From 60a4f769cf5c126809f4a47e5252f63df58e3ddb Mon Sep 17 00:00:00 2001
From: Spencer Gibb <spencer@gibb.us>
Date: Tue, 10 Oct 2017 13:02:04 -0400
Subject: [PATCH] If hystrix timesout, return status 504 gateway timeout.

fixes gh-82
---
 .../factory/HystrixWebFilterFactory.java      | 23 +++++++++++++++----
 .../factory/HystrixWebFilterFactoryTests.java |  2 +-
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactory.java b/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactory.java
index 75f42fd3..f85a893d 100644
--- a/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactory.java
+++ b/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactory.java
@@ -17,6 +17,11 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Function;
+
+import org.springframework.http.HttpStatus;
 import org.springframework.tuple.Tuple;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilter;
@@ -25,15 +30,16 @@ import org.springframework.web.server.WebFilterChain;
 import com.netflix.hystrix.HystrixCommandGroupKey;
 import com.netflix.hystrix.HystrixCommandKey;
 import com.netflix.hystrix.HystrixObservableCommand;
+import com.netflix.hystrix.exception.HystrixRuntimeException;
+
+import static com.netflix.hystrix.exception.HystrixRuntimeException.FailureType.TIMEOUT;
+import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.setResponseStatus;
 
 import reactor.core.publisher.Mono;
 import rx.Observable;
 import rx.RxReactiveStreams;
 import rx.Subscription;
 
-import java.util.Arrays;
-import java.util.List;
-
 /**
  * @author Spencer Gibb
  */
@@ -61,7 +67,16 @@ public class HystrixWebFilterFactory implements WebFilterFactory {
 			return Mono.create(s -> {
 				Subscription sub = command.toObservable().subscribe(s::success, s::error, s::success);
 				s.onCancel(sub::unsubscribe);
-			});
+			}).onErrorResume((Function<Throwable, Mono<Void>>) throwable -> {
+				if (throwable instanceof HystrixRuntimeException) {
+					HystrixRuntimeException e = (HystrixRuntimeException) throwable;
+					if (e.getFailureType() == TIMEOUT) { //TODO: optionally set status
+						setResponseStatus(exchange, HttpStatus.GATEWAY_TIMEOUT);
+						return exchange.getResponse().setComplete();
+					}
+				}
+				return Mono.empty();
+			}).then();
 		};
 	}
 
diff --git a/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactoryTests.java b/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactoryTests.java
index 94a87fed..1b43b543 100644
--- a/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactoryTests.java
+++ b/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactoryTests.java
@@ -70,7 +70,7 @@ public class HystrixWebFilterFactoryTests extends BaseWebClientTests {
 
 		StepVerifier.create(result)
 				.consumeNextWith(
-						response -> assertStatus(response, HttpStatus.INTERNAL_SERVER_ERROR))
+						response -> assertStatus(response, HttpStatus.GATEWAY_TIMEOUT))
 				.expectComplete()
 				.verify(DURATION);
 	}