[
https://issues.apache.org/jira/browse/FLINK-7738?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16556257#comment-16556257
]
ASF GitHub Bot commented on FLINK-7738:
---------------------------------------
EronWright closed pull request #4767: [FLINK-7738] [flip-6] Create WebSocket
handler (server, client)
URL: https://github.com/apache/flink/pull/4767
This is a PR merged from a forked repository.
As GitHub hides the original diff on merge, it is displayed below for
the sake of provenance:
As this is a foreign pull request (from a fork), the diff is supplied
below (as it won't show otherwise due to GitHub magic):
diff --git
a/flink-runtime-web/src/test/java/org/apache/flink/runtime/webmonitor/RedirectHandlerTest.java
b/flink-runtime-web/src/test/java/org/apache/flink/runtime/webmonitor/RedirectHandlerTest.java
index 4808781c7b8..cf465294f5a 100644
---
a/flink-runtime-web/src/test/java/org/apache/flink/runtime/webmonitor/RedirectHandlerTest.java
+++
b/flink-runtime-web/src/test/java/org/apache/flink/runtime/webmonitor/RedirectHandlerTest.java
@@ -29,17 +29,24 @@
import org.apache.flink.util.TestLogger;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext;
+import
org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter;
+import
org.apache.flink.shaded.netty4.io.netty.channel.embedded.EmbeddedChannel;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.DefaultFullHttpRequest;
+import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpMethod;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponse;
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.router.KeepAliveWrite;
import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.router.Routed;
import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.router.Router;
+import org.apache.flink.shaded.netty4.io.netty.util.ReferenceCountUtil;
import org.junit.Assert;
import org.junit.Test;
import javax.annotation.Nonnull;
+import java.util.HashMap;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
@@ -137,6 +144,35 @@ public void testRedirectHandler() throws Exception {
}
}
+ /**
+ * Tests the approach of using the redirect handler as a standalone
handler.
+ */
+ @Test
+ public void testUserEvent() {
+ final String correctAddress = "foobar:21345";
+ final CompletableFuture<String> localAddressFuture =
CompletableFuture.completedFuture(correctAddress);
+ final Time timeout = Time.seconds(10L);
+
+ final RestfulGateway localGateway = mock(RestfulGateway.class);
+
when(localGateway.requestRestAddress(any(Time.class))).thenReturn(CompletableFuture.completedFuture(correctAddress));
+ final GatewayRetriever<RestfulGateway> gatewayRetriever =
mock(GatewayRetriever.class);
+
when(gatewayRetriever.getNow()).thenReturn(Optional.of(localGateway));
+
+ final RedirectHandler<RestfulGateway> redirectHandler = new
RedirectHandler<>(
+ localAddressFuture,
+ gatewayRetriever,
+ timeout);
+ final UserEventHandler eventHandler = new UserEventHandler();
+ EmbeddedChannel channel = new EmbeddedChannel(redirectHandler,
eventHandler);
+
+ // write a (routed) HTTP request, then validate that a user
event was propagated
+ DefaultFullHttpRequest request = new
DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/");
+ Routed routed = new Routed(null, false, request, "/", new
HashMap<>(), new HashMap<>());
+ channel.writeInbound(routed);
+ Assert.assertNotNull(eventHandler.gateway);
+ Assert.assertNotNull(eventHandler.routed);
+ }
+
private static class TestingHandler extends
RedirectHandler<RestfulGateway> {
protected TestingHandler(
@@ -154,4 +190,25 @@ protected void respondAsLeader(ChannelHandlerContext
channelHandlerContext, Rout
}
}
+ private static class UserEventHandler<T extends RestfulGateway> extends
ChannelInboundHandlerAdapter {
+
+ public volatile T gateway;
+
+ public volatile Routed routed;
+
+ @Override
+ @SuppressWarnings("unchecked")
+ public void userEventTriggered(ChannelHandlerContext ctx,
Object evt) throws Exception {
+ if (evt instanceof RedirectHandler.GatewayRetrieved) {
+ gateway =
((RedirectHandler.GatewayRetrieved<T>) evt).getGateway();
+ }
+ super.userEventTriggered(ctx, evt);
+ }
+
+ @Override
+ public void channelRead(ChannelHandlerContext ctx, Object msg)
throws Exception {
+ routed = (Routed) msg;
+ ReferenceCountUtil.release(msg);
+ }
+ }
}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/RestClient.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/RestClient.java
index 3fcb85c5096..9c1de986ba0 100644
--- a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/RestClient.java
+++ b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/RestClient.java
@@ -20,6 +20,7 @@
import org.apache.flink.api.common.time.Time;
import org.apache.flink.configuration.ConfigConstants;
+import org.apache.flink.runtime.rest.handler.JsonWebSocketMessageCodec;
import org.apache.flink.runtime.rest.handler.PipelineErrorHandler;
import org.apache.flink.runtime.rest.messages.EmptyMessageParameters;
import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
@@ -28,9 +29,12 @@
import org.apache.flink.runtime.rest.messages.MessageParameters;
import org.apache.flink.runtime.rest.messages.RequestBody;
import org.apache.flink.runtime.rest.messages.ResponseBody;
+import org.apache.flink.runtime.rest.messages.WebSocketSpecification;
import org.apache.flink.runtime.rest.util.RestClientException;
import org.apache.flink.runtime.rest.util.RestConstants;
import org.apache.flink.runtime.rest.util.RestMapperUtils;
+import org.apache.flink.runtime.rest.websocket.WebSocket;
+import org.apache.flink.runtime.rest.websocket.WebSocketListener;
import org.apache.flink.util.FlinkRuntimeException;
import org.apache.flink.util.Preconditions;
@@ -38,6 +42,7 @@
import org.apache.flink.shaded.netty4.io.netty.buffer.ByteBuf;
import org.apache.flink.shaded.netty4.io.netty.buffer.ByteBufInputStream;
import org.apache.flink.shaded.netty4.io.netty.buffer.Unpooled;
+import org.apache.flink.shaded.netty4.io.netty.channel.Channel;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelFuture;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelInitializer;
@@ -46,6 +51,7 @@
import org.apache.flink.shaded.netty4.io.netty.channel.socket.SocketChannel;
import
org.apache.flink.shaded.netty4.io.netty.channel.socket.nio.NioSocketChannel;
import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.DefaultFullHttpRequest;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.DefaultHttpHeaders;
import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.FullHttpRequest;
import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.FullHttpResponse;
import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpClientCodec;
@@ -54,7 +60,10 @@
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponse;
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.websocketx.WebSocketClientProtocolHandler;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.websocketx.WebSocketVersion;
import org.apache.flink.shaded.netty4.io.netty.handler.ssl.SslHandler;
+import org.apache.flink.shaded.netty4.io.netty.util.ReferenceCountUtil;
import
org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultThreadFactory;
import com.fasterxml.jackson.core.JsonParseException;
@@ -69,7 +78,11 @@
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
+import java.net.URI;
+import java.util.Arrays;
+import java.util.List;
import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
@@ -81,38 +94,23 @@
private static final ObjectMapper objectMapper =
RestMapperUtils.getStrictObjectMapper();
+ private final RestClientConfiguration configuration;
+
// used to open connections to a rest server endpoint
private final Executor executor;
private Bootstrap bootstrap;
public RestClient(RestClientConfiguration configuration, Executor
executor) {
- Preconditions.checkNotNull(configuration);
+ this.configuration = Preconditions.checkNotNull(configuration);
this.executor = Preconditions.checkNotNull(executor);
- SSLEngine sslEngine = configuration.getSslEngine();
- ChannelInitializer<SocketChannel> initializer = new
ChannelInitializer<SocketChannel>() {
- @Override
- protected void initChannel(SocketChannel socketChannel)
throws Exception {
- // SSL should be the first handler in the
pipeline
- if (sslEngine != null) {
- socketChannel.pipeline().addLast("ssl",
new SslHandler(sslEngine));
- }
-
- socketChannel.pipeline()
- .addLast(new HttpClientCodec())
- .addLast(new HttpObjectAggregator(1024
* 1024))
- .addLast(new ClientHandler())
- .addLast(new PipelineErrorHandler(LOG));
- }
- };
NioEventLoopGroup group = new NioEventLoopGroup(1, new
DefaultThreadFactory("flink-rest-client-netty"));
bootstrap = new Bootstrap();
bootstrap
.group(group)
- .channel(NioSocketChannel.class)
- .handler(initializer);
+ .channel(NioSocketChannel.class);
LOG.info("Rest client endpoint started.");
}
@@ -175,7 +173,17 @@ public void shutdown(Time timeout) {
}
private <P extends ResponseBody> CompletableFuture<P>
submitRequest(String targetAddress, int targetPort, FullHttpRequest
httpRequest, Class<P> responseClass) {
- return CompletableFuture.supplyAsync(() ->
bootstrap.connect(targetAddress, targetPort), executor)
+ Bootstrap bootstrap1 = bootstrap.clone().handler(new
ClientBootstrap() {
+ @Override
+ protected void initChannel(SocketChannel channel)
throws Exception {
+ super.initChannel(channel);
+ channel.pipeline()
+ .addLast(new ClientHandler())
+ .addLast(new PipelineErrorHandler(LOG));
+ }
+ });
+
+ return CompletableFuture.supplyAsync(() ->
bootstrap1.connect(targetAddress, targetPort), executor)
.thenApply((channel) -> {
try {
