Nagios

installing Nagios on Ubuntu
http://www.bogotobogo.com/DevOps/DevOps_Nginx_Nagios-Remote-Plugin-Executor-NRPE.php.NOT-Working
adding new services to nagios
https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/4/en/monitoring-publicservices.html
check the validity of configuration
/usr/local/nagios/bin/nagios -v nagios.cfg
configuration file for nagios
/etc/nagios/nagios.cfg
Nagios utilities
/usr/local/nagios/libexec
restart Nagios
sudo systemctl restart nagios