How to install Nagios Plugin on Linux

Login as root

# wget http://nagios-plugins.org/download/nagios-plugins-2.0.2.tar.gz
# tar -zxf nagios-plugins-2.0.2.tar.gz
# cd nagios-plugins-2.0.2
# ./configure
# make
# make install
# useradd nagios
# chown nagios.nagios /usr/local/nagios
# chown -R nagios.nagios /usr/local/nagios/libexec

Install nrpe

# yum install xinetd -y
# yum install openssl-devel
# 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
# ./configure
# make all
# make install-plugin
# make install-daemon
# make install-daemon-config
# make install-xinetd
# 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
# chkconfig xinetd on
# service xinetd restart
# 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

add this into nrpe.cfg
If the server installed with qmail, please change with qmail on below line, if postfix, please change it ( this is for check_mailq command ):

command[check_mailq]=/usr/local/nagios/libexec/check_mailq -w 50 -c 100 -M qmail/postfix/exim
command[check_swap]=/usr/local/nagios/libexec/check_swap -w 70% -c 50%
# Check load average
command[check_load]=/usr/local/nagios/libexec/check_stat -L -w 10,8,5 -c 20,18,15
# Check memory & swap usage
command[check_mem]=/usr/local/nagios/libexec/check_stat -M -w 100,25 -c 100,50
# Check cpu usage
command[check_cpu]=/usr/local/nagios/libexec/check_stat -C -w 99 -c 100 -s 5
# Check open files
command[check_open_file]=/usr/local/nagios/libexec/check_stat -F -w 10000,250000 -c 15000,350000
# Check io disk on device sda1, sda3 and sda4
command[check_io]=/usr/local/nagios/libexec/check_stat -I -w 2000,600 -c 3000,800 -p sda1,sda3,sda4 -s 5
# Check processes
command[check_procs]=/usr/local/nagios/libexec/check_stat -P -w 1000 -c 2000
# Check network usage on eth0
command[check_net]=/usr/local/nagios/libexec/check_stat -N -w 1000000 -c 1500000 -p eth0 -s 5
# Check socket usage
command[check_socket]=/usr/local/nagios/libexec/check_stat -S -w 500 -c 1000
# Check uptime
command[check_uptime]=/usr/local/nagios/libexec/check_stat -U -w 5
# Check CPU context switch
command[check_ctxt]=/usr/local/nagios/libexec/check_stat -X -w 6000 -c 70000 -s 2