My SNMP "dashboard" consisted of three parts: one, a set of Round Robin Databases created with rrdtool
; two, a set of shell scripts run frequently by cron
to add new data to the databases; three, a set of less-frequently run scripts to generate the graph PNGs displayed on a web page.
The empty Round Robin Databases need to be initialized first, before you can add data to them.
Tutorial here: https://oss.oetiker.ch/rrdtool/tut/rrd-beginners.en.html