Nagios is a popular open source computer system and network monitoring software application. It watches hosts and services, alerting users when things go wrong and again when they get better, if required.

Nagios, originally created under the name NetSaint, was written and is currently maintained by Ethan Galstad, along with a group of developers actively maintaining both official and unofficial plugins. N.A.G.I.O.S. is a recursive acronym: “Nagios Ain’t Gonna Insist On Sainthood”, “Sainthood” being a reference to the original name of the software, which was changed in response to a legal challenge by owners of a similar trademark. “Agios” is also Greek for ‘saint’.

Nagios was originally designed to run under GNU/Linux, but also runs well on other Unix variants. It is free software, licensed under the terms of the GNU General Public License version 2 as published by the Free Software Foundation.

Pre-requisites

Hardware Requirement

Any Server grade machine with 1GB RAM and 120GB HDD is needed for a normal installation. This may vary according to the number of hosts and services managed by the Nagios server.

Software Requirement

Linux – As an operating system to install Nagios. Better to go for CentOS, which is a free and 100% binary compatible stable release of RedHat Enterprise Linux.

RPM Forge Repo – RPM Forge repo for the yum has to be installed on this. The installation requires the Linux machines to be connected to the direct internet so that the installation will be started directly from the RPM Forge Repository available in the internet.

Nagios packages – Needed the following packages for the complete installation of Nagios.

–           nagios  – Core nagios package.

–           nagios-plugins – Nagios plugins for configuring services of the hosts.

–           nagios-plugins-nrpe  – Nagios plugin for linux/unix machines.

–           nagios-devel – Nagios development packages.

Centreon Packages – Contains the binaries for centreon.

Installation

Installing RPM Forge Repo

After installing the Operating System (CentOS 5.5) , connect the machine directly to the internet. This is needed for installing the packages, as we will do that using YUM package manager.

Execute the following commands to download and install the RPM Forge repository (Repository where the RPMs of all the packages needed for the installation)

# wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.3.6-1.el5.rf.i386.rpm

(This will download this rpm file from the rpmforge website)

[root@yourmachine  ~] rpm –ivh rpmforge-release-0.3.6-1.el5.rf.i386.rpm

(Install RPM Forge repo on your machine)

[root@yourmachine  ~] yum check-update

( Analyze the output to check whether it is contacting the RPM Forge directory.

[root@yourmachine  ~] yum update

(Will update all installed packages on your machine to the latest stable version.)

Nagios Installation

Once the RPM Forge repo is installed, you can run the following command to install Nagios and all other supporting packages.

[root@yourmachine  ~] yum install httpd* nagios nagios-plugins nagios-plugins-nrpe nagios-devel

Once the installation is over, this will create all the binaries, users, groups configuration files and supporting files for Nagios.

The installation of Nagios via YUM will install the nagios as a apache module, so you would be able to see a configuration file nagios.conf inside the directory /etc/httpd/conf.d

Then go to the command line and enter the following command for setting up the password for the Nagios Web Interface.

[root@yourmachine  ~] htpasswd -c /etc/nagios/htpasswd.users nagiosadmin

Which will show you the following output

New password: type_your_password
Re-type new password: re-type_your_password
Adding password for user nagiosadmin

Check the cgi.cfg file and make sure that the following directives are enabled (Remove the # from start of each line to enable it)

[root@yourmachine  ~] cd /etc/nagios
[root@yourmachine  nagios] vim cgi.cfg

# AUTHENTICATION USAGE
use_authentication=1

# SYSTEM/PROCESS INFORMATION ACCESS
authorized_for_system_information=nagiosadmin

# CONFIGURATION INFORMATION ACCESS
authorized_for_configuration_information=nagiosadmin

# SYSTEM/PROCESS COMMAND ACCESS
authorized_for_system_commands=nagiosadmin

# GLOBAL HOST/SERVICE VIEW ACCESS
authorized_for_all_services=nagiosadmin
authorized_for_all_hosts=nagiosadmin

# GLOBAL HOST/SERVICE COMMAND ACCESS
authorized_for_all_service_commands=nagiosadmin
authorized_for_all_host_commands=nagiosadmin

To make the apache more secure, run the apache with a less privileged user than root user. So go to the /etc/httpd/conf/httpd.conf file and search for User and Group directives. Put the group and user as nagios and enable that line (Remove the # from the starting of the line) so that it should look like this

User nagios

Group nagios

To reflect the changes you have made, you need to restart the apache service using the following command.

