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swift 08/07/07 18:04:59 |
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Added: nagios-guide.xml |
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Log: |
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Starting of nagios guide draft |
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Revision Changes Path |
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1.1 xml/htdocs/doc/en/nagios-guide.xml |
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file : http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/doc/en/nagios-guide.xml?rev=1.1&view=markup |
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plain: http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/doc/en/nagios-guide.xml?rev=1.1&content-type=text/plain |
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Index: nagios-guide.xml |
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=================================================================== |
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<?xml version="1.0" encoding="UTF-8"?> |
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<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/nagios-guide.xml,v 1.1 2008/07/07 18:04:59 swift Exp $ --> |
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<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> |
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|
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<guide disclaimer="draft"> |
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<title>Gentoo System Monitoring with Nagios</title> |
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|
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<author title="Author"> |
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<mail link="swift@g.o">Sven Vermeulen</mail> |
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</author> |
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|
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<abstract> |
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For system and network monitoring, the Nagios tool is a popular choice amongst |
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various free software users. This guide helps you discover Nagios and how you |
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can integrate it with your existing Gentoo infrastructure. |
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</abstract> |
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|
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<license/> |
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|
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<version>0.1</version> |
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<date>2008-07-06</date> |
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|
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<chapter> |
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<title>Introduction</title> |
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<section> |
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<title>System Monitoring</title> |
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<body> |
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|
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<p> |
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Single system users usually don't need a tool to help them identify the state of |
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their system. However, when you have a couple of systems to administer, you will |
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require an overview of your systems' health: do the partitions still have |
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sufficient free space, is your CPU not overloaded, how many people are logged |
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on, are your systems up to date with the latest security fixes, etc. |
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</p> |
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|
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<p> |
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System monitoring tools, such as the Nagios software we discuss here, offer an |
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easy way of dealing with the majority of metrics you want to know about your |
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system. In larger environments, often called "enterprise |
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environments", the tools aggregate the metrics of the various systems onto |
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a single location, allowing for centralized monitoring management. |
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</p> |
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|
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</body> |
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</section> |
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<section> |
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<title>About Nagios</title> |
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<body> |
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|
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<p> |
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The <uri link="http://www.nagios.org">Nagios</uri> software is a popular |
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software tool for host, service and network monitoring for Unix (although it can |
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also capture metrics from the Microsoft Windows operating system family). It |
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supports: |
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</p> |
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|
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<ul> |
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<li> |
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obtaining metrics for local system resources, such as diskspace, CPU usage, |
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memory consumption, ... |
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</li> |
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<li> |
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discovering service availability (such as SSH, SMTP and other protocols), |
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</li> |
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<li> |
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assuming network outages (when a group of systems that are known to be |
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available on a network are all unreachable), |
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</li> |
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</ul> |
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|
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<p> |
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and more. |
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</p> |
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|
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<p> |
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Basically, the Nagios software consists of a core tool (which manages the |
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metrics), a web server module (which manages displaying the metrics) and a set |
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of plugins (which obtain and send the metrics to the core tool). |
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</p> |
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|
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</body> |
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</section> |
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<section> |
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<title>About this Document</title> |
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<body> |
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|
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<p> |
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The primary purpose of this document is to introduce you, Gentoo users, to the |
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Nagios software and how you can integrate it within your Gentoo environment. The |
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guide is not meant to describe Nagios in great detail - I leave this up to the |
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documentation editors of Nagios itself. |
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</p> |
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|
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</body> |
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</section> |
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</chapter> |
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<chapter> |
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<title>Setting Up Nagios</title> |
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<section> |
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<title>Installing Nagios</title> |
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<body> |
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|
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<p> |
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Before you start installing Nagios, draw out and decide which system will become |
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your master Nagios system (i.e. where the Nagios software is fully installed |
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upon and where all metrics are stored) and what kind of metrics you want to |
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obtain. You will not install Nagios on every system you want to monitor, but |
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rather install Nagios on the master system and the TODO on the systems you want |
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to receive metrics from. |
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</p> |
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|
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<p> |
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Install the Nagios software on your central server: |
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</p> |
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|
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<warn> |
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Nagios 3 is currently still ~arch masked, so you first need to unmask it. |
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</warn> |
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|
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<pre caption="Installing Nagios"> |
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# <i>emerge nagios</i> |
