Fixes SSE issue by properly flushing for streaming media types.

fixes gh-161

spring-cloud-gateway-core/pom.xml

@@ -88,6 +88,11 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-validation</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-test-support</artifactId>

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2017 the original author or authors.
+ * Copyright 2013-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -140,8 +140,8 @@ public class GatewayAutoConfiguration {
 		}
 
 		@Bean
-		public NettyWriteResponseFilter nettyWriteResponseFilter() {
-			return new NettyWriteResponseFilter();
+		public NettyWriteResponseFilter nettyWriteResponseFilter(GatewayProperties properties) {
+			return new NettyWriteResponseFilter(properties.getStreamingMediaTypes());
 		}
 
 		@Bean

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/config/GatewayProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2017 the original author or authors.
+ * Copyright 2013-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@
 package org.springframework.cloud.gateway.config;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 import javax.validation.Valid;
@@ -27,6 +28,7 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.cloud.gateway.filter.FilterDefinition;
 import org.springframework.cloud.gateway.filter.factory.RemoveNonProxyHeadersGatewayFilterFactory;
 import org.springframework.cloud.gateway.route.RouteDefinition;
+import org.springframework.http.MediaType;
 import org.springframework.validation.annotation.Validated;
 
 import static org.springframework.cloud.gateway.support.NameUtils.normalizeFilterName;
@@ -50,6 +52,9 @@ public class GatewayProperties {
 	 */
 	private List<FilterDefinition> defaultFilters = loadDefaults();
 
+	private List<MediaType> streamingMediaTypes = Arrays.asList(MediaType.TEXT_EVENT_STREAM,
+			MediaType.APPLICATION_STREAM_JSON);
+
 	private ArrayList<FilterDefinition> loadDefaults() {
 		ArrayList<FilterDefinition> defaults = new ArrayList<>();
 		FilterDefinition definition = new FilterDefinition();
@@ -73,4 +78,21 @@ public class GatewayProperties {
 	public void setDefaultFilters(List<FilterDefinition> defaultFilters) {
 		this.defaultFilters = defaultFilters;
 	}
+
+	public List<MediaType> getStreamingMediaTypes() {
+		return streamingMediaTypes;
+	}
+
+	public void setStreamingMediaTypes(List<MediaType> streamingMediaTypes) {
+		this.streamingMediaTypes = streamingMediaTypes;
+	}
+
+	@Override
+	public String toString() {
+		return "GatewayProperties{" +
+				"routes=" + routes +
+				", defaultFilters=" + defaultFilters +
+				", streamingMediaTypes=" + streamingMediaTypes +
+				'}';
+	}
 }

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/NettyWriteResponseFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2017 the original author or authors.
+ * Copyright 2013-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,20 +17,24 @@
 
 package org.springframework.cloud.gateway.filter;
 
+import java.util.List;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.springframework.core.Ordered;
-import org.springframework.core.io.buffer.NettyDataBuffer;
-import org.springframework.core.io.buffer.NettyDataBufferFactory;
-import org.springframework.http.server.reactive.ServerHttpResponse;
-import org.springframework.web.server.ServerWebExchange;
-
-import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR;
-
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.ipc.netty.http.client.HttpClientResponse;
 
+import org.springframework.core.Ordered;
+import org.springframework.core.io.buffer.NettyDataBuffer;
+import org.springframework.core.io.buffer.NettyDataBufferFactory;
+import org.springframework.http.MediaType;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.lang.Nullable;
+import org.springframework.web.server.ServerWebExchange;
+
+import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR;
+
 /**
  * @author Spencer Gibb
  */
@@ -40,6 +44,12 @@ public class NettyWriteResponseFilter implements GlobalFilter, Ordered {
 
 	public static final int WRITE_RESPONSE_FILTER_ORDER = -1;
 
+	private final List<MediaType> streamingMediaTypes;
+
+	public NettyWriteResponseFilter(List<MediaType> streamingMediaTypes) {
+		this.streamingMediaTypes = streamingMediaTypes;
+	}
+
 	@Override
 	public int getOrder() {
 		return WRITE_RESPONSE_FILTER_ORDER;
@@ -65,8 +75,17 @@ public class NettyWriteResponseFilter implements GlobalFilter, Ordered {
 					.retain() //TODO: needed?
 					.map(factory::wrap);
 
-			return response.writeWith(body);
+			MediaType contentType = response.getHeaders().getContentType();
+			return (isStreamingMediaType(contentType) ?
+					response.writeAndFlushWith(body.map(Flux::just)) : response.writeWith(body));
 		}));
 	}
 
+	//TODO: use framework if possible
+	//TODO: port to WebClientWriteResponseFilter
+	private boolean isStreamingMediaType(@Nullable MediaType contentType) {
+		return (contentType != null && this.streamingMediaTypes.stream()
+						.anyMatch(contentType::isCompatibleWith));
+	}
+
 }

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/sse/SseIntegrationTests.java

