How to install Nagios client (NRPE)

You need to do installation and basic client configuration on remote server to monitor your host and services with Nagios Core.

Step 1: First of all you need to install all required packages.

# yum install gcc glibc glibc-common gd gd-devel make net-snmp openssl-devel vim wget xinetd

Step 2: Create user using below command.

# useradd -s /usr/sbin/nologin nagios

Step 3: Download required packages from web using wget command.

# wget https://github.com/NagiosEnterprises/nrpe/releases/download/nrpe-3.2.1/nrpe-3.2.1.tar.gz
# wget https://www.nagios-plugins.org/download/nagios-plugins-2.1.2.tar.gz

Step 4: Now extract downloaded files to compile.

# tar xzf nagios-plugins-2.1.2.tar.gz
# cd nagios-plugins-2.1.2
# ./configure
# make
# make install

** Now extract nrpe file as well **
# tar xzf nrpe-3.2.1.tar.gz
# cd nrpe-3.2.1
# ./configure
# make all
# make install-plugin;
# make install-daemon;
# make install-daemon-config;
# make install-xinetd

Step 5: Setup permissions for required directories.

# chown nagios:nagios /usr/local/nagios
# chown -R nagios:nagios /usr/local/nagios/libexec

Step 6: Make an entry into /etc/services

# echo "nrpe 5666/tcp # NRPE" >> /etc/services

Sample Entry:

Step 7: Add nagios server ip in to /etc/xinetd.d/nrpe file

# sed -i 's/127.0.0.1/127.0.0.1 <nagios-server-ip>/g' /etc/xinetd.d/nrpe

Note: Replace <nagios-server-ip> with your nagios core IP.

Step 8: Restart service and check if it is configured correctly or not.

# systemctl restart xinetd.service
# /usr/local/nagios/libexec/check_nrpe -H 127.0.0.1

The Out put should like this.

[root@nagios-client]# /usr/local/nagios/libexec/check_nrpe -H 127.0.0.1
NRPE v2.3.1

That’s it!! You are good to go.

NOTE: If you are using iptables or firewall in your servers then you need to allow 5666 port.

Read how to intall Nagios Core in ubuntu.