Prometheus: Add resource for suggestions that include scopes/adhoc filters (#94001)

Co-authored-by: Dominik Prokop <dominik.prokop@grafana.com>
Co-authored-by: Bogdan Matei <bogdan.matei@grafana.com>

packages/grafana-prometheus/src/datasource.ts

@@ -74,7 +74,13 @@ import {
 import { PrometheusVariableSupport } from './variables';
 
 const ANNOTATION_QUERY_STEP_DEFAULT = '60s';
-const GET_AND_POST_METADATA_ENDPOINTS = ['api/v1/query', 'api/v1/query_range', 'api/v1/series', 'api/v1/labels'];
+const GET_AND_POST_METADATA_ENDPOINTS = [
+  'api/v1/query',
+  'api/v1/query_range',
+  'api/v1/series',
+  'api/v1/labels',
+  'suggestions',
+];
 
 export const InstantQueryRefIdIndex = '-Instant';
 
@@ -263,7 +269,9 @@ export class PrometheusDatasource
             .join('&');
       }
     } else {
-      options.headers!['Content-Type'] = 'application/x-www-form-urlencoded';
+      if (!options.headers!['Content-Type']) {
+        options.headers!['Content-Type'] = 'application/x-www-form-urlencoded';
+      }
       options.data = data;
     }
 
@@ -599,6 +607,20 @@ export class PrometheusDatasource
   // it is used in metric_find_query.ts
   // and in Tempo here grafana/public/app/plugins/datasource/tempo/QueryEditor/ServiceGraphSection.tsx
   async getTagKeys(options: DataSourceGetTagKeysOptions<PromQuery>): Promise<MetricFindValue[]> {
+    if (config.featureToggles.promQLScope && !!options) {
+      const suggestions = await this.languageProvider.fetchSuggestions(
+        options.timeRange,
+        options.queries,
+        options.scopes,
+        options.filters
+      );
+
+      // filter out already used labels and empty labels
+      return suggestions
+        .filter((labelName) => !!labelName && !options.filters.find((filter) => filter.key === labelName))
+        .map((k) => ({ value: k, text: k }));
+    }
+
     if (!options || options.filters.length === 0) {
       await this.languageProvider.fetchLabels(options.timeRange, options.queries);
       return this.languageProvider.getLabelKeys().map((k) => ({ value: k, text: k }));
@@ -621,6 +643,21 @@ export class PrometheusDatasource
 
   // By implementing getTagKeys and getTagValues we add ad-hoc filters functionality
   async getTagValues(options: DataSourceGetTagValuesOptions<PromQuery>) {
+    const requestId = `[${this.uid}][${options.key}]`;
+    if (config.featureToggles.promQLScope) {
+      return (
+        await this.languageProvider.fetchSuggestions(
+          options.timeRange,
+          options.queries,
+          options.scopes,
+          options.filters,
+          options.key,
+          undefined,
+          requestId
+        )
+      ).map((v) => ({ value: v, text: v }));
+    }
+
     const labelFilters: QueryBuilderLabelFilter[] = options.filters.map((f) => ({
       label: f.key,
       value: f.value,
@@ -630,7 +667,6 @@ export class PrometheusDatasource
     const expr = promQueryModeller.renderLabels(labelFilters);
 
     if (this.hasLabelsMatchAPISupport()) {
-      const requestId = `[${this.uid}][${options.key}]`;
       return (
         await this.languageProvider.fetchSeriesValuesWithMatch(options.key, expr, requestId, options.timeRange)
       ).map((v) => ({

packages/grafana-prometheus/src/language_provider.ts

@@ -6,8 +6,12 @@ import {
   AbstractLabelMatcher,
   AbstractLabelOperator,
   AbstractQuery,
+  AdHocVariableFilter,
   getDefaultTimeRange,
   LanguageProvider,
+  Scope,
+  scopeFilterOperatorMap,
+  ScopeSpecFilter,
   TimeRange,
 } from '@grafana/data';
 import { BackendSrvRequest } from '@grafana/runtime';
@@ -407,6 +411,64 @@ export default class PromQlLanguageProvider extends LanguageProvider {
     const values = await Promise.all(DEFAULT_KEYS.map((key) => this.fetchLabelValues(key)));
     return DEFAULT_KEYS.reduce((acc, key, i) => ({ ...acc, [key]: values[i] }), {});
   });
+
+  /**
+   * Fetch labels or values for a label based on the queries, scopes, filters and time range
+   * @param timeRange
+   * @param queries
+   * @param scopes
+   * @param adhocFilters
+   * @param labelName
+   * @param limit
+   * @param requestId
+   */
+  fetchSuggestions = async (
+    timeRange?: TimeRange,
+    queries?: PromQuery[],
+    scopes?: Scope[],
+    adhocFilters?: AdHocVariableFilter[],
+    labelName?: string,
+    limit?: number,
+    requestId?: string
+  ): Promise<string[]> => {
+    if (timeRange) {
+      this.timeRange = timeRange;
+    }
+
+    const url = '/suggestions';
+    const timeParams = this.datasource.getAdjustedInterval(this.timeRange);
+    const value = await this.request(
+      url,
+      [],
+      {
+        labelName,
+        queries: queries?.map((q) => q.expr),
+        scopes: scopes?.reduce<ScopeSpecFilter[]>((acc, scope) => {
+          acc.push(...scope.spec.filters);
+
+          return acc;
+        }, []),
+        adhocFilters: adhocFilters?.map((filter) => ({
+          key: filter.key,
+          operator: scopeFilterOperatorMap[filter.operator],
+          value: filter.value,
+          values: filter.values,
+        })),
+        limit,
+        ...timeParams,
+      },
+      {
+        ...(requestId && { requestId }),
+        headers: {
+          ...this.getDefaultCacheHeaders()?.headers,
+          'Content-Type': 'application/json',
+        },
+        method: 'POST',
+      }
+    );
+
+    return value ?? [];
+  };
 }
 
 function getNameLabelValue(promQuery: string, tokens: Array<string | Prism.Token>): string {