Nagios

Client Important Files

/etc/nagios/nrpe.cfg           <- allowed_hosts of server goes here
/usr/lib/nagios/plugins 	<- specific checks go here

Directory Structure Server

/usr/share/nagios/htdocs
/usr/lib/nagios/plugins		<-
/var/chef/backup/etc/nagios
/var/chef/cache/cookbooks/nagios
/etc/nagios
/run/nagios3
/usr/share/doc/nagios3
/usr/share/nagios3
/usr/share/lintian/overrides/nagios3
/etc/init.d/nagios3
/etc/nagios3

Nagios Config

• make sure IPs are allowed for communicatin
• make sure ports are allowed for communication
• client: put the custom plugin in /usr/lib/nagios/plugins/echo_ok3
• client: in /etc/nagios/nrpe.cfg:

 command[echo_ok3]=/usr/lib/nagios/plugins/echo_ok3

• client: restart service

 /usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -d

• server:

define command {
  command_name echo-ok3
  command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c echo_ok3
}
define service {
  service_description echo-ok3
  hostgroup_name microsites3_api
  check_command echo-ok3
  use default-service
}

Nagios Utils

Setup Client

apt-get install -y nagios-plugins nagios-nrpe-server

Change password

htpasswd -c -b  /etc/nagios/htpasswd.users nagiosadmin admin

Nagios Custom Plugin

CHECK_NRPE: Error – Could not complete SSL handshake

From: https://geekpeek.net/could-not-complete-ssl-handshake/