Disk Space Monitoring

Hi
I have actually two questions

first: how can I see how many nodes do I have in a cluster and how many disks do I have Per node?

second: how can I see total disk space of disks of a node and total disk space of a cluster in Netdata?

Actually I want to maintain them in grafana and my data source is Influxdb and it collect data from netdata, so I would be happy if anyone could help

thanks a lot
Marshal