Step by Step to Add Linux Host in Nagios Monitoring

What is NAGIOS:

                            Nagios is a powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes.

                      Nagios monitors your entire IT infrastructure to ensure systems, applications, services, and business processes are functioning properly. In the event of a failure, Nagios can alert technical staff of the problem, allowing them to begin remediation processes before outages affect business processes, end-users, or customers. With Nagios you’ll never be left having to explain why an unseen infrastructure outage hurt your organization’s bottom line

STEP 1:

1) Install the below listed packages and their binaries & libraries with necessary dependencies:

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[root@quickfixlinux ~]# yum install -y gcc glibc glibc-common gd make net-snmp [/stextbox]

Additionally, httpd and php will reuqired to install on the nagios monitoring server.

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STEP 2:

To Create the nagios user in the client Machine: 

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 STEP 3: 

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[root@quickfixlinux ~]# tar xvf nagios-plugin-2.1.4.tar.gz [/stextbox]

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[root@quickfixlinux ~]# cd /root/nagios/nrpe-3.0.1

[root@quickfixlinux ~]# ./configure –with-nagios-user=nagios –with-nagios-group=nagios

[root@quickfixlinux ~]# make all [/stextbox]

The installation should be successfully completed now.. So next…

# default: off # description: NRPE (Nagios Remote Plugin Executor) service nrpe { flags           = REUSE type            = UNLISTED port            = 5666 socket_type     = stream wait            = no user            = nagios group           = nagios server          = /usr/local/nagios/bin/nrpe server_args     = -c /etc/nagios/nrpe.cfg –inetd log_on_failure  += USERID disable         = no only_from       =  space }

 

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STEP 10:

Next, you need to make an entry in the /etc/service file.. Before you edit take a backup of this file for safety consideration:

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[root@quickfixlinux ~]# cp /etc/services /etc/services.31MAR17  [/stextbox]

and add the below line at the file :

nrpe            5666/tcp                 NRPE

Now, restart the xinetd service:

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[root@quickfixlinux ~]# service xinetd restart [/stextbox]

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STEP 11:

To verify the nrpe service is running and responding in the client machine:

And to verify the nrpe daemon is listening as expected:

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STEP 12:

To make changes in the nagios configuration file:

Open the path /usr/local/nagios/etc/nagios.cfg  [ Make a backup of this file before making changes].

NOTE: Place your client IP address and Hostname in /etc/hosts as well as in Nagios monitoring server too.

Then, create a directory under /etc for nagios:

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[root@quickfixlinux ~] # mkdir /etc/nagios

[root@quickfixlinux ~]# cp /usr/local/nagios/etc/nrpe.cfg /etc/nagios/ [/stextbox]

 

Once done, restart the xinetd service.. to verify the NRPE daemon service is working or not:

Now, the communication is working fine, which can be verified using the ip address loaded in the web browser.

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