Configure Icinga on Open Source Linux Server -A Monitoring Tool for RHEL/CentOS 7.0

Icinga is a monitoring system checking hosts and services you specify and notifying you when things go wrong and when they recover. It runs on multiple Linux distributions (including Fedora, Ubuntu, and openSuSE) as well as several Unix platforms (including Solaris and HP). The systems to be monitored can be nearly anything connected to a network.

Some of the many features of Icinga include:

• Monitoring of network services (SMTP, POP3, HTTP, NNTP, PING, etc.)
• Monitoring of host resources (CPU load, disk usage, etc.)
• Simple plugin design that allows users to easily develop their own service checks
• Parallelized service checks
• Ability to define network host hierarchy using "parent" hosts, allowing detection of and distinction between hosts that are down and those that are unreachable
• Contact notifications when service or host problems occur and get resolved (via email, pager, or user-defined method)
• Ability to define event handlers to be run during service or host events for proactive problem resolution
• Automatic log file rotation
• Support for implementing redundant monitoring hosts
• Optional classic web interface for viewing current network status, notification and problem history, log file, etc.
• Optional new Icinga web interface based on Icinga Core, IDOUtils, API using a modern and refreshed web 2.0 GUI showing current states, historical information, using cronks and filters, creating reports with multilanguage support
  
  

System requirements

As mentioned above you'll need a machine running Linux or a Unix variant. If there is no precompiled version or if you want to compile from source you need a C compiler like gcc.

• Some compilers may not be suitable. That includes the C compiler on HP-UX which is used to compile a new kernel.

• You may also want to have TCP/IP configured as most checks will require access via the network.

• You are not required to use one of the web interfaces included with Icinga. However, if you do decide to use them, you will need additional software:
  A Web-Server (preferrably Apache)
• Thomas Boutells gd library Version 1.6.3 or higher (required by the statusmap- and trends-CGIs)
• PHP

Licensing

Icinga is licensed under the terms of the GNU General Public License Version 2 as published by the Free Software Foundation. This gives you legal permission to copy, distribute and/or modify Icinga under certain conditions. Read the 'LICENSE' file in the Icinga distribution or read the online version of the license for more details. Icinga is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE WARRANTY OF DESIGN, MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgements

Several people have contributed to Icinga by either reporting bugs, suggesting improvements, writing plugins, etc. A list of some of the many contributors to the development of Icinga can be found at https://www.icinga.com/.

Downloading The Latest Version

You can check for new versions of Icinga at https://www.icinga.com/.

Compatibility

Icinga is a fork of the well-known monitoring system Nagios. Being 100% compatible with the internal structures of the latter Icinga enables you to use all plugins and add-ons which were/are developed by several companies and the large community.

Install Icinga Monitoring Tool in CentOS/RHEL 7.0

This topic will concentrate on a basic installation of Icinga 1 Monitoring Tool from binaries on CentOS or RHEL 7, using RepoForge (previously known as RPMforge) repositories for CentOS 6, with the classical web interface held by Apache Webserver and the use of Nagios Plugins that will be installed on your system.

Requirements

A basic LAMP installation on RHEL/CentOS 7.0 without MySQL and PhpMyAdmin, but with these PHP modules: php-cli
php-pear php-xmlrpc php-xsl php-pdo php-soap php-gd.

Step 1: Installing Icinga Monitoring Tool

1. Before proceeding with Icinga installation from binaries add RepoForge repositories on your system by issuing the following command, depending on your machine.

For 86-64-bit

# rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm

For 32-bit

# rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.i686.rpm

rpm -Uvh ftp://195.220.108.108/linux/dag/redhat/el6/en/i386/dag/RPMS/rpmforge-release-0.5.3-1.el6.rf.i686.rpm

Install RepoForge Repository

2. After RepoForge repositories had been added on your system, start with Icinga basic installation without the web interface yet, by running the following command.

yum install icinga icinga-doc

Install Icinga Monitoring Tool

3. The next step is to try to install Icinga web interface provided by icinga-gui package. It seems that for the moment this package has some unresolved issues with CentOS/RHEL 7, and will generate some transaction check errors, but you can feel free to try to install the package, maybe meanwhile the problem was resolved.

Still, if you get the same errors on your machine as the pictures below shows you, use the following approach as further described, to be able to install Icinga web interface.

yum install icinga-gui

4. The procedure to install icinga-gui package which provides the web interface is the following. First download the binary package form RepoForge website using wget command.

