite install
  * xinetd
  * openssl-devel

Redhat 3rd party libraries if added to yum can let you install nrpe via yum.  However, below is an explanation of now to compile this locally.

===== Download and Extract files =====
Download and copy files to /tmp
  * nrpe-2.15.tar.gz
  * nagios-plugins-1.5.tar.gz
Extract files
<code bash>
cd /tmp
tar zxvf nrpe-2.15.tar.gz
tar zxvf nagios-plugins-1.5.tar.gz
</code>

===== Create nagios Account =====
<code>
groupadd nagios
useradd -d /var/log/nagios -g nagios -m -p somepassword nagios
date|md5sum|cut -b "1-10" | passwd --stdin nagios
id nagios
</code>

===== Install the Nagios Plugins =====
<code>
cd nagios-plugins-1.5
./configure
make
make install
chown -R nagios:nagios /usr/local/nagios
</code>

===== Install the NRPE daemon =====
<code>
cd nrpe-2.15
./configure
make all
make install-plugin
make install-daemon
make install-daemon-config
make install-xinetd

chown -R nagios:nagios /usr/local/nagios
</code>

Update nagios server IP address here.  Included additional IP separated by spaces.
<code>
grep only /etc/xinetd.d/nrpe
</code>

Use the following example to replace easily!
<code>
sed -i 's@only_from       = 127.0.0.1@only_from       = 127.0.0.1 10.50.60.0/24 204.67.86.0/24@' /etc/xinetd.d/nrpe
</code>

Add the NRPE daemon to services
<code>
echo "nrpe            5666/tcp                # NRPE" >> /etc/services
service xinetd restart
</code>


===== Test NRPE daemon =====
Check for Listening port
<code>
netstat -at | grep nrpe
</code>
should have output as
<code>
tcp        0      0 *:nrpe                      *:*                         LISTEN
</code>

Run the call to service
<code>
/usr/local/nagios/libexec/check_nrpe -H 127.0.0.1
</code>
Should return **NRPE v2.15**

===== Additional plugins =====
Copy any additional plugins to ''/usr/local/nagios/libexec/'' such as ''check_linux_stats.pl''


===== File locations =====
Nagios Core, Nagios NRPE Deamon and Nagios Plugin Locations

==== Compiled Version ====
=== Plugins (executables) ===
/usr/local/nagios/libexec/check_nrpe

=== NRPE Deamon config file (settings) ===
/etc/xinetd.d/nrpe

=== NRPE Config file (commands) ===
/usr/local/nagios/etc/nrpe.cfg

==== Ubuntu ====
=== Core Nagios Monitoring config directory (settings) ===
/etc/nagios3/conf.d/

=== Plugin Location (executables) ===
/usr/lib/nagios/plugins

==== Redhat ====
=== NRPE Config file (commands) ===
/etc/nagios/nrpe.cfg
=== Plugin Location ===
/usr/lib64/nagios/plugins/


===== Related =====
Install ''Sys:Statistics:Linux'' via CPAN

[[http://search.cpan.org/~bloonix/Sys-Statistics-Linux-0.66/lib/Sys/Statistics/Linux.pm|Sys:Statistics:Linux]]