1. NAGIOS MEMBER WITH NRPE
How To Monitor Remote Linux Host using Nagios 3.0
Download Nagios Plugins and NRPE Add-on
1. Create nagios account
2. Install Nagios Plugins
3. Install NRPE
4. Setup NRPE to run as daemon
5. Modify the /usr/local/nagios/etc/nrpe.cfg
steps to install Nagios Plugins and NRPE on the remote host
Download following files from Nagios.org and move to /home/downloads:
• nagios-plugins-1.4.11.tar.gz
• nrpe-2.12.tar.gz
Create nagios account
[remotehost]# useradd nagios
[remotehost]# passwd nagios
3. Install nagios-plugin
[remotehost]# cd /home/downloads
[remotehost]# tar xvfz nagios-plugins-1.4.11.tar.gz
[remotehost]# cd nagios-plugins-1.4.11
[remotehost]# export LDFLAGS=-ldl
[remotehost]# ./configure --with-nagios-user=nagios --with-nagios-group=nagios
--enable-redhat-pthread-workaround
[remotehost]# make
[remotehost]# make install
[remotehost]# chown nagios.nagios /usr/local/nagios
[remotehost]# chown -R nagios.nagios /usr/local/nagios/libexec/
4. Install NRPE
[remotehost]# cd /home/downloads
[remotehost]# tar xvfz nrpe-2.12.tar.gz
[remotehost]# cd nrpe-2.12
[remotehost]# ./configure
[remotehost]# make all
[remotehost]# make install-plugin
[remotehost]# make install-daemon
[remotehost]# make install-daemon-config
[remotehost]# make install-xinetd

2. [remotehost]#vim /etc/xinetd.d/nrpe
only_from = 127.0.0.1 192.168.1.2
Modify the /etc/services and add the following at the end of the file.
[remotehost]#vim /etc/services
nrpe 5666/tcp # NRPE
[remotehost]#service xinetd restart
[remotehost]# netstat -at | grep nrpe
tcp 0 0 *:nrpe *:* LISTEN
[remotehost]# /usr/local/nagios/libexec/check_nrpe -H localhost
NRPE v2.12
command[check_disk]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
[remotehost]#/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
DISK CRITICAL - free space: / 6420 MB (10% inode=98%);|
/=55032MB;51792;58266;0;64741
Configuration steps on the Nagios monitoring server to monitor
NAGIOS SERVER
1. Download NRPE Add-on
Download nrpe-2.12.tar.gz from Nagios.org and move to /home/downloads:
2. Install check_nrpe on the nagios monitoring server
[nagios-server]# tar xvfz nrpe-2.12.tar.gz
[nagios-server]# cd nrpe-2.1.2
[nagios-server]# ./configure
[nagios-server]# make all
[nagios-server]# make install-plugin
./configure will give a configuration summary as shown below:
*** Configuration summary for nrpe 2.12 05-31-2008 ***:
General Options:
————————-
NRPE port: 5666
NRPE user: nagios
NRPE group: nagios
Nagios user: nagios
Nagios group: nagios

3. [nagios-server]# rpm -ivh openssl-devel-0.9.7a-43.16.i386.rpm krb5-devel-1.3.4-
47.i386.rpm zlib-devel-1.2.1.2-1.2.i386.rpm e2fsprogs-devel-1.35-12.5.
el4.i386.rpm
warning: openssl-devel-0.9.7a-43.16.i386.rpm: V3 DSA signature: NOKEY, key ID
db42a60e
Preparing… ########################################### [100%]
1:e2fsprogs-devel ########################################### [ 25%]
2:krb5-devel ########################################### [ 50%]
3:zlib-devel ########################################### [ 75%]
4:openssl-devel ########################################### [100%]
[nagios-server]#/usr/local/nagios/libexec/check_nrpe -H 192.168.0.8
NRPE v2.12
NOTE:- 192.168.0.8 is client IP
[nagios-server]#vim /usr/local/nagios/etc/objects/remotehost.cfg
define host{
use linux-server
host_name remotehost
alias Remote Host
address 192.168.1.3
contact_groups admins
}
define service{
use generic-service
service_description Root Partition
contact_groups admins
check_command check_nrpe!check_disk
}
[nagios-server]#vim /usr/local/nagios/etc/nagios.cfg
cfg_file=/usr/local/nagios/etc/objects/remotehost.cfg {add This line}
[nagios-server]# service nagios reload
NOTE
ERROR:-
checking for SSL headers... configure: error: Cannot find ssl headers
Then install this packages
yum install openssl-devel

