They sure did. It was in response to volt typhoon: https://en.m.wikipedia.org/wiki/Volt_Typhoon

You could add encryption and authentication via ssh: https://guide.munin-monitoring.org/en/latest/example/transport/ssh.html or you could put it behind an nginx and wrap it in tls if you just want encryption.

Munin might be what you’re looking for. Very simple and easy to write your own plugins for if some information is missing.

http://munin-monitoring.org/