Grafana/Loki: Adds support for new Loki endpoints and metrics (#20158)

* Grafana/Loki: Adds support for new Loki endpoints and metrics

* Adds `/loki/` prefix to new loki endpoints and updates response interfaces

* Improved legacy support

* Removed changes related to plugin.json and added Loki-specific hacks

* Fixes live streaming for legacy loki datasources

packages/grafana-data/src/dataframe/DataFrameView.ts

@@ -26,22 +26,24 @@ export class DataFrameView<T = any> implements Vector<T> {
 
   constructor(private data: DataFrame) {
     const obj = ({} as unknown) as T;
+
     for (let i = 0; i < data.fields.length; i++) {
       const field = data.fields[i];
-      const getter = () => {
-        return field.values.get(this.index);
-      };
+      const getter = () => field.values.get(this.index);
+
       if (!(obj as any).hasOwnProperty(field.name)) {
         Object.defineProperty(obj, field.name, {
           enumerable: true, // Shows up as enumerable property
           get: getter,
         });
       }
+
       Object.defineProperty(obj, i, {
         enumerable: false, // Don't enumerate array index
         get: getter,
       });
     }
+
     this.obj = obj;
   }
 
@@ -59,11 +61,7 @@ export class DataFrameView<T = any> implements Vector<T> {
   }
 
   toArray(): T[] {
-    const arr: T[] = [];
-    for (let i = 0; i < this.data.length; i++) {
-      arr.push({ ...this.get(i) });
-    }
-    return arr;
+    return new Array(this.data.length).fill(0).map((_, i) => ({ ...this.get(i) }));
   }
 
   toJSON(): T[] {

packages/grafana-data/src/types/datasource.ts

@@ -261,6 +261,8 @@ export abstract class DataSourceApi<
    */
   languageProvider?: any;
 
+  getVersion?(): Promise<string>;
+
   /**
    * Can be optionally implemented to allow datasource to be a source of annotations for dashboard. To be visible
    * in the annotation editor `annotations` capability also needs to be enabled in plugin.json.
@@ -302,6 +304,7 @@ export interface ExploreQueryFieldProps<
 
 export interface ExploreStartPageProps {
   datasource?: DataSourceApi;
+  exploreMode: 'Logs' | 'Metrics';
   onClickExample: (query: DataQuery) => void;
 }
 
@@ -443,18 +446,22 @@ export interface DataQueryError {
 
 export interface DataQueryRequest<TQuery extends DataQuery = DataQuery> {
   requestId: string; // Used to identify results and optionally cancel the request in backendSrv
+
+  dashboardId: number;
+  interval: string;
+  intervalMs?: number;
+  maxDataPoints?: number;
+  panelId: number;
+  range?: TimeRange;
+  reverse?: boolean;
+  scopedVars: ScopedVars;
+  targets: TQuery[];
   timezone: string;
-  range: TimeRange;
+
+  cacheTimeout?: string;
+  exploreMode?: 'Logs' | 'Metrics';
   rangeRaw?: RawTimeRange;
   timeInfo?: string; // The query time description (blue text in the upper right)
-  targets: TQuery[];
-  panelId: number;
-  dashboardId: number;
-  cacheTimeout?: string;
-  interval: string;
-  intervalMs: number;
-  maxDataPoints: number;
-  scopedVars: ScopedVars;
 
   // Request Timing
   startTime: number;

packages/grafana-data/src/types/graph.ts

@@ -10,11 +10,10 @@ export type GraphSeriesValue = number | null;
 
 /** View model projection of a series */
 export interface GraphSeriesXY {
-  label: string;
   color: string;
   data: GraphSeriesValue[][]; // [x,y][]
-  info?: DisplayValue[]; // Legend info
   isVisible: boolean;
+  label: string;
   yAxis: YAxis;
   // Field with series' time values
   timeField: Field;
@@ -22,6 +21,8 @@ export interface GraphSeriesXY {
   valueField: Field;
   seriesIndex: number;
   timeStep: number;
+
+  info?: DisplayValue[]; // Legend info
 }
 
 export interface CreatePlotOverlay {