Lab Snooping...
I wanted a way to monitor all of the uptimes and statuses of both my physical and software appliances in my lab. I poked with LibreNMS, Zabbix, DataDog, etc. But none of them fit the bill.
Some were too expensive, some were cheesy looking, and some were outright not what I was looking for at all...
After some further digging, I found CheckMk, an open-source SNMP agent/server that could monitor it all. I hooked up all of my appliances and VMs to CheckMk via their respective SNMP clients and bam!
I even built a dedicated kiosk-like display for displaying the data that comes out of CheckMk using a Raspberry Pi 0w and an old display, and put it next to the rack on my workbench.