Return 404 upstream when using Eureka and RestTemplate. Fixes #2861 (#3023)

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/http/RestTemplateTransportClientFactory.java

@@ -19,8 +19,10 @@ package org.springframework.cloud.netflix.eureka.http;
 import java.net.URI;
 import java.net.URISyntaxException;
 
+import org.springframework.http.HttpStatus;
 import org.springframework.http.client.support.BasicAuthorizationInterceptor;
 import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
+import org.springframework.web.client.DefaultResponseErrorHandler;
 import org.springframework.web.client.RestTemplate;
 
 import com.fasterxml.jackson.databind.BeanDescription;
@@ -74,6 +76,7 @@ public class RestTemplateTransportClientFactory implements TransportClientFactor
 		}
 
 		restTemplate.getMessageConverters().add(0, mappingJacksonHttpMessageConverter());
+		restTemplate.setErrorHandler(new ErrorHanlder());
 
 		return restTemplate;
 	}
@@ -134,4 +137,20 @@ public class RestTemplateTransportClientFactory implements TransportClientFactor
 	public void shutdown() {
 	}
 
+	class ErrorHanlder extends DefaultResponseErrorHandler {
+		@Override
+		protected boolean hasError(HttpStatus statusCode) {
+			/**
+			 * When the Eureka server restarts and a client tries to sent a heartbeat the server
+			 * will respond with a 404.  By default RestTemplate will throw an exception in this case.
+			 * What we want is to return the 404 to the upstream code so it will send another registration
+			 * request to the server.
+			 */
+			if(statusCode.is4xxClientError()) {
+				return false;
+			}
+			return super.hasError(statusCode);
+		}
+	}
+
 }

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/http/EurekaServerMockApplication.java

@@ -20,6 +20,7 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -82,13 +83,16 @@ public class EurekaServerMockApplication {
 	@ResponseStatus(HttpStatus.OK)
 	@PutMapping(value = "/apps/{appName}/{id}", params = { "status",
 			"lastDirtyTimestamp" })
-	public InstanceInfo sendHeartBeat(@PathVariable String appName,
-			@PathVariable String id, @RequestParam String status,
-			@RequestParam String lastDirtyTimestamp,
-			@RequestParam(required = false) String overriddenstatus) {
-		return new InstanceInfo(null, null, null, null, null, null, null, null, null,
+	public ResponseEntity sendHeartBeat(@PathVariable String appName,
+										@PathVariable String id, @RequestParam String status,
+										@RequestParam String lastDirtyTimestamp,
+										@RequestParam(required = false) String overriddenstatus) {
+		if("fourOFour".equals(appName)) {
+			return new ResponseEntity(HttpStatus.NOT_FOUND);
+		}
+		return new ResponseEntity<InstanceInfo>(new InstanceInfo(null, null, null, null, null, null, null, null, null,
 				null, null, null, null, 0, null, null, null, null, null, null, null, 0l,
-				0l, null, null);
+				0l, null, null), HttpStatus.OK);
 	}
 
 	@ResponseStatus(HttpStatus.OK)

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/http/RestTemplateEurekaHttpClientTest.java

@@ -92,6 +92,12 @@ public class RestTemplateEurekaHttpClientTest {
 	}
 
 	@Test
+	public void testSendHeartBeatFourOFour() {
+		Assert.assertEquals(HttpStatus.NOT_FOUND.value(), eurekaHttpClient
+				.sendHeartBeat("fourOFour", "test", info, null).getStatusCode());
+	}
+
+	@Test
 	public void testStatusUpdate() {
 		Assert.assertEquals(HttpStatus.OK.value(), eurekaHttpClient
 				.statusUpdate("test", "test", InstanceStatus.UP, info).getStatusCode());