Azure Monitor: Fix empty/errored responses for Logs variables (#59240)

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

@@ -190,7 +190,10 @@ func (e *AzureLogAnalyticsDatasource) executeQuery(ctx context.Context, logger l
 	if err != nil {
 		return dataResponseErrorWithExecuted(err)
 	}
-	appendErrorNotice(frame, logResponse.Error)
+	frame = appendErrorNotice(frame, logResponse.Error)
+	if frame == nil {
+		return dataResponse
+	}
 
 	model, err := simplejson.NewJson(query.JSON)
 	if err != nil {
@@ -222,10 +225,15 @@ func (e *AzureLogAnalyticsDatasource) executeQuery(ctx context.Context, logger l
 	return dataResponse
 }
 
-func appendErrorNotice(frame *data.Frame, err *AzureLogAnalyticsAPIError) {
-	if err != nil {
-		frame.AppendNotices(apiErrorToNotice(err))
+func appendErrorNotice(frame *data.Frame, err *AzureLogAnalyticsAPIError) *data.Frame {
+	if err == nil {
+		return frame
 	}
+	if frame == nil {
+		frame = &data.Frame{}
+	}
+	frame.AppendNotices(apiErrorToNotice(err))
+	return frame
 }
 
 func (e *AzureLogAnalyticsDatasource) createRequest(ctx context.Context, logger log.Logger, url string) (*http.Request, error) {

pkg/tsdb/azuremonitor/loganalytics/azure-response-table-frame.go

@@ -45,12 +45,7 @@ func apiErrorToNotice(err *AzureLogAnalyticsAPIError) data.Notice {
 // ResponseTableToFrame converts an AzureResponseTable to a data.Frame.
 func ResponseTableToFrame(table *types.AzureResponseTable, refID string, executedQuery string) (*data.Frame, error) {
 	if len(table.Rows) == 0 {
-		return &data.Frame{
-			RefID: refID,
-			Meta: &data.FrameMeta{
-				ExecutedQueryString: executedQuery,
-			},
-		}, nil
+		return nil, nil
 	}
 
 	converterFrame, err := converterFrameForTable(table)

pkg/tsdb/azuremonitor/loganalytics/azure-response-table-frame_test.go

@@ -173,12 +173,7 @@ func TestLogTableToFrame(t *testing.T) {
 			name:     "empty data response",
 			testFile: "loganalytics/11-log-analytics-response-empty.json",
 			expectedFrame: func() *data.Frame {
-				return &data.Frame{
-					RefID: "A",
-					Meta: &data.FrameMeta{
-						ExecutedQueryString: "query",
-					},
-				}
+				return nil
 			},
 		},
 	}

public/app/plugins/datasource/grafana-azure-monitor-datasource/variables.test.ts

@@ -489,6 +489,38 @@ describe('VariableSupport', () => {
     });
   });
 
+  it('passes on the query error for a log query', (done) => {
+    const variableSupport = new VariableSupport(
+      createMockDatasource({
+        query: () =>
+          from(
+            Promise.resolve({
+              data: [],
+              error: {
+                message: 'boom',
+              },
+            })
+          ),
+      })
+    );
+    const mockRequest = {
+      targets: [
+        {
+          queryType: AzureQueryType.LogAnalytics,
+          azureLogAnalytics: {
+            query: 'some log thing',
+          },
+        } as AzureMonitorQuery,
+      ],
+    } as DataQueryRequest<AzureMonitorQuery>;
+    const observables = variableSupport.query(mockRequest);
+    observables.subscribe((result: DataQueryResponseData) => {
+      expect(result.data).toEqual([]);
+      expect(result.error.message).toEqual('boom');
+      done();
+    });
+  });
+
   it('should handle http error', (done) => {
     const error = invalidSubscriptionError();
     const variableSupport = new VariableSupport(

public/app/plugins/datasource/grafana-azure-monitor-datasource/variables.ts

@@ -94,6 +94,7 @@ export class VariableSupport extends CustomVariableSupport<DataSource, AzureMoni
             const queryResp = await lastValueFrom(this.datasource.query(request));
             return {
               data: queryResp.data,
+              error: queryResp.error ? new Error(messageFromError(queryResp.error)) : undefined,
             };
         }
       } catch (err) {