Github user uce commented on a diff in the pull request:
https://github.com/apache/flink/pull/6031#discussion_r190274982
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/router/RouterHandler.java
---
@@ -0,0 +1,109 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.runtime.rest.handler.router;
+
+import org.apache.flink.runtime.rest.handler.AbstractRestHandler;
+import org.apache.flink.runtime.rest.handler.util.HandlerUtils;
+import org.apache.flink.runtime.rest.messages.ErrorResponseBody;
+
+import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler;
+import
org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext;
+import
org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler;
+import org.apache.flink.shaded.netty4.io.netty.channel.ChannelPipeline;
+import
org.apache.flink.shaded.netty4.io.netty.channel.SimpleChannelInboundHandler;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.DefaultFullHttpResponse;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpHeaders;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpMethod;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpRequest;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpVersion;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.QueryStringDecoder;
+
+import java.util.Map;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * This class replaces the standard error response to be identical with
those sent by the {@link AbstractRestHandler}.
+ */
+public class RouterHandler extends
SimpleChannelInboundHandler<HttpRequest> {
+ public static final String ROUTER_HANDLER_NAME =
RouterHandler.class.getName() + "_ROUTER_HANDLER";
+ public static final String ROUTED_HANDLER_NAME =
RouterHandler.class.getName() + "_ROUTED_HANDLER";
+
+ private final Map<String, String> responseHeaders;
+ private final Router router;
+
+ public RouterHandler(Router router, final Map<String, String>
responseHeaders) {
+ this.router = requireNonNull(router);
+ this.responseHeaders = requireNonNull(responseHeaders);
+ }
+
+ public String getName() {
+ return ROUTER_HANDLER_NAME;
+ }
+
+ @Override
+ protected void channelRead0(ChannelHandlerContext
channelHandlerContext, HttpRequest httpRequest) throws Exception {
+ if (HttpHeaders.is100ContinueExpected(httpRequest)) {
+ channelHandlerContext.writeAndFlush(new
DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.CONTINUE));
+ return;
+ }
+
+ // Route
+ HttpMethod method = httpRequest.getMethod();
+ QueryStringDecoder qsd = new
QueryStringDecoder(httpRequest.getUri());
+ RouteResult routeResult = router.route(method, qsd.path(),
qsd.parameters());
+
+ if (routeResult == null) {
+ respondNotFound(channelHandlerContext, httpRequest);
+ return;
+ }
+
+ routed(channelHandlerContext, routeResult, httpRequest);
+ }
+
+ private void routed(
+ ChannelHandlerContext channelHandlerContext,
+ RouteResult routeResult,
+ HttpRequest httpRequest) throws Exception {
+ ChannelInboundHandler handler = (ChannelInboundHandler)
routeResult.target();
+
+ // The handler may have been added (keep alive)
+ ChannelPipeline pipeline = channelHandlerContext.pipeline();
+ ChannelHandler addedHandler = pipeline.get(ROUTED_HANDLER_NAME);
+ if (handler != addedHandler) {
+ if (addedHandler == null) {
+ pipeline.addAfter(ROUTER_HANDLER_NAME,
ROUTED_HANDLER_NAME, handler);
+ } else {
+ pipeline.replace(addedHandler,
ROUTED_HANDLER_NAME, handler);
+ }
+ }
+
+ channelHandlerContext.fireChannelRead(new
RoutedRequest(routeResult, httpRequest).retain());
--- End diff --
:+1:
---
