Nagios

Installation

Update System:

sudo apt update -y
sudo apt upgrade -y

Install Dependencies:

sudo apt install php php-cgi libapache2-mod-php php-common php-pear php-mbstring apache2

Install Nagios3:

sudo apt install nagios3 nagios-plugins-basic nagios-nrpe-plugin

Edit Config:

sudo nano /etc/nagios3/nagios.cfg
check_external_commands=1

Adding a Host

sudo nano aman-client1.cfg

define host {
    use         generic-host        ; Inherit default values from a template
    host_name   PROD_aman-client1   ; The name we're giving to this host
    alias       XYZ_aman-client1    ; A longer name associated with the host
    address     10.10.30.81         ; IP address of the host
    #hostgroups  allhosts           ; Host groups this host is associated with
}

sudo service nagios3 restart

Monitoring python process

Checking output using cli

/usr/lib/nagios/plugins/check_procs -c 1: -C python3 -a watchdog.py

sudo nano /etc/nagios3/commands.cfg

#################
# Check_Python
#################

define command{
    command_name check_python
    command_line /usr/lib/nagios/plugins/check_procs -c 1: -C '$ARG1$' -a '$ARG2$'
}

sudo nano /etc/nagios3/conf.d/aman-client1.cfg

## Check Watchdog Script

define service {
    use                 generic-service     ; Inherit default values from a template
    host_name           localhost
    service_description Watchdog Script
    check_command       check_python!python3!watchdog.py
}

Monitor HTTP Site

Checking output using cli

/usr/lib/nagios/plugins/check_http -H localhost -u /aviwiki/index.php/Main_Page

sudo nano /etc/nagios3/conf.d/aman-client1.cfg

## Check Mediawiki Site

define service {
    use                 generic-service     ; Inherit default values from a template
    host_name           localhost
    service_description MediaWiki Server
    check_command       check_http!-H localhost!-u /aviwiki/index.php/Main_Page
}

NRPE

egrep -v '^#|^$' /etc/nagios/nrpe.cfg