Create dashboard for customers

[Nikita Koltsov]

Customers often want to have dashboards with hostnames instead of juju applications or unit names.
To do that I suggest to render template using dns_name label as a variable instead of hostname.

[Eric Chen (eric-chen)]

Soon or later, the monitoring system will migrate to COS.
(https://charmhub.io/topics/canonical-observability-stack)
Therefore, the priority of this feature would be very low and probably won't implement.