reset zuul routes when eureka sends catalog delta.

fixes gh-76

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

@@ -16,20 +16,24 @@
 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.netflix.appinfo.UniqueIdentifier;
+import com.netflix.discovery.converters.Converters.ApplicationsConverter;
 import com.netflix.discovery.converters.Converters.InstanceInfoConverter;
+import com.netflix.discovery.shared.Applications;
 import com.thoughtworks.xstream.MarshallingStrategy;
-import com.thoughtworks.xstream.converters.Converter;
-import com.thoughtworks.xstream.converters.ConverterLookup;
-import com.thoughtworks.xstream.converters.DataHolder;
-import com.thoughtworks.xstream.converters.MarshallingContext;
-import com.thoughtworks.xstream.converters.UnmarshallingContext;
+import com.thoughtworks.xstream.converters.*;
 import com.thoughtworks.xstream.core.TreeMarshallingStrategy;
 import com.thoughtworks.xstream.io.HierarchicalStreamReader;
 import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
 import com.thoughtworks.xstream.mapper.Mapper;
+import lombok.extern.slf4j.Slf4j;
+import org.aopalliance.intercept.MethodInterceptor;
+import org.aopalliance.intercept.MethodInvocation;
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.cloud.client.discovery.DiscoveryHeartbeatEvent;
+import org.springframework.context.ApplicationContext;
 
 /**
  * A special purpose wrapper for an XStream TreeMarshallingStrategy that is aware of the
@@ -47,18 +51,23 @@ import com.thoughtworks.xstream.mapper.Mapper;
 public class DataCenterAwareMarshallingStrategy implements MarshallingStrategy {
 
 	private TreeMarshallingStrategy delegate = new TreeMarshallingStrategy();
+	private ApplicationContext context;
+
+	public DataCenterAwareMarshallingStrategy(ApplicationContext context) {
+		this.context = context;
+	}
 
 	@Override
 	public Object unmarshal(Object root, HierarchicalStreamReader reader,
 			DataHolder dataHolder, ConverterLookup converterLookup, Mapper mapper) {
-		ConverterLookup wrapped = new DataCenterAwareConverterLookup(converterLookup);
+		ConverterLookup wrapped = new DataCenterAwareConverterLookup(converterLookup, context);
 		return delegate.unmarshal(root, reader, dataHolder, wrapped, mapper);
 	}
 
 	@Override
 	public void marshal(HierarchicalStreamWriter writer, Object obj,
 			ConverterLookup converterLookup, Mapper mapper, DataHolder dataHolder) {
-		ConverterLookup wrapped = new DataCenterAwareConverterLookup(converterLookup);
+		ConverterLookup wrapped = new DataCenterAwareConverterLookup(converterLookup, context);
 		delegate.marshal(writer, obj, wrapped, mapper, dataHolder);
 	}
 
@@ -86,9 +95,11 @@ public class DataCenterAwareMarshallingStrategy implements MarshallingStrategy {
 	private static class DataCenterAwareConverterLookup implements ConverterLookup {
 
 		private ConverterLookup delegate;
+		private ApplicationContext context;
 
-		public DataCenterAwareConverterLookup(ConverterLookup delegate) {
+		public DataCenterAwareConverterLookup(ConverterLookup delegate, ApplicationContext context) {
 			this.delegate = delegate;
+			this.context = context;
 		}
 
 		@Override
@@ -96,12 +107,52 @@ public class DataCenterAwareMarshallingStrategy implements MarshallingStrategy {
 			Converter converter = delegate.lookupConverterForType(type);
 			if (InstanceInfo.class == type) {
 				return new DataCenterAwareConverter();
+			} else if (Applications.class == type) {
+				return new PublishingApplicationsConverter(context);
 			}
 			return converter;
 		}
 
 	}
 
+	private static class PublishingApplicationsConverter extends ApplicationsConverter {
+
+		private ApplicationContext context;
+
+		public PublishingApplicationsConverter(ApplicationContext context) {
+			this.context = context;
+		}
+
+		@Override
+		public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext unmarshallingContext) {
+			Object obj = super.unmarshal(reader, unmarshallingContext);
+
+			ProxyFactory factory = new ProxyFactory(obj);
+			factory.addAdvice(new SetVersionInterceptor(this.context));
+			return factory.getProxy();
+		}
+	}
+
+	@Slf4j
+	private static class SetVersionInterceptor implements MethodInterceptor {
+		private ApplicationContext context;
+
+		public SetVersionInterceptor(ApplicationContext context) {
+			this.context = context;
+		}
+
+		@Override
+		public Object invoke(MethodInvocation invocation) throws Throwable {
+			Object ret = invocation.proceed();
+			if ("setVersion".equals(invocation.getMethod().getName())) {
+				Long version = Long.class.cast(invocation.getArguments()[0]);
+				log.debug("Applications.setVersion() called with version: " + version);
+				context.publishEvent(new DiscoveryHeartbeatEvent(invocation.getThis(), version));
+			}
+			return ret;
+		}
+	}
+
 	private static class DataCenterAwareConverter extends InstanceInfoConverter {
 		