[root@yourmachine  ~] service httpd restart

[root@yourmachine  ~] service nagios restart

[root@yourmachine  ~] chkconfig –level 2345 httpd on (This will enable the service httpd at the boot time)

[root@yourmachine  ~] chkconfig –level 2345 nagios on

Access the Nagios Web Interface using the following URL.

http://localhost/nagios

You will be prompted for a username and password. Username will be nagiosadmin and password will be the password you set for the nagiosadmin.

Next step is to setup NDOUtils for storing all the nagios related information to the database (MySQL).

NDOUtils Installation

Install NDOUtils package using YUM with the following command. The configuration of NDOUtils will be done only after installing the Centreon.

[root@yourmachine  ~] yum -y install mysql-* ndoutils

[root@yourmachine  ~] service ndoutils start

[root@yourmachine  ~] chkconfig –level 2345 ndoutils on

[root@yourmachine  ~] service mysqld start

[root@yourmachine  ~] chkconfig –level 2345 mysqld on

After starting the MySQL Server, you need to secure the same using the following command

[root@yourmachine  ~] mysql_secure_installation

This will ask you for the following details.

–          Set the root password for the root user.

–          Remove anonymous users

–          Disallow root logins remotely.

–          Remove test database

–          Reload privileges table

Put “y” for all the questions asked. You can check the password for root user using the following command.

[root@yourmachine  ~]mysql -u root -p [Enter]

Enter your mysql root password, which will take you to the mysql prompt.

Execute the MySQL query “show databases” to list the databases

mysql> show databases;

+——————–+

| Database           |

+——————–+

| information_schema |

+——————–+

1 row in set (0.00 sec)

Centreon Prerequisites

Before starting the installation of the Centreon, we need to install all the pre-requisites needed for the Centreon.

Run the following commands to install the pre-requisites.

[root@yourmachine  ~] yum -y install php-mysql php-posix libgd2 libpng gd fontconfig-devel libjpeg-devel libpng-devel gd-devel perl-GD openssl-devel perl-DBD-MySQL php php-mysql php-gd php-ldap php-xml php-mbstring perl-DBI perl-Config-IniFiles rrdtool perl-rrdtool perl-Crypt-DES perl-Digest-SHA1 perl-Digest-HMAC net-snmp-utils perl-Socket6 perl-IO-Socket-INET6 net-snmp net-snmp-libs php-snmp dmidecode lm_sensors perl-Net-SNMP net-snmp-perl fping cpp gcc gcc-c++ libstdc++ glib2-devel php-pear sudo make gcc

This will install the following packages needed for Centreon

–          GD Modules

–          PHP and Dependencies

–          DBI Modules

–          PERL modules

–          RRDTool modules

–          SNMP and Supporting Packages

–          PEAR modules

Next step is to install PEAR modules needed for Centreon.

For that, run the following commands.

[root@yourmachine  ~] pear channel-update pear.php.net

[root@yourmachine  ~] pear upgrade-all

[root@yourmachine  ~] pear install -o -f –alldeps DB DB_DataObject DB_DataObject_FormBuilder MDB2 Date Numbers_Roman Numbers_Words HTML_Common HTML_QuickForm HTML_QuickForm_advmultiselect HTML_Table Auth_SASL HTTP Image_Canvas Image_Color Image_Graph Image_GraphViz Mail Mail_Mime Net_SMTP Net_Socket Net_Traceroute Net_Ping Validate SOAP

[root@yourmachine  ~] pear install Auth_SASL Date DB DB_DataObject DB_DataObject_FormBuilder HTML_Common HTML_QuickForm HTML_QuickForm_advmultiselect HTML_Table Image_Canvas Image_Canvas Image_Graph Image_GraphViz Mail_Mime MDB2 Net_Ping Net_Traceroute Numbers_Roman Numbers_Words PEAR Validate XML_RPC

This will install the following PEAR packages needed for the centreon.

