Added BlockHound integration

pom.xml

@@ -56,6 +56,7 @@
 		<spring-cloud-netflix.version>2.2.0.BUILD-SNAPSHOT</spring-cloud-netflix.version>
 		<spring-cloud-circuitbreaker.version>1.0.0.BUILD-SNAPSHOT</spring-cloud-circuitbreaker.version>
 		<embedded-redis.version>0.6</embedded-redis.version>
+		<blockhound.version>1.0.1.RELEASE</blockhound.version>
 	</properties>
 
 	<dependencyManagement>
@@ -134,6 +135,11 @@
 				<artifactId>embedded-redis</artifactId>
 				<version>${embedded-redis.version}</version>
 			</dependency>
+			<dependency>
+				<groupId>io.projectreactor.tools</groupId>
+				<artifactId>blockhound-junit-platform</artifactId>
+				<version>${blockhound.version}</version>
+			</dependency>
 		</dependencies>
 	</dependencyManagement>
 

spring-cloud-gateway-core/pom.xml

@@ -112,6 +112,11 @@
 			<artifactId>reactor-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>io.projectreactor.tools</groupId>
+			<artifactId>blockhound-junit-platform</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.assertj</groupId>
 			<artifactId>assertj-core</artifactId>

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/RetryGatewayFilterFactoryIntegrationTests.java

@@ -31,6 +31,7 @@ import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import reactor.core.publisher.Mono;
 
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.SpringBootConfiguration;
@@ -193,19 +194,15 @@ public class RetryGatewayFilterFactoryIntegrationTests extends BaseWebClientTest
 		private String uri;
 
 		@RequestMapping("/httpbin/sleep")
-		public ResponseEntity<String> sleep(@RequestParam("key") String key,
+		public Mono<ResponseEntity<String>> sleep(@RequestParam("key") String key,
 				@RequestParam("millis") long millisToSleep) {
 			AtomicInteger num = getCount(key);
 			int retryCount = num.incrementAndGet();
 			log.warn("Retry count: " + retryCount);
-			try {
-				Thread.sleep(millisToSleep);
-			}
-			catch (InterruptedException e) {
-			}
-			return ResponseEntity.status(HttpStatus.OK)
-					.header("X-Retry-Count", String.valueOf(retryCount))
-					.body("slept " + millisToSleep + " ms");
+			return Mono.delay(Duration.ofMillis(millisToSleep))
+					.thenReturn(ResponseEntity.status(HttpStatus.OK)
+							.header("X-Retry-Count", String.valueOf(retryCount))
+							.body("slept " + millisToSleep + " ms"));
 		}
 
 		@RequestMapping("/httpbin/retryalwaysfail")

spring-cloud-gateway-core/src/test/java/reactor/blockhound/integration/CustomBlockHoundIntegration.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2019-2019 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
+ *
+ *      https://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 reactor.blockhound.integration;
+
+import reactor.blockhound.BlockHound;
+
+/**
+ * @author Tim Ysewyn
+ */
+public class CustomBlockHoundIntegration implements BlockHoundIntegration {
+
+	@Override
+	public void applyTo(BlockHound.Builder builder) {
+		// Uses
+		// ch.qos.logback.classic.spi.PackagingDataCalculator#getImplementationVersion
+		builder.allowBlockingCallsInside(
+				"org.springframework.boot.autoconfigure.web.reactive.error.AbstractErrorWebExceptionHandler",
+				"logError");
+		builder.allowBlockingCallsInside("reactor.util.Loggers$Slf4JLogger", "debug");
+
+		// Uses org.springframework.util.JdkIdGenerator#generateId
+		// Uses UUID#randomUUID
+		builder.allowBlockingCallsInside(
+				"org.springframework.web.server.session.InMemoryWebSessionStore",
+				"lambda$createWebSession$0");
+
+		// Uses java.util.Random#nextInt
+		builder.allowBlockingCallsInside("org.springframework.util.MimeTypeUtils",
+				"generateMultipartBoundary");
+
+		// SECURITY RELATED
+
+		// For HTTPS traffic
+		builder.allowBlockingCallsInside("io.netty.handler.ssl.SslHandler",
+				"channelActive");
+		builder.allowBlockingCallsInside("io.netty.handler.ssl.SslHandler", "unwrap");
+		builder.allowBlockingCallsInside("io.netty.handler.ssl.SslContext",
+				"newClientContextInternal");
+
+		// Uses
+		// org.springframework.cloud.commons.httpclient.DefaultApacheHttpClientConnectionManagerFactory#newConnectionManager
+		// Uses javax.net.ssl.SSLContext#init
+		builder.allowBlockingCallsInside(
+				"org.springframework.cloud.netflix.ribbon.SpringClientFactory",
+				"getContext");
+
+		// Uses org.springframework.security.crypto.bcrypt.BCrypt#gensalt
+		// Uses java.security.SecureRandom#nextBytes
+		builder.allowBlockingCallsInside(
+				"org.springframework.security.authentication.AbstractUserDetailsReactiveAuthenticationManager",
+				"lambda$authenticate$4");
+	}
+
+}

spring-cloud-gateway-core/src/test/java/reactor/blockhound/integration/CustomBlockHoundIntegrationTest.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2019-2019 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
+ *
+ *      https://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 reactor.blockhound.integration;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+/**
+ * @author Tim Ysewyn
+ */
+public class CustomBlockHoundIntegrationTest {
+
+	@Test
+	public void shouldThrowErrorForBlockingCallWithCustomBlockHoundIntegration() {
+		Assertions.assertThrows(RuntimeException.class, () -> Mono.fromCallable(() -> {
+			Thread.sleep(1);
+			return null;
+		}).subscribeOn(Schedulers.parallel()).block());
+	}
+
+}

spring-cloud-gateway-core/src/test/resources/META-INF/services/reactor.blockhound.integration.BlockHoundIntegration

@@ -0,0 +1 @@
+reactor.blockhound.integration.CustomBlockHoundIntegration