Clean up eureka lifecycle

When the parent (bootstrap) context registers the app as well as consuming
the registry it causes problems, e.g. when you refresh that context is
re-created and destroyed, which tends to unregister the app and it's hard
to get it back. It is simpler if the parent context use eureka read-only.
To ensure this we have to remove the @EnableDiscoveryClient from the
bootstrap context.

Tested with vanilla config server and eureka with the 'eureka-first'
sample and the 'zuul-proxy-eureka' sample.

Fixes gh-421

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/config/DiscoveryClientConfigServiceAutoConfiguration.java

@@ -49,11 +49,11 @@ public class DiscoveryClientConfigServiceAutoConfiguration {
 	private ConfigurationPropertiesBindingPostProcessor binder;
 
 	@Autowired
-	private EurekaDiscoveryClientConfiguration lifecycle;
+	private EurekaDiscoveryClientConfiguration clientConfiguration;
 
 	@PostConstruct
 	public void init() {
-		this.lifecycle.stop();
+		this.clientConfiguration.stop();
 		rebind(this.clientConfig, "eurekaClientConfig");
 		rebind(this.instanceConfig, "eurekaInstanceConfig");
 		// Danger, here be dragons (once it shuts down it's hard to resurrect it)
@@ -61,7 +61,7 @@ public class DiscoveryClientConfigServiceAutoConfiguration {
 		// FIXME: reinit EurekaClient and ApplicationInfoManager
 		// applicationInfoManager.initComponent(this.instanceConfig);
 		// discoveryManager.initComponent(this.instanceConfig, this.clientConfig);
-		this.lifecycle.start();
+		this.clientConfiguration.start();
 	}
 
 	private void rebind(Object bean, String name) {

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/config/DiscoveryClientConfigServiceBootstrapConfiguration.java

@@ -19,17 +19,13 @@ package org.springframework.cloud.netflix.config;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
-import org.springframework.cloud.client.discovery.event.HeartbeatEvent;
-import org.springframework.cloud.client.discovery.event.HeartbeatMonitor;
 import org.springframework.cloud.config.client.ConfigClientProperties;
 import org.springframework.cloud.config.client.ConfigServicePropertySourceLocator;
 import org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration;
-import org.springframework.context.ApplicationEvent;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.context.event.ContextRefreshedEvent;
-import org.springframework.context.event.SmartApplicationListener;
+import org.springframework.context.event.EventListener;
 
 import com.netflix.appinfo.InstanceInfo;
 import com.netflix.discovery.EurekaClient;
@@ -45,13 +41,9 @@ import lombok.extern.apachecommons.CommonsLog;
 @ConditionalOnClass({ EurekaClient.class, ConfigServicePropertySourceLocator.class })
 @ConditionalOnProperty(value = "spring.cloud.config.discovery.enabled", matchIfMissing = false)
 @Configuration
-@EnableDiscoveryClient
 @Import(EurekaClientAutoConfiguration.class)
 @CommonsLog
-public class DiscoveryClientConfigServiceBootstrapConfiguration implements
-		SmartApplicationListener {
-
-	private HeartbeatMonitor monitor = new HeartbeatMonitor();
+public class DiscoveryClientConfigServiceBootstrapConfiguration {
 
 	@Autowired
 	private ConfigClientProperties config;
@@ -59,40 +51,18 @@ public class DiscoveryClientConfigServiceBootstrapConfiguration implements
 	@Autowired
 	private EurekaClient eurekaClient;
 
-	@Override
-	public void onApplicationEvent(ApplicationEvent event) {
-		if (event instanceof ContextRefreshedEvent) {
-			refresh();
-		}
-		else if (event instanceof HeartbeatEvent) {
-			if (this.monitor.update(((HeartbeatEvent) event).getValue())) {
-				refresh();
-			}
-		}
+	@EventListener(ContextRefreshedEvent.class)
+	public void onApplicationEvent(ContextRefreshedEvent event) {
+		refresh();
 	}
 
-	@Override
-	public int getOrder() {
-		return 0;
-	}
-
-	@Override
-	public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
-		return ContextRefreshedEvent.class.isAssignableFrom(eventType)
-				|| HeartbeatEvent.class.isAssignableFrom(eventType);
-	}
-
-	@Override
-	public boolean supportsSourceType(Class<?> sourceType) {
-		return true;
-	}
+	// TODO: re-instate heart beat (maybe? isn't it handled in the child context?)
 
