From 951876b46562f9a64c1e4ae0c5007738fc84e372 Mon Sep 17 00:00:00 2001
From: Brendan O'Handley <brendan.ohandley@grafana.com>
Date: Mon, 11 Sep 2023 12:13:16 -0400
Subject: [PATCH] Prometheus: Add classic query option to variable query editor
 (#74060)

* add classic query to variable query editor

* copy fixes

* update test
---
 .../prometheus/template-variables/index.md    | 15 +++--
 .../components/VariableQueryEditor.test.tsx   | 36 +++++++++-
 .../components/VariableQueryEditor.tsx        | 66 ++++++++++++++++---
 .../migrations/variableMigration.ts           |  4 +-
 .../plugins/datasource/prometheus/types.ts    |  2 +
 5 files changed, 103 insertions(+), 20 deletions(-)

diff --git a/docs/sources/datasources/prometheus/template-variables/index.md b/docs/sources/datasources/prometheus/template-variables/index.md
index 5e4c66520cd..3085d3dcf5f 100644
--- a/docs/sources/datasources/prometheus/template-variables/index.md
+++ b/docs/sources/datasources/prometheus/template-variables/index.md
@@ -31,13 +31,14 @@ You have the option to use several different variable types, but variables of th
 
 Select a Prometheus data source query type and enter the required inputs:
 
-| Query Type     | Input(\* required)        | Description                                                                           | Used API endpoints                             |
-| -------------- | ------------------------- | ------------------------------------------------------------------------------------- | ---------------------------------------------- |
-| `Label names`  | `metric`                  | Returns a list of all label names matching the specified `metric` regex.              | /api/v1/labels                                 |
-| `Label values` | `label`\*, `metric`       | Returns a list of label values for the `label` in all metrics or the optional metric. | /api/v1/label/`label`/values or /api/v1/series |
-| `Metrics`      | `metric`                  | Returns a list of metrics matching the specified `metric` regex.                      | /api/v1/label/\_\_name\_\_/values              |
-| `Query result` | `query`                   | Returns a list of Prometheus query result for the `query`.                            | /api/v1/query                                  |
-| `Series query` | `metric`, `label` or both | Returns a list of time series associated with the entered data.                       | /api/v1/series                                 |
+| Query Type      | Input(\* required)        | Description                                                                                                                                                   | Used API endpoints                             |
+| --------------- | ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------- |
+| `Label names`   | `metric`                  | Returns a list of all label names matching the specified `metric` regex.                                                                                      | /api/v1/labels                                 |
+| `Label values`  | `label`\*, `metric`       | Returns a list of label values for the `label` in all metrics or the optional metric.                                                                         | /api/v1/label/`label`/values or /api/v1/series |
+| `Metrics`       | `metric`                  | Returns a list of metrics matching the specified `metric` regex.                                                                                              | /api/v1/label/\_\_name\_\_/values              |
+| `Query result`  | `query`                   | Returns a list of Prometheus query result for the `query`.                                                                                                    | /api/v1/query                                  |
+| `Series query`  | `metric`, `label` or both | Returns a list of time series associated with the entered data.                                                                                               | /api/v1/series                                 |
+| `Classic query` | classic query string      | Deprecated, classic version of variable query editor. Enter a string with the query type using a syntax like the following: `label_values(<metric>, <label>)` | all                                            |
 
 For details on _metric names_, _label names_, and _label values_, refer to the [Prometheus documentation](http://prometheus.io/docs/concepts/data_model/#metric-names-and-labels).
 
diff --git a/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.test.tsx b/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.test.tsx
index 8a722907550..ae76f2a2dcc 100644
--- a/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.test.tsx
+++ b/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.test.tsx
@@ -149,6 +149,7 @@ describe('PromVariableQueryEditor', () => {
     await waitFor(() => expect(screen.getByText('Metrics')).toBeInTheDocument());
     await waitFor(() => expect(screen.getByText('Query result')).toBeInTheDocument());
     await waitFor(() => expect(screen.getByText('Series query')).toBeInTheDocument());
+    await waitFor(() => expect(screen.getByText('Classic query')).toBeInTheDocument());
   });
 
   test('Calls onChange for label_names(match) query', async () => {
@@ -167,10 +168,11 @@ describe('PromVariableQueryEditor', () => {
     expect(onChange).toHaveBeenCalledWith({
       query: 'label_names(that)',
       refId,
+      qryType: 0,
     });
   });
 
