it works

package.json

@@ -20,6 +20,7 @@
     "nodemon": "^2.0.20",
     "ts-loader": "^9.4.2",
     "typescript": "^4.9.4",
+    "uuid": "^9.0.0",
     "webpack": "^5.75.0",
     "webpack-cli": "^5.0.1"
   }

src/models/target.ts

@@ -0,0 +1,8 @@
+import { DataSourceSettings, PanelModel } from '../types';
+
+export class Target {
+  constructor(
+    public panel: PanelModel,
+    public datasource: DataSourceSettings,
+  ) {}
+}

src/routes/tasks.ts

@@ -1,26 +1,24 @@
-import { Target } from '../types/target';
 import { exporterFactory } from '../services/exporter.factory';
 import { EXPORTED_PATH } from '../config';
 
-import { Task, TaskTableRowConfig } from '../types';
+import { ExportTask } from '../types';
 
 import * as express from 'express';
 
+import * as _ from 'lodash';
+
 import * as path from 'path';
 import * as fs from 'fs';
 
 type TRequest = {
   body: {
-    from: string,
-    to: string,
-    username: string,
-    tasks: Task[],
+    task: ExportTask,
     url: string,
   },
 };
 
 async function getTasks(req, res) {
-  const resp: TaskTableRowConfig[] = [];
+  const resp: ExportTask[] = [];
   fs.readdir(EXPORTED_PATH, (err, items) => {
     if(err) {
       console.error(err);
@@ -34,15 +32,7 @@ async function getTasks(req, res) {
         // TODO: read async
         let data = fs.readFileSync(path.join(EXPORTED_PATH, item), 'utf8');
         let status = JSON.parse(data);
-        resp.push({
-          timestamp: status.time,
-          username: status.username,
-          datasourceRef: status.datasourceRef,
-          rowsCount: status.exportedRows,
-          progress: status.progress,
-          status: status.status,
-          filename: file.name,
-        });
+        resp.push(status);
       }
 
       res.status(200).send(resp);
@@ -51,38 +41,36 @@ async function getTasks(req, res) {
 }
 
 async function addTask(req: TRequest, res) {
-
   const body = req.body;
 
   const clientUrl = body.url;
-  const from = parseInt(body.from);
-  const to = parseInt(body.to);
-  const username = body.username;
-  const tasks = body.tasks;
+  if (_.isEmpty(clientUrl)) {
+    res.status(400).send('"url" field is required');
+  }
+  const task = body.task;
+  if (_.isEmpty(task)) {
+    res.status(400).send('"task" field is required');
+  }
 
   const datasourceUrl = `${new URL(clientUrl).origin}/api/ds/query`;
 
+  const from = +task.timeRange.from;
+  const to = +task.timeRange.to;
   if (isNaN(from) || isNaN(to)) {
     res.status(400).send('Range error: please fill both "from" and "to" fields');
   } else if (from >= to) {
     res.status(400).send('Range error: "from" should be less than "to"');
-  } else {
-    const names = tasks.map(item => item.datasource.name).join(', ');
+  }
 
-    const targets = tasks.map((task: Task) => new Target(
-      task.panel,
-      task.datasource,
-    ));
   const exporter = exporterFactory.getExporter();
-    exporter.export(targets, datasourceUrl, username, from, to);
-    res.status(200).send(`Exporting ${names} data from ${new Date(from).toLocaleString()} to ${new Date(to).toLocaleString()}`);
-  }
+  exporter.export(task, datasourceUrl);
+  res.status(200).send(`Export process started`);
 }
 
 async function deleteTask(req, res) {
-  let filename = req.body.filename;
-  let csvFilePath = path.join(EXPORTED_PATH, `${filename}.csv`);
-  let jsonFilePath = path.join(EXPORTED_PATH, `${filename}.json`);
+  let taskId = req.body.taskId;
+  let csvFilePath = path.join(EXPORTED_PATH, `${taskId}.csv`);
+  let jsonFilePath = path.join(EXPORTED_PATH, `${taskId}.json`);
 
   if(fs.existsSync(csvFilePath)) {
     fs.unlink(csvFilePath, err => console.error(err));

src/services/exporter.ts

@@ -1,14 +1,15 @@
-import { Target } from '../types/target';
+import { Target } from '../models/target';
 import { URL } from 'url';
 import { apiKeys } from '../config';
 import { promisify } from '../utils';
-import { ExportStatus } from '../types/export-status';
-import { DataSourceRef } from '../types';
+import { DashboardQuery, ExportProgress, ExportStatus, ExportTask } from '../types';
 
 import { QueryConfig, queryByConfig } from '@corpglory/tsdb-kit';
 // TODO: export QueryType directly from @corpglory/tsdb-kit
 import { QueryType } from '@corpglory/tsdb-kit/lib/connectors';
 
+import { v4 as uuidv4 } from 'uuid';
+
 import * as moment from 'moment';
 import * as csv from 'fast-csv';
 import * as fs from 'fs';
@@ -17,67 +18,32 @@ import * as _ from 'lodash';
 
 const MS_IN_DAY = 24 * 60 * 60 * 1000;
 
