### OS - CentOS 7 64bit
### IP - 172.17.25.100
### Hostname - webserver.example.com
Step 1:
Setup NRPE Service on Linux Host
vi /etc/hosts
Install Package & Plugin
yum install epel*
yum install nrpe nagios-plugins* # CentOS/RHEL/Fedora
OR
apt-get install nagios-nrpe-server nagios-plugins # Debian/Ubuntu/LinuxMint
Step 2:
Configure NRPE
vi /etc/nagios/nrpe.cfg
#Add Nagios Server IP
allowed_hosts=127.0.0.1, 172.17.20.100
#Allow Argument
# Values: 0=do not allow arguments, 1=allow command arguments
dont_blame_nrpe=1
Step 3:
Add Command
# The following examples use hard-coded command arguments...
command[check_users]=/usr/lib64/nagios/plugins/check_users -w 5 -c 10
command[check_load]=/usr/lib64/nagios/plugins/check_load -w 15,10,5 -c 30,25,20
command[check_root]=/usr/lib64/nagios/plugins/check_disk -w 20% -c 10% -p /dev/mapper/centos-root
command[check_total_procs]=/usr/lib64/nagios/plugins/check_procs -w 150 -c 200
command[check_swap]=/usr/lib64/nagios/plugins/check_swap -w 20 -c 10
command[check_http]=/usr/lib64/nagios/plugins/check_http -H 172.17.20.103
Step 4:
Restart Service
systemctl restart nrpe.service
or
service nrpe restart
or
sudo /etc/init.d/nagios-nrpe-server restart
## Allow on Firewalld
firewall-cmd --add-port=5666/tcp --permanent
firewall-cmd --reload
### Server Side Configuration ######
### OS - CentOS 7 64bit ######
### IP - 172.17.25.200 #####
### Hostname - nagios.linuxtopic.com ####
Step 5:
## Install nrpe
yum install openssl-devel xinetd unzip
# Download nrpe
cd /tmp
curl -L -O http://downloads.sourceforge.net/project/nagios/nrpe-2.x/nrpe-2.15/nrpe-2.15.tar.gz
tar xvf nrpe-2.15.tar.gz
cd nrpe-2.15
./configure --enable-command-args --with-nagios-user=nagios --with-nagios-group=nagiosgroup --with-ssl=/usr/bin/openssl --with-ssl-lib=/usr/lib/x86_64-linux-gnu
make all
make install
make install-xinetd
make install-daemon-config
# Test nrpe client
telnet <client ip> 5666
/usr/local/nagios/libexec/check_nrpe -H 172.17.25.100
Step 6:
# Configure HOST
vi /usr/local/nagios/etc/servers/webserver.linuxtopic.cfg
## Host Details ###
define host {
use linux-server
host_name webserver.linuxtopic.com
alias MyWeb
address 172.17.20.103
max_check_attempts 10
check_period 24x7
notification_interval 10 # Notification
notification_period 24x7
}
# Define Group
define hostgroup{
hostgroup_name Webserver_Group
alias MyWebserver
# members 172.17.20.103
}
####
# Check Ping
define service {
use generic-service
host_name webserver.linuxtopic.com
service_description PING
check_command check_ping!100.0,20%!500.0,60%
check_interval 1 # 1 min
retry_interval 1 # 1 min
}
# Define a service to check the load on the local machine.
define service{
use local-service
host_name webserver.linuxtopic.com
service_description Current Load
check_command check_nrpe!check_load!15.0,12.0,10.0!20.0,18.0,15.0
check_interval 1
retry_interval 1
}
# Check Users
define service{
use generic-service
host_name webserver.linuxtopic.com
service_description Current Users
check_command check_nrpe!check_users
check_interval 1
retry_interval 1
}
# Check Process
define service{
use local-service
host_name webserver.linuxtopic.com
service_description Total Processes
check_command check_nrpe!check_total_procs!250!400!RSZDT
check_interval 1
retry_interval 1
}
# Check Root Part.
define service{
use local-service
host_name webserver.linuxtopic.com
service_description Disk-Root-Partition
check_command check_nrpe!check_root!10%!5%!/
check_interval 1
retry_interval 1
}
# Define a service to check the swap usage the local machine.
# Critical if less than 10% of swap is free, warning if less than 20% is free
define service{
use local-service
host_name webserver.linuxtopic.com
service_description Disk-Swap-Partition
check_command check_nrpe!check_swap!20!10
check_interval 1
retry_interval 1
}
## Check HTTP Server
define service{
use local-service
host_name webserver.linuxtopic.com
service_description WEB-HTTP
check_command check_nrpe!check_http
check_interval 1
retry_interval 1
}
Part 1: Nagios Core 4.X configuration in Linux
Part 2: Add Remote hosts and service in Nagios
Part 3: Monitor MySQL/MariaDB Using check_mysql Plugin
Part 4: Monitor Tomcat using check_tomcat Plugin
