Exemplars: always query exemplars (#31673)

* Exemplars: always query exemplars

* Update exemplar button to be an eye

* Add tooltip to eye button

public/app/plugins/datasource/prometheus/components/PromExemplarField.tsx

@@ -1,21 +1,68 @@
-import { InlineField, InlineSwitch } from '@grafana/ui';
-import React from 'react';
+import { GrafanaTheme } from '@grafana/data';
+import { FetchError } from '@grafana/runtime';
+import { IconButton, InlineLabel, Tooltip, useStyles } from '@grafana/ui';
+import { css, cx } from 'emotion';
+import React, { useEffect, useState } from 'react';
+import { PrometheusDatasource } from '../datasource';
 import { PromQuery } from '../types';
 
 interface Props {
   query: PromQuery;
   onChange: (value: PromQuery) => void;
+  datasource: PrometheusDatasource;
 }
 
-const onExemplarsChange = ({ query, onChange }: Props) => (e: React.ChangeEvent<HTMLInputElement>) => {
-  const exemplar = e.target.checked;
-  onChange({ ...query, exemplar });
-};
-
 export function PromExemplarField(props: Props) {
+  const [error, setError] = useState<FetchError>();
+  const styles = useStyles(getStyles);
+
+  useEffect(() => {
+    const subscription = props.datasource.exemplarErrors.subscribe((err) => {
+      setError(err);
+    });
+    return () => {
+      subscription.unsubscribe();
+    };
+  }, [props]);
+
+  const iconButtonStyles = cx(
+    {
+      [styles.activeIcon]: !!props.query.exemplar,
+    },
+    styles.eyeIcon
+  );
+
   return (
-    <InlineField label="Exemplars" labelWidth="auto">
-      <InlineSwitch label="Exemplars" value={!!props.query.exemplar} onChange={onExemplarsChange(props)} />
-    </InlineField>
+    <InlineLabel width="auto">
+      <Tooltip content={!!error ? 'Exemplars are not supported in this version of prometheus.' : ''}>
+        <div className={styles.iconWrapper}>
+          Exemplars
+          <IconButton
+            name="eye"
+            tooltip={!!props.query.exemplar ? 'Disable query with exemplars' : 'Enable query with exemplars'}
+            disabled={!!error}
+            className={iconButtonStyles}
+            onClick={() => {
+              props.onChange({ ...props.query, exemplar: !props.query.exemplar });
+            }}
+          />
+        </div>
+      </Tooltip>
+    </InlineLabel>
   );
 }
+
+function getStyles(theme: GrafanaTheme) {
+  return {
+    eyeIcon: css`
+      margin-left: ${theme.spacing.md};
+    `,
+    activeIcon: css`
+      color: ${theme.palette.blue95};
+    `,
+    iconWrapper: css`
+      display: flex;
+      align-items: center;
+    `,
+  };
+}

public/app/plugins/datasource/prometheus/components/PromExploreExtraField.test.tsx

@@ -1,11 +1,13 @@
 import React from 'react';
 import { render, screen } from '@testing-library/react';
 import { PromExploreExtraFieldProps, PromExploreExtraField } from './PromExploreExtraField';
+import { Observable } from 'rxjs';
 
 const setup = (propOverrides?: PromExploreExtraFieldProps) => {
   const queryType = 'range';
   const stepValue = '1';
   const query = { exemplar: false };
+  const datasource = { exemplarErrors: new Observable() };
   const onStepChange = jest.fn();
   const onQueryTypeChange = jest.fn();
   const onKeyDownFunc = jest.fn();
@@ -17,6 +19,7 @@ const setup = (propOverrides?: PromExploreExtraFieldProps) => {
     onStepChange,
     onQueryTypeChange,
     onKeyDownFunc,
+    datasource,
   };
 
   Object.assign(props, propOverrides);

public/app/plugins/datasource/prometheus/components/PromExploreExtraField.tsx

@@ -6,6 +6,7 @@ import { css, cx } from 'emotion';
 import { InlineFormLabel, RadioButtonGroup } from '@grafana/ui';
 import { PromQuery } from '../types';
 import { PromExemplarField } from './PromExemplarField';
+import { PrometheusDatasource } from '../datasource';
 
 export interface PromExploreExtraFieldProps {
   queryType: string;
@@ -15,10 +16,11 @@ export interface PromExploreExtraFieldProps {
   onKeyDownFunc: (e: React.KeyboardEvent<HTMLInputElement>) => void;
   onQueryTypeChange: (value: string) => void;
   onChange: (value: PromQuery) => void;
+  datasource: PrometheusDatasource;
 }
 
 export const PromExploreExtraField: React.FC<PromExploreExtraFieldProps> = memo(
-  ({ queryType, stepValue, query, onChange, onStepChange, onQueryTypeChange, onKeyDownFunc }) => {
+  ({ queryType, stepValue, query, onChange, onStepChange, onQueryTypeChange, onKeyDownFunc, datasource }) => {
     const rangeOptions = [
       { value: 'range', label: 'Range', description: 'Run query over a range of time.' },
       {
@@ -75,7 +77,7 @@ export const PromExploreExtraField: React.FC<PromExploreExtraFieldProps> = memo(
           />
         </div>
 
-        <PromExemplarField query={query} onChange={onChange} />
+        <PromExemplarField query={query} onChange={onChange} datasource={datasource} />
       </div>
     );
   }

public/app/plugins/datasource/prometheus/components/PromExploreQueryEditor.tsx

@@ -1,4 +1,4 @@
-import React, { memo, FC } from 'react';
+import React, { memo, FC, useEffect } from 'react';
 