–          Auth_SASL

–          Date

–          DB

–          DB_DataObject

–          DB_DataObject_FormBuilder

–          HTML_Common

–          HTML_QuickForm

–          HTML_QuickForm_advmultiselect

–          HTML_Table

–          Image_Canvas

–          Image_Color

–          Image_Graph

–          Image_GraphViz

–          Mail_Mime

–          MDB2

–          Net_Ping

–          Net_Traceroute

–          Numbers_Roman

–          Numbers_Words

–          PEAR

–          Validate

–          XML_RPC

Sometimes, during the installation of these PEAR packages you may encounter the following error.

pear/Some_Pear_Package requires PEAR Installer (version >= 1.9.1), installed version is 1.4.9

In this case, you need to upgrade the PEAR Installer to the latest version by the following command and try installing those failed PEAR packages again.

[root@yourmachine  ~] pear upgrade –force PEAR

After this installation, you need to restart httpd, mysqld and nagios services.

[root@yourmachine  ~] service httpd restart

[root@yourmachine  ~] service mysqld restart

[root@yourmachine  ~] service nagios restart

Centreon Installation

Now we are ready for the installation of Centreon.

First, download the tar file from the following URL.

[root@yourmachine  ~] wget http://download.centreon.com/centreon/centreon-2.1.9.tar.gz

[root@yourmachine  ~] tar -xvf centreon-2.1.9.tar.gz

[root@yourmachine  ~] cd centreon-2.1.9

Now the installation script is called. In this script you will be asked a number of questions pertaining to the installation, different dependencies etc… In between you will find some comments on questions which are asked during the script.

[root@yourmachine centreon-2.1.9 ] ./install.sh –i  (Output of the script is show below. Questions and answers asked during the installation are highlighted in red.)

First step: checking prerequisites

————————————————————————

Checking all needed binaries

————————————————————————

Now the Centreon license (GPL2) is shown. If you don’t accept it the setup will terminate. This General Public License does not permit incorporating your program into  proprietary programs.  If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the  library.  If this is what you want to do, use the GNU Library General Public License instead of this License.

Do you accept GPL license ?

[y/n], default to [n]:

> y

Now some questions regarding the modules to be installed: Centreon web interface, centcore (distributing module), Centreon plugins and Centreon Trap-Handler.

————————————————————————

Please choose what do you want to install

————————————————————————

Do you want to install Centreon Web Front

[y/n], default to [n]:

> y

Do you want to install Centreon CentCore

[y/n], default to [n]:

> y

Do you want to install Centreon Nagios Plugins

[y/n], default to [n]:

> y

Do you want to install Centreon Snmp Traps process

[y/n], default to [n]:

> y

Now the installation of the different modules begins, starting with Centreon Web, the centreon interface.

————————————————————————

Start CentWeb Installation

————————————————————————

Where is your Centreon directory?

default to [/usr/local/centreon]

>[Press Enter]

Where should centreon be installed? <Enter> accepts the shown default value. You can specify another path. If the directory doesn’t exist you are asked if it should be created:

Do you want me to create this directory ? [/usr/local/centreon]

[y/n], default to [n]:

> y

Path /usr/local/centreon                                   OK

Here you should specify where to put the centreon journals/logs.