return channel.sync();
@@ -221,6 +229,21 @@ public void shutdown(Time timeout) {
return responseFuture;
}
+ private class ClientBootstrap extends ChannelInitializer<SocketChannel>
{
+ @Override
+ protected void initChannel(SocketChannel channel) throws
Exception {
+ SSLEngine sslEngine = configuration.getSslEngine();
+
+ // SSL should be the first handler in the pipeline
+ if (sslEngine != null) {
+ channel.pipeline().addLast("ssl", new
SslHandler(sslEngine));
+ }
+ channel.pipeline()
+ .addLast(new HttpClientCodec())
+ .addLast(new HttpObjectAggregator(1024 * 1024));
+ }
+ }
+
private static class ClientHandler extends
SimpleChannelInboundHandler<Object> {
private final CompletableFuture<JsonResponse> jsonFuture = new
CompletableFuture<>();
@@ -300,4 +323,116 @@ public HttpResponseStatus getHttpResponseStatus() {
return httpResponseStatus;
}
}
+
+ //M messageHeaders
+ @SuppressWarnings("unchecked")
+ public <M extends WebSocketSpecification<U, O, I>, U extends
MessageParameters, I extends ResponseBody, O extends RequestBody>
CompletableFuture<WebSocket<I, O>> sendWebSocketRequest(String targetAddress,
int targetPort, M spec, U messageParameters, WebSocketListener<I>... listeners)
throws IOException {
+ Preconditions.checkNotNull(targetAddress);
+ Preconditions.checkArgument(0 <= targetPort && targetPort <
65536, "The target port " + targetPort + " is not in the range (0, 65536].");
+ Preconditions.checkNotNull(spec);
+ Preconditions.checkNotNull(messageParameters);
+ Preconditions.checkState(messageParameters.isResolved(),
"Message parameters were not resolved.");
+
+ String targetUrl =
MessageParameters.resolveUrl(spec.getTargetRestEndpointURL(),
messageParameters);
+ URI webSocketURL = URI.create("ws://" + targetAddress + ":" +
targetPort).resolve(targetUrl);
+ LOG.debug("Sending WebSocket request to {}", webSocketURL);
+
+ final HttpHeaders headers = new DefaultHttpHeaders()
+ .add(HttpHeaders.Names.CONTENT_TYPE,
RestConstants.REST_CONTENT_TYPE);
+
+ Bootstrap bootstrap1 = bootstrap.clone().handler(new
ClientBootstrap() {
+ @Override
+ protected void initChannel(SocketChannel channel)
throws Exception {
+ super.initChannel(channel);
+ channel.pipeline()
+ .addLast(new
WebSocketClientProtocolHandler(webSocketURL, WebSocketVersion.V13,
spec.getSubprotocol(), false, headers, 65535))
+ .addLast(new
JsonWebSocketMessageCodec<>(spec.getServerClass(), spec.getClientClass()))
+ .addLast(new
WsResponseHandler<>(channel, spec.getServerClass(), spec.getClientClass(),
listeners));
+ }
+ });
+
+ return CompletableFuture.supplyAsync(() ->
bootstrap1.connect(targetAddress, targetPort), executor)
+ .thenApply((channel) -> {
+ try {
+ return channel.sync();
+ } catch (InterruptedException e) {
+ throw new FlinkRuntimeException(e);
+ }
+ })
+ .thenApply((ChannelFuture::channel))
+ .thenCompose(channel -> {
+ WsResponseHandler<I, O> handler =
channel.pipeline().get(WsResponseHandler.class);
+ return handler.getWebSocketFuture();
+ });
+ }
+
+ private static class WsResponseHandler<I extends ResponseBody, O
extends RequestBody> extends SimpleChannelInboundHandler<I> implements
WebSocket<I, O> {
+
+ private final Channel channel;
+ private final List<WebSocketListener<I>> listeners = new
CopyOnWriteArrayList<>();
+
+ private final CompletableFuture<WebSocket<I, O>>
webSocketFuture = new CompletableFuture<>();
+
+ CompletableFuture<WebSocket<I, O>> getWebSocketFuture() {
+ return webSocketFuture;
+ }
+
+ public WsResponseHandler(Channel channel, Class<I>
inboundClass, Class<O> outboundClass, WebSocketListener<I>[] listeners) {
+ super(inboundClass);
+ this.channel = channel;
+ this.listeners.addAll(Arrays.asList(listeners));
+ }
+
+ @Override
+ public void exceptionCaught(ChannelHandlerContext ctx,
Throwable cause) throws Exception {
+ LOG.warn("WebSocket exception caught", cause);
+ webSocketFuture.completeExceptionally(cause);
+ }
+
+ @Override
+ public void userEventTriggered(ChannelHandlerContext ctx,
Object evt) throws Exception {
+ if (evt instanceof
WebSocketClientProtocolHandler.ClientHandshakeStateEvent) {
+
WebSocketClientProtocolHandler.ClientHandshakeStateEvent wsevt =
(WebSocketClientProtocolHandler.ClientHandshakeStateEvent) evt;
+ switch (wsevt) {
+ case HANDSHAKE_ISSUED:
+ LOG.debug("WebSocket handshake
initiated");
+ break;
+ case HANDSHAKE_COMPLETE:
+ LOG.debug("WebSocket handshake
completed");
+ webSocketFuture.complete(this);
+ break;
+ }
+ }
+ else {
+ super.userEventTriggered(ctx, evt);
+ }
+ }
+
+ @Override
+ protected void channelRead0(ChannelHandlerContext
channelHandlerContext, I msg) throws Exception {
+ for (WebSocketListener<I> listener : listeners) {
+ listener.onEvent(msg);
+ }
+ }
+
+ @Override
+ public void addListener(WebSocketListener<I> listener) {
+ listeners.add(listener);
+ }
+
+ @Override
+ public ChannelFuture send(O message) {
+ try {
+ return channel.writeAndFlush(message);
+ }
+ finally {
+ ReferenceCountUtil.release(message);
+ }
+ }
+
+ @Override
+ public ChannelFuture close() {
+ return channel.close();
+ }
+ }
}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/AbstractWebSocketHandler.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/AbstractWebSocketHandler.java
new file mode 100644
index 00000000000..3a21d8a77d9
--- /dev/null
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/AbstractWebSocketHandler.java
@@ -0,0 +1,304 @@
+/*
+ * 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;
+
+import org.apache.flink.api.common.time.Time;
+import org.apache.flink.runtime.concurrent.FutureUtils;
+import org.apache.flink.runtime.rest.handler.util.HandlerUtils;
+import org.apache.flink.runtime.rest.messages.ErrorResponseBody;
+import org.apache.flink.runtime.rest.messages.MessageParameters;
+import org.apache.flink.runtime.rest.messages.RequestBody;
+import org.apache.flink.runtime.rest.messages.ResponseBody;
+import org.apache.flink.runtime.rest.messages.WebSocketSpecification;
+import org.apache.flink.runtime.webmonitor.RestfulGateway;
+import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
+import org.apache.flink.util.ExceptionUtils;
+import org.apache.flink.util.Preconditions;
+
+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.ChannelInboundHandlerAdapter;
+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.router.Routed;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
+import org.apache.flink.shaded.netty4.io.netty.util.AttributeKey;
+import org.apache.flink.shaded.netty4.io.netty.util.ReferenceCountUtil;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.Nonnull;
+
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * A channel handler for WebSocket resources.
+ *
+ * <p>This handler handles handshaking and ongoing messaging with a WebSocket
client,
+ * based on a {@link WebSocketSpecification} that describes the REST resource
location,
+ * parameter type, and message inbound/outbound types. Messages are
automatically
+ * encoded from (and decoded to) JSON text.
+ *
+ * <p>Subclasses should override the following methods to extend the
respective phases.
+ * <ol>
+ * <li>{@code handshakeInitiated} - occurs upon receipt of a handshake
request from an HTTP client. Useful for parameter validation.</li>
+ * <li>{@code handshakeCompleted} - occurs upon successful completion;
WebSocket is ready for I/O.</li>
+ * <li>{@code messageReceived} - occurs when a WebSocket message is
received on the channel.</li>
+ * </ol>
+ *
+ * <p>The handler supports gateway availability announcements.
+ *
+ * @param <T> The gateway type.
+ * @param <M> The REST parameter type.
+ * @param <I> The inbound message type.
+ * @param <O> The outbound message type.
+ */
+public abstract class AbstractWebSocketHandler<T extends RestfulGateway, M
extends MessageParameters, I extends RequestBody, O extends ResponseBody>
extends ChannelInboundHandlerAdapter {
+
+ protected final Logger log = LoggerFactory.getLogger(getClass());
+
+ private final RedirectHandler redirectHandler;
+
+ private final AttributeKey<T> gatewayAttr;
+
+ private final WebSocketSpecification<M, I, O> specification;
+
+ private final ChannelHandler messageCodec;
+
+ private final AttributeKey<M> parametersAttr;
+
+ /**
+ * Creates a new handler.
+ */
+ public AbstractWebSocketHandler(
+ @Nonnull CompletableFuture<String> localAddressFuture,
+ @Nonnull GatewayRetriever<? extends T> leaderRetriever,
+ @Nonnull Time timeout,
+ @Nonnull WebSocketSpecification<M, I, O> specification) {
+ this.redirectHandler = new
RedirectHandler<>(localAddressFuture, leaderRetriever, timeout);
+ this.gatewayAttr = AttributeKey.valueOf("gateway");
+ this.specification = specification;
+ this.messageCodec = new
JsonWebSocketMessageCodec<>(specification.getClientClass(),
specification.getServerClass());
+ this.parametersAttr = AttributeKey.valueOf("parameters");
+ }
+
+ /**
+ * Sets the gateway associated with the channel.
+ */
+ private void setGateway(ChannelHandlerContext ctx, T gateway) {
+ ctx.attr(gatewayAttr).set(gateway);
+ }
+
+ /**
+ * Returns the gateway associated with the channel.
+ */
+ public T getGateway(ChannelHandlerContext ctx) {
+ T t = ctx.attr(gatewayAttr).get();
+ Preconditions.checkState(t != null, "Gateway is not
available.");
+ return t;
+ }
+
+ /**
+ * Sets the resource parameters associated with the channel.
+ *
+ * <p>The parameters are established by the WebSocket handshake request.
+ */
+ private void setMessageParameters(ChannelHandlerContext ctx, M
parameters) {
+ ctx.attr(parametersAttr).set(parameters);
+ }
+
+ /**
+ * Returns the resource parameters associated with the channel.