 	private void refresh() {
 		try {
 			log.debug("Locating configserver via discovery");
-			InstanceInfo server = this.eurekaClient
-					.getNextServerFromEureka(this.config.getDiscovery().getServiceId(),
-							false);
+			InstanceInfo server = this.eurekaClient.getNextServerFromEureka(
+					this.config.getDiscovery().getServiceId(), false);
 			String url = server.getHomePageUrl();
 			if (server.getMetadata().containsKey("password")) {
 				String user = server.getMetadata().get("user");

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

@@ -16,9 +16,6 @@
 
 package org.springframework.cloud.netflix.eureka;
 
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-
 import javax.annotation.PostConstruct;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -27,16 +24,11 @@ import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 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.CommonsClientAutoConfiguration;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
-import org.springframework.cloud.client.discovery.event.HeartbeatEvent;
-import org.springframework.cloud.client.discovery.event.ParentHeartbeatEvent;
 import org.springframework.cloud.client.discovery.noop.NoopDiscoveryClientAutoConfiguration;
 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;
 
@@ -57,10 +49,9 @@ import lombok.SneakyThrows;
 @EnableConfigurationProperties
 @ConditionalOnClass(EurekaClientConfig.class)
 @ConditionalOnProperty(value = "eureka.client.enabled", matchIfMissing = true)
-@AutoConfigureBefore({NoopDiscoveryClientAutoConfiguration.class, CommonsClientAutoConfiguration.class})
-public class EurekaClientAutoConfiguration implements ApplicationListener<ParentContextApplicationContextInitializer.ParentContextAvailableEvent> {
-
-	private static final ConcurrentMap<String, String> listenerAdded = new ConcurrentHashMap<>();
+@AutoConfigureBefore({ NoopDiscoveryClientAutoConfiguration.class,
+		CommonsClientAutoConfiguration.class })
+public class EurekaClientAutoConfiguration {
 
 	@Autowired
 	private ApplicationContext context;
@@ -71,10 +62,10 @@ public class EurekaClientAutoConfiguration implements ApplicationListener<Parent
 	@PostConstruct
 	public void init() {
 		DataCenterAwareJacksonCodec.init();
-		XmlXStream.getInstance().setMarshallingStrategy(
-				new DataCenterAwareMarshallingStrategy());
-		JsonXStream.getInstance().setMarshallingStrategy(
-				new DataCenterAwareMarshallingStrategy());
+		XmlXStream.getInstance()
+				.setMarshallingStrategy(new DataCenterAwareMarshallingStrategy());
+		JsonXStream.getInstance()
+				.setMarshallingStrategy(new DataCenterAwareMarshallingStrategy());
 	}
 
 	@Bean
@@ -94,13 +85,15 @@ public class EurekaClientAutoConfiguration implements ApplicationListener<Parent
 	@Bean
 	@ConditionalOnMissingBean(EurekaClient.class)
 	@SneakyThrows
-	public EurekaClient eurekaClient(ApplicationInfoManager applicationInfoManager, EurekaClientConfig config) {
+	public EurekaClient eurekaClient(ApplicationInfoManager applicationInfoManager,
+			EurekaClientConfig config) {
 		return new CloudEurekaClient(applicationInfoManager, config, this.context);
 	}
 
 	@Bean
 	@ConditionalOnMissingBean(ApplicationInfoManager.class)
-	public ApplicationInfoManager applicationInfoManager(EurekaInstanceConfig config, InstanceInfo instanceInfo) {
+	public ApplicationInfoManager applicationInfoManager(EurekaInstanceConfig config,
+			InstanceInfo instanceInfo) {
 		return new ApplicationInfoManager(config, instanceInfo);
 	}
 
@@ -111,34 +104,9 @@ public class EurekaClientAutoConfiguration implements ApplicationListener<Parent
 	}
 
 	@Bean
-	public DiscoveryClient discoveryClient(EurekaInstanceConfig config, EurekaClient client) {
+	public DiscoveryClient discoveryClient(EurekaInstanceConfig config,
+			EurekaClient client) {
 		return new EurekaDiscoveryClient(config, client);
 	}
 
