1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty5.example.http.cors;
17
18 import io.netty5.bootstrap.ServerBootstrap;
19 import io.netty5.channel.EventLoopGroup;
20 import io.netty5.channel.MultithreadEventLoopGroup;
21 import io.netty5.channel.nio.NioHandler;
22 import io.netty5.channel.socket.nio.NioServerSocketChannel;
23 import io.netty5.handler.logging.LogLevel;
24 import io.netty5.handler.logging.LoggingHandler;
25 import io.netty5.handler.ssl.SslContext;
26 import io.netty5.handler.ssl.SslContextBuilder;
27 import io.netty5.handler.ssl.util.SelfSignedCertificate;
28
29 /**
30 * This example server aims to demonstrate
31 * <a href="https://www.w3.org/TR/cors/">Cross Origin Resource Sharing</a> (CORS) in Netty.
32 * It does not have a client like most of the other examples, but instead has
33 * a html page that is loaded to try out CORS support in a web browser.
34 * <p>
35 *
36 * CORS is configured in {@link HttpCorsServerInitializer} and by updating the config you can
37 * try out various combinations, like using a specific origin instead of a
38 * wildcard origin ('*').
39 * <p>
40 *
41 * The file {@code src/main/resources/cors/cors.html} contains a very basic example client
42 * which can be used to try out different configurations. For example, you can add
43 * custom headers to force a CORS preflight request to make the request fail. Then
44 * to enable a successful request, configure the CorsHandler to allow that/those
45 * request headers.
46 *
47 * <h2>Testing CORS</h2>
48 * You can either load the file {@code src/main/resources/cors/cors.html} using a web server
49 * or load it from the file system using a web browser.
50 *
51 * <h3>Using a web server</h3>
52 * To test CORS support you can serve the file {@code src/main/resources/cors/cors.html}
53 * using a web server. You can then add a new host name to your systems hosts file, for
54 * example if you are on Linux you may update /etc/hosts to add an additional name
55 * for you local system:
56 * <pre>
57 * 127.0.0.1 localhost domain1.com
58 * </pre>
59 * Now, you should be able to access {@code http://domain1.com/cors.html} depending on how you
60 * have configured you local web server the exact url may differ.
61 *
62 * <h3>Using a web browser</h3>
63 * Open the file {@code src/main/resources/cors/cors.html} in a web browser. You should see
64 * loaded page and in the text area the following message:
65 * <pre>
66 * 'CORS is not working'
67 * </pre>
68 *
69 * If you inspect the headers being sent using your browser you'll see that the 'Origin'
70 * request header is {@code 'null'}. This is expected and happens when you load a file from the
71 * local file system. Netty can handle this by configuring the CorsHandler which is done
72 * in the {@link HttpCorsServerInitializer}.
73 *
74 */
75 public final class HttpCorsServer {
76
77 static final boolean SSL = System.getProperty("ssl") != null;
78 static final int PORT = Integer.parseInt(System.getProperty("port", SSL? "8443" : "8080"));
79
80 public static void main(String[] args) throws Exception {
81 // Configure SSL.
82 final SslContext sslCtx;
83 if (SSL) {
84 SelfSignedCertificate ssc = new SelfSignedCertificate();
85 sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey()).build();
86 } else {
87 sslCtx = null;
88 }
89
90 EventLoopGroup bossGroup = new MultithreadEventLoopGroup(1, NioHandler.newFactory());
91 EventLoopGroup workerGroup = new MultithreadEventLoopGroup(NioHandler.newFactory());
92 try {
93 ServerBootstrap b = new ServerBootstrap();
94 b.group(bossGroup, workerGroup)
95 .channel(NioServerSocketChannel.class)
96 .handler(new LoggingHandler(LogLevel.INFO))
97 .childHandler(new HttpCorsServerInitializer(sslCtx));
98
99 b.bind(PORT).asStage().get().closeFuture().asStage().sync();
100 } finally {
101 bossGroup.shutdownGracefully();
102 workerGroup.shutdownGracefully();
103 }
104 }
105 }