Nagios Core has limited native support for graphical representation of metrics. Nagiosgraph is very useful plugin, that extends the functionality of Nagios Core and display historical graphs. Nagiosgraph parses output and performance data collected by Nagios and stores that data in RRD (Round Robin Data) files. Nagiosgraph creates graphs and generates HTML pages with graphical reports from the data.
In this article, we will install Nagiosgraph plugin to our preconfigured Nagios Core server on CentOS 7.
Before moving forward, it is required to have basic concepts of Nagios Core 4. Therefore, it is highly recommended that you should have Learning Nagios - Third Edition. It will be really helpful for you during your Nagios journey.
System Specification:
We have configured a CentOS 7 virtual machine with Nagios Core 4.2 Server and following specifications.
- CPU - 2.4 Ghz (2 Core)
- Memory - 1 GB
- Storage - 20 GB
- Swap - 2 GB
- Operating System - CentOS 7.6
- Nagios Version - Nagios Core 4.4
Install Nagiosgraph on CentOS 7:
Access the Nagios Core’s web interface to check its status.
Install the prerequisite packages using yum command.
# yum -y install perl-GD php-gd rrdtool-perl rrdtool-php rrdtool perl-CGI perl-Time-HiRes
Create a directory and download Nagiosgraph 1.5.2 (the latest version at the time of this writeup) from Nagiosgraph - Official Page.
# mkdir -p /soft/nagios # cd /soft/nagios # wget https://sourceforge.net/projects/nagiosgraph/files/nagiosgraph/1.5.2/nagiosgraph-1.5.2.tar.gz
Extract the contents of Nagiosgraph tarball.
# cd /soft/nagios # tar xvf nagiosgraph-1.5.2.tar.gz
Check prerequisites and install Nagiosgraph.
# cd /soft/nagios/nagiosgraph-1.5.2 # ./install.pl --check-prereq # ./install.pl --layout overlay --prefix /usr/local/nagios
During the installation, set the paths as follows:
(If you define the paths correctly, then most of the configurations will be automatically make by Nagiosgraph installer)
Destination directory (prefix)? [/usr/local/nagios] Location of configuration files (etc-dir)? [/usr/local/nagios/etc/nagiosgraph] Location of executables? [/usr/local/nagios/libexec] Location of CGI scripts? [/usr/local/nagios/sbin] Location of documentation (doc-dir)? [/usr/local/nagios/docs/nagiosgraph] Location of examples? [/usr/local/nagios/docs/nagiosgraph/examples] Location of CSS and JavaScript files? [/usr/local/nagios/share] Location of utilities? [/usr/local/nagios/docs/nagiosgraph/util] Location of state files (var-dir)? [/var/nagios] /usr/local/nagios/var Location of RRD files? [/usr/local/nagios/var/rrd] Location of log files (log-dir)? [/var/nagios] /usr/local/nagios/var Path of log file? [/usr/local/nagios/var/nagiosgraph.log] Path of CGI log file? [/usr/local/nagios/var/nagiosgraph-cgi.log] Base URL? [/nagios] URL of CGI scripts? [/nagios/cgi-bin] URL of CSS file? [/nagios/nagiosgraph.css] URL of JavaScript file? [/nagios/nagiosgraph.js] URL of Nagios CGI scripts? [/nagios/cgi-bin] Path of Nagios performance data file? [/tmp/perfdata.log] /usr/local/nagios/var/service-perfdata.log username or userid of Nagios user? [nagios] username or userid of web server user? [apache]
Edit /usr/local/nagios/etc/nagios.cfg file and comment (#) all the performance related parameters.
# vi /usr/local/nagios/etc/nagios.cfg
Set following parameters, to enable Nagios to keep history of performance data.
# process nagios performance data using nagiosgraph
process_performance_data=1
service_perfdata_file=/usr/local/nagios/var/service-perfdata.log
service_perfdata_file_template=$LASTSERVICECHECK$||$HOSTNAME$||$SERVICEDESC$||$SERVICEOUTPUT$||$SERVICEPERFDATA$
service_perfdata_file_mode=a
service_perfdata_file_processing_interval=30
service_perfdata_file_processing_command=process-service-perfdata-for-nagiosgraph
Edit /usr/local/nagios/etc/objects/commands.cfg.
# vi /usr/local/nagios/etc/objects/commands.cfg
Add following command to to enable storage of performance metrics.
define command {
command_name process-service-perfdata-for-nagiosgraph
command_line /usr/local/nagios/libexec/insert.pl
}
Check Nagios configurations now.
# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg Nagios Core 4.2.0 Copyright (c) 2009-present Nagios Core Development Team and Community Contributors Copyright (c) 1999-2009 Ethan Galstad Last Modified: 08-01-2016 License: GPL Website: https://www.nagios.org Reading configuration data... Read main config file okay... Read object config files okay... Running pre-flight check on configuration data... Checking objects... Checked 8 services. Checked 1 hosts. Checked 1 host groups. Checked 0 service groups. Checked 1 contacts. Checked 1 contact groups. Checked 25 commands. Checked 5 time periods. Checked 0 host escalations. Checked 0 service escalations. Checking for circular paths... Checked 1 hosts Checked 0 service dependencies Checked 0 host dependencies Checked 5 timeperiods Checking global event handlers... Checking obsessive compulsive processor commands... Checking misc settings... Total Warnings: 0 Total Errors: 0 Things look okay - No serious problems were detected during the pre-flight check
Restart nagios and httpd services to reload new configurations.
# systemctl restart nagios # systemctl restart httpd
Open URL http://192.168.229.129/nagios/cgi-bin/showconfig.cgi in the browser, to see the configurations. (Replace the IP address in the URL, with your CentOS 7 Server IP address).
You can see that Nagiosgraph has been integrated with Nagios Core.
Edit /usr/local/nagios/etc/objects/templates.cfg file.
# vi /usr/local/nagios/etc/objects/templates.cfg
Add following code to define a service graphed-service to be used to display Nagiosgraph graphs.
define service {
name graphed-service
action_url /nagios/cgi-bin/show.cgi?host=$HOSTNAME$&service=$SERVICEDESC$' onMouseOver='showGraphPopup(this)' onMouseOut='hideGraphPopup()' rel='/nagiosgraph/cgi-bin/showgraph.cgi?host=$HOSTNAME$&service=$SERVICEDESC$&period=week&rrdopts=-w+450+-j
register 0
}
And append graphed-service in use parameter of the services, for which you want to draw graphs. We have added it to some services, one service syntax is given below for reference.
define service{
use local-service,graphed-service ; Name of service template to use
host_name localhost
service_description HTTP
check_command check_http
notifications_enabled 0
}
Restart nagios service.
# systemctl restart nagios
Now, open the Nagios web interface in browser, you may see the small graph icon infront of the services for which you have enabled graphs.
Click on the graph icon to open graphs’ page.
Adjust the parameters on the top right side panel to draw graphs according to your needs.
We have successfully installed Nagiosgraph plugin for Nagios Core on CentOS 7. PNP4Nagios is another addon to display graphs in Nagios Core server. You might like our next article Install PNP4Nagios on Nagios Core over CentOS 7.
