Icinga2 모니터링 시스템 docs

- icinga2 install

https://docs.icinga.com/icinga2/latest/doc/module/icinga2/toc#!/icinga2/latest/doc/module/icinga2/chapter/getting-started#installation-enabled-features

- icinga web2 install

https://github.com/Icinga/icingaweb2/blob/master/doc/02-Installation.md

- icinga2 tutorial

http://zyradyl.github.io/2015/08/16/Icinga2-Tutorial-Part-0/