Close Fabric8 Client When Context Is Stopped (#1780)

spring-cloud-kubernetes-commons/src/main/java/org/springframework/cloud/kubernetes/commons/config/ConfigUtils.java

@@ -36,6 +36,7 @@ import org.apache.commons.logging.LogFactory;
 
 import org.springframework.boot.BootstrapRegistry;
 import org.springframework.boot.ConfigurableBootstrapContext;
+import org.springframework.context.ApplicationListener;
 import org.springframework.core.env.Environment;
 import org.springframework.core.style.ToStringCreator;
 import org.springframework.util.CollectionUtils;
@@ -60,6 +61,8 @@ public final class ConfigUtils {
 					|| sourceName.endsWith("-" + activeProfile + ".yaml")
 					|| sourceName.endsWith("-" + activeProfile + ".properties");
 
+	private static final ApplicationListener<?> NO_OP = (e) -> { };
+
 	private ConfigUtils() {
 	}
 
@@ -329,17 +332,23 @@ public final class ConfigUtils {
 	}
 
 	public static <T> void registerSingle(ConfigurableBootstrapContext bootstrapContext, Class<T> cls, T instance,
-			String name) {
+			String name, ApplicationListener<?> listener) {
 		bootstrapContext.registerIfAbsent(cls, BootstrapRegistry.InstanceSupplier.of(instance));
 		bootstrapContext.addCloseListener(event -> {
 			if (event.getApplicationContext().getBeanFactory().getSingleton(name) == null) {
 				event.getApplicationContext()
 					.getBeanFactory()
 					.registerSingleton(name, event.getBootstrapContext().get(cls));
+				event.getApplicationContext().addApplicationListener(listener);
 			}
 		});
 	}
 
+	public static <T> void registerSingle(ConfigurableBootstrapContext bootstrapContext, Class<T> cls, T instance,
+			String name) {
+		registerSingle(bootstrapContext, cls, instance, name, NO_OP);
+	}
+
 	/**
 	 * append prefix to the keys and return a new Map with the new values.
 	 */

spring-cloud-kubernetes-fabric8-autoconfig/src/main/java/org/springframework/cloud/kubernetes/fabric8/Fabric8AutoConfiguration.java

@@ -18,11 +18,13 @@ package org.springframework.cloud.kubernetes.fabric8;
 
 import java.time.Duration;
 
+import io.fabric8.kubernetes.client.Client;
 import io.fabric8.kubernetes.client.Config;
 import io.fabric8.kubernetes.client.ConfigBuilder;
 import io.fabric8.kubernetes.client.KubernetesClient;
 import io.fabric8.kubernetes.client.KubernetesClientBuilder;
 
+import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnCloudPlatform;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -31,6 +33,8 @@ import org.springframework.cloud.kubernetes.commons.KubernetesClientProperties;
 import org.springframework.cloud.kubernetes.commons.KubernetesCommonsAutoConfiguration;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.event.ContextClosedEvent;
+import org.springframework.context.event.EventListener;
 
 /**
  * Auto configuration for Kubernetes.
@@ -117,4 +121,11 @@ public class Fabric8AutoConfiguration {
 		return new Fabric8PodUtils(client);
 	}
 
+	@EventListener
+	void onContextClosed(ContextClosedEvent event) {
+		// Clean up any open connections from the KubernetesClient when the context is closed
+		BeanFactoryUtils.beansOfTypeIncludingAncestors(event.getApplicationContext(), KubernetesClient.class).values()
+				.forEach(Client::close);
+	}
+
 }

spring-cloud-kubernetes-fabric8-config/src/main/java/org/springframework/cloud/kubernetes/fabric8/config/Fabric8ConfigDataLocationResolver.java

@@ -34,6 +34,8 @@ import org.springframework.cloud.kubernetes.commons.config.KubernetesConfigDataL
 import org.springframework.cloud.kubernetes.commons.config.SecretsConfigProperties;
 import org.springframework.cloud.kubernetes.commons.config.SecretsPropertySourceLocator;
 import org.springframework.cloud.kubernetes.fabric8.Fabric8AutoConfiguration;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.event.ContextClosedEvent;
 import org.springframework.core.env.Environment;
 
 import static org.springframework.cloud.kubernetes.commons.config.ConfigUtils.registerSingle;
@@ -90,7 +92,8 @@ public class Fabric8ConfigDataLocationResolver extends KubernetesConfigDataLocat
 		registerSingle(bootstrapContext, Config.class, config, "fabric8Config");
 
 		KubernetesClient kubernetesClient = new Fabric8AutoConfiguration().kubernetesClient(config);
-		registerSingle(bootstrapContext, KubernetesClient.class, kubernetesClient, "configKubernetesClient");
+		registerSingle(bootstrapContext, KubernetesClient.class, kubernetesClient, "configKubernetesClient",
+				(ApplicationListener<ContextClosedEvent>) event -> kubernetesClient.close());
 		return kubernetesClient;
 	}