+const DEFAULT_PROGRESS = {
+  exportedRowsCount: 0,
+  progress: 0,
+  status: ExportStatus.EXPORTING,
+};
+
 export class Exporter {
-  private exportedRows = 0;
-  private createdTimestamp: number;
-  private username: string;
-  private datasourceRef: DataSourceRef;
-  private from: number;
-  private to: number;
-
-  private initCsvStream() {
-    const csvStream = csv.createWriteStream({ headers: true })
-      .on('error', error => console.error(error));
+  private _task: ExportTask;
 
-    const writableStream = fs.createWriteStream(this.getFilePath('csv'));
+  public async export(task: ExportTask, datasourceUrl: string) {
+    this._task = _.cloneDeep(task);
+    this._task.id = uuidv4();
+    this._task.progress = _.cloneDeep(DEFAULT_PROGRESS);
 
-    csvStream.pipe(writableStream);
-    writableStream.on('finish', async () => {
-      console.log(`Everything is written to ${this.getFilename('csv')}`);
-      await this.updateStatus(ExportStatus.FINISHED, 1);
-    })
+    const targets = task.queries.map((query: DashboardQuery) => new Target(
+      query.panel,
+      query.datasource,
+    ));
 
-    return csvStream;
-  }
+    this._validateTargets(datasourceUrl, targets);
 
-  public async updateStatus(status: string, progress: number, error?: string) {
-    try {
-      let time = moment().valueOf();
-      let data = {
-        time,
-        progress,
-        status,
-        error,
-        username: this.username,
-        exportedRows: this.exportedRows,
-        datasourceRef: this.datasourceRef,
-        from: this.from,
-        to: this.to,
-      };
+    await this._updateProgress();
 
-      await promisify(fs.writeFile, this.getFilePath('json'), JSON.stringify(data), 'utf8')
-    } catch(err) {
-      console.error(err);
-      throw new Error('Can`t write file');
-    }
-  }
-
-  // TODO: rename `data` to `targets` or `queries`
-  public async export(data: Target[], datasourceUrl: string, username: string, from: number, to: number) {
-    this.username = username;
-    this.from = from;
-    this.to = to;
-
-    this.validateTargets(datasourceUrl, data);
-
-    const targets = data.map(target => {
-      console.log('target', {
-        ...target.datasource,
-        url: datasourceUrl
-      });
-      return {
-        ...target,
-        metric: new QueryConfig(
+    const queryConfigs = targets.map(
+      target =>
+        new QueryConfig(
           QueryType.GRAFANA,
           {
             ...target.datasource,
@@ -85,19 +51,16 @@ export class Exporter {
           },
           target.panel.targets
         )
-      }
-    });
-
-    const datasource = data[0].datasource;
-    this.datasourceRef = { uid: datasource.uid, type: datasource.type };
-
-    await this.updateStatus(ExportStatus.EXPORTING, 0);
+    );
 
-    const stream = this.initCsvStream();
+    let from = +this._task.timeRange.from;
+    let to = +this._task.timeRange.to;
     const days = Math.ceil((to - from) / MS_IN_DAY);
 
     console.log(`Total days: ${days}`);
 
+    const stream = this._initCsvStream();
+    try {
       for(let day = 0; day < days; day++) {
         to = from + MS_IN_DAY;
 
@@ -106,36 +69,69 @@ export class Exporter {
         let columns = [];
         let values = [];
 
-      for(const [index, target] of targets.entries()) {
+        for(const queryConfig of queryConfigs) {
           const host = new URL(datasourceUrl).origin;
           const apiKey = apiKeys[host];
 
-        try {
-          const datasourceMetrics = await queryByConfig(target.metric, datasourceUrl, from, to, apiKey);
+          const datasourceMetrics = await queryByConfig(queryConfig, datasourceUrl, from, to, apiKey);
 
           columns = datasourceMetrics.columns;
           values = datasourceMetrics.values;
-        } catch (e) {
-          await this.updateStatus(ExportStatus.ERROR, (day + 1) / days, e.message);
-          break;
-        }
         }
 
         if(columns.length > 0) {
           console.log('values', values);
-        this.writeCsv(stream, {
+          this._writeCsv(stream, {
             columns,
             values,
           });
         }
-      await this.updateStatus(ExportStatus.EXPORTING, (day + 1) / days);
+        await this._updateProgress({ status: ExportStatus.EXPORTING, progress: (day + 1) / days });
 
         from += MS_IN_DAY;
       }
+    } catch (e) {
+      await this._updateProgress({ status: ExportStatus.ERROR, errorMessage: e.message });
+    }
     stream.end();
   }
 
