Azure/Log Analytics: return more error information (#25937)

When there is an error message in the HTTP response, this copies that error so it is relayed to the user by being shown in the frontend.

This also makes it so when there is an error the interpolated query string (ExecutedQueryString) is returned so users can see it in the query inspector.

pkg/tsdb/azuremonitor/azure-log-analytics-datasource.go

@@ -110,16 +110,26 @@ func (e *AzureLogAnalyticsDatasource) buildQueries(queries []*tsdb.Query, timeRa
 }
 
 func (e *AzureLogAnalyticsDatasource) executeQuery(ctx context.Context, query *AzureLogAnalyticsQuery, queries []*tsdb.Query, timeRange *tsdb.TimeRange) *tsdb.QueryResult {
-	queryResult := &tsdb.QueryResult{Meta: simplejson.New(), RefId: query.RefID}
+	queryResult := &tsdb.QueryResult{RefId: query.RefID}
 
-	queryResultError := func(err error) *tsdb.QueryResult {
+	queryResultErrorWithExecuted := func(err error) *tsdb.QueryResult {
 		queryResult.Error = err
+		frames := data.Frames{
+			&data.Frame{
+				RefID: query.RefID,
+				Meta: &data.FrameMeta{
+					ExecutedQueryString: query.Params.Get("query"),
+				},
+			},
+		}
+		queryResult.Dataframes = tsdb.NewDecodedDataFrames(frames)
 		return queryResult
 	}
 
 	req, err := e.createRequest(ctx, e.dsInfo)
 	if err != nil {
-		return queryResultError(err)
+		queryResult.Error = err
+		return queryResult
 	}
 
 	req.URL.Path = path.Join(req.URL.Path, query.URL)
@@ -138,28 +148,28 @@ func (e *AzureLogAnalyticsDatasource) executeQuery(ctx context.Context, query *A
 		span.Context(),
 		opentracing.HTTPHeaders,
 		opentracing.HTTPHeadersCarrier(req.Header)); err != nil {
-		return queryResultError(err)
+		return queryResultErrorWithExecuted(err)
 	}
 
 	azlog.Debug("AzureLogAnalytics", "Request ApiURL", req.URL.String())
 	res, err := ctxhttp.Do(ctx, e.httpClient, req)
 	if err != nil {
-		return queryResultError(err)
+		return queryResultErrorWithExecuted(err)
 	}
 
 	logResponse, err := e.unmarshalResponse(res)
 	if err != nil {
-		return queryResultError(err)
+		return queryResultErrorWithExecuted(err)
 	}
 
 	t, err := logResponse.GetPrimaryResultTable()
 	if err != nil {
-		return queryResultError(err)
+		return queryResultErrorWithExecuted(err)
 	}
 
 	frame, err := LogTableToFrame(t)
 	if err != nil {
-		return queryResultError(err)
+		return queryResultErrorWithExecuted(err)
 	}
 
 	err = setAdditionalFrameMeta(frame,
@@ -262,7 +272,7 @@ func (e *AzureLogAnalyticsDatasource) unmarshalResponse(res *http.Response) (Azu
 
 	if res.StatusCode/100 != 2 {
 		azlog.Debug("Request failed", "status", res.Status, "body", string(body))
-		return AzureLogAnalyticsResponse{}, fmt.Errorf("Request failed status: %v", res.Status)
+		return AzureLogAnalyticsResponse{}, fmt.Errorf("Request failed status: %v: %w", res.Status, fmt.Errorf(string(body)))
 	}
 
 	var data AzureLogAnalyticsResponse