I installed openstack with devstack on Ubuntu 20 and installed prometheus and grafana with node exporter and it showed on grafana no issues, but how to monitor openstack components Nova.... There is a Openstack Exporter in grafana but its show as empty
Thanks in advance
You write that you already have prometheus running so I will not go into details about that. The description in the docs are kind of straight forward. It offers different installation methods (docker/podman container or via snap). Both options to start the exporter worked for me (podman container and snap).
Configure the exporter
In my case I have prometheus server running on the control node as well (just a test environment), that's why I have the target defined as "localhost". Now you can use any of those metrics to create your own grafana dashboards to visualize the metrics with graphs.
Configure Grafana
You need a running grafana instance where you have permissions to add dashboards, I won't go into those details. You can import the dashboard you referred to, I imported the json file. During the import you're asked for the json file and the prometheus data source. As soon as the exporter is started and prometheus has collected its metrics you should see graphs in the imported dashboard:![Openstack exporter dashboard](https://i.stack.imgur.com/2uIiO.png)