Install Nagios Plugin on Linux Server

This tutorial for CentOS 7.x

1. Download and Install nagios Plugin on Customer Server

# wget http://nagios-plugins.org/download/nagios-plugins-2.2.1.tar.gz
# tar -zxf nagios-plugins-2.2.1.tar.gz
# cd nagios-plugins-2.2.1
# yum install gcc -y
# ./configure
# make
# make install

2. Download and Install Sysstat Plugin on Customer Server

# yum install perl-devel perl-Time-HiRes -y
# cd /usr/local/nagios/libexec/
# wget http://nitrogen.hostcentral.net/check_stat
# chmod 755 check_stat
# wget http://search.cpan.org/CPAN/authors/id/B/BL/BLOONIX/Sys-Statistics-Linux-0.66.tar.gz
# tar xvfz Sys-Statistics-Linux-0.66.tar.gz
# cd Sys-Statistics-Linux-0.66/
# perl Makefile.PL
# make
# make install

3. Add Nagios user on Customer Server

# useradd nagios
# chown nagios.nagios /usr/local/nagios
# chown -R nagios.nagios /usr/local/nagios/libexec

4. Download and Install NRPE plugin on Customer Server

# yum install xinetd -y
# cd /usr/local/src
# wget http://jaist.dl.sourceforge.net/project/nagios/nrpe-2.x/nrpe-2.12/nrpe-2.12.tar.gz
# tar -xzf nrpe-2.12.tar.gz
# cd nrpe-2.12
# yum install openssl-devel -y
# ./configure
# make all
# make install-plugin
# make install-daemon
# make install-daemon-config
# make install-xinetd

5. Edit NRPE conf to allow Nagios Server checked the server

# sed -i 's/127.0.0.1/103.26.40.132/g' /etc/xinetd.d/nrpe
# echo "nrpe 5666/tcp # Nagios Plugin NRPE" >> /etc/services
# sed -i 's/allowed_hosts=127.0.0.1/allowed_hosts=127.0.0.1 103.26.40.132/g' /usr/local/nagios/etc/nrpe.cfg

6. Restart Xinetd service Customer Server

# chkconfig xinetd on
# service xinetd restart

7. Edit NRPE conf to put Nagios Parameters

# vi /usr/local/nagios/etc/nrpe.cfg
command[check_swap]=/usr/local/nagios/libexec/check_swap -w 70% -c 50%
command[check_disk]=/usr/local/nagios/libexec/check_disk -w 10% -c 5% -x /backup -x /var/named/chroot/usr/lib/bind -x /var/named/chroot/etc/named -x /var/named/chroot/var/named -x /var/named/chroot/etc/named.rfc1912.zones -x /var/named/chroot/etc/rndc.key -x /var/named/chroot/usr/lib64/bind -x /var/named/chroot/etc/named.iscdlv.key -x /var/named/chroot/etc/named.root.key
command[check_eth]=/usr/local/nagios/libexec/check_eth -i venet0 -w 1024K Bps -c 2048K Bps
command[check_connections]=/usr/local/nagios/libexec/check_connections -s established '( sport = :443 )' -w 800 -c 1000
command[check_postfix_queue]=/usr/local/nagios/libexec/check_postfix_queue -w 20 -c 40
command[check_mem]=/usr/local/nagios/libexec/check_stat -M -w 100,25 -c 100,50
command[check_cpu]=/usr/local/nagios/libexec/check_stat -C -w 99 -c 100 -s 5
command[check_open_file]=/usr/local/nagios/libexec/check_stat -F -w 10000,250000 -c 15000,350000
command[check_io]=/usr/local/nagios/libexec/check_stat -I -w 2000,600 -c 3000,800 -p sda1,sda3,sda4 -s 5
command[check_procs]=/usr/local/nagios/libexec/check_stat -P -w 1000 -c 2000
command[check_net]=/usr/local/nagios/libexec/check_stat -N -w 1000000 -c 1500000 -p eth0 -s 5
command[check_socket]=/usr/local/nagios/libexec/check_stat -S -w 500 -c 1000
command[check_uptime]=/usr/local/nagios/libexec/check_stat -U -w 5
command[check_ctxt]=/usr/local/nagios/libexec/check_stat -X -w 6000 -c 70000 -s 2
command[check_mailq]=sudo /usr/local/nagios/libexec/check_mailq -w 50 -c 80 -M postfix

8. If needed, open port 5666 on Firewall
Centos 7 :

# firewall-cmd --permanent --zone=public --add-port=5666/tcp && firewall-cmd --reload

Centos 6 :

# iptables -A INPUT -p tcp --dport 5666 -s 103.26.40.132 -j ACCEPT

Ubuntu/Debian :

# iptables -A INPUT -p tcp --dport 5666 -s 103.26.40.132 -j ACCEPT