4. HELP
[remotehost]# make all
cd ./src/; make ; cd ..
make[1]: Entering directory `/usr/local/nrpe-2.13/src'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/usr/local/nrpe-2.13/src'
*** Compile finished ***
If the NRPE daemon and client compiled without any errors, you
can continue with the installation or upgrade process.
Read the PDF documentation (NRPE.pdf) for information on the next
steps you should take to complete the installation or upgrade.
[remotehost]# make install-plugin
cd ./src/ && make install-plugin
make[1]: Entering directory `/usr/local/nrpe-2.13/src'
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/libexec
/usr/bin/install -c -m 775 -o nagios -g nagios check_nrpe /usr/local/nagios/libexec
make[1]: Leaving directory `/usr/local/nrpe-2.13/src'
[remotehost]# cd ./src/ && make install-plugin
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/libexec
/usr/bin/install -c -m 775 -o nagios -g nagios check_nrpe /usr/local/nagios/libexec

5. [remotehost]#make install-plugin
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/libexec
/usr/bin/install -c -m 775 -o nagios -g nagios check_nrpe /usr/local/nagios/libexec
[remotehost]#/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/libexec
[remotehost]#[remotehost]#/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/libexec
Command not found. Failed to search for file: Invalid search term
[remotehost]#/usr/bin/install -c -m 775 -o nagios -g nagios check_nrpe /usr/local/nagios/libexec
[remotehost]#make install-daemon
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/bin
/usr/bin/install -c -m 775 -o nagios -g nagios nrpe /usr/local/nagios/bin
[remotehost]#/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/bin
[remotehost]#/usr/bin/install -c -m 775 -o nagios -g nagios nrpe /usr/local/nagios/bin
[remotehost]#make install-daemon-config
make: *** No rule to make target `install-daemon-config'. Stop.
[remotehost]#cd ..
[remotehost]# make install-daemon-config
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/etc
/usr/bin/install -c -m 644 -o nagios -g nagios sample-config/nrpe.cfg /usr/local/nagios/etc
[remotehost]# /usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/etc
[remotehost]# /usr/bin/install -c -m 644 -o nagios -g nagios sample-config/nrpe.cfg /usr/local/nagios/etc
[remotehost]# make install-xinetd
/usr/bin/install -c -m 644 sample-config/nrpe.xinetd /etc/xinetd.d/nrpe
[remotehost]# /usr/bin/install -c -m 644 sample-config/nrpe.xinetd /etc/xinetd.d/nrpe
[remotehost]# vim /etc/xinetd.d/nrpe

6. [remotehost]# vim /etc/services
[remotehost]# service xinetd restart
Stopping xinetd: [ OK ]
Starting xinetd: [ OK ]
[remotehost]# netstat -at | grep nrpe
tcp 0 0 *:nrpe *:* LISTEN
[remotehost]# /usr/local/nagios/libexec/check_nrpe -H localhost
NRPE v2.13
[remotehost]# vim /usr/local/nagios/etc/nrpe.cfg
[remotehost]# /usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
DISK CRITICAL - /dev/hda1 is not accessible: No such file or directory
[remotehost]# fdisk -l
Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000c1873
Device Boot Start End Blocks Id System
/dev/sda1 * 1 128 1024000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 128 4590 35840000 83 Linux

7. /dev/sda3 4590 4851 2097152 82 Linux swap / Solaris
/dev/sda4 4851 30402 205236224 5 Extended
/dev/sda5 4851 30402 205235200 83 Linux
[remotehost]# /usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda1
DISK OK - free space: /boot 880 MB (94% inode=99%);| /boot=53MB;787;885;0;984
[remotehost]# /usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda2
DISK OK - free space: / 13405 MB (40% inode=85%);| /=19295MB;27560;31005;0;34450
[remotehost]# /usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20
OK - load average: 0.01, 0.10, 0.10|load1=0.010;15.000;30.000;0; load5=0.100;10.000;25.000;0;
load15=0.100;5.000;20.000;0;
[remotehost]# /usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
DISK CRITICAL - /dev/hda1 is not accessible: No such file or directory
[remotehost]# /usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda1
DISK OK - free space: /boot 880 MB (94% inode=99%);| /boot=53MB;787;885;0;984
PAWAN KUMAR
SAIGUN TECHNOLOGIES PVT LTD