Icinga

Icinga is a flexible and powerful open-source monitoring system used to oversee the health of networked hosts and services. It could be used to monitor the load and uptime of a cluster of web workers, free disk space on a storage device, memory consumption on a caching service, and so on.

https://www.digitalocean.com/community/tutorials/how-to-install-icinga-and-icinga-web-on-ubuntu-16-04

https://hub.docker.com/search/?isAutomated=0&isOfficial=0&page=1&pullCount=1&q=icinga2&starCount=0