+ */
+ public M getMessageParameters(ChannelHandlerContext ctx) {
+ M o = ctx.attr(parametersAttr).get();
+ Preconditions.checkState(o != null, "Message parameters are not
available.");
+ return o;
+ }
+
+ @Override
+ public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
+ if (ctx.pipeline().get(RedirectHandler.class.getName()) ==
null) {
+ ctx.pipeline().addBefore(ctx.name(),
RedirectHandler.class.getName(), redirectHandler);
+ }
+ }
+
+ @Override
+ @SuppressWarnings("unchecked")
+ public void userEventTriggered(ChannelHandlerContext ctx, Object evt)
throws Exception {
+ if (evt instanceof RedirectHandler.GatewayRetrieved) {
+ T gateway = ((RedirectHandler.GatewayRetrieved<T>)
evt).getGateway();
+ setGateway(ctx, gateway);
+ log.debug("Gateway retrieved: {}", gateway);
+ }
+ else if (evt instanceof
WebSocketServerProtocolHandler.ServerHandshakeStateEvent) {
+
WebSocketServerProtocolHandler.ServerHandshakeStateEvent handshakeEvent =
(WebSocketServerProtocolHandler.ServerHandshakeStateEvent) evt;
+ if (handshakeEvent ==
WebSocketServerProtocolHandler.ServerHandshakeStateEvent.HANDSHAKE_COMPLETE) {
+ log.debug("Handshake completed with client IP:
{}", ctx.channel().remoteAddress());
+ M parameters = getMessageParameters(ctx);
+ handshakeCompleted(ctx, parameters);
+ }
+ }
+
+ super.userEventTriggered(ctx, evt);
+ }
+
+ @Override
+ @SuppressWarnings("unchecked")
+ public void channelRead(ChannelHandlerContext ctx, Object o) throws
Exception {
+ if
(specification.getClientClass().isAssignableFrom(o.getClass())) {
+ // process an inbound message
+ M parameters = getMessageParameters(ctx);
+ try {
+ messageReceived(ctx, parameters, (I) o);
+ }
+ finally {
+ ReferenceCountUtil.release(o);
+ }
+ return;
+ }
+
+ if (!(o instanceof Routed)) {
+ // a foreign message
+ ctx.fireChannelRead(o);
+ return;
+ }
+
+ // process an inbound HTTP request
+ Routed request = (Routed) o;
+
+ // parse the REST request parameters
+ M messageParameters =
specification.getUnresolvedMessageParameters();
+ try {
+
messageParameters.resolveParameters(request.pathParams(),
request.queryParams());
+ if (!messageParameters.isResolved()) {
+ throw new IllegalArgumentException("One or more
mandatory parameters is missing.");
+ }
+ }
+ catch (IllegalArgumentException e) {
+ HandlerUtils.sendErrorResponse(
+ ctx,
+ request.request(),
+ new ErrorResponseBody(String.format("Bad
request, could not parse parameters: %s", e.getMessage())),
+ HttpResponseStatus.BAD_REQUEST);
+ ReferenceCountUtil.release(request);
+ return;
+ }
+ setMessageParameters(ctx, messageParameters);
+
+ // validate the inbound handshake request with the subclass
+ CompletableFuture<Void> handshakeReady;
+ try {
+ handshakeReady = handshakeInitiated(ctx,
messageParameters);
+ } catch (Exception e) {
+ handshakeReady = FutureUtils.completedExceptionally(e);
+ }
+ handshakeReady.whenCompleteAsync((Void v, Throwable throwable)
-> {
+ try {
+ if (throwable != null) {
+ Throwable error =
ExceptionUtils.stripCompletionException(throwable);
+ if (error instanceof
RestHandlerException) {
+ final RestHandlerException rhe
= (RestHandlerException) error;
+ log.error("Exception occurred
in REST handler.", error);
+
HandlerUtils.sendErrorResponse(ctx, request.request(), new
ErrorResponseBody(rhe.getMessage()), rhe.getHttpResponseStatus());
+ } else {
+ log.error("Implementation
error: Unhandled exception.", error);
+
HandlerUtils.sendErrorResponse(ctx, request.request(), new
ErrorResponseBody("Internal server error."),
HttpResponseStatus.INTERNAL_SERVER_ERROR);
+ }
+ } else {
+ upgradeToWebSocket(ctx, request);
+ }
+ }
+ finally {
+ ReferenceCountUtil.release(request);
+ }
+ }, ctx.executor());
+ }
+
+ private void upgradeToWebSocket(final ChannelHandlerContext ctx, Routed
msg) {
+
+ // store the context of the handler that precedes the current
handler,
+ // to use that context later to forward the HTTP request to the
WebSocket protocol handler
+ String before =
ctx.pipeline().names().get(ctx.pipeline().names().indexOf(ctx.name()) - 1);
+ ChannelHandlerContext beforeCtx =
ctx.pipeline().context(before);
+
+ // inject the websocket protocol handler into this channel, to
be active
+ // until the channel is closed. note that the handshake may or
may not complete synchronously.
+ ctx.pipeline().addBefore(ctx.name(),
WebSocketServerProtocolHandler.class.getName(),
+ new WebSocketServerProtocolHandler(msg.path(),
specification.getSubprotocol()));
+
+ // inject the message codec
+ ctx.pipeline().addBefore(ctx.name(),
messageCodec.getClass().getName(), messageCodec);
+
+ log.debug("Upgraded channel with WS protocol handler and
message codec.");
+
+ // forward the message to the installed protocol handler to
initiate handshaking
+ HttpRequest request = msg.request();
+ ReferenceCountUtil.retain(request);
+ beforeCtx.fireChannelRead(request);
+ }
+
+ @Override
+ public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
throws Exception {
+ log.error("WebSocket channel error; closing the channel.",
cause);
+ ctx.close();
+ }
+
+ /**
+ * Handles a client handshake request to open a WebSocket resource.
Returns a {@link CompletableFuture} to complete handshaking.
+ *
+ * <p>Implementations may decide whether to throw {@link
RestHandlerException}s or fail the returned
+ * {@link CompletableFuture} with a {@link RestHandlerException}.
+ *
+ * <p>Failing the future with another exception type or throwing
unchecked exceptions is regarded as an
+ * implementation error as it does not allow us to provide a meaningful
HTTP status code. In this case a
+ * {@link HttpResponseStatus#INTERNAL_SERVER_ERROR} will be returned.
+ *
+ * @param parameters the REST parameters
+
+ * @return future indicating completion of handshake pre-processing.
+ * @throws RestHandlerException to produce a pre-formatted HTTP error
response.
+ */
+ protected CompletableFuture<Void>
handshakeInitiated(ChannelHandlerContext ctx, M parameters) throws Exception {
+ return CompletableFuture.completedFuture(null);
+ }
+
+ /**
+ * Invoked when the current channel has completed the handshaking to
establish a WebSocket connection.
+ *
+ * @param ctx the channel handler context
+ * @param parameters the REST parameters
+ * @throws Exception if processing failed.
+ */
+ protected void handshakeCompleted(ChannelHandlerContext ctx, M
parameters) throws Exception {
+ }
+
+ /**
+ * Invoked when the current channel has received a WebSocket message.
+ *
+ * <p>The message object is automatically released after this method is
called.
+ *
+ * @param ctx the channel handler context
+ * @param parameters the REST parameters
+ * @param msg the message received
+ * @throws Exception if the message could not be processed.
+ */
+ protected abstract void messageReceived(ChannelHandlerContext ctx, M
parameters, I msg) throws Exception;
+}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/HandlerRequest.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/HandlerRequest.java
index aacf0a22a16..f92282956b2 100644
---
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/HandlerRequest.java
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/HandlerRequest.java
@@ -25,10 +25,10 @@
import org.apache.flink.util.Preconditions;
import java.util.Collections;
-import java.util.HashMap;
import java.util.List;
import java.util.Map;
-import java.util.StringJoiner;
+import java.util.function.Function;
+import java.util.stream.Collectors;
/**
* Simple container for the request to a handler, that contains the {@link
RequestBody} and path/query parameters.
