The Icinga Monitoring System watches over all hosts (disk space, load average, security updates, etc.). In addition services may add specific monitoring probes such as loading a web page and verifying its content is valid.
The Icinga web interface is at icinga.example.com. The user name and password with administrator rights must be defined in ~/.enough/example.com/inventory/host_vars/icinga-host/icinga-secrets.yml with variables documented in this file
Problems found by Icinga will be notified via email to the address defined in ~/.enough/example.com/inventory/host_vars/icinga-host/mail.yml with a variable doumented in this file.