Where is your Centreon log directory

default to [/usr/local/centreon/log/]

>[Press Enter]

Do you want me to create this directory ? [/usr/local/centreon/log/]

[y/n], default to [n]:

> y

Path /usr/local/centreon/log/                              OK

Very important : the location of centreon config file.\ ATTENTION: changing the path may result in problems…

Where is your Centreon etc directory

default to [/etc/centreon]

[Press Enter]

Do you want me to create this directory ? [/etc/centreon]

[y/n], default to [n]:

> y

Path /etc/centreon                                         OK

Where is your Centreon generation_files directory?

default to [/usr/local/centreon/]

> [Press Enter]

Path /usr/local/centreon/                                  OK

Where is your Centreon variable library directory?

default to [/var/lib/centreon]

> [Press Enter]

Do you want me to create this directory ? [/var/lib/centreon]

[y/n], default to [n]:

> y

Path /var/lib/centreon

Where is your CentPlugins Traps binary

default to [/usr/local/centreon/bin]

>[Press Enter]

Do you want me to create this directory ? [/usr/local/centreon/bin]

[y/n], default to [n]:

> y

Path /usr/local/centreon/bin                               OK

Before the next step, run the following commands in another shell.

[root@localhost perl5]# yum install php-rrdtool

[root@yourmachine  ~] updatedb

[root@yourmachine  ~] locate RRDs.pm (This will show you the correct path to RRDs.pm file)

This will output the location of RRDs.pm file. For eg. /usr/lib/perl5/vendor_perl/5.8.8/i386-linux-thread-multi/RRDs.pm

Create a sybmbolic link to /usr/lib/perl5/RRDs.pm with the following command.

[root@yourmachine  ~] ln -s /usr/lib/perl5/vendor_perl/5.8.8/i386-linux-thread-multi/RRDs.pm /usr/lib/perl5/RRDs.pm

Go back to the shell where you are running the Centreon Installation script.

Where is the RRD perl module installed [RRDs.pm]

default to [/usr/lib/perl5/RRDs.pm]

>[Press Enter]

Path /usr/lib/perl5                                        OK

/usr/bin/rrdtool                                           OK

/usr/bin/mail                                              OK

Where is PEAR [PEAR.php]

default to [/usr/share/php/PEAR.php]

>/usr/share/pear/PEAR.php  (Enter this path to PEAR.php file)

Path /usr/share/pear                                        OK

Where is installed Nagios ?

default to [/usr/local/nagios]

>/usr/share/nagios

Path/usr/share/nagios                                     OK

Where is your nagios config directory

default to [/usr/local/nagios/etc]

>/etc/nagios

Path /etc                                                                             OK

Where is your Nagios var directory ?

default to [/usr/local/nagios/var]

>/var/log/nagios

Path /var/log                                                               OK

Where is your Nagios plugins (libexec) directory ?

default to [/usr/local/nagios/libexec]

>/usr/lib/nagios/plugins

Path /usr/lib/nagios/plugins                             OK

/usr/local/nagios/bin//nagios                              OK

Where is your Nagios image directory ?

default to [/usr/local/nagios/share/images/logos]

>/usr/share/nagios/images/logos

Path /usr/share/nagios/images/logos                        OK

/usr/bin/nagiostats                                                       OK

p1_file : /usr/bin/p1.pl                                   OK

/usr/bin/php                                               OK

/usr/bin/perl                                              OK

Finding Apache group :                                     nagios

Finding Apache user :                                      nagios

Finding Nagios user :                                      nagios

Finding Nagios group :                                     nagios

Where is your NDO ndomod binary ?

default to [/usr/sbin/ndomod.o]

> /usr/libexec/ndomod-3x.o

/usr/libexec/ndomod-3x.o                                   OK

————————————————————————

Configure Sudo

————————————————————————

Where is sudo configuration file default to [/etc/sudoers]

>[Press Enter]

/etc/sudoers                                               OK

Nagios init script                                         OK

Your sudo is not configured

Do you want me to configure your sudo? (WARNING)

[y/n], default to [n]:

> y

Configuring Sudo                                           OK

Setting up the centreon Aliases etc

————————————————————————

Configure Apache server

————————————————————————

Do you want to add Centreon Apache sub configuration file ?

[y/n], default to [n]:

> y

Create ‘/etc/apache2/conf.d/centreon.conf’                 OK

Configuring Apache                                         OK

Do you want to reload your Apache ?

[y/n], default to [n]:

> y

Finding Apache Centreon configuration file

‘/etc/httpd/conf.d/centreon.conf’ :                        OK

Do you want to update Centreon Apache sub configuration file ?