@@ -39,52 +39,29 @@
public class HandlerRequest<R extends RequestBody, M extends
MessageParameters> {
private final R requestBody;
- private final Map<Class<? extends MessagePathParameter<?>>,
MessagePathParameter<?>> pathParameters = new HashMap<>(2);
- private final Map<Class<? extends MessageQueryParameter<?>>,
MessageQueryParameter<?>> queryParameters = new HashMap<>(2);
+ private final Map<Class<? extends MessagePathParameter<?>>,
MessagePathParameter<?>> pathParameters;
+ private final Map<Class<? extends MessageQueryParameter<?>>,
MessageQueryParameter<?>> queryParameters;
public HandlerRequest(R requestBody, M messageParameters) throws
HandlerRequestException {
this(requestBody, messageParameters, Collections.emptyMap(),
Collections.emptyMap());
}
+ @SuppressWarnings("unchecked")
public HandlerRequest(R requestBody, M messageParameters, Map<String,
String> receivedPathParameters, Map<String, List<String>>
receivedQueryParameters) throws HandlerRequestException {
this.requestBody = Preconditions.checkNotNull(requestBody);
Preconditions.checkNotNull(messageParameters);
Preconditions.checkNotNull(receivedQueryParameters);
Preconditions.checkNotNull(receivedPathParameters);
- for (MessagePathParameter<?> pathParameter :
messageParameters.getPathParameters()) {
- String value =
receivedPathParameters.get(pathParameter.getKey());
- if (value != null) {
- try {
- pathParameter.resolveFromString(value);
- } catch (Exception e) {
- throw new
HandlerRequestException("Cannot resolve path parameter (" +
pathParameter.getKey() + ") from value \"" + value + "\".");
- }
-
- @SuppressWarnings("unchecked")
- Class<? extends MessagePathParameter<?>> clazz
= (Class<? extends MessagePathParameter<?>>) pathParameter.getClass();
- pathParameters.put(clazz, pathParameter);
- }
+ try {
+
messageParameters.resolveParameters(receivedPathParameters,
receivedQueryParameters);
}
-
- for (MessageQueryParameter<?> queryParameter :
messageParameters.getQueryParameters()) {
- List<String> values =
receivedQueryParameters.get(queryParameter.getKey());
- if (values != null && !values.isEmpty()) {
- StringJoiner joiner = new StringJoiner(",");
- values.forEach(joiner::add);
-
- try {
-
queryParameter.resolveFromString(joiner.toString());
- } catch (Exception e) {
- throw new
HandlerRequestException("Cannot resolve query parameter (" +
queryParameter.getKey() + ") from value \"" + joiner + "\".");
- }
-
- @SuppressWarnings("unchecked")
- Class<? extends MessageQueryParameter<?>> clazz
= (Class<? extends MessageQueryParameter<?>>) queryParameter.getClass();
- queryParameters.put(clazz, queryParameter);
- }
-
+ catch (IllegalArgumentException e) {
+ throw new HandlerRequestException("Unable to resolve
the request parameters: " + e.getMessage());
}
+
+ pathParameters =
messageParameters.getPathParameters().stream().collect(Collectors.toMap(p ->
(Class<? extends MessagePathParameter<?>>) p.getClass(), Function.identity()));
+ queryParameters =
messageParameters.getQueryParameters().stream().collect(Collectors.toMap(p ->
(Class<? extends MessageQueryParameter<?>>) p.getClass(), Function.identity()));
}
/**
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/JsonWebSocketMessageCodec.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/JsonWebSocketMessageCodec.java
new file mode 100644
index 00000000000..48127bd88fe
--- /dev/null
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/JsonWebSocketMessageCodec.java
@@ -0,0 +1,100 @@
+/*
+ * 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;
+
+import org.apache.flink.runtime.rest.util.RestMapperUtils;
+
+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.CombinedChannelDuplexHandler;
+import org.apache.flink.shaded.netty4.io.netty.handler.codec.DecoderException;
+import org.apache.flink.shaded.netty4.io.netty.handler.codec.EncoderException;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.MessageToMessageDecoder;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.MessageToMessageEncoder;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.util.List;
+
+/**
+ * A codec for JSON-encoded WebSocket messages.
+ *
+ * @param <I> the inbound message type (converted from JSON).
+ * @param <O> the outbound message type (converted to JSON).
+ */
+@ChannelHandler.Sharable
+public class JsonWebSocketMessageCodec<I, O> extends
CombinedChannelDuplexHandler<JsonWebSocketMessageCodec.WebSocketMessageDecoder<I>,
JsonWebSocketMessageCodec.WebSocketMessageEncoder<O>> {
+
+ private static final ObjectMapper mapper =
RestMapperUtils.getStrictObjectMapper();
+
+ public JsonWebSocketMessageCodec(Class<I> inboundMessageClass, Class<O>
outboundMessageClass) {
+ super(new WebSocketMessageDecoder<>(inboundMessageClass), new
WebSocketMessageEncoder<>(outboundMessageClass));
+ }
+
+ @ChannelHandler.Sharable
+ static class WebSocketMessageDecoder<I> extends
MessageToMessageDecoder<TextWebSocketFrame> {
+
+ private final ObjectReader reader;
+
+ public WebSocketMessageDecoder(Class<I> messageClass) {
+ reader = mapper.readerFor(messageClass);
+ }
+
+ @Override
+ protected void decode(ChannelHandlerContext
channelHandlerContext, TextWebSocketFrame frame, List<Object> list) throws
Exception {
+ try {
+ try (StringReader sr = new
StringReader(frame.text())) {
+ I i = reader.readValue(sr);
+ list.add(i);
+ }
+ }
+ catch (Exception e) {
+ throw new DecoderException("Unable to decode
the WebSocket frame as a JSON object", e);
+ }
+ }
+ }
+
+ @ChannelHandler.Sharable
+ static class WebSocketMessageEncoder<O> extends
MessageToMessageEncoder<O> {
+
+ private final ObjectWriter writer;
+
+ protected WebSocketMessageEncoder(Class<O> messageClass) {
+ super(messageClass);
+ writer = mapper.writerFor(messageClass);
+ }
+
+ @Override
+ protected void encode(ChannelHandlerContext ctx, O o,
List<Object> list) throws Exception {
+ try {
+ StringWriter sw = new StringWriter();
+ writer.writeValue(sw, o);
+ list.add(new TextWebSocketFrame(sw.toString()));
+ }
+ catch (Exception e) {
+ throw new EncoderException("Unable to encode
the JSON object as a WebSocket frame", e);
+ }
+ }
+ }
+}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/RedirectHandler.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/RedirectHandler.java
index 40b67767737..07a79e11902 100644
---
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/RedirectHandler.java
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/RedirectHandler.java
@@ -49,10 +49,16 @@
* {@link SimpleChannelInboundHandler} which encapsulates the redirection
logic for the
* REST endpoints.
*
+ * <p>This handler supports two modes of use.
+ * <ol>
+ * <li>Inheritance - subclasses override {@code respondAsLeader}.</li>
+ * <li>Composition - upstream handlers receive a user event containing the
gateway, see {@link GatewayRetrieved}.</li>
+ * </ol>
+ *
* @param <T> type of the leader to retrieve
*/
@ChannelHandler.Sharable
-public abstract class RedirectHandler<T extends RestfulGateway> extends
SimpleChannelInboundHandler<Routed> {
+public class RedirectHandler<T extends RestfulGateway> extends
SimpleChannelInboundHandler<Routed> {
protected final Logger logger = LoggerFactory.getLogger(getClass());
@@ -64,7 +70,7 @@
private String localAddress;
- protected RedirectHandler(
+ public RedirectHandler(
@Nonnull CompletableFuture<String> localAddressFuture,
@Nonnull GatewayRetriever<? extends T> leaderRetriever,
@Nonnull Time timeout) {
@@ -172,5 +178,39 @@ protected void channelRead0(
}
}
- protected abstract void respondAsLeader(ChannelHandlerContext
channelHandlerContext, Routed routed, T gateway) throws Exception;
+ /**
+ * Responds to an HTTP request in combination with the leader gateway.
+ *
+ * <p>The default behavior is to announce the leader gateway with a
user event,
+ * and then to forward the HTTP request to the next handler.
+ *
+ * @param ctx the channel handler context
+ * @param routed the HTTP request
+ * @param gateway the leader gateway
+ */
+ protected void respondAsLeader(ChannelHandlerContext ctx, Routed
routed, T gateway) throws Exception {
+
+ // announce the gateway to upstream handlers
+ ctx.fireUserEventTriggered(new GatewayRetrieved<>(gateway));
+
+ // propagate the HTTP request
+ ReferenceCountUtil.retain(routed);
+ ctx.fireChannelRead(routed);
+ }
+
+ /**
+ * A gateway retrieval event.
+ * @param <T> the gateway type
+ */
+ public static class GatewayRetrieved<T> {
+ private final T gateway;
+
+ public GatewayRetrieved(T gateway) {
+ this.gateway = gateway;
+ }
+
+ public T getGateway() {
+ return gateway;
+ }
+ }
}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/MessageParameters.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/MessageParameters.java
index b19b12e7206..b91c4510e83 100644
---
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/MessageParameters.java
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/MessageParameters.java
@@ -21,9 +21,15 @@
import org.apache.flink.util.Preconditions;
import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.StringJoiner;
/**
* This class defines the path/query {@link MessageParameter}s that can be
used for a request.
+ *
+ * <p>An instance of {@link MessageParameters} is mutable.
*/
public abstract class MessageParameters {
@@ -61,7 +67,7 @@ public final boolean isResolved() {
* <p>Unresolved optional parameters will be ignored.
*
* @param genericUrl URL to resolve
- * @param parameters message parameters parameters
+ * @param parameters message parameters
* @return resolved url, e.g "/jobs/1234?state=running"
* @throws IllegalStateException if any mandatory parameter was not
resolved
*/
@@ -100,4 +106,74 @@ public static String resolveUrl(String genericUrl,
MessageParameters parameters)
return path.toString();
}
+
+ /**
+ * Resolves the message parameters using the given path and query
parameter values.
+ *
+ * <p>This method updates the state of the parameters of this message.
+ *
+ * @param receivedPathParameters the received path parameters.
+ * @param receivedQueryParameters the received query parameters.
+ * @throws IllegalArgumentException if a parameter value cannot be
processed.
+ */
+ public void resolveParameters(Map<String, String>
receivedPathParameters, Map<String, List<String>> receivedQueryParameters) {
+ for (MessagePathParameter<?> pathParameter :
getPathParameters()) {
+ String value =
receivedPathParameters.get(pathParameter.getKey());
+ if (value != null) {
+ try {
+ pathParameter.resolveFromString(value);
+ } catch (Exception e) {
+ throw new
IllegalArgumentException("Cannot resolve path parameter (" +
pathParameter.getKey() + ") from value \"" + value + "\".");
+ }
+ }
+ }
+
+ for (MessageQueryParameter<?> queryParameter :
getQueryParameters()) {
+ List<String> values =
receivedQueryParameters.get(queryParameter.getKey());
+ if (values != null && !values.isEmpty()) {
+ StringJoiner joiner = new StringJoiner(",");
+ values.forEach(joiner::add);
+
+ try {
+
queryParameter.resolveFromString(joiner.toString());
+ } catch (Exception e) {
+ throw new
IllegalArgumentException("Cannot resolve query parameter (" +
queryParameter.getKey() + ") from value \"" + joiner + "\".");
+ }
+ }
+ }
+ }
+
+
+ /**
+ * Returns the value of the {@link MessagePathParameter} for the given
class.
