add keep-alive headers to connect response

I think the problem is there's no SSL handshake – the original CONNECT request is getting slung over to the SSL proxy. LittleProxy is doing effectively this but with an earlier version of Netty so it's quite hard to figure out what's going on.

betamax-netty/src/main/java/co/freeside/betamax/proxy/netty/ProxyConnectHandler.java

@@ -5,6 +5,8 @@
 import io.netty.channel.*;
 import io.netty.channel.socket.nio.*;
 import io.netty.handler.codec.http.*;
+import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
+import static io.netty.handler.codec.http.HttpHeaders.Values.KEEP_ALIVE;
 import static io.netty.handler.codec.http.HttpMethod.*;
 
 public class ProxyConnectHandler extends SimpleChannelInboundHandler<HttpRequest> {
@@ -27,8 +29,8 @@ protected void channelRead0(final ChannelHandlerContext context, final HttpReque
         CallbackNotifier callback = new CallbackNotifier() {
             @Override
             public void onSuccess(final ChannelHandlerContext outboundContext) {
-                HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
-                context.channel().writeAndFlush(response)
+                context.channel()
+                        .writeAndFlush(createConnectResponse())
                         .addListener(new ChannelFutureListener() {
                             @Override
                             public void operationComplete(ChannelFuture channelFuture) {
@@ -56,6 +58,13 @@ public void onFailure(ChannelHandlerContext outboundCtx, Throwable cause) {
         bootstrap.connect(proxyAddress);
     }
 
+    private HttpResponse createConnectResponse() {
+        DefaultHttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
+        response.headers().add(CONNECTION, KEEP_ALIVE);
+        response.headers().add("Proxy-Connection", KEEP_ALIVE);
+        return response;
+    }
+
     private boolean isConnectRequest(HttpRequest request) {
         return CONNECT.equals(request.getMethod());
     }