CentOS deployment Nagios+apache for server monitoring

1.Nagios Introduction

Nagios is a powerful network monitoring tool, it can effectively monitor the Windows, Linux, UNIX host status and router switch network settings, printer work status, and the status of abnormal services in a timely manner in the form of mail, MSN SMS, such as the first time to notify the administrator. Because it is a follow GPLV2 open-source network monitoring software, with its excellent performance low cost of use, by the vast numbers of users.

2. Installation Prerequisites

2.1 determine if the following components are available:

GCC glibc glibc-common gd gd-devel xinetd openssl-devel

Proc-devel Pcre-devel Perl Libxml2-devel

Install directly from Yum:

Yum install-y gcc glibc glibc-common gd gd-devel xinetd openssl-devel proc-devel pcre-devel perl libxml2-devel

3. Installing Nagios,nagios-plugin

Create Nagios Users

# AddUser Nagios

Installing Nagios

# tar XVF Nagios-cn-3.2.0.tar

# CD nagios-cn-3.2.0

#./configure–prefix=/usr/local/nagios

# make All

# make Install

# Make Install-init

# Make Install-commandmode

# Make Install-config

Installing Nagios-plugin

# tar XVF nagios-plugins-2.0.tar.gz

# CD nagios-plugins-2.0

#./configure–prefix=/usr/local/nagios

# Make && make install

4. Installing Apache

# tar XVF httpd-2.4.9.tar.gz

#cd httpd-2.4.9

#./configure--prefix=/usr/local/apache2

# Make && make install

If installation prompts are missing APR and Apr-util package

#tar XVF apr-1.5.0.tar.gz

#cd apr-1.5.0

#./configure–prefix=/usr/local/apr

#make && make Install

#tar XVF apr-1.5.0.tar.gz

#cd apr-1.5.0

#./configure–prefix=/usr/local/apr-util–with-apr=/usr/local/apr

#make && make Install

Install Apache after installation

#./configure--prefix=/usr/local/apache2–with-apr-util=/usr/local/apr-util

#make && make Install

5. Install PHP

#tar XVF php-5.4.10.tar.gz

#cd php-5.4.10

#./configure--prefix=/usr/local/php--with-apxs2=/usr/local/apache2/bin/apxs

#make && make Install

6. Configure Apahe

Locate the Apache configuration file/usr/local/apache2/conf/httpd.conf

Found it:

User Daemon

Group Daemon

Revision changed to

User Nagios

Group Nagios

And then find

<ifmodule dir_module>

DirectoryIndex index.html

</IfModule>

Revision changed to

<ifmodule dir_module>

DirectoryIndex index.html index.php

AddType application/x-httpd-php. php

</IfModule>

For security reasons, it is generally necessary for Nagios's web monitoring pages to be authorized for access, which requires an additional authentication configuration, i.e. the following information is added at the end of the httpd.conf file:

#setting for Nagios

Scriptalias/nagios/cgi-bin "/usr/local/nagios/sbin"

<directory "/usr/local/nagios/sbin" >

AuthType Basic

Options execcgi

AllowOverride None

Order Allow,deny

Allow from all

AuthName "Nagios Access"

authuserfile/usr/local/nagios/etc/htpasswd

Require Valid-user

</Directory>

Alias/nagios "/usr/local/nagios/share"

<directory "/usr/local/nagios/share" >

AuthType Basic

Options None

AllowOverride None

Order Allow,deny

Allow from all

AuthName "Nagios Access"

authuserfile/usr/local/nagios/etc/htpasswd

Require Valid-user

</Directory>

Create Apache directory validation files

#/usr/local/apache2/bin/htpasswd-c/USR/LOCAL/NAGIOS/ETC/HTPASSWD SSAP

7. Launch Apache and Nagios

Launch Apache

#/usr/local/apache2/bin/apachectl Start

Start Nagios

Service Nagios Start

Nagios Login

Nagios Home

8. Configure Nagios

After the Nagios installation is complete, you need to configure Nagios, which is under the/usr/local/nagios/etc directory.

