Note for a official Grafana MongoDB plugin,

Note for a official Grafana MongoDB plugin, please view: https://grafana.com/grafana/plugins/grafana-mongodb-datasource This is a MongoDB Prometheus Exporter Dashboard. Works well with https://github.com/dcu/mongodb_exporter If you have the node_exporter running on the mongo instance, you will also get some useful alert panels related to disk io and cpu.

https://grafana.com/grafana/dashboards/2583-mongodb/