+ *
+ * @param parameterClass class of the parameter
+ * @param <X> the value type that the parameter contains
+ * @param <PP> type of the path parameter
+ * @return path parameter value for the given class
+ * @throws IllegalStateException if no value is defined for the given
parameter class
+ */
+ @SuppressWarnings("unchecked")
+ public <X, PP extends MessagePathParameter<X>> X
getPathParameter(Class<PP> parameterClass) {
+ return getPathParameters().stream()
+ .filter(p -> parameterClass.equals(p.getClass()))
+ .map(p -> ((PP) p).getValue())
+ .findAny().orElseThrow(() -> new
IllegalStateException("No parameter could be found for the given class."));
+ }
+
+ /**
+ * Returns the value of the {@link MessageQueryParameter} for the given
class.
+ *
+ * @param parameterClass class of the parameter
+ * @param <X> the value type that the parameter contains
+ * @param <QP> type of the query parameter
+ * @return query parameter value for the given class, or an empty list
if no parameter value exists for the given class
+ */
+ @SuppressWarnings("unchecked")
+ public <X, QP extends MessageQueryParameter<X>> List<X>
getQueryParameter(Class<QP> parameterClass) {
+ return getQueryParameters().stream()
+ .filter(p -> parameterClass.equals(p.getClass()))
+ .map(p -> ((QP) p).getValue())
+ .findAny().orElse(Collections.emptyList());
+ }
}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/RequestBody.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/RequestBody.java
index ca55b17532b..7e2ef568448 100644
---
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/RequestBody.java
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/RequestBody.java
@@ -19,7 +19,7 @@
package org.apache.flink.runtime.rest.messages;
/**
- * Marker interface for all requests of the REST API. This class represents
the http body of a request.
+ * Marker interface for all requests of the REST API. This class represents
the body of an HTTP request or WebSocket message.
*
* <p>Subclass instances are converted to JSON using jackson-databind.
Subclasses must have a constructor that accepts
* all fields of the JSON request, that should be annotated with {@code
@JsonCreator}.
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/ResponseBody.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/ResponseBody.java
index d4e94d1d6ab..6d183903637 100644
---
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/ResponseBody.java
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/ResponseBody.java
@@ -19,7 +19,7 @@
package org.apache.flink.runtime.rest.messages;
/**
- * Marker interface for all responses of the REST API. This class represents
the http body of a response.
+ * Marker interface for all responses of the REST API. This class represents
the body of an HTTP response or WebSocket message.
*
* <p>Subclass instances are converted to JSON using jackson-databind.
Subclasses must have a constructor that accepts
* all fields of the JSON response, that should be annotated with {@code
@JsonCreator}.
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/WebSocketSpecification.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/WebSocketSpecification.java
new file mode 100644
index 00000000000..38ca0e86743
--- /dev/null
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/WebSocketSpecification.java
@@ -0,0 +1,65 @@
+/*
+ * 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.messages;
+
+import org.apache.flink.runtime.rest.HttpMethodWrapper;
+import org.apache.flink.runtime.rest.handler.RestHandlerSpecification;
+
+/**
+ * Extended REST handler specification with websocket information.
+ *
+ * <p>Implementations must be state-less.
+ *
+ * @param <M> message parameters type
+ * @param <I> inbound message type
+ * @param <O> outbound message type
+ */
+public interface WebSocketSpecification<M extends MessageParameters, I extends
RequestBody, O extends ResponseBody> extends RestHandlerSpecification {
+
+ @Override
+ default HttpMethodWrapper getHttpMethod() {
+ return HttpMethodWrapper.GET;
+ }
+
+ /**
+ * Returns the WebSocket subprotocol associated with the REST resource.
+ */
+ String getSubprotocol();
+
+ /**
+ * Returns the base class of client-to-server messages.
+ *
+ * @return class of the message
+ */
+ Class<I> getClientClass();
+
+ /**
+ * Returns the base class of server-to-client messages.
+ *
+ * @return class of the message
+ */
+ Class<O> getServerClass();
+
+ /**
+ * Returns a new {@link MessageParameters} object.
+ *
+ * @return new message parameters object
+ */
+ M getUnresolvedMessageParameters();
+}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/KeyedChannelRouter.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/KeyedChannelRouter.java
new file mode 100644
index 00000000000..4fecafb4100
--- /dev/null
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/KeyedChannelRouter.java
@@ -0,0 +1,96 @@
+/*
+ * 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.websocket;
+
+import org.apache.flink.shaded.netty4.io.netty.channel.Channel;
+import org.apache.flink.shaded.netty4.io.netty.channel.group.ChannelGroup;
+import
org.apache.flink.shaded.netty4.io.netty.channel.group.ChannelGroupFuture;
+import org.apache.flink.shaded.netty4.io.netty.util.AttributeKey;
+
+import javax.annotation.Nonnull;
+
+import java.util.Objects;
+
+import static org.apache.flink.util.Preconditions.checkNotNull;
+
+/**
+ * Routes messages to channels based on a routing key.
+ * @param <K> the key type.
+ */
+public class KeyedChannelRouter<K> {
+
+ private final AttributeKey<K> attributeKey;
+
+ private final ChannelGroup channels;
+
+ public KeyedChannelRouter(AttributeKey<K> attributeKey, ChannelGroup
channelGroup) {
+ this.attributeKey = checkNotNull(attributeKey);
+ this.channels = checkNotNull(channelGroup);
+ }
+
+ /**
+ * Registers a channel to receive messages for a given routing key.
+ *
+ * @param channel the channel to register.
+ */
+ public void register(@Nonnull Channel channel, @Nonnull K routingKey) {
+ channel.attr(attributeKey).set(routingKey);
+ channels.add(channel);
+ }
+
+ /**
+ * Unregisters a channel.
+ *
+ * @param channel the channel to unregister.
+ */
+ public void unregister(@Nonnull Channel channel) {
+ channels.remove(channel);
+ }
+
+ /**
+ * Writes and flushes an object to select channels based on a routing
key.
+ *
+ * @param routingKey the key to select the target channel(s).
+ * @param o the object to write and flush.
+ */
+ public ChannelGroupFuture write(@Nonnull K routingKey, @Nonnull Object
o) {
+ return channels.write(o, channel -> isMatch(channel,
routingKey));
+ }
+
+ /**
+ * Writes and flushes an object to select channels based on a routing
key.
+ *
+ * @param routingKey the key to select the target channel(s).
+ * @param o the object to write and flush.
+ */
+ public ChannelGroupFuture writeAndFlush(@Nonnull K routingKey, @Nonnull
Object o) {
+ return channels.writeAndFlush(o, channel -> isMatch(channel,
routingKey));
+ }
+
+ /**
+ * Closes all channels associated with the given routing key.
+ */
+ public ChannelGroupFuture close(@Nonnull K routingKey) {
+ return channels.close(channel -> isMatch(channel, routingKey));
+ }
+
+ private boolean isMatch(Channel channel, K routingKey) {
+ return Objects.equals(routingKey,
channel.attr(attributeKey).get());
+ }
+}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/WebSocket.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/WebSocket.java
new file mode 100644
index 00000000000..77d53ef4427
--- /dev/null
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/WebSocket.java
@@ -0,0 +1,48 @@
+/*
+ * 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.websocket;
+
+import org.apache.flink.runtime.rest.messages.RequestBody;
+import org.apache.flink.runtime.rest.messages.ResponseBody;
+
+import org.apache.flink.shaded.netty4.io.netty.channel.ChannelFuture;
+
+/**
+ * A WebSocket for sending and receiving messages.
+ *
+ * @param <I> type of the server-to-client messages.
+ * @param <O> type of the client-to-server messages.
+ */
+public interface WebSocket<I extends ResponseBody, O extends RequestBody> {
+
+ /**
+ * Adds a listener for websocket messages.
+ */
+ void addListener(WebSocketListener<I> listener);
+
+ /**
+ * Sends a message.
+ */
+ ChannelFuture send(O message);
+
+ /**
+ * Closes the websocket.
+ */
+ ChannelFuture close();
+}
diff --git
a/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/WebSocketListener.java
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/WebSocketListener.java
new file mode 100644
index 00000000000..33410fc4fcc
--- /dev/null
+++
b/flink-runtime/src/main/java/org/apache/flink/runtime/rest/websocket/WebSocketListener.java
@@ -0,0 +1,29 @@
+/*
+ * 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.websocket;
+
+import org.apache.flink.runtime.rest.messages.ResponseBody;
+import org.apache.flink.runtime.util.event.EventListener;
+
+/**
+ * A listener for WebSocket messages.
+ *
+ * @param <T> type of the server-to-client messages.
