private setupProxyListener(server: HapiServer) {
    const legacyProxy = new LegacyPlatformProxy(
      this.logger.get('legacy', 'proxy'),
      server.listener
    );

    // We register Kibana proxy middleware right before we start server to allow
    // all new platform plugins register their routes, so that `legacyProxy`
    // handles only requests that aren't handled by the new platform.
    server.route({
      path: '/{p*}',
      method: '*',
      options: {
        payload: {
          output: 'stream',
          parse: false,
          timeout: false,
          // Having such a large value here will allow legacy routes to override
          // maximum allowed payload size set in the core http server if needed.
          maxBytes: Number.MAX_SAFE_INTEGER,
        },
      },
      handler: async ({ raw: { req, res } }, responseToolkit) => {
        if (this.kbnServer === undefined) {
          this.log.debug(`Kibana server is not ready yet ${req.method}:${req.url}.`);

          // If legacy server is not ready yet (e.g. it's still in optimization phase),
          // we should let client know that and ask to retry after 30 seconds.
          return responseToolkit
            .response('Kibana server is not ready yet')
            .code(503)
            .header('Retry-After', '30');
        }

        this.log.trace(`Request will be handled by proxy ${req.method}:${req.url}.`);

        // Forward request and response objects to the legacy platform. This method
        // is used whenever new platform doesn't know how to handle the request.
        legacyProxy.emit('request', req, res);

        return responseToolkit.abandon;
      },
    });

    return legacyProxy;
  }

  public async stop() {
    this.log.info('stopping HTTPS redirect server');

    if (this.server !== undefined) {
      await this.server.stop();
      this.server = undefined;
    }
  }

  public async stop() {
    if (this.server === undefined) {
      return;
    }

    this.log.debug('stopping http --> https redirect server');
    await this.server.stop();
    this.server = undefined;
  }

  public async stop() {
    this.log.info('stopping basepath proxy server');

    if (this.server !== undefined) {
      await this.server.stop();
      this.server = undefined;
    }

    if (this.httpsAgent !== undefined) {
      this.httpsAgent.destroy();
      this.httpsAgent = undefined;
    }
  }

  public async stop() {
    if (this.server === undefined) {
      return;
    }

    this.log.debug('stopping basepath proxy server');
    await this.server.stop();
    this.server = undefined;

    if (this.httpsAgent !== undefined) {
      this.httpsAgent.destroy();
      this.httpsAgent = undefined;
    }
  }