Installing Nagios 4.0.2 On CentOS 6.5 (Including NRPE installation)

Installing Nagios 4.0.2 On CentOS 6.5 x86_64

Introduction

Nagios is a monitoring tool under GPL licence. This tool lets you  monitor servers, network hardware (switches, routers, ...) and  applications. A lot of plugins are available and its big community makes  Nagios the biggest open source monitoring tool. This tutorial shows how  to install Nagios 4.0.2 on CentOS 6.5.

Note: you should config postfix mail running correctly first.

please setup NTP for time synchronization

Prerequisites

Make sure you've set the hostname correctly, otherwise to modify /etc/sysconfig/network file.

After installing your CentOS server, you have to disable selinux & install some packages to make nagios work.

To disable selinux, open the file: /etc/selinux/config

# vi /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=permissive // change this value to disabled
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted 

Now, download all packages you need:

# yum -y install gd gd-devel httpd php gcc glibc glibc-common make net-snmp net-snmp-devel net-snmp-utils openssl-devel mysql-devel (使用check_mysql所需) openssh-clients (使用check_by_ssh所需)

[root@tecmint]# groupadd nagios

useradd -s /bin/false -g nagios nagios

Next, add apache user to the nagios group.
[root@tecmint]# usermod -G nagios apache

Nagios Installation

Create a directory:

# mkdir /root/nagios

Navigate to this directory:

# cd /root/nagios

Download nagios-core & plugin:

# wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-4.0.2.tar.gz.
# wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.5.tar.gz

Untar nagios core:

# tar xvzf nagios-4.0.2.tar.gz

Go to the nagios dir:

# cd nagios

Configure before make:

# ./configure --with-command-group=nagios --enable-nanosleep --enable-event-broker

Make all necessary files for Nagios:

# make all

Installation:

# make install

# make install-init

# make install-commandmode

# make install-config

Open the “contacts.cfg” file with your choice of editor and set the  email address  associated with the nagiosadmin contact definition to receiving email alerts.
# vi /usr/local/nagios/etc/objects/contacts.cfg

# make install-webconf

Create a password to log into the web interface:

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

chown nagios.nagios /usr/local/nagios/etc/htpasswd.users

Note: more users can be added with htpasswd /usr/local/nagios/etc/htpasswd.users username, this username should be matched with contacts in the contacts.cfg

Now, you have to install the plugins:

# cd ..
# tar xvzf nagios-plugins-1.5.tar.gz
# cd nagios-plugins-1.5
# ./configure --with-nagios-user=nagios --with-nagios-group=nagios

# make
# make install

Verify Nagios Configuration Files

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

Start the service and start it on boot:

# chkconfig --add nagios

# chkconfig --level 35 nagios on

# chkconfig --level 35 httpd on

vi /etc/hosts to add ip_address and hostname

vi /etc/httpd/conf/httpd.conf to modify "ServerName"

touch /var/www/html/index.html to avoid get localhost HTTP error “Nagios HTTP WARNING: HTTP/1.1 403 Forbidden”

# service nagios start

# service httpd start

Now, connect to your nagios system:

http://Your-Nagios-IP/nagios and enter login : nagiosadmin & password you have chosen above.

And after the installation ?

After  the installation you have to configure all your host & services in  nagios configuration files.This step is performed in command line and is  complicated, so I recommand to install tool like Centreon, that is a  beautiful front-end to add you host & services.

Install NRPE:

On Remote Linux Host:
1. yum -y install gcc glibc glibc-common gd gd-devel make net-snmp net-snmp-devel net-snmp-utils openssl-devel mysql-devel (使用check_mysql所需)

2. groupadd nagios

useradd -s /bin/false -g nagios nagios

3. mkdir /root/nagios

cd /root/nagios

wget https://www.nagios-plugins.org/download/nagios-plugins-1.5.tar.gz

tar xvf nagios-plugins-1.5.tar.gz

4. cd nagios-plugins-1.5

./configure

make; make install

chown nagios.nagios /usr/local/nagios

chown -R nagios.nagios /usr/local/nagios

5. cd /root/nagios

wget http://garr.dl.sourceforge.net/project/nagios/nrpe-2.x/nrpe-2.15/nrpe-2.15.tar.gz

 tar xzf nrpe-2.15.tar.gz

6. cd nrpe-2.15

./configure

make all

make install-plugin

make install-daemon

make install-daemon-config

7. vi /usr/local/nagios/etc/nrpe.cfg add monitoring server ip to "allowed_hosts=127.0.0.1,monitoring_ip_address" line

所有需要检测本地资源的命令都写在此文件中 -- nrpe.cfg

8. cp /root/nagios/nrpe-2.15/init-script /etc/init.d/nrpe

chmod 755 /etc/init.d/nrpe

chkconfig --add nrpe

service nrpe start

9. check nrpe version: /usr/local/nagios/libexec/check_nrpe -H 127.0.0.1

10. configure firewall rules

iptables -A INPUT -p tcp -m tcp --dport 5666 -j ACCEPT

service iptables save

On Monitoring Host:
1. cd /root/nagios

wget http://garr.dl.sourceforge.net/project/nagios/nrpe-2.x/nrpe-2.15/nrpe-2.15.tar.gz

 tar xzf nrpe-2.15.tar.gz

2. cd nrpe-2.15

./configure

make all

make install-plugin

3. check remote host nrpe version:

/usr/local/nagios/libexec/check_nrpe -H remote_ip_address

4. create check_nrpe command:
vi /usr/local/nagios/etc/objects/commands.cfg
define command{
   command_name    check_nrpe
   command_line    $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
   }

5. cd /usr/local/nagios/etc/objects/

touch hosts.cfg services.cfg

chown nagios.nagios hosts.cfg services.cfg

chmod 664 hosts.cfg services.cfg

6. vi /usr/local/nagios/etc/nagios.cfg
add

"cfg_file=/usr/local/nagios/etc/objects/hosts.cfg'

"cfg_file=/usr/local/nagios/etc/objects/services.cfg'

7. service nagios restart

For Windows client using NSClient++ x64

1. install NSCP-0.4.1.102-x64.msi on Windows Server 2012

2. on nagios monitoring server

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

根据需要修改windows主机的名称及IP address

3. vi /usr/local/nagios/etc/nagios.cfg

cfg_file=/usr/local/nagios/etc/objects/windows.cfg

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

service nagios restart

Nagstamon桌面报警器

1. 从 http://nagstamon.ifw-dresden.de/  下载最新的版本，我这里下载的是windows版--Nagstamon_0.9.11_setup.exe

2. 安装完后配置下

3. 显示效果