+ */
+public interface WebSocketListener<T extends ResponseBody> extends
EventListener<T> { }
diff --git
a/flink-runtime/src/test/java/org/apache/flink/runtime/rest/RestEndpointITCase.java
b/flink-runtime/src/test/java/org/apache/flink/runtime/rest/RestEndpointITCase.java
index be5985f3a2c..0e4218c31ff 100644
---
a/flink-runtime/src/test/java/org/apache/flink/runtime/rest/RestEndpointITCase.java
+++
b/flink-runtime/src/test/java/org/apache/flink/runtime/rest/RestEndpointITCase.java
@@ -23,6 +23,7 @@
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.runtime.rest.handler.AbstractRestHandler;
+import org.apache.flink.runtime.rest.handler.AbstractWebSocketHandler;
import org.apache.flink.runtime.rest.handler.HandlerRequest;
import org.apache.flink.runtime.rest.handler.RestHandlerException;
import org.apache.flink.runtime.rest.handler.RestHandlerSpecification;
@@ -33,7 +34,10 @@
import org.apache.flink.runtime.rest.messages.MessageQueryParameter;
import org.apache.flink.runtime.rest.messages.RequestBody;
import org.apache.flink.runtime.rest.messages.ResponseBody;
+import org.apache.flink.runtime.rest.messages.WebSocketSpecification;
import org.apache.flink.runtime.rest.util.RestClientException;
+import org.apache.flink.runtime.rest.websocket.KeyedChannelRouter;
+import org.apache.flink.runtime.rest.websocket.WebSocket;
import org.apache.flink.runtime.rpc.RpcUtils;
import org.apache.flink.runtime.testingUtils.TestingUtils;
import org.apache.flink.runtime.webmonitor.RestfulGateway;
@@ -42,8 +46,14 @@
import org.apache.flink.util.Preconditions;
import org.apache.flink.util.TestLogger;
+import org.apache.flink.shaded.netty4.io.netty.channel.ChannelFutureListener;
+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.group.ChannelGroup;
+import
org.apache.flink.shaded.netty4.io.netty.channel.group.DefaultChannelGroup;
import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
+import org.apache.flink.shaded.netty4.io.netty.util.AttributeKey;
+import
org.apache.flink.shaded.netty4.io.netty.util.concurrent.GlobalEventExecutor;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
@@ -55,11 +65,14 @@
import javax.annotation.Nonnull;
import java.net.InetSocketAddress;
+import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
+import java.util.concurrent.LinkedBlockingQueue;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.mock;
@@ -78,6 +91,8 @@
private RestServerEndpoint serverEndpoint;
private RestClient clientEndpoint;
+ private TestEventProvider eventProvider;
+
@Before
public void setup() throws Exception {
Configuration config = new Configuration();
@@ -91,12 +106,22 @@ public void setup() throws Exception {
GatewayRetriever<RestfulGateway> mockGatewayRetriever =
mock(GatewayRetriever.class);
when(mockGatewayRetriever.getNow()).thenReturn(Optional.of(mockRestfulGateway));
+ // a REST operation
TestHandler testHandler = new TestHandler(
CompletableFuture.completedFuture(restAddress),
mockGatewayRetriever,
RpcUtils.INF_TIMEOUT);
- serverEndpoint = new TestRestServerEndpoint(serverConfig,
testHandler);
+ // a WebSocket operation
+ ChannelGroup eventChannelGroup = new
DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
+ eventProvider = new TestEventProvider(eventChannelGroup);
+ TestWebSocketOperation.WsRestHandler testWebSocketHandler = new
TestWebSocketOperation.WsRestHandler(
+ CompletableFuture.completedFuture(restAddress),
+ mockGatewayRetriever,
+ eventProvider,
+ RpcUtils.INF_TIMEOUT);
+
+ serverEndpoint = new TestRestServerEndpoint(serverConfig,
testHandler, testWebSocketHandler);
clientEndpoint = new TestRestClient(clientConfig);
serverEndpoint.start();
@@ -194,19 +219,74 @@ public void testBadHandlerRequest() throws Exception {
}
}
+ /**
+ * Tests that a web socket operation works end-to-end.
+ */
+ @Test
+ public void testWebSocketEndToEnd() throws Exception {
+ TestWebSocketOperation.WsParameters parameters = new
TestWebSocketOperation.WsParameters();
+ parameters.jobIDPathParameter.resolve(PATH_JOB_ID);
+
+ final LinkedBlockingQueue<TestMessage> messageQueue = new
LinkedBlockingQueue<>();
+ final InetSocketAddress serverAddress =
serverEndpoint.getServerAddress();
+
+ // open a websocket connection with a listener that simply
enqueues incoming messages
+ CompletableFuture<WebSocket<TestMessage, TestMessage>> response
= clientEndpoint.sendWebSocketRequest(
+ serverAddress.getHostName(),
+ serverAddress.getPort(),
+ new TestWebSocketOperation.WsHeaders(),
+ parameters,
+ (event) -> {
+ try {
+ messageQueue.put(event);
+ }
+ catch (Exception e) {
+ throw new RuntimeException(e);
+ }
+ });
+
+ // wait for the connection to be established
+ WebSocket<TestMessage, TestMessage> webSocket = response.get();
+ try {
+ // wait for the server to register the channel (happens
asynchronously after handshake complete)
+ TestWebSocketOperation.WsRestHandler.LATCH.await();
+
+ // play ping-pong (server goes first)
+ eventProvider.writeAndFlush(PATH_JOB_ID, new
TestMessage(42));
+ TestMessage received = messageQueue.take();
+ Assert.assertEquals(42, received.sequenceNumber);
+ webSocket.send(received.incr());
+ received = messageQueue.take();
+ Assert.assertEquals(44, received.sequenceNumber);
+ }
+ finally {
+ webSocket.close();
+ }
+ }
+
private static class TestRestServerEndpoint extends RestServerEndpoint {
private final TestHandler testHandler;
+ private final TestWebSocketOperation.WsRestHandler
testWebSocketHandler;
- TestRestServerEndpoint(RestServerEndpointConfiguration
configuration, TestHandler testHandler) {
+ TestRestServerEndpoint(RestServerEndpointConfiguration
configuration, TestHandler testHandler, TestWebSocketOperation.WsRestHandler
testWebSocketHandler) {
super(configuration);
this.testHandler =
Preconditions.checkNotNull(testHandler);
+ this.testWebSocketHandler =
Preconditions.checkNotNull(testWebSocketHandler);
}
@Override
protected Collection<Tuple2<RestHandlerSpecification,
ChannelInboundHandler>> initializeHandlers(CompletableFuture<String>
restAddressFuture) {
- return Collections.singleton(Tuple2.of(new
TestHeaders(), testHandler));
+ return Arrays.asList(
+ Tuple2.of(new TestHeaders(), testHandler),
+ Tuple2.of(new
TestWebSocketOperation.WsHeaders(), testWebSocketHandler));
+ }
+ }
+
+ private static class TestEventProvider extends
KeyedChannelRouter<JobID> {
+ public TestEventProvider(ChannelGroup channelGroup) {
+ super(AttributeKey.valueOf("jobID"), channelGroup);
}
}
@@ -325,6 +405,88 @@ public TestParameters getUnresolvedMessageParameters() {
}
}
+ private static class TestWebSocketOperation {
+
+ private static class WsParameters extends MessageParameters {
+ private final JobIDPathParameter jobIDPathParameter =
new JobIDPathParameter();
+
+ @Override
+ public Collection<MessagePathParameter<?>>
getPathParameters() {
+ return
Collections.singleton(jobIDPathParameter);
+ }
+
+ @Override
+ public Collection<MessageQueryParameter<?>>
getQueryParameters() {
+ return Collections.emptyList();
+ }
+ }
+
+ static class WsHeaders implements
WebSocketSpecification<WsParameters, TestMessage, TestMessage> {
+
+ @Override
+ public String getTargetRestEndpointURL() {
+ return "/test/:jobid/subscribe";
+ }
+
+ @Override
+ public String getSubprotocol() {
+ return "test";
+ }
+
+ @Override
+ public Class<TestMessage> getServerClass() {
+ return TestMessage.class;
+ }
+
+ @Override
+ public Class<TestMessage> getClientClass() {
+ return TestMessage.class;
+ }
+
+ @Override
+ public WsParameters getUnresolvedMessageParameters() {
+ return new WsParameters();
+ }
+ }
+
+ static class WsRestHandler extends
AbstractWebSocketHandler<RestfulGateway, WsParameters, TestMessage,
TestMessage> {
+
+ public static final CountDownLatch LATCH = new
CountDownLatch(1);
+
+ private final TestEventProvider eventProvider;
+
+ WsRestHandler(
+ CompletableFuture<String> localAddressFuture,
+ GatewayRetriever<RestfulGateway>
leaderRetriever,
+ TestEventProvider eventProvider,
+ Time timeout) {
+ super(localAddressFuture, leaderRetriever,
timeout, new WsHeaders());
+ this.eventProvider = eventProvider;
+ }
+
+ @Override
+ protected CompletableFuture<Void>
handshakeInitiated(ChannelHandlerContext ctx, WsParameters parameters) throws
Exception {
+ // validate request before completing the
handshake
+ JobID jobID =
parameters.getPathParameter(JobIDPathParameter.class);
+ Assert.assertEquals(PATH_JOB_ID, jobID);
+ return CompletableFuture.completedFuture(null);
+ }
+
+ @Override
+ protected void handshakeCompleted(ChannelHandlerContext
ctx, WsParameters parameters) throws Exception {
+ // handshake complete; register for server
events
+ JobID jobID =
parameters.getPathParameter(JobIDPathParameter.class);
+ eventProvider.register(ctx.channel(), jobID);
+ LATCH.countDown();
+ }
+
+ @Override
+ protected void messageReceived(ChannelHandlerContext
ctx, WsParameters parameters, TestMessage msg) throws Exception {
+
ctx.channel().writeAndFlush(msg.incr()).addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
+ }
+ }
+ }
+
static class JobIDPathParameter extends MessagePathParameter<JobID> {
JobIDPathParameter() {
super(JOB_ID_KEY);
@@ -373,4 +535,17 @@ public String convertStringToValue(JobID value) {
return value.toString();
}
}
+
+ static class TestMessage implements ResponseBody, RequestBody {
+ public final int sequenceNumber;
+
+ @JsonCreator
+ public TestMessage(@JsonProperty("sequenceNumber") int
sequenceNumber) {
+ this.sequenceNumber = sequenceNumber;
+ }
+
+ public TestMessage incr() {
+ return new TestMessage(sequenceNumber + 1);
+ }
+ }
}
diff --git
a/flink-runtime/src/test/java/org/apache/flink/runtime/rest/handler/AbstractWebSocketHandlerTest.java
b/flink-runtime/src/test/java/org/apache/flink/runtime/rest/handler/AbstractWebSocketHandlerTest.java
new file mode 100644
index 00000000000..951ecfa8899
--- /dev/null
+++
b/flink-runtime/src/test/java/org/apache/flink/runtime/rest/handler/AbstractWebSocketHandlerTest.java
@@ -0,0 +1,456 @@
+/*
+ * 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;
+
+import org.apache.flink.api.common.JobID;
+import org.apache.flink.api.common.time.Time;
+import org.apache.flink.runtime.rest.messages.MessageParameters;
+import org.apache.flink.runtime.rest.messages.MessagePathParameter;
+import org.apache.flink.runtime.rest.messages.MessageQueryParameter;
+import org.apache.flink.runtime.rest.messages.RequestBody;
+import org.apache.flink.runtime.rest.messages.ResponseBody;
+import org.apache.flink.runtime.rest.messages.WebSocketSpecification;
+import org.apache.flink.runtime.rpc.RpcUtils;
+import org.apache.flink.runtime.webmonitor.RestfulGateway;
+import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
+
+import org.apache.flink.shaded.netty4.io.netty.buffer.ByteBuf;
+import org.apache.flink.shaded.netty4.io.netty.channel.Channel;
+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.ChannelInitializer;
+import
org.apache.flink.shaded.netty4.io.netty.channel.embedded.EmbeddedChannel;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.FullHttpRequest;
+import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpHeaders;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpRequestDecoder;
+import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponse;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseEncoder;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.router.Handler;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.router.Router;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.websocketx.WebSocketClientHandshaker13;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.websocketx.WebSocketVersion;
+import org.apache.flink.shaded.netty4.io.netty.util.AbstractReferenceCounted;
+import org.apache.flink.shaded.netty4.io.netty.util.ReferenceCountUtil;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.net.URI;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.LinkedBlockingQueue;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Tests the {@link AbstractWebSocketHandler}.