[y/n], default to [n]:

> n

Create ‘/etc/httpd/conf.d/centreon.conf’                   OK

Configuring Apache                                         OK

Do you want to reload your Apache ?

[y/n], default to [n]:

> y

Reloading Apache service                                   OK

Preparing Centreon temporary files

Change right on /usr/local/centreon/log                    OK

Change right on /etc/centreon                              OK

Change right on /usr/share/nagios/images/logos             OK

Install nagios documentation                               OK

Change macros for insertBaseConf.sql                       OK

Change macros for php files

Change macros for php files                                OK

Change right on /etc/nagios                                OK

Copy CentWeb in system directory

Install CentWeb (web front of centreon)                    OK

Install libraries                                          OK

Copying libinstall                                         OK

Change macros for centreon.cron                            OK

Install Centreon cron.d file                               OK

Change macros for archiveDayLog                            OK

Change macros for centAcl.php                              OK

Install cron directory                                     OK

PEAR libraries: a set of libraries is still missing but they will be installed or updated as nessecary (if you have a connection to the internet). Otherwise you have to install them manually

————————————————————————

Pear Modules

————————————————————————

Check PEAR modules

PEAR                            1.4.9       1.6.1          OK

After displaying the current versions you may get the request to update some libraries.

Do you want me to install/upgrade your PEAR modules

[y/n], default to [y]: [Press Enter]

Upgrading PEAR modules

Installing PEAR modules

All PEAR modules                                           OK

The script will continue.

————————————————————————

Centreon Post Install

————————————————————————

Create /usr/local/centreon/www/install/install.conf.php    OK

Create /etc/centreon/instCentWeb.conf                      OK

Now CentStorage will be installed, also called ODS (Oreon Data Storage). At the moment this module permits archiving on the basis of RRD and MySQL. Additionally CentStorage enables you to create graphs for monitoring the different metrics.

————————————————————————

Start CentStorage Installation

————————————————————————

Where is your Centreon Run Dir directory?

default to [/var/run/centreon]

>[Press Enter]

Do you want me to create this directory ? [/var/run/centreon]

[y/n], default to [n]:

> y

Path /var/run/centreon                                     OK

Where is your CentStorage binary directory

default to [/usr/local/centreon/bin]

>[Press Enter]

Path /usr/local/centreon/bin                               OK

Where is your CentStorage RRD directory

default to [/var/lib/centreon]

>[Press Enter]

Path /var/lib/centreon                                     OK

Attention: the centreon lib directory should be placed on a continuously available partition to avoid problems. The directory contains the RRDTools. Consider to place the MySQl data on large partition. The logs and performance data also need a lot of space.

Path /var/lib/centreon                                     OK

Finding Nagios group :                                     nagios

Finding Nagios user :                                      nagios

Preparing Centreon temporary files

/tmp/centreon-setup exists, it will be moved…

install www/install/createTablesCentstorage.sql            OK

Creating Centreon Directory ‘/var/lib/centreon/status’     OK

Creating Centreon Directory ‘/var/lib/centreon/metrics’    OK

Change macros for centstorage binary                       OK

Install CentStorage binary                                 OK

Install library for centstorage                            OK

Change right : /var/run/centreon                           OK

Change macros for centstorage init script                  OK

Do you want me to install CentStorage init script ?

[y/n], default to [n]:

> y

CentStorage init script installed                          OK

Do you want me to install CentStorage run level ?

