Enable Netty 4 extensions

modules/transport-netty4/src/main/java/org/elasticsearch/http/netty4/Netty4HttpRequest.java

@@ -34,7 +34,7 @@
 import java.util.HashMap;
 import java.util.Map;
 
-class Netty4HttpRequest extends RestRequest {
+public class Netty4HttpRequest extends RestRequest {
 
     private final FullHttpRequest request;
     private final Channel channel;

modules/transport-netty4/src/main/java/org/elasticsearch/http/netty4/Netty4HttpServerTransport.java

@@ -525,12 +525,12 @@ public ChannelHandler configureServerChannelHandler() {
         return new HttpChannelHandler(this, detailedErrorsEnabled, threadPool.getThreadContext());
     }
 
-    static class HttpChannelHandler extends ChannelInitializer<SocketChannel> {
+    protected static class HttpChannelHandler extends ChannelInitializer<Channel> {
 
         private final Netty4HttpServerTransport transport;
         private final Netty4HttpRequestHandler requestHandler;
 
-        HttpChannelHandler(
+        protected HttpChannelHandler(
             final Netty4HttpServerTransport transport,
             final boolean detailedErrorsEnabled,
             final ThreadContext threadContext) {
@@ -539,7 +539,7 @@ static class HttpChannelHandler extends ChannelInitializer<SocketChannel> {
         }
 
         @Override
-        protected void initChannel(SocketChannel ch) throws Exception {
+        protected void initChannel(Channel ch) throws Exception {
             ch.pipeline().addLast("openChannels", transport.serverOpenChannels);
             final HttpRequestDecoder decoder = new HttpRequestDecoder(
                 Math.toIntExact(transport.maxInitialLineLength.bytes()),

modules/transport-netty4/src/main/java/org/elasticsearch/transport/netty4/Netty4Transport.java

@@ -25,6 +25,7 @@
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
@@ -199,16 +200,7 @@ private Bootstrap createBootstrap() {
             bootstrap.channel(NioSocketChannel.class);
         }
 
-        bootstrap.handler(new ChannelInitializer<SocketChannel>() {
-
-            @Override
-            protected void initChannel(SocketChannel ch) throws Exception {
-                ch.pipeline().addLast("size", new Netty4SizeHeaderFrameDecoder());
-                // using a dot as a prefix means this cannot come from any settings parsed
-                ch.pipeline().addLast("dispatcher", new Netty4MessageChannelHandler(Netty4Transport.this, ".client"));
-            }
-
-        });
+        bootstrap.handler(getClientChannelInitializer());
 
         bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, Math.toIntExact(connectTimeout.millis()));
         bootstrap.option(ChannelOption.TCP_NODELAY, TCP_NO_DELAY.get(settings));
@@ -292,14 +284,7 @@ private void createServerBootstrap(String name, Settings settings) {
             serverBootstrap.channel(NioServerSocketChannel.class);
         }
 
-        serverBootstrap.childHandler(new ChannelInitializer<SocketChannel>() {
-            @Override
-            protected void initChannel(SocketChannel ch) throws Exception {
-                ch.pipeline().addLast("open_channels", Netty4Transport.this.serverOpenChannels);
-                ch.pipeline().addLast("size", new Netty4SizeHeaderFrameDecoder());
-                ch.pipeline().addLast("dispatcher", new Netty4MessageChannelHandler(Netty4Transport.this, name));
-            }
-        });
+        serverBootstrap.childHandler(getServerChannelInitializer(name, settings));
 
         serverBootstrap.childOption(ChannelOption.TCP_NODELAY, TCP_NO_DELAY.get(settings));
         serverBootstrap.childOption(ChannelOption.SO_KEEPALIVE, TCP_KEEP_ALIVE.get(settings));
@@ -326,6 +311,14 @@ protected void initChannel(SocketChannel ch) throws Exception {
         serverBootstraps.put(name, serverBootstrap);
     }
 
+    protected ChannelHandler getServerChannelInitializer(String name, Settings settings) {
+        return new ServerChannelInitializer(name, settings);
+    }
+
+    protected ChannelHandler getClientChannelInitializer() {
+        return new ClientChannelInitializer();
+    }
+
     protected final void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         final Throwable unwrapped = ExceptionsHelper.unwrap(cause, ElasticsearchException.class);
         final Throwable t = unwrapped != null ? unwrapped : cause;
@@ -348,7 +341,9 @@ protected NodeChannels connectToChannelsLight(DiscoveryNode node) {
         Channel[] channels = new Channel[1];
         channels[0] = connect.channel();
         channels[0].closeFuture().addListener(new ChannelCloseListener(node));
-        return new NodeChannels(channels, channels, channels, channels, channels);
+        NodeChannels nodeChannels = new NodeChannels(channels, channels, channels, channels, channels);
+        onAfterChannelsConnected(nodeChannels);
+        return nodeChannels;
     }
 
     protected NodeChannels connectToChannels(DiscoveryNode node) {
@@ -409,6 +404,7 @@ protected NodeChannels connectToChannels(DiscoveryNode node) {
                 }
                 throw e;
             }
+            onAfterChannelsConnected(nodeChannels);
             success = true;
         } finally {
             if (success == false) {
@@ -422,6 +418,14 @@ protected NodeChannels connectToChannels(DiscoveryNode node) {
         return nodeChannels;
     }
 
+    /**
+     * Allows for logic to be executed after a connection has been made on all channels. While this method is being executed, the node is
+     * not listed as being connected to.
+     * @param nodeChannels the {@link NodeChannels} that have been connected
+     */
+    protected void onAfterChannelsConnected(NodeChannels nodeChannels) {
+    }
+
     private class ChannelCloseListener implements ChannelFutureListener {
 
         private final DiscoveryNode node;
@@ -503,4 +507,33 @@ protected void stopInternal() {
         });
     }
 
+    protected class ClientChannelInitializer extends ChannelInitializer<Channel> {
+
+        @Override
+        protected void initChannel(Channel ch) throws Exception {
+            ch.pipeline().addLast("size", new Netty4SizeHeaderFrameDecoder());
+            // using a dot as a prefix means this cannot come from any settings parsed
+            ch.pipeline().addLast("dispatcher", new Netty4MessageChannelHandler(Netty4Transport.this, ".client"));
+        }
+
+    }
+
+    protected class ServerChannelInitializer extends ChannelInitializer<Channel> {
+
+        protected final String name;
+        protected final Settings settings;
+
+        protected ServerChannelInitializer(String name, Settings settings) {
+            this.name = name;
+            this.settings = settings;
+        }
+
+        @Override
+        protected void initChannel(Channel ch) throws Exception {
+            ch.pipeline().addLast("open_channels", Netty4Transport.this.serverOpenChannels);
+            ch.pipeline().addLast("size", new Netty4SizeHeaderFrameDecoder());
+            ch.pipeline().addLast("dispatcher", new Netty4MessageChannelHandler(Netty4Transport.this, name));
+        }
+    }
+
 }

modules/transport-netty4/src/test/java/org/elasticsearch/http/netty4/Netty4HttpServerPipeliningTests.java

@@ -21,6 +21,7 @@
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.SimpleChannelInboundHandler;
@@ -179,7 +180,7 @@ private class CustomHttpChannelHandler extends Netty4HttpServerTransport.HttpCha
         }
 
         @Override
-        protected void initChannel(SocketChannel ch) throws Exception {
+        protected void initChannel(Channel ch) throws Exception {
             super.initChannel(ch);
             ch.pipeline().replace("handler", "handler", new PossiblySlowUpstreamHandler(executorService));
         }