If you are wanting to install Nagios on an SME Server version 8 then you will probably start with the Wiki Contribs page for a Nagios Server install. http://wiki.contribs.org/Nagios
Which is going to lead you down a path of installing a complete Nagios Server assuming you overcome the issues with those instructions.
But if you have a Nagios Server elsewhere and you want to just add the SME Server as a client then a different set of instructions can be found in the forums.
http://forums.contribs.org/index.php/topic,48587.msg241615.html#msg241615
Which is really helpful but is missing a couple of key points for a complete set of instructions. So here is a re-write of that instruction set.
NRPE SME Server 8 Installation
1. Configure the dag repository
The following command will configure the dag repository on SME Server.
[text]
/sbin/e-smith/db yum_repositories set dag repository
Name ‘Dag – EL5’
BaseURL ‘<a href="http://apt.sw.be/redhat/el5/en/" target="_blank">http://apt.sw.be/redhat/el5/en/</a>$basearch/dag’
EnableGroups no
GPGCheck yes
GPGKey <a href="http://dag.wieers.com/packages/RPM-GPG-KEY.dag.txt" target="_blank">http://dag.wieers.com/packages/RPM-GPG-KEY.dag.txt</a>
Visible no
Exclude freetype,htop,iptraf,rsync,syslinux
status disabled
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2. After adding it to the database we have to update the changes to the configuration file:
[text]signal-event yum-modify[/text]
3. Then run this to enable the repo
[text]
/usr/bin/yum –enablerepo=dag install
nagios-plugins
nagios-plugins-setuid
perl-Config-Tiny
perl-Class-Accessor
[/text]
4. Copy nrpe rpm’s
Current download for the files are:
http://pkgs.repoforge.org/nagios/nagios-3.2.1-5.el5.rf.i386.rpm
http://pkgs.repoforge.org/nagios-nrpe/nagios-nrpe-2.5.2-1.el5.rf.i386.rpm
http://pkgs.repoforge.org/nagios-nrpe/nagios-plugins-nrpe-2.5.2-1.el5.rf.i386.rpm
5. Install the nrpe rpm’s
[text]
yum localinstall nagios-3.2.1-5.el5.rf.i386.rpm
yum localinstall nagios-nrpe-2.5.2-1.el5.rf.i386.rpm
yum localinstall nagios-plugins-nrpe-2.5.2-1.el5.rf.i386.rpm
[/text]
6. Modify the nrpe.cfg file to allow the external ip of your Nagios server (swap vim for your favourite editor)
[text]
vim /etc/nagios/nrpe.cfg
[/text]
the allowed_hosts parameter is already in the file, remove the # from the start of the line and add your nagios server ip
[text]
allowed_hosts=127.0.0.1,nagios.server.ip.here
[/text]
Save the file and exit.
7. Add the service
[text]
cd /etc/rc7.d
cp -s /etc/init.d/nrpe S95nrpe
[/text]
8. Port forward 5666 to localhost (swap vim for your favourite editor)
a)
[text]
mkdir -p /etc/e-smith/templates-custom/etc/hosts.allow/
[/text]
(if you get an error it means the directory already exists.)
b)
[text]
vim /etc/e-smith/templates-custom/etc/hosts.allow/nrpe
[/text]
and add the following lines to the nrpe file, adding your nagios server ip
[text]
{
$OUT="nrpe: " . ($nrpe{HostsAllow} ? $nrpe{HostsAllow} : "127.0.0.1 nagios.server.ip.here" );
}
[/text]
Save the file and exit.
9. Configure the new template
[text]
expand-template /etc/hosts.allow
[/text]
10. Start NRPE
[text]
service nrpe restart
[/text]
And then off to your Nagios server to add the new SME Server as a client.