[y/n], default to [n]:

> y

Adding system startup for /etc/init.d/centstorage …

/etc/rc0.d/K30centstorage -> ../init.d/centstorage

/etc/rc1.d/K30centstorage -> ../init.d/centstorage

/etc/rc6.d/K30centstorage -> ../init.d/centstorage

/etc/rc2.d/S40centstorage -> ../init.d/centstorage

/etc/rc3.d/S40centstorage -> ../init.d/centstorage

/etc/rc4.d/S40centstorage -> ../init.d/centstorage

/etc/rc5.d/S40centstorage -> ../init.d/centstorage

Change macros for logAnalyser                              OK

Install logAnalyser                                        OK

Change macros for nagiosPerfTrace                          OK

Install nagiosPerfTrace                                    OK

Change macros for purgeLogs                                OK

Install purgeLogs                                          OK

Change macros for purgeCentstorage                         OK

Install purgeCentstorage                                   OK

Change macros for centreonPurge.sh                         OK

Install centreonPurge.sh                                   OK

Change macros for centstorage.cron                         OK

Install CentStorage cron                                   OK

Create /etc/centreon/instCentStorage.conf                  OK

CentStorage is installed now.

————————————————————————

Start CentCore Installation

————————————————————————

Where is your CentCore binary directory

default to [/usr/local/centreon/bin]

>[Press Enter]

Path /usr/local/centreon/bin                               OK

/usr/bin/ssh                                               OK

/usr/bin/scp                                               OK

Finding Nagios group :                                     nagios

Finding Nagios user :                                      nagios

Preparing Centreon temporary files

/tmp/centreon-setup exists, it will be moved…

Change CentCore Macro                                      OK

Copy CentCore in binary directory                          OK

Change right : /var/run/centreon                           OK

Change right : /var/lib/centreon                           OK

Replace CentCore init script Macro                         OK

Do you want me to install CentCore init script ?

[y/n], default to [n]:

> y

CentCore init script installed                             OK

Do you want me to install CentCore run level ?

[y/n], default to [n]:

> y

Adding system startup for /etc/init.d/centcore …

/etc/rc0.d/K30centcore -> ../init.d/centcore

/etc/rc1.d/K30centcore -> ../init.d/centcore

/etc/rc6.d/K30centcore -> ../init.d/centcore

/etc/rc2.d/S40centcore -> ../init.d/centcore

/etc/rc3.d/S40centcore -> ../init.d/centcore

/etc/rc4.d/S40centcore -> ../init.d/centcore

/etc/rc5.d/S40centcore -> ../init.d/centcore

Create /etc/centreon/instCentCore.conf                     OK

Please answer some questions regarding the installation of the centreon plugins.

————————————————————————

Start CentPlugins Installation

————————————————————————

Where is your CentPlugins lib directory

default to [/var/lib/centreon/centplugins]

>[Press Enter]

Do you want me to create this directory ? [/var/lib/centreon/centplugins]

[y/n], default to [n]:

> y

Path /var/lib/centreon/centplugins                         OK

Finding Nagios user :                                      nagios

Finding Nagios group :                                     nagios

Preparing Centreon temporary files

/tmp/centreon-setup exists, it will be moved…

Change macros for CentPlugins                              OK

Installing the plugins                                     OK

Change right on centreon.conf                              OK

CentPlugins is installed

————————————————————————

Start CentPlugins Traps Installation

————————————————————————

Where is your SNMP configuration directory

default to [/etc/snmp]

>[Press Enter]

/etc/snmp                                                  OK

Where is your SNMPTT binaries directory

default to [/usr/local/centreon/bin/]

>[Press Enter]

/usr/local/centreon/bin/                                   OK

Finding Nagios group :                                     nagios

Finding Apache user :                                      nagios

Preparing Centreon temporary files

/tmp/centreon-setup exists, it will be moved…

Change macros for CentPluginsTraps                         OK

Installing the plugins Trap binaries                       OK

Backup all your snmp files                                 OK

Change macros for snmptrapd.conf                           OK

Change macros for snmptt.ini                               OK

Install : snmptrapd.conf                                   OK

Install : snmp.conf                                        OK

Install : snmptt.ini                                       OK

Install : snmptt                                           OK

Install : snmpttconvertmib                                 OK

Create /etc/centreon/instCentPlugins.conf                  OK

Reloading Apache configuration on CentOS:

[root@yourmachine ~]service httpd reload

Now the Centreon is installed.

Now go to the URL http://yourserver-ip/centreon

Next step is to start the Web Installation during which it will initialize the database and set the administrator login information.

This URL will redirect you in web setup frontend.