proxy DiscoveryHeartbeatEvent's from parent to child be publishing a…

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

@@ -22,8 +22,12 @@ 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.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.builder.ParentContextApplicationContextInitializer;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.cloud.client.discovery.DiscoveryHeartbeatEvent;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
@@ -32,6 +36,9 @@ import com.netflix.discovery.EurekaClientConfig;
 import com.netflix.discovery.converters.JsonXStream;
 import com.netflix.discovery.converters.XmlXStream;
 
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
 /**
  * @author Dave Syer
  */
@@ -39,17 +46,19 @@ import com.netflix.discovery.converters.XmlXStream;
 @EnableConfigurationProperties
 @ConditionalOnClass(EurekaClientConfig.class)
 @ConditionalOnProperty(value = "eureka.client.enabled", matchIfMissing = true)
-public class EurekaClientAutoConfiguration {
+public class EurekaClientAutoConfiguration implements ApplicationListener<ParentContextApplicationContextInitializer.ParentContextAvailableEvent> {
 
 	@Autowired
-	private ApplicationContext context;
+	private ApplicationContext applicationContext;
+
+	private static final ConcurrentMap<String, String> listenerAdded = new ConcurrentHashMap<>();
 
 	@PostConstruct
 	public void init() {
 		XmlXStream.getInstance().setMarshallingStrategy(
-				new DataCenterAwareMarshallingStrategy(this.context));
+				new DataCenterAwareMarshallingStrategy(this.applicationContext));
 		JsonXStream.getInstance().setMarshallingStrategy(
-				new DataCenterAwareMarshallingStrategy(this.context));
+				new DataCenterAwareMarshallingStrategy(this.applicationContext));
 	}
 
 	@Bean
@@ -64,4 +73,29 @@ public class EurekaClientAutoConfiguration {
 		return new EurekaInstanceConfigBean();
 	}
 
+
+	/**
+	 * propagate DiscoveryHeartbeatEvent from parent to child.
+	 * Do it via a EurekaHeartbeatEvent since events get published to the
+	 * parent context, otherwise results in a stack overflow
+	 * @param event
+	 */
+	@Override
+	public void onApplicationEvent(final ParentContextApplicationContextInitializer.ParentContextAvailableEvent event) {
+		final ConfigurableApplicationContext context = event.getApplicationContext();
+		String childId = context.getId();
+		ApplicationContext parent = context.getParent();
+		if (parent != null && "bootstrap".equals(parent.getId())
+				&& parent instanceof ConfigurableApplicationContext) {
+			if (listenerAdded.putIfAbsent(childId, childId) == null) {
+				ConfigurableApplicationContext ctx = (ConfigurableApplicationContext) parent;
+				ctx.addApplicationListener(new ApplicationListener<DiscoveryHeartbeatEvent>() {
+					@Override
+					public void onApplicationEvent(DiscoveryHeartbeatEvent dhe) {
+						context.publishEvent(new EurekaHeartbeatEvent(dhe));
+					}
+				});
+			}
+		}
+	}
 }

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

@@ -94,11 +94,14 @@ public class EurekaDiscoveryClientConfiguration implements SmartLifecycle, Order
 		if (jerseyClientField != null) {
 			try {
 				jerseyClientField.setAccessible(true);
-				Object obj = jerseyClientField.get(DiscoveryManager.getInstance()
-						.getDiscoveryClient());
-				if (obj != null) {
-					EurekaJerseyClient.JerseyClient jerseyClient = (EurekaJerseyClient.JerseyClient) obj;
-					jerseyClient.destroyResources();
+				if (DiscoveryManager.getInstance() != null &&
+						DiscoveryManager.getInstance().getDiscoveryClient() != null) {
+					Object obj = jerseyClientField.get(DiscoveryManager.getInstance()
+							.getDiscoveryClient());
+					if (obj != null) {
+						EurekaJerseyClient.JerseyClient jerseyClient = (EurekaJerseyClient.JerseyClient) obj;
+						jerseyClient.destroyResources();
+					}
 				}
 			}
 			catch (Exception ex) {

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

+package org.springframework.cloud.netflix.eureka;
+
+import org.springframework.cloud.client.discovery.DiscoveryHeartbeatEvent;
+import org.springframework.context.ApplicationEvent;
+
+/**
+ * Specifically used when eureka is in the parent bootstrap context to relay the DiscoveryHeartbeatEvent to the child.  Avoids stack overflow
+ * @author Spencer Gibb
+ */
+public class EurekaHeartbeatEvent extends ApplicationEvent {
+
+	private final Object value;
+
+	public EurekaHeartbeatEvent(DiscoveryHeartbeatEvent e) {
+		super(e.getSource());
+		value = e.getValue();
+	}
+
+	public Object getValue() {
+		return value;
+	}
+}

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

@@ -26,6 +26,7 @@ import org.springframework.cloud.client.discovery.DiscoveryClient;
 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.cloud.netflix.eureka.EurekaHeartbeatEvent;
 import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
 import org.springframework.cloud.netflix.zuul.filters.ProxyRequestHelper;
 import org.springframework.cloud.netflix.zuul.filters.pre.PreDecorationFilter;
@@ -126,17 +127,25 @@ public class ZuulProxyConfiguration extends ZuulConfiguration {
 					|| event instanceof RoutesRefreshedEvent) {
 				reset();
 			}
+			else if (event instanceof EurekaHeartbeatEvent) {
+				EurekaHeartbeatEvent e = (EurekaHeartbeatEvent) event;
+				resetIfNeeded(e.getValue());
+			}
 			else if (event instanceof DiscoveryHeartbeatEvent) {
 				DiscoveryHeartbeatEvent e = (DiscoveryHeartbeatEvent) event;
-				if (this.latestHeartbeat.get() == null
-						|| !this.latestHeartbeat.get().equals(e.getValue())) {
-					this.latestHeartbeat.set(e.getValue());
-					reset();
-				}
+				resetIfNeeded(e.getValue());
 			}
 
 		}
 
+		private void resetIfNeeded(Object value) {
+			if (this.latestHeartbeat.get() == null
+					|| !this.latestHeartbeat.get().equals(value)) {
+				this.latestHeartbeat.set(value);
+				reset();
+			}
+		}
+
 		private void reset() {
 			this.routeLocator.resetRoutes();
 			this.zuulHandlerMapping.registerHandlers();