Nagios

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Introduction

Nagios is a host and service monitor designed to inform you of network problems before your clients, end-users or managers do. Read more...

This contrib installs Nagios Version 2.9 and was tested on SME Releases 7.1.2, 7.1.3 and 7.2. It provides all packgages needed to setup a SME Server as a central Nagios monitoring server and all packages needed to monitor SME Servers via the NRPE (Nagios Remote Plugin Executer).

Statusmap screenshot of a sample Nagios configuration

The base packages and all dependencies are installed via yum from the Centos and DAG repostitories. Additionally the following packages are included in this contrib:

Package	Purpose
smeserver-nagios RPM	integrates Nagios service into the SME Server
smeserver-nagios-nrpe RPM	integrates NRPE service into the SME Server
smeserver-nagios-nsca RPM	integrates NSCA service into the SME Server (needed in a Distributed Installation)
smeserver-nagios-backup RPM	Nagios backup integration. Includes Nagios configuration and status data into the SME standard backup
perl-Nagios-Plugin RPM	a family of perl modules to streamline writing Nagios plugins
nagios-plugins-temptrax RPM	Plugins for the Sensatronics Ethernet Temperature Devices E4/E16/F
smeserver-nagios-plugins-mysql RPM	Plugin that checks the mysqld service on a smeserver
nagios-of-plugins RPM	Additional plugins written by Gavin Carr of Open Fusion
nagios-plugins-generic RPM	A generic plugin. Read more...
Mail-SendEasy-CLI RPM perl-Mail-SendEasy RPM	Provide /usr/bin/mailsend, a more powerful replacement for the /bin/mail command. Run mailsend --help for help.
smeserver-ajaxterm RPM	Web-based terminal. Linked into the Nagios Home menu. See Ajaxterm
nagios-nuvola-1.0.3.tar.gz	Nuvola GUI theme
nagios-icons-nx.tgz	additional useful icons, inlucding the SME logo

Download

smeserver-nagios-complete-1.0.0.tgz

Installation

Download and unpack the tarball on your central Nagios server and on all other SME Servers you want to monitor:
tar xzf smeserver-nagios-complete-1.0.0.tgz
cd smeserver-nagios-complete-1.0.0
Edit install.sh and set the variable NAGIOS_CENTRAL_SERVER to the IP address of your central Nagios server. Use the local IP if you check the servers over the local network or over a VPN, otherwise use the WAN IP.

Central Nagios server installation

cd smeserver-nagios-complete-1.0.0
./install.sh central
Test the installation by pointing your browser to https://nagios_central_server_ip/nagios/
Basic login in as admin.

NRPE installation on the servers to monitor

cd smeserver-nagios-complete-1.0.0
./install.sh nrpe
If the server is behind a firewall, you must forward port 5666/tcp to the server.
Test the installation by running this command on the central Nagios server:
/usr/lib/nagios/plugins/check_nrpe -H IPADDRESS
Expected result: NRPE v2.5.1

Configuration

It is strongly recommended to read the Nagios and NRPE documentation to understand the principles of operation before you start to configure Nagios.

Hints

• place all your configuration files in /etc/nagios/, the Logfile /var/log/nagios/nagios.log, the Log-Archives in /var/log/nagios/archives/ and the status file in /var/log/nagios/status.dat. These are the default settings. Leave them unchanged. The smeserver-nagios-backup RPM requires these settings to work properly.
• Set the following in /etc/nagios/cgi.cfg to grant full accces to the user admin:
  

use_authentication=1
authorized_for_system_information=admin
authorized_for_system_commands=admin
authorized_for_configuration_information=admin
authorized_for_all_hosts=admin
authorized_for_all_host_commands=admin
authorized_for_all_services=admin
authorized_for_all_service_commands=admin


• On the NRPE Server you find a /etc/nagios/nrpe.cfg with many predefined commands. Modify them to fit your needs.
• It is a good idea to make your Nagios server as independent as possible from the infrastructure it monitors. That means use a dedicated hardware, network, firewall and internet connection if possible. Consider to setup a second Nagios somewhere inside your network, which monitors your central Nagios server.

Additional information

• The install.sh script installs all available packages, including a few which are not necessarily needed for running Nagios, e.g. smeserver-ajaxterm. Feel free to comment out those package names in install.sh you do not want to have installed.
• If you plan a distributed Nagios setup, you need the NSCA packages. Remove the comments of the NSCA package names in install.sh to get them installed. The NSCA setup is not used (and will not be used) by the author and therefore untested. They may not work as expected.

References

perl-Nagios-Plugin: http://members.financial.com/~cmr/rpmforge/perl-Nagios-Plugin/
nagios-of-plugins: http://www.nagiosexchange.org/Plugin_Packages.52.0.html?&tx_netnagext_pi1%5Bp_view%5D=323
Nuvola theme: http://www.nagiosexchange.org/Image_Packs.75.0.html?&tx_netnagext_pi1%5Bp_view%5D=252&tx_netnagext_pi1%5Bpage%5D=10%3A10
Temptrax Plugin: http://www.nagiosexchange.org/Environmental.60.0.html?&tx_netnagext_pi1%5Bp_view%5D=246&tx_netnagext_pi1%5Bpage%5D=20%3A10
Nagios books: "Nagios : system and network monitoring / Wolfgang Barth / ISBN 1-59327-070-4", "Building a Monitoring Infrastructure with Nagios / David Josephsen / ISBN 0-13-223693-1"

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