 		@Override

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

@@ -17,10 +17,12 @@ package org.springframework.cloud.netflix.eureka;
 
 import javax.annotation.PostConstruct;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
@@ -39,12 +41,15 @@ import com.netflix.discovery.converters.XmlXStream;
 @ConditionalOnExpression("${eureka.client.enabled:true}")
 public class EurekaClientAutoConfiguration {
 
+	@Autowired
+	ApplicationContext context;
+
 	@PostConstruct
 	public void init() {
 		XmlXStream.getInstance().setMarshallingStrategy(
-				new DataCenterAwareMarshallingStrategy());
+				new DataCenterAwareMarshallingStrategy(context));
 		JsonXStream.getInstance().setMarshallingStrategy(
-				new DataCenterAwareMarshallingStrategy());
+				new DataCenterAwareMarshallingStrategy(context));
 	}
 
 	@Bean

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

@@ -1,6 +1,7 @@
 package org.springframework.cloud.netflix.eureka;
 
 import com.google.common.base.Function;
+import com.google.common.base.Predicates;
 import com.google.common.collect.Lists;
 import com.netflix.appinfo.InstanceInfo;
 import com.netflix.discovery.shared.Application;
@@ -95,13 +96,16 @@ public class EurekaDiscoveryClient implements DiscoveryClient {
         if (applications == null) {
             return Collections.emptyList();
         }
-        return Lists.newArrayList(transform(applications.getRegisteredApplications(), new Function<Application, String>() {
+        return Lists.newArrayList(filter(transform(applications.getRegisteredApplications(), new Function<Application, String>() {
             @Nullable
             @Override
             public String apply(@Nullable Application app) {
+                if (app.getInstances().isEmpty()) {
+                    return null;
+                }
                 return app.getName().toLowerCase();
             }
-        }));
+        }), Predicates.notNull()));
     }
 
     @Override

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/ZuulHandlerMapping.java

@@ -1,6 +1,7 @@
 package org.springframework.cloud.netflix.zuul;
 
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cloud.client.discovery.DiscoveryHeartbeatEvent;
 import org.springframework.cloud.client.discovery.InstanceRegisteredEvent;
 import org.springframework.cloud.context.scope.refresh.RefreshScopeRefreshedEvent;
 import org.springframework.context.ApplicationEvent;
@@ -12,6 +13,7 @@ import org.springframework.web.servlet.handler.AbstractUrlHandlerMapping;
 
 import java.util.Collection;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * MVC HandlerMapping that maps incoming request paths to remote services.
@@ -27,6 +29,8 @@ public class ZuulHandlerMapping extends AbstractUrlHandlerMapping implements
 
 	private ZuulController zuul;
 
+	private AtomicReference<Object> latestHeartbeat = new AtomicReference<>();
+
 	@Autowired
 	public ZuulHandlerMapping(ProxyRouteLocator routeLocator, ZuulController zuul) {
 		this.routeLocator = routeLocator;
@@ -39,6 +43,12 @@ public class ZuulHandlerMapping extends AbstractUrlHandlerMapping implements
 		if (event instanceof InstanceRegisteredEvent
 				|| event instanceof RefreshScopeRefreshedEvent) {
 			reset();
+		} else if (event instanceof DiscoveryHeartbeatEvent) {
+			DiscoveryHeartbeatEvent e = (DiscoveryHeartbeatEvent) event;
+			if (latestHeartbeat.get() == null || !latestHeartbeat.get().equals(e.getValue())) {
+				latestHeartbeat.set(e.getValue());
+				reset();
+			}
 		}
 	}
 

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

@@ -120,9 +120,9 @@ public class EurekaServerInitializerConfiguration implements ServletContextAware
 							EurekaServerConfigurationManager.getInstance()
 									.setConfiguration(eurekaServerConfig);
 							XmlXStream.getInstance().setMarshallingStrategy(
-									new DataCenterAwareMarshallingStrategy());
+									new DataCenterAwareMarshallingStrategy(applicationContext));
 							JsonXStream.getInstance().setMarshallingStrategy(
-									new DataCenterAwareMarshallingStrategy());
+									new DataCenterAwareMarshallingStrategy(applicationContext));
 							// PeerAwareInstanceRegistry.getInstance();
 							applicationContext
 									.publishEvent(new EurekaRegistryAvailableEvent(