Vert.x Http Proxy

Vert.x Http Proxy is a reverse proxy based on Vert.x, it aims to implement reusable reverse proxy logic to focus on higher concerns.

Warning
This module has Tech Preview status, this means the API can change between versions.

Using Vert.x Http Proxy

To use Vert.x Http Proxy, add the following dependency to the dependencies section of your build descriptor:

  • Maven (in your pom.xml):

<dependency>
 <groupId>io.vertx</groupId>
 <artifactId>vertx-http-proxy</artifactId>
 <version>4.3.1</version>
</dependency>
  • Gradle (in your build.gradle file):

dependencies {
 compile 'io.vertx:vertx-http-proxy:4.3.1'
}

Reverse proxy server

In order to accomplish a reverse proxy with Vert.x Http Proxy you need the following:

  1. Proxy Server that handles user-agent requests and forward them to the origin server

  2. Origin Server that handles requests from the proxy server and respond accordingly

You can create a proxy server that listens to port 8080 and implement reverse proxy logic

HttpClient proxyClient = vertx.createHttpClient();

HttpProxy proxy = HttpProxy.reverseProxy(proxyClient);
proxy.origin(7070, "origin");

HttpServer proxyServer = vertx.createHttpServer();

proxyServer.requestHandler(proxy).listen(8080);

All user-agent requests are forwarded to the origin server conveniently.

WebSockets

The proxy supports WebSocket by default.

WebSocket handshake requests are forwarded to the origin server (including the connection header) and the handshake happens between the user agent and the origin server.

You can configure WebSocket support with setSupportWebSocket.

Proxy caching

By default the proxy does not cache response and ignores most cache directives, you can enable caching by setting the cache options.

HttpProxy proxy = HttpProxy.reverseProxy(new ProxyOptions().setCacheOptions(new CacheOptions()), proxyClient);

Proxy interception

Interception is a powerful way to extend the proxy withg new features.

You can implement handleProxyRequest to perform any operation on the proxy request

proxy.addInterceptor(new ProxyInterceptor() {
  @Override
  public Future<ProxyResponse> handleProxyRequest(ProxyContext context) {
    ProxyRequest proxyRequest = context.request();

    filter(proxyRequest.headers());

    // Continue the interception chain
    return context.sendRequest();
  }
});

Likewise with the proxy response

proxy.addInterceptor(new ProxyInterceptor() {
  @Override
  public Future<Void> handleProxyResponse(ProxyContext context) {
    ProxyResponse proxyResponse = context.response();

    filter(proxyResponse.headers());

    // Continue the interception chain
    return context.sendResponse();
  }
});

Body filtering

You can filter body by simply replacing the original Body with a new one

proxy.addInterceptor(new ProxyInterceptor() {
  @Override
  public Future<Void> handleProxyResponse(ProxyContext context) {
    ProxyResponse proxyResponse = context.response();

    // Create a filtered body
    Body filteredBody = filter(proxyResponse.getBody());

    // And then let the response use it
    proxyResponse.setBody(filteredBody);

    // Continue the interception chain
    return context.sendResponse();
  }
});

Interception control

sendRequest and sendResponse continue the current interception chain and then send the result to the origin server or the user-agent.

You can change the control, e.g you can send a response immediately to the user-agent without even requesting the origin server

proxy.addInterceptor(new ProxyInterceptor() {
  @Override
  public Future<ProxyResponse> handleProxyRequest(ProxyContext context) {

    ProxyRequest proxyRequest = context.request();

    // Release the underlying resources
    proxyRequest.release();

    // Create a response and populate it
    ProxyResponse proxyResponse = proxyRequest.response()
      .setStatusCode(200)
      .putHeader("content-type", "text/plain")
      .setBody(Body.body(Buffer.buffer("Hello World")));

    return Future.succeededFuture(proxyResponse);
  }
});