+ */
+public class AbstractWebSocketHandlerTest {
+
+ private static final String TEST_SUBPROTOCOL = "test";
+ private static final String REST_ADDRESS = "http://localhost:1234";;
+ private static final JobID TEST_JOB_ID = new JobID();
+
+ private GatewayRetriever<RestfulGateway> gatewayRetriever;
+
+ @Before
+ public void setup() throws Exception {
+ // setup a mock gateway and retriever to satisfy the
RedirectHandler
+ RestfulGateway mockRestfulGateway = mock(RestfulGateway.class);
+
when(mockRestfulGateway.requestRestAddress(any(Time.class))).thenReturn(CompletableFuture.completedFuture(REST_ADDRESS));
+ gatewayRetriever = mock(GatewayRetriever.class);
+
when(gatewayRetriever.getNow()).thenReturn(Optional.of(mockRestfulGateway));
+ }
+
+ /**
+ * Tests the parameter processing logic.
+ */
+ @Test
+ public void testInvalidMessageParameter() {
+
+ EmbeddedChannel channel = channel(TestSpecification.INSTANCE,
new TestHandler());
+
+ // write a handshake request that is lacking a mandatory
parameter
+ TestParameters params = TestParameters.from(TEST_JOB_ID, 42);
+ URI requestUri =
URI.create(requestUri(TestSpecification.INSTANCE, params).toString()
+ .replace("42", "NA"));
+ FullHttpRequest request = handshakeRequest(requestUri,
TEST_SUBPROTOCOL);
+ channel.writeInbound(request);
+
+ // verify that the request was rejected
+ HttpResponse response = (HttpResponse) channel.readOutbound();
+ Assert.assertEquals(0, request.refCnt());
+ Assert.assertEquals(HttpResponseStatus.BAD_REQUEST,
response.getStatus());
+ Assert.assertTrue(channel.isOpen());
+ }
+
+ /**
+ * Tests the parameter processing logic.
+ */
+ @Test
+ public void testMissingMessageParameter() {
+
+ EmbeddedChannel channel = channel(TestSpecification.INSTANCE,
new TestHandler());
+
+ // write a handshake request that is lacking a mandatory
parameter
+ TestParameters params = TestParameters.from(TEST_JOB_ID, 42);
+ URI requestUri =
URI.create(requestUri(TestSpecification.INSTANCE, params).toString()
+ .replace("q", "_"));
+ FullHttpRequest request = handshakeRequest(requestUri,
TEST_SUBPROTOCOL);
+ channel.writeInbound(request);
+
+ // verify that the request was rejected
+ HttpResponse response = (HttpResponse) channel.readOutbound();
+ Assert.assertEquals(0, request.refCnt());
+ Assert.assertEquals(HttpResponseStatus.BAD_REQUEST,
response.getStatus());
+ Assert.assertTrue(channel.isOpen());
+ }
+
+ /**
+ * Tests the parameter processing logic.
+ */
+ @Test
+ public void testValidMessageParameters() {
+
+ TestHandler handler = new TestHandler();
+ EmbeddedChannel channel = channel(TestSpecification.INSTANCE,
handler);
+
+ // write a handshake request with the mandatory parameter
+ TestParameters params = TestParameters.from(TEST_JOB_ID, 42);
+ FullHttpRequest request =
handshakeRequest(requestUri(TestSpecification.INSTANCE, params),
TEST_SUBPROTOCOL);
+ channel.writeInbound(request);
+
+ // verify that the request was accepted and that the message
parameters were available in numerous callbacks
+ HttpResponse response = (HttpResponse) channel.readOutbound();
+ Assert.assertEquals(0, request.refCnt());
+ Assert.assertEquals(HttpResponseStatus.SWITCHING_PROTOCOLS,
response.getStatus());
+ Assert.assertNotNull(handler.handshakeInitiated);
+ Assert.assertEquals(Collections.singletonList(42),
handler.handshakeInitiated.queryParameter.getValue());
+ }
+
+ /**
+ * Tests the websocket upgrade logic.
+ */
+ @Test
+ public void testWebSocketUpgrade() {
+
+ EmbeddedChannel channel = channel(TestSpecification.INSTANCE,
new TestHandler());
+
+ // write a handshake request
+ TestParameters params = TestParameters.from(TEST_JOB_ID, 42);
+ FullHttpRequest request =
handshakeRequest(requestUri(TestSpecification.INSTANCE, params),
TEST_SUBPROTOCOL);
+ channel.writeInbound(request);
+
+ // check for a websocket handshaker and message handler in the
pipeline
+
Assert.assertNotNull(channel.pipeline().get(WebSocketServerProtocolHandler.class));
+
Assert.assertNotNull(channel.pipeline().get(JsonWebSocketMessageCodec.class));
+
+ // check for a websocket handshake response
+ HttpResponse response = (HttpResponse) channel.readOutbound();
+ Assert.assertEquals(0, request.refCnt());
+ Assert.assertNotNull(response);
+ Assert.assertEquals(HttpResponseStatus.SWITCHING_PROTOCOLS,
response.getStatus());
+ }
+
+ /**
+ * Tests upgrade failure due to a handshaking issue.
+ */
+ @Test
+ public void testWebSocketUpgradeFailure() {
+
+ EmbeddedChannel channel = channel(TestSpecification.INSTANCE,
new TestHandler());
+
+ // write an invalid handshake request
+ TestParameters params = TestParameters.from(TEST_JOB_ID, 42);
+ FullHttpRequest request =
handshakeRequest(requestUri(TestSpecification.INSTANCE, params),
TEST_SUBPROTOCOL);
+ request.headers().remove("Sec-WebSocket-Key");
+ channel.writeInbound(request);
+
+ // check for a websocket handshake response
+ HttpResponse response = (HttpResponse) channel.readOutbound();
+ Assert.assertEquals(0, request.refCnt());
+ Assert.assertNotNull(response);
+ Assert.assertEquals(HttpResponseStatus.BAD_REQUEST,
response.getStatus());
+ Assert.assertFalse(channel.isOpen());
+ }
+
+ /**
+ * Tests message reading and writing.
+ */
+ @Test
+ public void testMessageReadWrite() throws Exception {
+ TestHandler handler = new TestHandler();
+ EmbeddedChannel channel = channel(TestSpecification.INSTANCE,
handler);
+
+ TestParameters params = TestParameters.from(TEST_JOB_ID, 42);
+ FullHttpRequest request =
handshakeRequest(requestUri(TestSpecification.INSTANCE, params),
TEST_SUBPROTOCOL);
+ channel.writeInbound(request);
+ HttpResponse response = (HttpResponse) channel.readOutbound();
+ Assert.assertEquals(HttpResponseStatus.SWITCHING_PROTOCOLS,
response.getStatus());
+
+ ClientMessage expected = new ClientMessage(42);
+ channel.writeInbound(expected);
+ ClientMessage actual = handler.messages.take();
+ Assert.assertEquals(expected.sequenceNumber,
actual.sequenceNumber);
+ Assert.assertEquals(1, expected.refCnt());
+ Assert.assertTrue(channel.isOpen());
+
+ ByteBuf msg = (ByteBuf) channel.readOutbound();
+ Assert.assertEquals(23, msg.readableBytes()); // contains an
on-the-wire text frame
+ ReferenceCountUtil.release(msg);
+ }
+
+ /**
+ * A path parameter for test purposes.
+ */
+ static class TestPathParameter extends MessagePathParameter<JobID> {
+ TestPathParameter() {
+ super("jobid");
+ }
+
+ @Override
+ public JobID convertFromString(String value) {
+ return JobID.fromHexString(value);
+ }
+
+ @Override
+ protected String convertToString(JobID value) {
+ return value.toString();
+ }
+ }
+
+ /**
+ * A query parameter for test purposes.
+ */
+ private static class TestQueryParameter extends
MessageQueryParameter<Integer> {
+
+ TestQueryParameter() {
+ super("q", MessageParameterRequisiteness.MANDATORY);
+ }
+
+ @Override
+ public Integer convertValueFromString(String value) {
+ return Integer.parseInt(value);
+ }
+
+ @Override
+ public String convertStringToValue(Integer value) {
+ return value.toString();
+ }
+ }
+
+ /**
+ * Parameters for the test WebSocket resource.