-  test('Calls onChange for label_names, label_values, metrics, and query result queries', async () => {
+  test('Calls onChange for label_names, label_values, metrics, query result and and classic query.', async () => {
     const onChange = jest.fn();
 
     props.query = {
@@ -184,8 +186,9 @@ describe('PromVariableQueryEditor', () => {
     await selectOptionInTest(screen.getByLabelText('Query type'), 'Label values');
     await selectOptionInTest(screen.getByLabelText('Query type'), 'Metrics');
     await selectOptionInTest(screen.getByLabelText('Query type'), 'Query result');
+    await selectOptionInTest(screen.getByLabelText('Query type'), 'Classic query');
 
-    expect(onChange).toHaveBeenCalledTimes(4);
+    expect(onChange).toHaveBeenCalledTimes(5);
   });
 
   test('Does not call onChange for series query', async () => {
@@ -220,6 +223,7 @@ describe('PromVariableQueryEditor', () => {
       expect(onChange).toHaveBeenCalledWith({
         query: 'metrics(a)',
         refId,
+        qryType: 2,
       })
     );
   });
@@ -230,6 +234,7 @@ describe('PromVariableQueryEditor', () => {
     props.query = {
       refId: 'test',
       query: 'label_names()',
+      qryType: 0,
     };
 
     render(<PromVariableQueryEditor {...props} onChange={onChange} />);
@@ -243,6 +248,7 @@ describe('PromVariableQueryEditor', () => {
       expect(onChange).toHaveBeenCalledWith({
         query: 'label_values(this)',
         refId,
+        qryType: 1,
       })
     );
   });
@@ -270,6 +276,7 @@ describe('PromVariableQueryEditor', () => {
       expect(onChange).toHaveBeenCalledWith({
         query: 'label_values(that,this)',
         refId,
+        qryType: 1,
       })
     );
   });
@@ -292,6 +299,7 @@ describe('PromVariableQueryEditor', () => {
     expect(onChange).toHaveBeenCalledWith({
       query: 'query_result(a)',
       refId,
+      qryType: 3,
     });
   });
 
@@ -313,6 +321,30 @@ describe('PromVariableQueryEditor', () => {
     expect(onChange).toHaveBeenCalledWith({
       query: '{a: "example"}',
       refId,
+      qryType: 4,
+    });
+  });
+
+  test('Calls onChange for classic query onBlur', async () => {
+    const onChange = jest.fn();
+
+    props.query = {
+      refId: 'test',
+      qryType: 5,
+      query: 'label_values(instance)',
+    };
+
+    render(<PromVariableQueryEditor {...props} onChange={onChange} />);
+
+    const labelSelect = screen.getByLabelText('Classic Query');
+    await userEvent.click(labelSelect);
+    const functionSelect = screen.getByLabelText('Query type').parentElement!;
+    await userEvent.click(functionSelect);
+
+    expect(onChange).toHaveBeenCalledWith({
+      query: 'label_values(instance)',
+      refId,
+      qryType: 5,
     });
   });
 });
diff --git a/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.tsx b/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.tsx
index c448b4058df..d18bc7003b1 100644
--- a/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.tsx
+++ b/public/app/plugins/datasource/prometheus/components/VariableQueryEditor.tsx
@@ -26,6 +26,7 @@ export const variableOptions = [
   { label: 'Metrics', value: QueryType.MetricNames },
   { label: 'Query result', value: QueryType.VarQueryResult },
   { label: 'Series query', value: QueryType.SeriesQuery },
+  { label: 'Classic query', value: QueryType.ClassicQuery },
 ];
 
 export type Props = QueryEditorProps<PrometheusDatasource, PromQuery, PromOptions, PromVariableQuery>;
@@ -49,6 +50,9 @@ export const PromVariableQueryEditor = ({ onChange, query, datasource }: Props)
   // seriesQuery is only a whole
   const [seriesQuery, setSeriesQuery] = useState('');
 
+  // the original variable query implementation
+  const [classicQuery, setClassicQuery] = useState('');
+
   // list of label names for label_values(), /api/v1/labels, contains the same results as label_names() function
   const [labelOptions, setLabelOptions] = useState<Array<SelectableValue<string>>>([]);
 
@@ -59,17 +63,24 @@ export const PromVariableQueryEditor = ({ onChange, query, datasource }: Props)
     if (!query) {
       return;
     }
-    // 1. Changing from standard to custom variable editor changes the string attr from expr to query
-    // 2. jsonnet grafana as code passes a variable as a string
-    const variableQuery = variableMigration(query);
 
