@elastic/synthetics/src/core/browser-service.ts

Elastic synthetic monitoring agent

/**
 * MIT License
 *
 * Copyright (c) 2020-present, Elastic NV
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

import { URL } from 'url';
import { createServer } from 'http';
import { createProxyServer } from 'http-proxy';
import { chromium } from 'playwright-core';
import { log } from './logger';

export class BrowserService {
  closeCallbacks = [];
  proxyServer = createServer();

  constructor(private options = { port: 9322 }) {}

  init() {
    const proxy = createProxyServer();

    this.proxyServer.on('upgrade', async (req, socket, head) => {
      const browserServer = await chromium.launchServer({ headless: true });
      const wsEndpoint = browserServer.wsEndpoint();
      const { pathname, origin } = new URL(wsEndpoint);
      req.url = pathname;
      log(`New browser: ${wsEndpoint}`);
      proxy.ws(req, socket, head, { target: origin });
      const closeBrowser = async () => {
        const index = this.closeCallbacks.indexOf(closeBrowser);
        if (index >= 0) {
          this.closeCallbacks.splice(index, 1);
        }
        await browserServer.close();
        log(`Socket closed: ${wsEndpoint}`);
      };
      this.closeCallbacks.push(closeBrowser);
      socket.on('close', closeBrowser);
      socket.on('error', closeBrowser);
    });

    this.proxyServer.listen(this.options.port, () => {
      log(`Listening on port: ${this.options.port}`);
    });
  }

  async dispose() {
    for (let i = 0; i < this.closeCallbacks.length; i++) {
      const callback = this.closeCallbacks[i];
      await callback();
    }
    this.closeCallbacks = [];

    await new Promise(resolve => {
      this.proxyServer.close(resolve);
    });
  }
}