-	/**
-	 * propagate HeartbeatEvent from parent to child. Do it via a
-	 * ParentHeartbeatEvent 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) {
-				@SuppressWarnings("resource")
-				ConfigurableApplicationContext ctx = (ConfigurableApplicationContext) parent;
-				ctx.addApplicationListener(new ApplicationListener<HeartbeatEvent>() {
-					@Override
-					public void onApplicationEvent(HeartbeatEvent dhe) {
-						context.publishEvent(new ParentHeartbeatEvent(dhe
-								.getSource(), dhe.getValue()));
-					}
-				});
-			}
-		}
-	}
 }

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

@@ -21,8 +21,6 @@ import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import lombok.extern.apachecommons.CommonsLog;
-
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.actuate.endpoint.Endpoint;
 import org.springframework.boot.actuate.health.HealthAggregator;
@@ -37,11 +35,13 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.embedded.EmbeddedServletContainerInitializedEvent;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.client.discovery.event.InstanceRegisteredEvent;
+import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
 import org.springframework.context.ApplicationContext;
-import org.springframework.context.ApplicationListener;
 import org.springframework.context.SmartLifecycle;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.event.ContextClosedEvent;
+import org.springframework.context.event.EventListener;
 import org.springframework.core.Ordered;
 
 import com.netflix.appinfo.ApplicationInfoManager;
@@ -51,6 +51,8 @@ import com.netflix.appinfo.InstanceInfo.InstanceStatus;
 import com.netflix.discovery.EurekaClient;
 import com.netflix.discovery.EurekaClientConfig;
 
+import lombok.extern.apachecommons.CommonsLog;
+
 /**
  * @author Dave Syer
  * @author Spencer Gibb
@@ -100,25 +102,24 @@ public class EurekaDiscoveryClientConfiguration implements SmartLifecycle, Order
 					+ " with eureka with status "
 					+ this.instanceConfig.getInitialStatus());
 
-			applicationInfoManager.setInstanceStatus(
-					this.instanceConfig.getInitialStatus());
+			this.applicationInfoManager
+					.setInstanceStatus(this.instanceConfig.getInitialStatus());
 
 			if (this.healthCheckHandler != null) {
-				eurekaClient.registerHealthCheck(this.healthCheckHandler);
+				this.eurekaClient.registerHealthCheck(this.healthCheckHandler);
 			}
-			this.context.publishEvent(new InstanceRegisteredEvent<>(this,
-					this.instanceConfig));
+			this.context.publishEvent(
+					new InstanceRegisteredEvent<>(this, this.instanceConfig));
 			this.running.set(true);
 		}
 	}
 
 	@Override
 	public void stop() {
-		log.info("Unregistering application " + this.instanceConfig.getAppname()
-				+ " with eureka with status DOWN");
-		if (applicationInfoManager.getInfo() != null) {
-			applicationInfoManager.setInstanceStatus(
-					InstanceStatus.DOWN);
+		if (this.applicationInfoManager.getInfo() != null) {
+			log.info("Unregistering application " + this.instanceConfig.getAppname()
+					+ " with eureka with status DOWN");
+			this.applicationInfoManager.setInstanceStatus(InstanceStatus.DOWN);
 		}
 		this.running.set(false);
 	}
@@ -149,18 +150,26 @@ public class EurekaDiscoveryClientConfiguration implements SmartLifecycle, Order
 		return this.order;
 	}
 
-	@Bean
-	protected ApplicationListener<EmbeddedServletContainerInitializedEvent> containerPortInitializer() {
-		return new ApplicationListener<EmbeddedServletContainerInitializedEvent>() {
+	@EventListener(EmbeddedServletContainerInitializedEvent.class)
+	public void onApplicationEvent(EmbeddedServletContainerInitializedEvent event) {
+		// TODO: take SSL into account when Spring Boot 1.2 is available
+		EurekaDiscoveryClientConfiguration.this.port.compareAndSet(0,
+				event.getEmbeddedServletContainer().getPort());
+		EurekaDiscoveryClientConfiguration.this.start();
+	}
+
+	@EventListener(EnvironmentChangeEvent.class)
+	public void onApplicationEvent(EnvironmentChangeEvent event) {
+		// register in case meta data changed
+		stop();
+		start();
+	}
 