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</pre> |
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|
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<p> |
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Follow the instructions the ebuild displays at the end of the installation (i.e. |
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adding <c>nagios</c> to your active runlevel, configuring web server read access |
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and more). |
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</p> |
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|
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<p> |
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Really. Read it. |
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</p> |
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|
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<!-- TODO directory structure: plugins and so forth --> |
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|
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</body> |
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</section> |
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<section> |
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<title>Restricting Access to the Nagios Web Interface</title> |
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<body> |
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|
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<p> |
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The Nagios web interface allows for executing commands on the various systems |
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monitored by the Nagios plugins. For this purpose (and also because the metrics |
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can have sensitive information) it is best to restrict access to the interface. |
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</p> |
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|
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<p> |
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For this purpose, we introduce two access restrictions: one on IP level (from |
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what systems can a user connect to the interface) and a basic authentication one |
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(using the username / password scheme). |
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</p> |
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|
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<p> |
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First, edit <path>/etc/apache2/modules/99_nagios3.conf</path> and edit the |
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<c>allow from</c> definitions: |
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</p> |
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|
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<pre caption="Allow from definitions"> |
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<comment>(Example allowing access from the local host and the local network)</comment> |
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Order allow,deny |
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Allow from 127.0.0.1 192.168.1.1/24 |
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</pre> |
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|
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<p> |
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Next, create an Apache authorization table where you define the users who have |
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access to the interface as well as their authorizations. The authentication |
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definition file is called <path>.htaccess</path> and contains where the |
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authentication information itself is stored. |
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</p> |
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|
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<pre caption="Example .htaccess file"> |
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AuthName "Nagios Access" |
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AuthType Basic |
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AuthUserFile /etc/nagios/auth.users |
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Require valid-user |
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</pre> |
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|
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<p> |
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Place this file inside the <path>/usr/share/nagios/htdocs</path> and |
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<path>/usr/lib/nagios/cgi-bin</path> directories. |
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</p> |
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|
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<p> |
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Create the <path>/etc/nagios/auth.users</path> file with the necessary user |
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credentials. By default, the Gentoo nagios ebuild defines a single user called |
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<c>nagiosadmin</c>. Let's create that user first: |
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</p> |
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|
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<pre caption="Creating the nagiosadmin user"> |
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# <i>htpasswd2 -c /etc/nagios/auth.users nagiosadmin</i> |
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</pre> |
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|
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</body> |
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</section> |
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<section> |
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<title>Accessing Nagios</title> |
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<body> |
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|
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<p> |
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Once Nagios and its dependencies are installed, fire up Apache and Nagios: |
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</p> |
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<pre caption="Starting the services"> |
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# <i>/etc/init.d/nagios start</i> |
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# <i>/etc/init.d/apache2 start</i> |
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</pre> |
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|
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<p> |
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Next, fire up your browser and connect to <uri |
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link="http://localhost/nagios">http://localhost/nagios</uri>. Log on as the |
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<c>nagiosadmin</c> user and navigate to the <e>Host Detail</e> page. You should |
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be able to see the monitoring states for the local system. |
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</p> |
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|
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</body> |
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</section> |
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<section> |
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<title>Installing Client Daemons</title> |
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<body> |
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|
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<p> |
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TODO Inform what to install on systems that will not run the nagios interface, |
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both for active (performs checks and communicates with the main nagios system) |
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and passive (polled by main nagios system through check_ssh). |
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</p> |
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|
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</body> |
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</section> |
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</chapter> |
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<chapter> |
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<title>Adding Gentoo Support</title> |
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<section> |
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<title>System Security Checks</title> |
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<body> |
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|
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<p> |
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TODO integrate glsa-check plugin, cf. wschlich stuff? |
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</p> |
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</body> |
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</section> |
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</chapter> |
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<chapter> |
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<title>More Resources</title> |
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<section> |
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<title>Nagios Resources</title> |
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<body> |
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|
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<p> |
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TODO check plugins (nagiosexchange.org) |
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</p> |
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<p> |
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TODO additional nagios packages |
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</p> |
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|
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</body> |
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</section> |
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</chapter> |
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<!-- TODO additional chapter "Extending the Nagios Installation", |
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dixit dertobi123 |
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--> |
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</guide> |
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-- |
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