 // Types
 import { ExploreQueryFieldProps } from '@grafana/data';
@@ -14,6 +14,12 @@ export type Props = ExploreQueryFieldProps<PrometheusDatasource, PromQuery, Prom
 export const PromExploreQueryEditor: FC<Props> = (props: Props) => {
   const { range, query, data, datasource, history, onChange, onRunQuery } = props;
 
+  useEffect(() => {
+    if (query.exemplar === undefined) {
+      onChange({ ...query, exemplar: true });
+    }
+  }, [query]);
+
   function onChangeQueryStep(value: string) {
     const { query, onChange } = props;
     const nextQuery = { ...query, interval: value };
@@ -65,6 +71,7 @@ export const PromExploreQueryEditor: FC<Props> = (props: Props) => {
           onKeyDownFunc={onReturnKeyDown}
           query={query}
           onChange={onChange}
+          datasource={datasource}
         />
       }
     />

public/app/plugins/datasource/prometheus/components/PromQueryEditor.tsx

@@ -41,7 +41,7 @@ export class PromQueryEditor extends PureComponent<Props, State> {
   constructor(props: Props) {
     super(props);
     // Use default query to prevent undefined input values
-    const defaultQuery: Partial<PromQuery> = { expr: '', legendFormat: '', interval: '' };
+    const defaultQuery: Partial<PromQuery> = { expr: '', legendFormat: '', interval: '', exemplar: true };
     const query = Object.assign({}, defaultQuery, props.query);
     this.query = query;
     // Query target properties that are fully controlled inputs
@@ -186,7 +186,7 @@ export class PromQueryEditor extends PureComponent<Props, State> {
             </InlineFormLabel>
           </div>
 
-          <PromExemplarField query={query} onChange={onChange} />
+          <PromExemplarField query={this.query} onChange={onChange} datasource={this.props.datasource} />
         </div>
       </div>
     );

public/app/plugins/datasource/prometheus/components/__snapshots__/PromExploreQueryEditor.test.tsx.snap

@@ -4,6 +4,13 @@ exports[`PromExploreQueryEditor should render component 1`] = `
 <PromQueryField
   ExtraFieldElement={
     <Memo
+      datasource={
+        Object {
+          "languageProvider": Object {
+            "syntax": [Function],
+          },
+        }
+      }
       onChange={[MockFunction]}
       onKeyDownFunc={[Function]}
       onQueryTypeChange={[Function]}

public/app/plugins/datasource/prometheus/components/__snapshots__/PromQueryEditor.test.tsx.snap

@@ -172,6 +172,7 @@ exports[`Render PromQueryEditor with basic options should render 1`] = `
           }
           query={
             Object {
+              "exemplar": true,
               "expr": "",
               "interval": "",
               "legendFormat": "",
@@ -182,10 +183,19 @@ exports[`Render PromQueryEditor with basic options should render 1`] = `
       </FormLabel>
     </div>
     <PromExemplarField
+      datasource={
+        Object {
+          "createQuery": [MockFunction],
+          "getPrometheusTime": [MockFunction],
+        }
+      }
       onChange={[MockFunction]}
       query={
         Object {
+          "exemplar": true,
           "expr": "",
+          "interval": "",
+          "legendFormat": "",
           "refId": "A",
         }
       }

public/app/plugins/datasource/prometheus/datasource.ts

@@ -20,7 +20,7 @@ import { getTemplateSrv, TemplateSrv } from 'app/features/templating/template_sr
 import cloneDeep from 'lodash/cloneDeep';
 import defaults from 'lodash/defaults';
 import LRU from 'lru-cache';
-import { forkJoin, merge, Observable, of, pipe, throwError } from 'rxjs';
+import { forkJoin, merge, Observable, of, pipe, Subject, throwError } from 'rxjs';
 import { catchError, filter, map, tap } from 'rxjs/operators';
 import addLabelToQuery from './add_label_to_query';
 import PrometheusLanguageProvider from './language_provider';
@@ -62,6 +62,7 @@ export class PrometheusDatasource extends DataSourceApi<PromQuery, PromOptions>
   exemplarTraceIdDestinations: ExemplarTraceIdDestination[] | undefined;
   lookupsDisabled: boolean;
   customQueryParameters: any;
+  exemplarErrors: Subject<FetchError> = new Subject();
 
   constructor(
     instanceSettings: DataSourceInstanceSettings<PromOptions>,
@@ -308,7 +309,16 @@ export class PrometheusDatasource extends DataSourceApi<PromQuery, PromOptions>
       }
 
       if (query.exemplar) {
-        return this.getExemplars(query).pipe(filterAndMapResponse);
+        return this.getExemplars(query).pipe(
+          catchError((err: FetchError) => {
+            this.exemplarErrors.next(err);
+            return of({
+              data: [],
+              state: LoadingState.Done,
+            });
+          }),
+          filterAndMapResponse
+        );
       }
 
       return this.performTimeSeriesQuery(query, query.start, query.end).pipe(filterAndMapResponse);
@@ -346,7 +356,16 @@ export class PrometheusDatasource extends DataSourceApi<PromQuery, PromOptions>
       }
 
       if (query.exemplar) {
-        return this.getExemplars(query).pipe(filterAndMapResponse);
+        return this.getExemplars(query).pipe(
+          catchError((err: FetchError) => {
+            this.exemplarErrors.next(err);
+            return of({
+              data: [],
+              state: LoadingState.Done,
+            });
+          }),
+          filterAndMapResponse
+        );
       }
 
       return this.performTimeSeriesQuery(query, query.start, query.end).pipe(filterAndMapResponse);