在CentOS5.5上安装Nagios指南

本文档参考了Nagios官方的安装文档。解决了再 CentOS5.5 上安装 Nagios 和 plugin 过程中，编译出错的问题，及安装后无法发现本机localhost状态的问题。

 

Introduction

This guide is intended to provide you with simple instructions on how to install Nagios from source (code) on Fedora and have it monitoring your local machine inside of 20 minutes. No advanced installation options are discussed here - just the basics that will work for 95% of users who want to get started.

These instructions were written based on a standard Fedora Core 6 (CentOS-5.5) Linux distribution.

What You'll End Up With

If you follow these instructions, here's what you'll end up with:

• Nagios and the plugins will be installed underneath /usr/local/nagios
• Nagios will be configured to monitor a few aspects of your local system (CPU load, disk usage, etc.)
• The Nagios web interface will be accessible at

Prerequisites

During portions of the installation you'll need to have root access to your machine.

Make sure you've installed the following packages on your Fedora installation before continuing.

• Apache
• PHP
• GCC compiler
•  development libraries

You can use yum to install these packages by running the following commands (as root):

 

yum install httpd php

 

yum install gcc glibc glibc-common

 

yum install gd gd-devel

 

1) Create Account Information

Become the root user.

 

su -l

 

Create a new nagios user account and give it a password.

 

/usr/sbin/useradd -m nagios

 

passwd nagios

 

Create a new nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user to the group.

 

/usr/sbin/groupadd nagcmd

 

/usr/sbin/usermod -a -G nagcmd nagios

 

/usr/sbin/usermod -a -G nagcmd apache

 

2) Download Nagios and the Plugins

Create a directory for storing the downloads.

 

mkdir ~/downloads

 

cd ~/downloads

 

Download the source code tarballs of both Nagios and the Nagios plugins (visit  for links to the latest versions). These directions were tested with Nagios 3.2.3 and Nagios Plugins 1.4.15.

 

wget

 

wget

 

3) Compile and Install Nagios

Extract the Nagios source code tarball.

 

cd ~/downloads

 

tar xzf nagios-3.2.3.tar.gz

 

cd nagios-3.2.3

 

Run the Nagios configure script, passing the name of the group you created earlier like so:

 

./configure --with-command-group=nagcmd

 

Compile the Nagios source code.

 

make all

 

Install binaries, init script, sample config files and set permissions on the external command directory.

 

make install

 

make install-init

 

make install-config

 

make install-commandmode

 

Don't start Nagios yet - there's still more that needs to be done...

4) Customize Configuration

Sample  have now been installed in the /usr/local/nagios/etc directory. These sample files should work fine for getting started with Nagios. You'll need to make just one change before you proceed...

Edit the /usr/local/nagios/etc/objects/contacts.cfg config file with your favorite editor and change the email address associated with the nagiosadmin contact definition to the address you'd like to use for receiving alerts.

 

vi /usr/local/nagios/etc/objects/contacts.cfg

 

5) Configure the Web Interface

Install the Nagios web config file in the Apache conf.d directory.

 

make install-webconf

 

Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account - you'll need it later.

 

htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

 

Restart Apache to make the new settings take effect.

 

service httpd restart

 

 Note: Consider implementing the ehanced CGI security measures described here to ensure that your web authentication credentials are not compromised.

6) Compile and Install the Nagios Plugins

Extract the Nagios plugins source code tarball.

 

cd ~/downloads

 

tar xzf nagios-plugins-1.4.15.tar.gz

 

 

Compile and install the plugins.

 

./configure --with-nagios-user=nagios --with-nagios-group=nagios

 

make

 

make install

 

Mark:

我在编译plugin的时候，安装上面的步骤做出错，如下：

 

===================================================

/usr/bin/install: invalid group `nagio'

make[2]: *** [install-libexecPROGRAMS] Error 1

make[2]: Leaving directory `/root/nagios-plugins-1.4.15/plugins'

make[1]: *** [install-am] Error 2

make[1]: Leaving directory `/root/nagios-plugins-1.4.15/plugins'

make: *** [install-recursive] Error 1

 

在忽略这些报错后，执行后续的操作能够启动Nagios，但是无法检测到本机即localhost的状态。

========================================================

 

所以，我查找了google， 发现需要再配置一下 plugin，请进行如下的操作

# cd nagios-plugins-1.4.15

./configure --with-command-group=nagcmd

Make all

Make install

这样，在编译、安装的过程中没有任何的报错。

而且，再执行完下面的操作后，能够顺利的发现本机localhost的状态。

 

 

7) Start Nagios

Add Nagios to the list of system services and have it automatically start when the system boots.

 

chkconfig --add nagios

 

chkconfig nagios on

 

Verify the sample Nagios configuration files.

 

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

 

If there are no errors, start Nagios.

 

service nagios start

 

8) Modify SELinux Settings

Fedora ships with SELinux (Security Enhanced Linux) installed and in Enforcing mode by default. This can result in "Internal Server Error" messages when you attempt to access the Nagios CGIs.

See if SELinux is in Enforcing mode.

 

getenforce

 

Put SELinux into Permissive mode.

 

setenforce 0

 

To make this change permanent, you'll have to modify the settings in /etc/selinux/config and reboot.

Instead of disabling SELinux or setting it to permissive mode, you can use the following command to run the CGIs under SELinux enforcing/targeted mode:

 

chcon -R -t httpd_sys_content_t /usr/local/nagios/sbin/

 

chcon -R -t httpd_sys_content_t /usr/local/nagios/share/

 

For information on running the Nagios CGIs under Enforcing mode with a targeted policy, visit the  or .

9) Login to the Web Interface

You should now be able to access the Nagios web interface at the URL below. You'll be prompted for the username (nagiosadmin) and password you specified earlier.

 

 

Click on the "Service Detail" navbar link to see details of what's being monitored on your local machine. It will take a few minutes for Nagios to check all the services associated with your machine, as the checks are spread out over time.

10) Other Modifications

Make sure your machine's firewall rules are configured to allow access to the web server if you want to access the Nagios interface remotely.

Configuring email notifications is out of the scope of this documentation. While Nagios is currently configured to send you email notifications, your system may not yet have a mail program properly installed or configured. Refer to your system documentation, search the web, or look to the  or  for specific instructions on configuring your system to send email messages to external addresses. More information on notifications can be found .

11) You're Done

Congratulations! You sucessfully installed Nagios. Your journey into monitoring is just beginning. You'll no doubt want to monitor more than just your local machine, so check out the following docs...