+ */
+ private static class TestParameters extends MessageParameters {
+ private final TestPathParameter pathParameter = new
TestPathParameter();
+ private final TestQueryParameter queryParameter = new
TestQueryParameter();
+
+ @Override
+ public Collection<MessagePathParameter<?>> getPathParameters() {
+ return Collections.singleton(pathParameter);
+ }
+
+ @Override
+ public Collection<MessageQueryParameter<?>>
getQueryParameters() {
+ return Collections.singleton(queryParameter);
+ }
+
+ public static TestParameters from(JobID jobID, int
sequenceNumber) {
+ TestParameters p = new TestParameters();
+ p.pathParameter.resolve(jobID);
+
p.queryParameter.resolve(Collections.singletonList(sequenceNumber));
+ return p;
+ }
+ }
+
+ /**
+ * The specification for the test WebSocket resource.
+ */
+ static class TestSpecification implements
WebSocketSpecification<TestParameters, ClientMessage, ServerMessage> {
+
+ static final TestSpecification INSTANCE = new
TestSpecification();
+
+ @Override
+ public String getTargetRestEndpointURL() {
+ return "/jobs/:jobid/subscribe";
+ }
+
+ @Override
+ public String getSubprotocol() {
+ return "test";
+ }
+
+ @Override
+ public Class<ServerMessage> getServerClass() {
+ return ServerMessage.class;
+ }
+
+ @Override
+ public Class<ClientMessage> getClientClass() {
+ return ClientMessage.class;
+ }
+
+ @Override
+ public TestParameters getUnresolvedMessageParameters() {
+ return new TestParameters();
+ }
+ }
+
+ /**
+ * The channel handler for the test WebSocket resource.
+ */
+ private class TestHandler extends
AbstractWebSocketHandler<RestfulGateway, TestParameters, ClientMessage,
ServerMessage> {
+
+ TestParameters handshakeInitiated = null;
+
+ TestParameters handshakeCompleted = null;
+
+ final LinkedBlockingQueue<ClientMessage> messages = new
LinkedBlockingQueue<>();
+
+ public TestHandler() {
+ super(CompletableFuture.completedFuture(REST_ADDRESS),
gatewayRetriever, RpcUtils.INF_TIMEOUT, TestSpecification.INSTANCE);
+ }
+
+ @Override
+ protected CompletableFuture<Void>
handshakeInitiated(ChannelHandlerContext ctx, TestParameters parameters) throws
Exception {
+ handshakeInitiated = parameters;
+ return CompletableFuture.completedFuture(null);
+ }
+
+ @Override
+ protected void handshakeCompleted(ChannelHandlerContext ctx,
TestParameters parameters) throws Exception {
+ handshakeCompleted = parameters;
+ }
+
+ @Override
+ protected void messageReceived(ChannelHandlerContext ctx,
TestParameters parameters, ClientMessage msg) throws Exception {
+ ReferenceCountUtil.retain(msg);
+ messages.put(msg);
+
+ ctx.channel().writeAndFlush(new
ServerMessage(msg.sequenceNumber));
+ }
+ }
+
+ /**
+ * A WebSocket message for test purposes.
+ */
+ private static class ClientMessage extends AbstractReferenceCounted
implements RequestBody {
+ public final int sequenceNumber;
+
+ public ClientMessage(@JsonProperty("sequenceNumber") int
sequenceNumber) {
+ this.sequenceNumber = sequenceNumber;
+ }
+
+ @Override
+ protected void deallocate() {
+ }
+ }
+
+ /**
+ * A WebSocket message for test purposes.
+ */
+ private static class ServerMessage extends AbstractReferenceCounted
implements ResponseBody {
+ public final int sequenceNumber;
+
+ public ServerMessage(@JsonProperty("sequenceNumber") int
sequenceNumber) {
+ this.sequenceNumber = sequenceNumber;
+ }
+
+ @Override
+ protected void deallocate() {
+ }
+ }
+
+ // ----- Utility -----
+
+ /**
+ * Creates an embedded channel for HTTP/websocket test purposes.
+ */
+ private EmbeddedChannel channel(RestHandlerSpecification spec,
ChannelInboundHandler handler) {
+
+ // the websocket handshaker looks for HTTP decoder/encoder (to
know where to inject WS handlers).
+ // For test purposes, use a passthru encoder so that tests may
assert various aspects of the response.
+ return new EmbeddedChannel(new ChannelInitializer<Channel>() {
+ @Override
+ protected void initChannel(Channel channel) throws
Exception {
+ Router router = new Router();
+ router.GET(spec.getTargetRestEndpointURL(),
handler);
+ Handler routerHandler = new Handler(router);
+ channel.pipeline()
+ .addLast(new HttpRequestDecoder(), new
MockHttpResponseEncoder())
+ .addLast(routerHandler.name(),
routerHandler);
+ }
+ });
+ }
+
+ /**
+ * Creates an URI for the given REST spec.
+ */
+ private static URI requestUri(RestHandlerSpecification spec,
MessageParameters parameters) {
+ URI resolved =
URI.create(MessageParameters.resolveUrl(spec.getTargetRestEndpointURL(),
parameters));
+ return URI.create(REST_ADDRESS).resolve(resolved);
+ }
+
+ /**
+ * Creates a handshake request for the given request URI.
+ */
+ private static FullHttpRequest handshakeRequest(URI requestUri, String
subprotocol) {
+ URI wsURL = URI.create(requestUri.toString().replace("http:",
"ws:").replace("https:", "wss:"));
+ MockHandshaker handshaker = new MockHandshaker(wsURL,
subprotocol, HttpHeaders.EMPTY_HEADERS);
+ FullHttpRequest httpRequest = handshaker.newHandshakeRequest();
+ return httpRequest;
+ }
+
+ /**
+ * A helper class for using Netty's built-in handshaking class to
construct valid handshake requests.
+ */
+ private static class MockHandshaker extends WebSocketClientHandshaker13
{
+ public MockHandshaker(URI webSocketURL, String subprotocol,
HttpHeaders customHeaders) {
+ super(webSocketURL, WebSocketVersion.V13, subprotocol,
false, customHeaders, Integer.MAX_VALUE);
+ }
+
+ @Override
+ public FullHttpRequest newHandshakeRequest() {
+ return super.newHandshakeRequest();
+ }
+ }
+
+ /**
+ * A no-op encoder that must exist to satisfy the WS handshaker.
+ */
+ private static class MockHttpResponseEncoder extends
HttpResponseEncoder {
+ @Override
+ protected void encode(ChannelHandlerContext ctx, Object msg,
List<Object> out) throws Exception {
+ if (msg != null) {
+ ReferenceCountUtil.retain(msg);
+ out.add(msg);
+ }
+ }
+ }
+}
diff --git
a/flink-runtime/src/test/java/org/apache/flink/runtime/rest/handler/JsonWebSocketMessageCodecTest.java
b/flink-runtime/src/test/java/org/apache/flink/runtime/rest/handler/JsonWebSocketMessageCodecTest.java
new file mode 100644
index 00000000000..48283f34bb5
--- /dev/null
+++
b/flink-runtime/src/test/java/org/apache/flink/runtime/rest/handler/JsonWebSocketMessageCodecTest.java
@@ -0,0 +1,82 @@
+/*
+ * 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;
+
+import
org.apache.flink.shaded.netty4.io.netty.channel.embedded.EmbeddedChannel;
+import org.apache.flink.shaded.netty4.io.netty.handler.codec.DecoderException;
+import org.apache.flink.shaded.netty4.io.netty.handler.codec.EncoderException;
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Tests the {@link JsonWebSocketMessageCodec}.
+ */
+public class JsonWebSocketMessageCodecTest {
+
+ @Test
+ public void testDecodeSuccess() {
+ EmbeddedChannel channel = new EmbeddedChannel(new
JsonWebSocketMessageCodec<>(TestMessage.class, TestMessage.class));
+ channel.writeInbound(new
TextWebSocketFrame("{\"sequenceNumber\":42}"));
+ TestMessage actual = (TestMessage) channel.readInbound();
+ Assert.assertNotNull(actual);
+ Assert.assertEquals(42, actual.sequenceNumber);
+ }
+
+ @Test(expected = DecoderException.class)
+ public void testDecodeFailure() {
+ EmbeddedChannel channel = new EmbeddedChannel(new
JsonWebSocketMessageCodec<>(TestMessage.class, TestMessage.class));
+ channel.writeInbound(new TextWebSocketFrame(""));
+ }
+
+ @Test
+ public void testEncodeSuccess() {
+ EmbeddedChannel channel = new EmbeddedChannel(new
JsonWebSocketMessageCodec<>(TestMessage.class, TestMessage.class));
+ channel.writeOutbound(new TestMessage(42));
+ TextWebSocketFrame actual = (TextWebSocketFrame)
channel.readOutbound();
+ Assert.assertNotNull(actual);
+ Assert.assertEquals("{\"sequenceNumber\":42}", actual.text());
+ }
+
+ @Test(expected = EncoderException.class)
+ public void testEncodeFailure() {
+ EmbeddedChannel channel = new EmbeddedChannel(new
JsonWebSocketMessageCodec<>(TestMessage.class, TestMessage.class));
+ channel.writeOutbound(new TestMessage(-1));
+ }
+
+ private static class TestMessage {
+
+ private final int sequenceNumber;
+
+ public int getSequenceNumber() {
+ if (sequenceNumber < 0) {
+ throw new IllegalStateException();
+ }
+ return sequenceNumber;
+ }
+
+ @JsonCreator
+ public TestMessage(@JsonProperty("sequenceNumber") int
sequenceNumber) {
+ this.sequenceNumber = sequenceNumber;
+ }
+ }
+}
----------------------------------------------------------------
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us...@infra.apache.org
> Create WebSocket handler (server)
> ---------------------------------
>
> Key: FLINK-7738
> URL: https://issues.apache.org/jira/browse/FLINK-7738
> Project: Flink
> Issue Type: Sub-task
> Components: Cluster Management, Mesos
> Reporter: Eron Wright
> Assignee: Eron Wright
> Priority: Major
> Labels: pull-request-available
>
> An abstract handler is needed to support websocket communication.
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