Extract ID from instance info

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/eureka/DataCenterAwareMarshallingStrategy.java

+/*
+ * Copyright 2013-2014 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.netflix.eureka;
+
+import com.netflix.appinfo.DataCenterInfo;
+import com.netflix.appinfo.UniqueIdentifier;
+import com.netflix.appinfo.DataCenterInfo.Name;
+import com.netflix.appinfo.InstanceInfo;
+import com.thoughtworks.xstream.MarshallingStrategy;
+import com.thoughtworks.xstream.converters.ConverterLookup;
+import com.thoughtworks.xstream.converters.DataHolder;
+import com.thoughtworks.xstream.core.TreeMarshallingStrategy;
+import com.thoughtworks.xstream.io.HierarchicalStreamReader;
+import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
+import com.thoughtworks.xstream.mapper.Mapper;
+
+/**
+ * A special purpose wrapper for an XStream TreeMarshallingStrategy that is aware of the
+ * {@link InstanceInfo} type and can create a more useful {@link DataCenterInfo} for it
+ * after unmarshalling. If the InstanceInfo has a metadataMap containing an
+ * <code>instanceId</code>, and the DataCenterInfo is not already an AmazonInfo, then the
+ * instanceId is used to create an identifier, but appending it to the existing one. This
+ * is useful when not running Eureka in bare EC2 VMs, so the EC2 metadata is not available
+ * for uniquely identifying the InstanceInfo (the default is to just use the hostname, but
+ * that isn't very useful when sitting behind a proxy).
+ * 
+ * @author Dave Syer
+ *
+ */
+public class DataCenterAwareMarshallingStrategy implements MarshallingStrategy {
+
+	private TreeMarshallingStrategy delegate = new TreeMarshallingStrategy();
+
+	@Override
+	public Object unmarshal(Object root, HierarchicalStreamReader reader,
+			DataHolder dataHolder, ConverterLookup converterLookup, Mapper mapper) {
+		Object obj = delegate
+				.unmarshal(root, reader, dataHolder, converterLookup, mapper);
+		if (obj instanceof InstanceInfo) {
+			InstanceInfo info = (InstanceInfo) obj;
+			String instanceId = info.getMetadata().get("instanceId");
+			DataCenterInfo dataCenter = info.getDataCenterInfo();
+			if (instanceId != null && Name.Amazon != dataCenter.getName()) {
+				String old = info.getId();
+				info = new InstanceInfo.Builder(info).setDataCenterInfo(
+						new InstanceIdDataCenterInfo(old + ":" + instanceId)).build();
+				obj = info;
+			}
+		}
+		return obj;
+	}
+
+	@Override
+	public void marshal(HierarchicalStreamWriter writer, Object obj,
+			ConverterLookup converterLookup, Mapper mapper, DataHolder dataHolder) {
+		delegate.marshal(writer, obj, converterLookup, mapper, dataHolder);
+	}
+	
+	public static class InstanceIdDataCenterInfo implements DataCenterInfo, UniqueIdentifier {
+
+		private String instanceId;
+
+		public InstanceIdDataCenterInfo(String instanceId) {
+			this.instanceId = instanceId;
+		}
+
+		@Override
+		public Name getName() {
+			return Name.MyOwn;
+		}
+
+		@Override
+		public String getId() {
+			return instanceId;
+		}
+
+	}
+
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/eureka/EurekaClientAutoConfiguration.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.cloud.netflix.eureka;
 
+import javax.annotation.PostConstruct;
+
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -24,6 +26,8 @@ import org.springframework.context.annotation.Configuration;
 
 import com.netflix.appinfo.EurekaInstanceConfig;
 import com.netflix.discovery.EurekaClientConfig;
+import com.netflix.discovery.converters.JsonXStream;
+import com.netflix.discovery.converters.XmlXStream;
 
 /**
  * @author Dave Syer
@@ -34,6 +38,12 @@ import com.netflix.discovery.EurekaClientConfig;
 @ConditionalOnClass(EurekaClientConfig.class)
 @ConditionalOnExpression("${eureka.client.enabled:true}")
 public class EurekaClientAutoConfiguration {
+	
+	@PostConstruct
+	public void init() {
+		XmlXStream.getInstance().setMarshallingStrategy(new DataCenterAwareMarshallingStrategy());
+		JsonXStream.getInstance().setMarshallingStrategy(new DataCenterAwareMarshallingStrategy());		
+	}
 
 	@Bean
 	@ConditionalOnMissingBean(EurekaClientConfig.class)

spring-cloud-netflix-eureka-server/src/main/java/org/springframework/cloud/netflix/eureka/server/EurekaServerInitializerConfiguration.java

@@ -30,6 +30,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.cloud.netflix.eureka.DataCenterAwareMarshallingStrategy;
 import org.springframework.cloud.netflix.eureka.DiscoveryManagerInitializer;
 import org.springframework.cloud.netflix.eureka.EurekaServerConfigBean;
 import org.springframework.cloud.netflix.eureka.server.advice.LeaseManagerLite;
@@ -47,6 +48,8 @@ import org.springframework.util.ReflectionUtils;
 import org.springframework.web.context.ServletContextAware;
 
 import com.netflix.blitz4j.LoggingConfiguration;
+import com.netflix.discovery.converters.JsonXStream;
+import com.netflix.discovery.converters.XmlXStream;
 import com.netflix.eureka.EurekaBootStrap;
 import com.netflix.eureka.EurekaServerConfig;
 import com.netflix.eureka.EurekaServerConfigurationManager;
@@ -100,6 +103,8 @@ public class EurekaServerInitializerConfiguration implements ServletContextAware
 							LoggingConfiguration.getInstance().configure();
 							EurekaServerConfigurationManager.getInstance()
 									.setConfiguration(eurekaServerConfig);
+							XmlXStream.getInstance().setMarshallingStrategy(new DataCenterAwareMarshallingStrategy());
+							JsonXStream.getInstance().setMarshallingStrategy(new DataCenterAwareMarshallingStrategy());
 							// PeerAwareInstanceRegistry.getInstance();
 							applicationContext
 									.publishEvent(new EurekaRegistryAvailableEvent(