Mellow

Synology Diskstation DS1522+ $699.00

Synology Diskstation DS1621+ $899.99

Some of those apps are available through the community package center. If not then you can run a docker environment or a virtual machine on the DS and run whatever you want. It’s got a lot more horsepower than a single board computer, but I still recommend separation of duties and let the NAS be a NAS. Put your services on a server or separate virtual environment.

This is my DS16xx+ and expansion bay

Influxdb is a “time series” database for storing metrics. Temperatures, ram usage, cpu usage with time stamps. Telegraf is the client side agent that sends those metrics to the database in json format. Prometheus does pretty much the same thing but is a bit too bloated for my liking, so I went back to Influx.

Grafana, influxdb, telegraf agents. Easy to setup. Barely any configuration required. Everything you asked for in the default telegraf agent config. There are dashboards with plenty of examples on grafanas website.