For 86-64-bit

# wget http://pkgs.repoforge.org/icinga/icinga-gui-1.8.4-4.el6.rf.x86_64.rpm

For 32-bit

# wget http://pkgs.repoforge.org/icinga/icinga-gui-1.8.4-4.el6.rf.i686.rpm

wget ftp://ftp.icm.edu.pl/vol/rzm6/linux-dag/redhat/el6/en/i386/dag/RPMS/icinga-gui-1.8.4-4.el6.rf.i686.rpm

Install Icinga RPM Package

5. After wget finishes downloading the package, create a directory named icinga-gui (you can choose other name if you want), move icinga-gui RPM binary to that folder, enter the folder and extract RPM package contents by issuing the next series of commands.

mkdir icinga-gui

mv icinga-gui-* icinga-gui

cd icinga-gui

rpm2cpio icinga-gui-* | cpio -idmvCopy Icinga GUI Packages

6. Now that you have the extracted icinga-gui package, use ls command to visualize folder content – it should result three new directories – etc, usr and var. Start by executing a recursive copying of all three resulted directories on your system root file system layout.

cp -r etc/* /etc/

cp -r usr/* /usr/

cp -r var/* /var/

Copy Directories Recursively

Step 2: Modify Icinga Apache Configuration file and System Permissions

7. As presented on this article introduction, your system needs to have Apache HTTP server and PHP installed in order to be able to run Icinga Web Interface.

After you finished the above steps, a new configuration file should be now present on Apache conf.d path named icinga.conf. In order to be able to access Icinga from a remote location from browser, open this configuration file and replace all its content with the following configurations.

# nano /etc/httpd/conf.d/icinga.conf

Make sure you replace all file content with the following.

ScriptAlias /icinga/cgi-bin "/usr/lib/icinga/cgi"
<Directory "/usr/lib/icinga/cgi">
#  SSLRequireSSL
Options ExecCGI
AllowOverride None
AuthName "Icinga Access"
AuthType Basic
AuthUserFile /etc/icinga/passwd
<IfModule mod_authz_core.c>
# Apache 2.4
<RequireAll>
Require all granted
# Require local
Require valid-user
</RequireAll>
</IfModule>
<IfModule !mod_authz_core.c>
# Apache 2.2
Order allow,deny
Allow from all
#  Order deny,allow
#  Deny from all
#  Allow from 127.0.0.1
Require valid-user
</IfModule>
</Directory>
Alias /icinga "/usr/share/icinga/"
<Directory "/usr/share/icinga/">
#  SSLRequireSSL
Options None
AllowOverride All
AuthName "Icinga Access"
AuthType Basic
AuthUserFile /etc/icinga/passwd
<IfModule mod_authz_core.c>
# Apache 2.4
<RequireAll>
Require all granted
# Require local
Require valid-user
</RequireAll>
</IfModule>
<IfModule !mod_authz_core.c>
# Apache 2.2
Order allow,deny
Allow from all
#  Order deny,allow
#  Deny from all
#  Allow from 127.0.0.1
Require valid-user
</IfModule>
</Directory>

8. After you have edited Icinga httpd configuration file, add Apache system user to Icinga system group and use the following system permissions on next system paths.

usermod -aG icinga apache

chown -R icinga:icinga /var/spool/icinga/*

chgrp -R icinga /etc/icinga/*
chgrp -R icinga /usr/lib64/icinga/*
chgrp -R icinga /usr/share/icinga/*

Make sure selinux is disabled

9. Before starting Icinga system process and Apache server, make sure you also disable SELinux security mechanism by running setenforce 0 command and make the changes permanent by editing /etc/selinux/configfile, changing SELINUX context from enforcing to disabled.

# nano /etc/selinux/config

Modify SELINUX directive to look like this.
SELINUX=disabled

Disable SELinux

You can also use getenforce command to view SELinux status.

10. As the last step before starting Icinga process and web interface, as a security measure you can now modify Icinga Admin password by running the following command, and then start both processes.

htpasswd -cm /etc/icinga/passwd icingaadmin
systemctl start icinga
systemctl start httpd

Create Icinga Admin Password

Start Icinga Service

Step 3: Install Nagios Plugins and Access Icinga Web Interface

11. In order to start monitoring public external services on hosts with Icinga, such as HTTP, IMAP, POP3, SSH, DNS, ICMP ping and many others services accessible from internet or LAN you need to install Nagios Pluginspackage provided by EPEL Repositories.

Install Epel Repository

rpm -Uvh ftp://195.220.108.108/linux/centos/7.3.1611/extras/x86_64/Packages/epel-release-7-6.noarch.rpm

yum install yum install nagios-plugins nagios-plugins-all

  Install Nagios Plugin

12. To login on Icinga Web Interface, open a browser and point it to the URL http://system_IP/icinga/. Use icingaadmin as username and the password that you changed earlier and you can now see your localhost system status.

yum install yum install nagios-plugins nagios-plugins-all

Icinga Admin Login

Icinga Monitoring Dashboard

That’s all! Now you have Icinga basic with the classical web interface – nagios like – installed and running on your system. Using Nagios Plugins you can now start adding new hosts and external services to check and monitor by editing Icinga configuration files located on /etc/icinga/ path. If you need to monitor internal services on remote hosts then you must install an agent on remote hosts like NRPE, NSClient++, SNMP to gather data and send it to Icinga main process.