| // Copyright 2019 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| import 'dart:async'; |
| import 'dart:io'; |
| |
| import 'package:meta/meta.dart'; |
| |
| import '../datastore/cocoon_config.dart'; |
| |
| import 'body.dart'; |
| import 'request_handler.dart'; |
| |
| /// A [RequestHandler] that acts as a proxy for another backend. |
| /// |
| /// All requests handled by this request handler will be forwarded (unmodified) |
| /// to the specified backend. |
| @immutable |
| class ProxyRequestHandler extends RequestHandler<Body> { |
| /// Creates a new [ProxyRequestHandler]. |
| const ProxyRequestHandler({ |
| @required Config config, |
| @required this.scheme, |
| @required this.host, |
| @required this.port, |
| }) : assert(scheme != null), |
| assert(host != null), |
| assert(port != null), |
| super(config: config); |
| |
| /// The URI scheme to use when forwarding requests (e.g. 'https'). |
| final String scheme; |
| |
| /// The host to use when forwarding requests. |
| final String host; |
| |
| /// The port to use when forwarding requests (e.g. 443 for HTTPS). |
| final int port; |
| |
| @override |
| Future<void> service(HttpRequest request) async { |
| final HttpClient httpClient = HttpClient()..autoUncompress = false; |
| final Uri forwardUri = |
| request.uri.replace(scheme: scheme, host: host, port: port); |
| final HttpClientRequest clientRequest = |
| await httpClient.openUrl(request.method, forwardUri); |
| clientRequest.followRedirects = false; |
| _transferHttpHeaders(from: request.headers, to: clientRequest.headers); |
| clientRequest.headers.set(HttpHeaders.hostHeader, '$host:$port'); |
| await request.cast<List<int>>().pipe(clientRequest); |
| await clientRequest.flush(); |
| final HttpClientResponse clientResponse = await clientRequest.close(); |
| final HttpResponse response = request.response; |
| response.statusCode = clientResponse.statusCode; |
| _transferHttpHeaders(from: clientResponse.headers, to: response.headers); |
| await clientResponse.pipe(response); |
| await response.flush(); |
| await response.close(); |
| } |
| |
| void _transferHttpHeaders( |
| {@required HttpHeaders from, @required HttpHeaders to}) { |
| to.clear(); |
| from.forEach((String name, List<String> values) { |
| for (String value in values) { |
| to.add(name, value); |
| } |
| }); |
| } |
| } |