@@ -0,0 +1,318 @@
+/*
+ * Copyright 2013-2018 the original author or authors.
+ *
+ * Licensed 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.springframework.cloud.gateway.test.sse;
+
+import java.time.Duration;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import reactor.core.publisher.Flux;
+import reactor.test.StepVerifier;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.cloud.gateway.route.RouteLocator;
+import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
+import org.springframework.cloud.gateway.test.PermitAllSecurityConfiguration;
+import org.springframework.cloud.gateway.test.support.HttpServer;
+import org.springframework.cloud.gateway.test.support.ReactorHttpServer;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.core.ResolvableType;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.http.codec.ServerSentEvent;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.reactive.DispatcherHandler;
+import org.springframework.web.reactive.config.EnableWebFlux;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.springframework.core.ResolvableType.forClassWithGenerics;
+import static org.springframework.http.MediaType.TEXT_EVENT_STREAM;
+import static org.springframework.web.reactive.function.BodyExtractors.toFlux;
+
+/**
+ * @author Sebastien Deleuze
+ */
+public class SseIntegrationTests {
+
+	protected Log logger = LogFactory.getLog(getClass());
+
+	protected int serverPort;
+
+	public HttpServer server;
+
+	private AnnotationConfigApplicationContext wac;
+
+	private WebClient webClient;
+
+	private ConfigurableApplicationContext gatewayContext;
+
+	private int gatewayPort;
+
+	@Before
+	public void setup() throws Exception {
+		this.server = new ReactorHttpServer();
+		this.server.setHandler(createHttpHandler());
+		this.server.afterPropertiesSet();
+		this.server.start();
+
+		// Set dynamically chosen port
+		this.serverPort = this.server.getPort();
+		logger.info("SSE Port: "+this.serverPort);
+
+
+		this.gatewayContext = new SpringApplicationBuilder(GatewayConfig.class)
+				.properties("sse.server.port:"+this.serverPort, "server.port=0", "spring.jmx.enabled=false")
+				.run();
+
+		ConfigurableEnvironment env = this.gatewayContext.getBean(ConfigurableEnvironment.class);
+		this.gatewayPort = new Integer(env.getProperty("local.server.port"));
+
+		this.webClient = WebClient.create("http://localhost:" + this.gatewayPort + "/sse");
+
+		logger.info("Gateway Port: "+this.gatewayPort);
+	}
+
+	@After
+	public void tearDown() throws Exception {
+		this.server.stop();
+		this.serverPort = 0;
+		this.gatewayPort = 0;
+		this.gatewayContext.close();
+		this.wac.close();
+	}
+
+	private HttpHandler createHttpHandler() {
+		this.wac = new AnnotationConfigApplicationContext();
+		this.wac.register(TestConfiguration.class);
+		this.wac.refresh();
+
+		return WebHttpHandlerBuilder.webHandler(new DispatcherHandler(this.wac)).build();
+	}
+
+	@Test
+	public void sseAsString() {
+		Flux<String> result = this.webClient.get()
+				.uri("/string")
+				.accept(TEXT_EVENT_STREAM)
+				.exchange()
+				.flatMapMany(response -> response.bodyToFlux(String.class));
+
+		StepVerifier.create(result)
+				.expectNext("foo 0")
+				.expectNext("foo 1")
+				.thenCancel()
+				.verify(Duration.ofSeconds(5L));
+	}
+
+	@Test
+	public void sseAsPerson() {
+		Flux<Person> result = this.webClient.get()
+				.uri("/person")
+				.accept(TEXT_EVENT_STREAM)
+				.exchange()
+				.flatMapMany(response -> response.bodyToFlux(Person.class));
+
+		StepVerifier.create(result)
+				.expectNext(new Person("foo 0"))
+				.expectNext(new Person("foo 1"))
+				.thenCancel()
+				.verify(Duration.ofSeconds(5L));
+	}
+
+	@Test
+	@SuppressWarnings("Duplicates")
+	public void sseAsEvent() {
+		ResolvableType type = forClassWithGenerics(ServerSentEvent.class, String.class);
+		Flux<ServerSentEvent<String>> result = this.webClient.get()
+				.uri("/event")
+				.accept(TEXT_EVENT_STREAM)
+				.exchange()
+				.flatMapMany(response -> response.body(
+						toFlux(new ParameterizedTypeReference<ServerSentEvent<String>>() {})));
+
+		StepVerifier.create(result)
+				.consumeNextWith( event -> {
+					assertEquals("0", event.id());
+					assertEquals("foo", event.data());
+					assertEquals("bar", event.comment());
+					assertNull(event.event());
+					assertNull(event.retry());
+				})
+				.consumeNextWith( event -> {
+					assertEquals("1", event.id());
+					assertEquals("foo", event.data());
+					assertEquals("bar", event.comment());
+					assertNull(event.event());
+					assertNull(event.retry());
+				})
+				.thenCancel()
+				.verify(Duration.ofSeconds(5L));
+	}
+
+	@Test
+	@SuppressWarnings("Duplicates")
+	public void sseAsEventWithoutAcceptHeader() {
+		Flux<ServerSentEvent<String>> result = this.webClient.get()
+				.uri("/event")
+				.accept(TEXT_EVENT_STREAM)
+				.exchange()
+				.flatMapMany(response -> response.body(
+						toFlux(new ParameterizedTypeReference<ServerSentEvent<String>>() {})));
+
+		StepVerifier.create(result)
+				.consumeNextWith( event -> {
+					assertEquals("0", event.id());
+					assertEquals("foo", event.data());
+					assertEquals("bar", event.comment());
+					assertNull(event.event());
+					assertNull(event.retry());
+				})
+				.consumeNextWith( event -> {
+					assertEquals("1", event.id());
+					assertEquals("foo", event.data());
+					assertEquals("bar", event.comment());
+					assertNull(event.event());
+					assertNull(event.retry());
+				})
+				.thenCancel()
+				.verify(Duration.ofSeconds(5L));
+	}
+
+	/**
+	 * Return an interval stream of with n number of ticks and buffer the
+	 * emissions to avoid back pressure failures (e.g. on slow CI server).
+	 */
+	public static Flux<Long> interval(Duration period, int count) {
+		return Flux.interval(period).take(count).onBackpressureBuffer(2);
+	}
+
+	@RestController
+	@SuppressWarnings("unused")
+	static class SseController {
+
+		private static final Flux<Long> INTERVAL = interval(Duration.ofMillis(100), 50);
+
+
+		@RequestMapping("/sse/string")
+		Flux<String> string() {
+			return INTERVAL.map(l -> "foo " + l);
+		}
+
+		@RequestMapping("/sse/person")
+		Flux<Person> person() {
+			return INTERVAL.map(l -> new Person("foo " + l));
+		}
+
+		@RequestMapping("/sse/event")
+		Flux<ServerSentEvent<String>> sse() {
+			return INTERVAL.map(l -> ServerSentEvent.builder("foo")
+					.id(Long.toString(l))
+					.comment("bar")
+					.build());
+		}
+
+	}
+
+
+	@Configuration
+	@EnableWebFlux
+	@SuppressWarnings("unused")
+	static class TestConfiguration {
+
+		@Bean
+		public SseController sseController() {
+			return new SseController();
+		}
+	}
+
+	@Configuration
+	@EnableAutoConfiguration
+	@Import(PermitAllSecurityConfiguration.class)
+	protected static class GatewayConfig {
+
+		@Value("${sse.server.port}")
+		private int port;
+
+		@Bean
+		public RouteLocator sseRouteLocator(RouteLocatorBuilder builder) {
+			return builder.routes()
+					.route("sse_route", r -> r.alwaysTrue()
+							.uri("http://localhost:"+this.port))
+					.build();
+		}
+	}
+
+
+	@SuppressWarnings("unused")
+	private static class Person {
+
+		private String name;
+
+		public Person() {
+		}
+
+		public Person(String name) {
+			this.name = name;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if (this == o) {
+				return true;
+			}
+			if (o == null || getClass() != o.getClass()) {
+				return false;
+			}
+			Person person = (Person) o;
+			return !(this.name != null ? !this.name.equals(person.name) : person.name != null);
+		}
+
+		@Override
+		public int hashCode() {
+			return this.name != null ? this.name.hashCode() : 0;
+		}
+
+		@Override
+		public String toString() {
+			return "Person{name='" + this.name + '\'' + '}';
+		}
+	}
+
+}

