Easy Install Nagios in Centos 6 via yum

Ok, i used to write the longer version when i was still using Centos 5, recently i went back to the article and found out that there is actually a shorter way to setup EVERYTHING. So here i am writing a shorter version to setup nagios on centos 6.

Setup Nagios Server

This is the server that will have vshell and nagios web interface. All you have to do is to install epel-release for your centos

yum install -y epel-release

and starts install nagios via yum

yum install -y nagios nagios-devel nagios-plugins* gd gd-devel httpd php gcc glibc glibc-common openssl

Now we need to make sure nagiosadmin is our username and password is set

htpasswd -c /etc/nagios/passwd nagiosadmin

which you can setup all the configuration at /etc/nagios/cgi.cfg and if you would like to change the configuration on apache, it is located at /etc/httpd/conf.d/nagios.conf

Once you have installed nagios, remember to startup nagios and apache whenever you restart!

service httpd restart
chkconfig httpd on

service nagios restart
chkconfig nagios on

and you can access it via http://localhost/nagios with username and password you have just setup above!!! Pretty easy ya!

Screen Shot 2015-03-30 at 6.38.04 PM

Now you might want to install nrpe on each server you wish to monitor next,

Installing nrpe with nagios-plugins on each server

Now, you really want to just have all these in yum when you have like 20 servers? It will be a nightmare if you just build all these by source (which i did last time instead of writing a scripts, yeah i'm dumb, i know). All you need to do via yum is

yum install nrpe nagios-plugins-all

And configure nrpe via

vi /etc/nagios/nrpe.cfg

adding your nagios ip into it so that your nagios server is allowed to penetrate each 'slave' you have lol.


Now all you need to do is to setup all the services you wish to let your man to do on your 'slaves'.

command[check_users]=/usr/lib64/nagios/plugins/check_users -w 5 -c 10
command[check_load]=/usr/lib64/nagios/plugins/check_load -w 15,10,5 -c 30,25,20
command[check_hda1]=/usr/lib64/nagios/plugins/check_disk -w 20% -c 10% -p /dev/hda1
command[check_zombie_procs]=/usr/lib64/nagios/plugins/check_procs -w 5 -c 10 -s Z
command[check_total_procs]=/usr/lib64/nagios/plugins/check_procs -w 150 -c 200 

and these can be setup at the same path as /etc/nagios/nrpe.cfg and you should be able to add more 'action' to it if you want.

and remember to setup nrpe to run on startup

service nrpe start
chkconfig nrpe on