How to display IOwait percentage in Prometheus

Prometheus has a few quirks, dealing with cpu time is one of these. this article explains how to deal with cpu time, and these are the rules I made for my own Prometheus/Grafana dashboard:

avg by (instance) (irate(node_cpu{mode="iowait"}[1m])) * 100

this rule groups by instance the iowait average for the system (all cpus)

avg by (instance) (irate(instance=~"hostname.*", node_cpu{mode="iowait"}[1m])) * 100

while this rule is like the one above, with the difference that you can filter which systems are reported, by hostname

hopefully this will be useful for someone out there :)