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/support/AbstractHttpServer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2013-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -12,9 +12,10 @@
  * 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.springframework.cloud.gateway.test.websocket;
+package org.springframework.cloud.gateway.test.support;
 
 import java.util.LinkedHashMap;
 import java.util.Map;

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/support/HttpServer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2013-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -12,9 +12,10 @@
  * 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.springframework.cloud.gateway.test.websocket;
+package org.springframework.cloud.gateway.test.support;
 
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.Lifecycle;

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/support/ReactorHttpServer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2013-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -12,9 +12,10 @@
  * 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.springframework.cloud.gateway.test.websocket;
+package org.springframework.cloud.gateway.test.support;
 
 import java.util.concurrent.atomic.AtomicReference;
 

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/websocket/WebSocketIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2013-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -12,6 +12,7 @@
  * 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.springframework.cloud.gateway.test.websocket;
@@ -38,6 +39,8 @@ import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.cloud.gateway.route.RouteLocator;
 import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
 import org.springframework.cloud.gateway.test.PermitAllSecurityConfiguration;
+import org.springframework.cloud.gateway.test.support.HttpServer;
+import org.springframework.cloud.gateway.test.support.ReactorHttpServer;
 import org.springframework.cloud.netflix.ribbon.RibbonClient;
 import org.springframework.cloud.netflix.ribbon.StaticServerList;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -115,7 +118,6 @@ public class WebSocketIntegrationTests {
 				.properties("ws.server.port:"+this.serverPort, "server.port=0", "spring.jmx.enabled=false")
 				.run();
 
-		GatewayConfig config = this.gatewayContext.getBean(GatewayConfig.class);
 		ConfigurableEnvironment env = this.gatewayContext.getBean(ConfigurableEnvironment.class);
 		this.gatewayPort = new Integer(env.getProperty("local.server.port"));
 	}