A grafana datasource for reading '.rrd' files via RRDTool and RRDsrv.
With this datasource you will be able to create grafana dashboards and use grafana alerts with RRD file metrics.
Install rrdtool and https://github.com/andrewchambers/rrdsrv.
From grafana add a new rrd datasource and point it at your rrdsrv instance.
Thanks to Tobias Oetiker and all other contributors to RRDTool