Alerting: Copy frame field labels to time series tags (#29886)

* Alerting: Copy frame field labels to time series tags

* keep comment

* add test case

pkg/services/alerting/conditions/query.go

@@ -330,13 +330,16 @@ func FrameToSeriesSlice(frame *data.Frame) (tsdb.TimeSeriesSlice, error) {
 			Points: make(tsdb.TimeSeriesPoints, field.Len()),
 		}
 
+		if len(field.Labels) > 0 {
+			ts.Tags = field.Labels.Copy()
+		}
+
 		switch {
 		case field.Config != nil && field.Config.DisplayName != "":
 			ts.Name = field.Config.DisplayName
 		case field.Config != nil && field.Config.DisplayNameFromDS != "":
 			ts.Name = field.Config.DisplayNameFromDS
 		case len(field.Labels) > 0:
-			ts.Tags = field.Labels.Copy()
 			// Tags are appended to the name so they are eventually included in EvalMatch's Metric property
 			// for display in notifications.
 			ts.Name = fmt.Sprintf("%v {%v}", field.Name, field.Labels.String())

pkg/services/alerting/conditions/query_test.go

@@ -324,7 +324,7 @@ func TestFrameToSeriesSlice(t *testing.T) {
 			name: "display name from data source",
 			frame: data.NewFrame("",
 				data.NewField("Time", data.Labels{}, []time.Time{}),
-				data.NewField(`Values`, data.Labels{}, []*int64{}).SetConfig(&data.FieldConfig{
+				data.NewField(`Values`, data.Labels{"Rating": "10"}, []*int64{}).SetConfig(&data.FieldConfig{
 					DisplayNameFromDS: "sloth",
 				})),
 
@@ -332,6 +332,7 @@ func TestFrameToSeriesSlice(t *testing.T) {
 				&tsdb.TimeSeries{
 					Name:   "sloth",
 					Points: tsdb.TimeSeriesPoints{},
+					Tags:   map[string]string{"Rating": "10"},
 				},
 			},
 			Err: require.NoError,