Install and Configure Icinga – A Network Monitoring Tool In Linux

Icinga is an open source system and network monitoring application. It’s a fork of Nagios and is backward compatible. It retains all the existing features of its predecessor, it builds on them to add many long awaited patches and features requested by the user community. New features include a modern Web 2.0 interface and support for popular SQL databases.

Icinga is an enterprise grade monitoring system which keeps watch over a network and any conceivable network resource, notifies the user of errors and recoveries, and generates performance data for reporting. Scalable and extensible, it can monitor complex, large environments across dispersed locations.

This guide will show you how to install Icinga on CentOS 7.

1. Installing Pre-Requirements

Before installing Icinga you need to download a number of pre-required packages, mainly the Apache web server, libraries needed to compile the source and tools needed for the web interface and network monitoring. You can install them using yum like this:

# yum install httpd gcc glibc glibc-common gd gd-devel
# yum install libjpeg libjpeg-devel libpng libpng-devel
# yum install net-snmp net-snmp-devel net-snmp-utils

2. Create user and group

You will have to add the icinga user to the system so we don’t have to run it as root:

# useradd icinga

And a new icingacmd group that will allow us to run external commands via the web interface:

# groupadd icinga-cmd
# usermod -a -G icinga-cmd icinga
# usermod -a -G icinga-cmd apache

3. Download Icinga and the Plugins

Create a new directory to store the downloaded packages:

# mkdir ~/icinga
# cd ~/icinga

The latest versions of Icinga and Plugins packages can be found on the following websites:

• Icinga – https://github.com/Icinga/icinga-core/releases
• Nagios Plugins – http://nagios-plugins.org/downloads/

You can use wget to download the files:

# wget https://github.com/Icinga/icinga-core/releases/download/v1.11.5/icinga-1.11.5.tar.gz
# wget http://www.nagios-plugins.org/download/nagios-plugins-2.0.3.tar.gz

And then extract the files with tar:

# tar zxvf icinga-1.11.5.tar.gz
# tar zxvf nagios-plugins-2.0.3.tar.gz

4. Compile and install Icinga

Now change to the Icinga directory and run the configuration file

# cd icinga-1.11.5
# ./configure –with-command-group=icinga-cmd –disable-idoutils

You should get the following output:

*** Configuration summary for icinga-core 1.11.5 06-20-2014 ***:

General Options:
————————-
Icinga executable: icinga
Icinga user/group: icinga,icinga
Command user/group: icinga,icinga-cmd
Apache user/group: apache,apache
Embedded Perl: no
Event Broker: yes
Enable compressed logs: yes
Enable Performance Data: no
Build IDOUtils: no
Install ${prefix}: /usr/local/icinga
Lock file: ${prefix}/var/icinga.lock
Temp file: /tmp/icinga.tmp
Chk file: ${prefix}/var/icinga.chk
HTTP auth file: ${prefix}/etc/htpasswd.users
Lib directory: ${exec_prefix}/lib
Bin directory: ${exec_prefix}/bin
Plugin directory: ${exec_prefix}/libexec
Eventhandler directory: ${exec_prefix}/libexec/eventhandlers
Log directory: ${prefix}/var
Check result directory: ${prefix}/var/spool/checkresults
Temp directory: /tmp
State directory: ${prefix}/var
Ext Cmd file directory: ${prefix}/var/rw
Init directory: /etc/rc.d/init.d
Apache conf.d directory: /etc/httpd/conf.d
Apache config file: /etc/httpd/conf.d/icinga.conf
Mail program: /usr/bin/mail
Host OS: linux-gnu
Environment Prefix: ICINGA_

Web Interface Options:
————————
HTML URL: http://localhost/icinga/
CGI URL: http://localhost/icinga/cgi-bin/
Main URL: http://localhost/icinga/cgi-bin/tac.cgi

Review the options above for accuracy. If they look okay,
type ‘make all’ to compile the main program and CGIs.

Next we need to compile and install the Icinga files with the following commands:

# make all
# make fullinstall
# make install-config

5. Change admin email address

With your favorite text editor you need to open /usr/local/icinga/etc/objects/contacts.cfg and modify the email field from icinga@localhost to the email address where you wish to receive notifications.

# vim /usr/local/icinga/etc/objects/contacts.cfg

And the configure file should look like this:

define contact{
contact_name icingaadmin ; Short name of user
use generic-contact ; Inherit default values from generic-contact template (defined above)
alias Icinga Admin ; Full name of user

email icinga@localhost ; <<***** CHANGE THIS TO YOUR EMAIL ADDRESS ******
}

6. Install and configure the classic web components

To compile and install the classic web interface run the following commands:

# make cgis
# make install-cgis
# make install-html
# make install-webconf

And we need to setup the password for the user icingaadmin. This username will be used to access the web interface so it is important to remember the password that you will input here. Set the password running the following command and enter the password twice:

# htpasswd -c /usr/local/icinga/etc/htpasswd.users icingaadmin
New password:
Re-type new password:
Adding password for user icingaadmin

Restart Apache for the settings to take effect:

# systemctl start httpd.service

7. Install the Plugins

Now it’s time to install the Plugins by running the following commands:

# cd ~/icinga/nagios-plugins-2.0.3
# ./configure –prefix=/usr/local/icinga –with-cgiurl=/icinga/cgi-bin –with-nagios-user=icinga –with-nagios-group=icinga
# make
# make install

8. Make Icinga run on system boot

First verify that the configuration file has no errors running the following command:
# /usr/local/icinga/bin/icinga -v /usr/local/icinga/etc/icinga.cfg

And you should get an output:

Total Warnings: 0
Total Errors: 0

Things look okay – No serious problems were detected during the pre-flight check

If everything is fine add the service to run on boot with this commands:

# chkconfig –add icinga
# chkconfig –level 35 icinga on
And start the service with the following command:
# systemctl start icinga.service

9. The web interface

Now that everything is installed and running you can access the web interface with a browser either by using the address http://localhost/icinga if you are doing so from the local computer or by using the address http://SERVER-IP/icinga if you are accessing it from a remote computer.
When prompted for username and password you will introduce the username “icingaadmin” and the password that you entered in step 6. In case you forget this password you can modify it by rerunning the htpasswd command in step 6.

It should look like this:

If the web interface doesn’t work check if SELinux is in enforcing mode by running:

# getenforce
Enforcing

If it is set it to permissive like this:

# setenforce 0

Congratulations, Icinga is now setup and ready to use