Azure Monitor: Change response to be dataframes (#25123)

note: This is just Azure Monitor within the Azure Monitor datasource (not insights, insights analytics, or log analytics yet).

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

packages/grafana-runtime/src/utils/DataSourceWithBackend.ts

@@ -5,8 +5,9 @@ import {
   DataSourceInstanceSettings,
   DataQuery,
   DataSourceJsonData,
+  ScopedVars,
 } from '@grafana/data';
-import { Observable, from } from 'rxjs';
+import { Observable, from, of } from 'rxjs';
 import { config } from '..';
 import { getBackendSrv } from '../services';
 import { toDataQueryResponse } from './queryResponse';
@@ -53,9 +54,13 @@ export class DataSourceWithBackend<
   /**
    * Ideally final -- any other implementation may not work as expected
    */
-  query(request: DataQueryRequest): Observable<DataQueryResponse> {
-    const { targets, intervalMs, maxDataPoints, range, requestId } = request;
+  query(request: DataQueryRequest<TQuery>): Observable<DataQueryResponse> {
+    const { intervalMs, maxDataPoints, range, requestId } = request;
     const orgId = config.bootData.user.orgId;
+    let targets = request.targets;
+    if (this.filterQuery) {
+      targets = targets.filter(q => this.filterQuery!(q));
+    }
     const queries = targets.map(q => {
       if (q.datasource === ExpressionDatasourceID) {
         return {
@@ -70,7 +75,7 @@ export class DataSourceWithBackend<
         throw new Error('Unknown Datasource: ' + q.datasource);
       }
       return {
-        ...this.applyTemplateVariables(q),
+        ...this.applyTemplateVariables(q, request.scopedVars),
         datasourceId: ds.id,
         intervalMs,
         maxDataPoints,
@@ -78,6 +83,11 @@ export class DataSourceWithBackend<
       };
     });
 
+    // Return early if no queries exist
+    if (!queries.length) {
+      return of({ data: [] });
+    }
+
     const body: any = {
       queries,
     };
@@ -105,12 +115,19 @@ export class DataSourceWithBackend<
     return from(req);
   }
 
+  /**
+   * Override to skip executing a query
+   *
+   * @virtual
+   */
+  filterQuery?(query: TQuery): boolean;
+
   /**
    * Override to apply template variables
    *
    * @virtual
    */
-  applyTemplateVariables(query: DataQuery) {
+  applyTemplateVariables(query: TQuery, scopedVars: ScopedVars): Record<string, any> {
     return query;
   }