We recently upgraded from grafana 4.3.0 to 5.1.0. and have noticed that some of our dashboards created prior to the upgrade are no longer working due to no results being returned in template variables.
Existing dashboards that had prometheus-backed template variables in the form of label_values(metric,label) now return no data.
Modifying these old dashboards and changing the function to label_values(label) does return values.
Creating a brand new (5.1.0) dashboard and using the same label_values(metric,label) function that was defined in the old dashboard does return data.
Is anyone aware of a dashboard migration step that needs to be performed in order to bring old dashboard definitions up to version 5 compliance?