"Hypervisors stats" panel in “[Juju] OpenStack Hypervisor Overview” dashboard is empty

[Nobuto Murata]

It's empty as per the title.

I found a description internally that it's because of the diff between Telegraf and node-exporter.

> Node exporter metrics are different now, so this panel cannot be ported. Could be re-implemented in the future.

And indeed, the query has Telegraf specific metrics:

https://git.launchpad.net/charm-prometheus-openstack-exporter/tree/src/templates/grafana-dashboards/overview-openstack-exporter-dashboard.json.j2#n1401
> "expr":"label_replace(sum by (dns_name)(system_uptime{juju_unit=~\".*nova-compute.*\"}), \"short_hostname\", \"$1\", \"dns_name\", \"([^\\\\.]*)\\\\..*\") and on (dns_name)label_replace(hypervisor_running_vms{cloud=~\"$cloud\", aggregate=~\"$aggregate\"}, \"dns_name\", \"$1\", \"hypervisor_hostname\", \"(.*)\")",

We need to either remove the panel or update the syntax.