File name or directory name	Use
Cgi.cfg	Control the configuration file for CGI access
Nagios.cfg	Nagios Master configuration file
Resource.cfg	A variable definition file, also known as a resource file, defines variables in some files so that they can be referenced by other configuration files, such as $user1$
Objects	Objects is a directory with many profile templates in this directory that define the Nagios object
Objects/commands.cfg	Command definition configuration file, where defined commands can be referenced by other configuration files
Objects/contacts.cfg	Define profiles for contacts and contact groups
Objects/localhost.cfg	Define a configuration file that monitors the local host
Objects/printer.cfg	Define a profile template for the monitoring printer, which is not enabled by default
Objects/switch.cfg	Define a profile template for the monitoring router, which is not enabled by default
Objects/templates.cfg	Defines a template configuration file for hosts and services that can be referenced in other configuration files
Objects/timeperiods.cfg	Define the configuration file for the Nagios monitoring time period
Objects/windows.cfg	Monitor a profile template for a Windows host that is not enabled by default

Assuming that we have Nagios installed on a server with IP 192.168.195.136 and need to monitor the 192.168.195.136 server, the following modifications will be made to the configuration file:

Modify Localhost.cfg

Define Host{

Use Linux-server

HOST_NAME Nagios-server

Alias Nagios-server

Address 127.0.0.1

}

Define Hostgroup{

Hostgroup_name linux-servers

Alias Linux Servers

Members Nagios-server

}

Define Service{

Use Local-service

HOST_NAME Nagios-server

Service_description PING

Check_command check_ping!100.0,20%!500.0,60%

}

Define Service{

Use Local-service

HOST_NAME Nagios-server

Service_description Root Partition

Check_command check_local_disk!20%!10%!/

}

Define Service{

Use Local-service

HOST_NAME Nagios-server

Service_description Current Users

Check_command check_local_users!20!50

}

Define Service{

Use Local-service

HOST_NAME Nagios-server

Service_description Total Processes

Check_command check_local_procs!250!400! Rszdt

}

Define Service{

Use Local-service,srv-pnp

HOST_NAME Nagios-server

Service_description Current Load

Check_command check_local_load!5.0,4.0,3.0!10.0,6.0,4.0

}

Define Service{

Use Local-service

HOST_NAME Nagios-server

Service_description Swap Usage

Check_command check_local_swap!20!10

}

Define Service{

Use Local-service

HOST_NAME Nagios-server

Service_description SSH

Check_command Check_ssh

notifications_enabled 0

}

Define Service{

Use Local-service

HOST_NAME Nagios-server

Service_description HTTP

Check_command check_http

notifications_enabled 0

}

New Hosts.cfg

Define Host{

Use Linux-server

HOST_NAME Test-linux

Alias Test-linux

Address 192.168.195.137

}

New Service.cfg

Define Service{

Use Local-service

HOST_NAME Test-linux

Service_description check-host-alive

Check_command check-host-alive

}

Modify Nagios.cfg

Add configuration file Hosts.cfg,service.cfg

Cfg_file=/usr/local/nagios/etc/objects/hosts.cfg

Cfg_file=/usr/local/nagios/etc/objects/service.cfg

Detection of modified configurations

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

Restart the Nagios service after detection is correct

Service Nagios Restart

Nagios Monitoring page

Precautions:

1) If the user name set is not nagiosadmin, there will be a permissions problem, you cannot access the monitoring page, you need to modify the cgi.cfg, after nagiosadmin append the user name set.

Nagios Logon User Rights configuration

2) Nagios garbled problem

The main is that Apache does not open CGI scripts for the sake of access to the main Apache configuration file httpd.conf;

#LoadModule Cgid_module modules/mod_cgid.so;

#LoadModule Actions_module modules/mod_actions.so;

Remove the # 2 lines above and reboot Apache to be OK.

CentOS deployment Nagios+apache for server monitoring