-  private validateTargets(datasourceUrl: string, targets: Target[]) {
+  private _initCsvStream() {
+    const csvStream = csv.createWriteStream({ headers: true })
+      .on('error', async e => await this._updateProgress({ status: ExportStatus.ERROR, errorMessage: e.message }));
+
+    const writableStream = fs.createWriteStream(this._getFilePath('csv'));
+
+    csvStream.pipe(writableStream);
+    writableStream.on('finish', async () => {
+      if(this._task.progress.status !== ExportStatus.ERROR) {
+        console.log(`Everything is written to ${this._getFilename('csv')}`);
+        await this._updateProgress({ status: ExportStatus.FINISHED, progress: 1 });
+      } else {
+        console.log(`${this._getFilename('csv')} export is finished with error`);
+      }
+    })
+
+    return csvStream;
+  }
+
+  private async _updateProgress(progress?: Partial<ExportProgress>) {
+    try {
+      let time = moment().valueOf();
+
+      const data = {
+        ...this._task,
+        progress: _.assign(this._task.progress, progress, { time }),
+      };
+
+      await promisify(fs.writeFile, this._getFilePath('json'), JSON.stringify(data), 'utf8');
+    } catch(err) {
+      console.error(err);
+      throw new Error('Can`t write file');
+    }
+  }
+
+  private _validateTargets(datasourceUrl: string, targets: Target[]) {
     if(!targets || !Array.isArray(targets)) {
       throw new Error('Incorrect targets format');
     }
@@ -152,7 +148,7 @@ export class Exporter {
     }
   }
 
-  private writeCsv(stream, series) {
+  private _writeCsv(stream, series) {
     for(let row of series.values) {
       const isEmpty = _.every(
         _.slice(row, 1),
@@ -164,20 +160,17 @@ export class Exporter {
           csvRow[series.columns[col]] = row[col];
         }
         stream.write(csvRow);
-        this.exportedRows++;
+        this._task.progress.exportedRowsCount++;
       }
     }
   }
 
-  private getFilename(extension) {
-    if(this.createdTimestamp === undefined) {
-      this.createdTimestamp = moment().valueOf();
-    }
-    return `${this.createdTimestamp}.${this.datasourceRef.uid}.${extension}`;
+  private _getFilename(extension: string): string {
+    return `${this._task.id}.${extension}`;
   }
 
-  private getFilePath(extension) {
-    let filename = this.getFilename(extension);
+  private _getFilePath(extension: string): string {
+    let filename = this._getFilename(extension);
     return path.join(__dirname, `../exported/${filename}`);
   }
 }

src/types.ts

@@ -80,19 +80,33 @@ export interface PanelModel {
   alert?: any;
 }
 
-// TODO: rename to query
-export type Task = Omit<DataQuery, 'datasource'> & {
-  selected: boolean;
-  panel: PanelModel;
-  datasource: DataSourceSettings;
+export enum ExportStatus {
+  EXPORTING = 'exporting',
+  FINISHED = 'finished',
+  ERROR = 'error',
+}
+
+export type ExportProgress = {
+  time: number;
+  exportedRowsCount: number;
+  progress: number;
+  status: ExportStatus;
+  errorMessage?: string;
 };
 
-export type TaskTableRowConfig = {
-  timestamp: number;
+export type ExportTask = {
   username: string;
-  datasourceRef: DataSourceRef;
-  rowsCount: number;
-  progress: number;
-  status: string;
-  filename?: string;
+  queries: DashboardQuery[];
+  timeRange: {
+    from: number;
+    to: number;
+  };
+  progress?: ExportProgress;
+  id?: string;
+};
+
+export type DashboardQuery = DataQuery & {
+  selected: boolean;
+  panel: PanelModel;
+  datasource: DataSourceSettings;
 };

src/types/export-status.ts

@@ -1,5 +0,0 @@
-export enum ExportStatus {
-  EXPORTING = 'exporting',
-  FINISHED = 'finished',
-  ERROR = 'error',
-}

src/types/target.ts

@@ -1,8 +0,0 @@
-import { DataSourceSettings, PanelModel } from '.';
-
-export class Target {
-    constructor(
-      public panel: PanelModel,
-      public datasource: DataSourceSettings,
-    ) {}
-}

yarn.lock

@@ -1555,6 +1555,11 @@ utils-merge@1.0.1:
   resolved "https://registry.yarnpkg.com/utils-merge/-/utils-merge-1.0.1.tgz#9f95710f50a267947b2ccc124741c1028427e713"
   integrity sha512-pMZTvIkT1d+TFGvDOqodOclx0QWkkgi6Tdoa8gC8ffGAAqz9pzPTZWAybbsHHoED/ztMtkv/VoYTYyShUn81hA==
 
+uuid@^9.0.0:
+  version "9.0.0"
+  resolved "https://registry.yarnpkg.com/uuid/-/uuid-9.0.0.tgz#592f550650024a38ceb0c562f2f6aa435761efb5"
+  integrity sha512-MXcSTerfPa4uqyzStbRoTgt5XIe3x5+42+q1sDuy3R5MDk66URdLMOZe5aPX/SQd+kuYAh0FdP/pO28IkQyTeg==
+
 vary@~1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/vary/-/vary-1.1.2.tgz#2299f02c6ded30d4a5961b0b9f74524a18f634fc"