I cannot template a datasource. I can add the template-variable and it shows up on top and populates correctly.
However, I cannot find the template variable in the Data Source drop-down above the queries. And trying to manually write $prometheus_ds is ignored, it magically jumps “–Mixed–” instead and uses “default” for the per-query datasource, which does not change when I change template datasource value.
Am I doing anything wrong, or is this a bug in the Data Source drop-down-select function?
Grafana v4.6.2 with Prometheus datasources.