grafana/public/app/plugins/datasource/jaeger/datasource.ts

import {
  dateMath,
  DateTime,
  MutableDataFrame,
  DataSourceApi,
  DataSourceInstanceSettings,
  DataQueryRequest,
  DataQueryResponse,
  DataQuery,
} from '@grafana/data';
import { getBackendSrv } from '@grafana/runtime';

import { getTimeSrv } from 'app/features/dashboard/services/TimeSrv';
import { DatasourceRequestOptions } from 'app/core/services/backend_srv';
import { serializeParams } from '../../../core/utils/fetch';

import { Observable, from, of } from 'rxjs';

export type JaegerQuery = {
  query: string;
} & DataQuery;

export class JaegerDatasource extends DataSourceApi<JaegerQuery> {
  constructor(private instanceSettings: DataSourceInstanceSettings) {
    super(instanceSettings);
  }

  _request(apiUrl: string, data?: any, options?: DatasourceRequestOptions): Observable<Record<string, any>> {
    // Hack for proxying metadata requests
    const baseUrl = `/api/datasources/proxy/${this.instanceSettings.id}`;
    const params = data ? serializeParams(data) : '';
    const url = `${baseUrl}${apiUrl}${params.length ? `?${params}` : ''}`;
    const req = {
      ...options,
      url,
    };

    return from(getBackendSrv().datasourceRequest(req));
  }

  async metadataRequest(url: string, params?: Record<string, any>) {
    const res = await this._request(url, params, { silent: true }).toPromise();
    return res.data.data;
  }

  query(options: DataQueryRequest<JaegerQuery>): Observable<DataQueryResponse> {
    //http://localhost:16686/search?end=1573338717880000&limit=20&lookback=6h&maxDuration&minDuration&service=app&start=1573317117880000
    const url =
      options.targets.length && options.targets[0].query
        ? `${this.instanceSettings.url}/trace/${options.targets[0].query}?uiEmbed=v0`
        : '';

    return of({
      data: [
        new MutableDataFrame({
          fields: [
            {
              name: 'url',
              values: [url],
            },
          ],
        }),
      ],
    });
  }

  async testDatasource(): Promise<any> {
    return true;
  }

  getTime(date: string | DateTime, roundUp: boolean) {
    if (typeof date === 'string') {
      date = dateMath.parse(date, roundUp);
    }
    return date.valueOf() * 1000;
  }

  getTimeRange(): { start: number; end: number } {
    const range = getTimeSrv().timeRange();
    return {
      start: this.getTime(range.from, false),
      end: this.getTime(range.to, true),
    };
  }
}