-    setLabelNamesMatch(variableQuery.match ?? '');
-    setQryType(variableQuery.qryType);
-    setLabel(variableQuery.label ?? '');
-    setMetric(variableQuery.metric ?? '');
-    setLabelFilters(variableQuery.labelFilters ?? []);
-    setVarQuery(variableQuery.varQuery ?? '');
-    setSeriesQuery(variableQuery.seriesQuery ?? '');
+    if (query.qryType === QueryType.ClassicQuery) {
+      setQryType(query.qryType);
+      setClassicQuery(query.query ?? '');
+    } else {
+      // 1. Changing from standard to custom variable editor changes the string attr from expr to query
+      // 2. jsonnet grafana as code passes a variable as a string
+      const variableQuery = variableMigration(query);
+
+      setLabelNamesMatch(variableQuery.match ?? '');
+      setQryType(variableQuery.qryType);
+      setLabel(variableQuery.label ?? '');
+      setMetric(variableQuery.metric ?? '');
+      setLabelFilters(variableQuery.labelFilters ?? []);
+      setVarQuery(variableQuery.varQuery ?? '');
+      setSeriesQuery(variableQuery.seriesQuery ?? '');
+      setClassicQuery(variableQuery.classicQuery ?? '');
+    }
   }, [query]);
 
   // set the label names options for the label values var query
@@ -116,6 +127,7 @@ export const PromVariableQueryEditor = ({ onChange, query, datasource }: Props)
       match: labelNamesMatch,
       varQuery,
       seriesQuery,
+      classicQuery,
       refId: 'PrometheusVariableQueryEditor-VariableQuery',
     };
 
@@ -128,6 +140,7 @@ export const PromVariableQueryEditor = ({ onChange, query, datasource }: Props)
     // setting query.query property allows for update of variable definition
     onChange({
       query: queryString,
+      qryType: updatedVar.qryType,
       refId,
     });
   };
@@ -200,6 +213,10 @@ export const PromVariableQueryEditor = ({ onChange, query, datasource }: Props)
     setSeriesQuery(e.currentTarget.value);
   };
 
+  const onClassicQueryChange = (e: FormEvent<HTMLInputElement>) => {
+    setClassicQuery(e.currentTarget.value);
+  };
+
   const promVisualQuery = useCallback(() => {
     return { metric: metric, labels: labelFilters, operations: [] };
   }, [metric, labelFilters]);
@@ -371,6 +388,35 @@ export const PromVariableQueryEditor = ({ onChange, query, datasource }: Props)
           </InlineField>
         </InlineFieldRow>
       )}
+
+      {qryType === QueryType.ClassicQuery && (
+        <InlineFieldRow>
+          <InlineField
+            label="Classic Query"
+            labelWidth={20}
+            tooltip={
+              <div>
+                The original implemetation of the Prometheus variable query editor. Enter a string with the correct
+                query type and parameters as described in these docs. For example, label_values(label, metric).
+              </div>
+            }
+          >
+            <Input
+              type="text"
+              aria-label="Classic Query"
+              placeholder="Classic Query"
+              value={classicQuery}
+              onChange={onClassicQueryChange}
+              onBlur={() => {
+                if (qryType === QueryType.ClassicQuery && classicQuery) {
+                  onChangeWithVariableString({ qryType });
+                }
+              }}
+              width={100}
+            />
+          </InlineField>
+        </InlineFieldRow>
+      )}
     </>
   );
 };
diff --git a/public/app/plugins/datasource/prometheus/migrations/variableMigration.ts b/public/app/plugins/datasource/prometheus/migrations/variableMigration.ts
index ec0df3dc5da..8cf87585d5d 100644
--- a/public/app/plugins/datasource/prometheus/migrations/variableMigration.ts
+++ b/public/app/plugins/datasource/prometheus/migrations/variableMigration.ts
@@ -123,7 +123,9 @@ export function migrateVariableEditorBackToVariableSupport(QueryVariable: PromVa
       const varQuery = removeLineBreaks(QueryVariable.varQuery);
       return `query_result(${varQuery})`;
     case QueryType.SeriesQuery:
-      return '' + QueryVariable.seriesQuery;
+      return QueryVariable.seriesQuery ?? '';
+    case QueryType.ClassicQuery:
+      return QueryVariable.classicQuery ?? '';
   }
 
   return '';
diff --git a/public/app/plugins/datasource/prometheus/types.ts b/public/app/plugins/datasource/prometheus/types.ts
index f74d9a6a7bf..266a0f089a0 100644
--- a/public/app/plugins/datasource/prometheus/types.ts
+++ b/public/app/plugins/datasource/prometheus/types.ts
@@ -183,6 +183,7 @@ export enum PromVariableQueryType {
   MetricNames,
   VarQueryResult,
   SeriesQuery,
+  ClassicQuery,
 }
 
 export interface PromVariableQuery extends DataQuery {
@@ -195,6 +196,7 @@ export interface PromVariableQuery extends DataQuery {
   seriesQuery?: string;
   labelFilters?: QueryBuilderLabelFilter[];
   match?: string;
+  classicQuery?: string;
 }
 
 export type StandardPromVariableQuery = {