macOS thermal throttling metrics

[STRRL]

Hi! I am using node_exporter to monitoring my macbook, and I want to extend more metrics for that.

I always use pmset -g therm for fetching the thermal throttling info, like that:

$ pmset -g therm
Note: No thermal warning level has been recorded
Note: No performance warning level has been recorded
2021-05-02 11:51:57 +0800 CPU Power notify
	CPU_Scheduler_Limit 	= 100
	CPU_Available_CPUs 	= 12
	CPU_Speed_Limit 	= 100

So I want to append these three metrics: cpu_scheduler_limit, cpu_available_cpus and cpu_speed_limit for the node_exporter on darwin. These values could be fetched by IOKit, reference