-			@Override
-			public void onApplicationEvent(EmbeddedServletContainerInitializedEvent event) {
-				// TODO: take SSL into account when Spring Boot 1.2 is available
-				EurekaDiscoveryClientConfiguration.this.port.compareAndSet(0, event
-						.getEmbeddedServletContainer().getPort());
-				EurekaDiscoveryClientConfiguration.this.start();
-			}
-		};
+	@EventListener(ContextClosedEvent.class)
+	public void onApplicationEvent(ContextClosedEvent event) {
+		// register in case meta data changed
+		stop();
+		this.eurekaClient.shutdown();
 	}
 
 	@Configuration
@@ -175,7 +184,8 @@ public class EurekaDiscoveryClientConfiguration implements SmartLifecycle, Order
 		@ConditionalOnMissingBean
 		public EurekaHealthIndicator eurekaHealthIndicator(EurekaClient eurekaClient,
 				EurekaInstanceConfig config) {
-			CompositeMetricReader metrics = new CompositeMetricReader(this.metricReaders.toArray(new MetricReader[0]));
+			CompositeMetricReader metrics = new CompositeMetricReader(
+					this.metricReaders.toArray(new MetricReader[0]));
 			return new EurekaHealthIndicator(eurekaClient, metrics, config);
 		}
 	}
@@ -191,7 +201,7 @@ public class EurekaDiscoveryClientConfiguration implements SmartLifecycle, Order
 		@Bean
 		@ConditionalOnMissingBean(HealthCheckHandler.class)
 		public EurekaHealthCheckHandler eurekaHealthCheckHandler() {
-			return new EurekaHealthCheckHandler(healthAggregator);
+			return new EurekaHealthCheckHandler(this.healthAggregator);
 		}
 	}
 }

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/config/DiscoveryClientConfigServiceAutoConfigurationTests.java

@@ -29,6 +29,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
 import org.springframework.boot.test.EnvironmentTestUtils;
 import org.springframework.cloud.config.client.ConfigClientProperties;
+import org.springframework.cloud.netflix.eureka.EurekaDiscoveryClientConfiguration;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.env.ConfigurableEnvironment;
@@ -61,19 +62,19 @@ public class DiscoveryClientConfigServiceAutoConfigurationTests {
 
 	@Test
 	public void onWhenRequested() throws Exception {
-		given(this.client.getNextServerFromEureka("CONFIGSERVER", false)).willReturn(
-				this.info);
+		given(this.client.getNextServerFromEureka("CONFIGSERVER", false))
+				.willReturn(this.info);
 		setup("spring.cloud.config.discovery.enabled=true");
-		assertEquals(
-				1,
-				this.context
-						.getBeanNamesForType(DiscoveryClientConfigServiceAutoConfiguration.class).length);
-		Mockito.verify(this.client, times(2)).getNextServerFromEureka("CONFIGSERVER", false);
+		assertEquals(1, this.context.getBeanNamesForType(
+				DiscoveryClientConfigServiceAutoConfiguration.class).length);
+		Mockito.verify(this.client, times(2)).getNextServerFromEureka("CONFIGSERVER",
+				false);
 		Mockito.verify(this.client, times(0)).shutdown();
 		ConfigClientProperties locator = this.context
 				.getBean(ConfigClientProperties.class);
 		assertEquals("http://foo:7001/", locator.getRawUri());
-		ApplicationInfoManager infoManager = this.context.getBean(ApplicationInfoManager.class);
+		ApplicationInfoManager infoManager = this.context
+				.getBean(ApplicationInfoManager.class);
 		assertEquals("bar", infoManager.getInfo().getMetadata().get("foo"));
 	}
 
@@ -88,7 +89,8 @@ public class DiscoveryClientConfigServiceAutoConfigurationTests {
 		parent.refresh();
 		this.context = new AnnotationConfigApplicationContext();
 		this.context.setParent(parent);
-		this.context.register(DiscoveryClientConfigServiceAutoConfiguration.class);
+		this.context.register(DiscoveryClientConfigServiceAutoConfiguration.class,
+				EurekaDiscoveryClientConfiguration.class);
 		this.context.refresh();
 	}