Adds support to set reactor netty websocket max frame payload length.

fixes gh-163

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

@@ -605,8 +605,14 @@ public class GatewayAutoConfiguration {
 
 		@Bean
 		public ReactorNettyWebSocketClient reactorNettyWebSocketClient(
-				HttpClient httpClient) {
-			return new ReactorNettyWebSocketClient(httpClient);
+				HttpClientProperties properties, HttpClient httpClient) {
+			ReactorNettyWebSocketClient webSocketClient = new ReactorNettyWebSocketClient(
+					httpClient);
+			if (properties.getWebsocket().getMaxFramePayloadLength() != null) {
+				webSocketClient.setMaxFramePayloadLength(
+						properties.getWebsocket().getMaxFramePayloadLength());
+			}
+			return webSocketClient;
 		}
 
 	}

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

@@ -57,6 +57,9 @@ public class HttpClientProperties {
 	/** SSL configuration for Netty HttpClient. */
 	private Ssl ssl = new Ssl();
 
+	/** Websocket configuration for Netty HttpClient. */
+	private Websocket websocket = new Websocket();
+
 	public Integer getConnectTimeout() {
 		return connectTimeout;
 	}
@@ -97,11 +100,27 @@ public class HttpClientProperties {
 		this.ssl = ssl;
 	}
 
+	public Websocket getWebsocket() {
+		return this.websocket;
+	}
+
+	public void setWebsocket(Websocket websocket) {
+		this.websocket = websocket;
+	}
+
 	@Override
 	public String toString() {
-		return new ToStringCreator(this).append("connectTimeout", connectTimeout)
-				.append("responseTimeout", responseTimeout).append("pool", pool)
-				.append("proxy", proxy).append("ssl", ssl).toString();
+		// @formatter:off
+		return new ToStringCreator(this)
+				.append("connectTimeout", connectTimeout)
+				.append("responseTimeout", responseTimeout)
+				.append("pool", pool)
+				.append("proxy", proxy)
+				.append("ssl", ssl)
+				.append("websocket", websocket)
+				.toString();
+		// @formatter:on
+
 	}
 
 	public static class Pool {
@@ -397,4 +416,25 @@ public class HttpClientProperties {
 
 	}
 
+	public class Websocket {
+
+		/** Max frame payload length. */
+		private Integer maxFramePayloadLength;
+
+		public Integer getMaxFramePayloadLength() {
+			return this.maxFramePayloadLength;
+		}
+
+		public void setMaxFramePayloadLength(Integer maxFramePayloadLength) {
+			this.maxFramePayloadLength = maxFramePayloadLength;
+		}
+
+		@Override
+		public String toString() {
+			return new ToStringCreator(this)
+					.append("maxFramePayloadLength", maxFramePayloadLength).toString();
+		}
+
+	}
+
 }

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/config/GatewayAutoConfigurationTests.java

@@ -29,6 +29,7 @@ import org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfigurat
 import org.springframework.boot.test.context.runner.ReactiveWebApplicationContextRunner;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.web.filter.reactive.HiddenHttpMethodFilter;
+import org.springframework.web.reactive.socket.client.ReactorNettyWebSocketClient;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -83,7 +84,8 @@ public class GatewayAutoConfigurationTests {
 						"spring.cloud.gateway.httpclient.connect-timeout=10",
 						"spring.cloud.gateway.httpclient.response-timeout=10s",
 						"spring.cloud.gateway.httpclient.pool.type=fixed",
-						"spring.cloud.gateway.httpclient.proxy.host=myhost")
+						"spring.cloud.gateway.httpclient.proxy.host=myhost",
+						"spring.cloud.gateway.httpclient.websocket.max-frame-payload-length=1024")
 				.run(context -> {
 					assertThat(context).hasSingleBean(HttpClient.class);
 					HttpClient httpClient = context.getBean(HttpClient.class);
@@ -103,6 +105,11 @@ public class GatewayAutoConfigurationTests {
 					 * assertThat(sslContext).isNotNull();
 					 */
 					// TODO: howto test SslContext
+					assertThat(context).hasSingleBean(ReactorNettyWebSocketClient.class);
+					ReactorNettyWebSocketClient webSocketClient = context
+							.getBean(ReactorNettyWebSocketClient.class);
+					assertThat(webSocketClient.getMaxFramePayloadLength())
+							.isEqualTo(1024);
 				});
 	}