So having btop in a webpage ?
post
I have been really happy with netdata. Can also view on their webportal. Probably more info than you need
Setup a zabbix node, and run an agent on each device. Data will be centralized... otherwise something like collectd is pretty darn tiny. That and|or rrdtool to store data for ad-hoc viewing.
You could setup Grafana with Prometheus and it should work fine.
all 4 comments