Unable to use $datasource when creating variables via query

[ldaneliukas]

What happened: Created a variable ds of the type datasource with "Include All option" enabled. Then used that variable as the datasource for another variable tier of type query. When I saved the dashboard - the $datasource variable dissapeared from the ds variable. As a result, the $tier variable is displayed the value which was retrieved from the first datasource that was available.

After saving the dashboard $ds dissapeared and the last (and only) result for the variable is still available:

• Note - Clicking 'Update' on the "Edit Variable" screen still works with an empty datasource. The $ds selection is no longer present when attempting to select a datasource. Other "static" datasource are still there.

What you expected to happen: I expected that the the panels which are repeated for all datasources (works fine), will have different values for the $tier variable as its taken from the datasource that is used for that panel at the time of repeating.

How to reproduce it (as minimally and precisely as possible):

• Create a variable ds of type datasource with Include All option enabled
• Create any variable of type query and pick $ds as the datasource.
• Save the dashboard, close it, re-open it and check the variables.
• Add a panel that displays the value of $any variable and repeat it for all instnaces of $ds variable

Anything else we need to know?:

Environment:

• Grafana version: Grafana v6.1.3 (9504db8)
• Data source type & version: Prometheus 2.6.0
• OS Grafana is installed on: Docker container
• User OS & Browser: Chrome on Fedora 29
• Grafana plugins:
• Others:

[torkelo]

I expected that the the panels which are repeated for all datasources (works fine), will have different values for the $tier variable as its taken from the datasource that is used for that panel at the time of repeating.

This is not supported and likely never will be. Repeating panels will not trigger new template variable queries. Template variable values will be shared for all repeating panels. Only the variable that your repeating by is going to be different. If you have nested variables and repeat using the parent variable, the panels will all have same value for the child variable as Grafana will not evaluate the child variable for every repeat instance.

Create a variable ds of type datasource with Include All option enabled
Create any variable of type query and pick $ds as the datasource.

Multi-valued data sources can only be used in repeat & panels not in as a datasource in other variables. We should add a validation warning for this!

[torkelo]

Created a new issue to create a warning for this: #16543