Merge remote-tracking branch 'origin/main' into add-hc-requestconfig-customizer

Signed-off-by: Olga Maciaszek-Sharma <olga.maciaszek-sharma@broadcom.com>

docs/antora.yml

@@ -6,7 +6,7 @@ nav:
 ext:
   collector:
     run:
-      command: ./mvnw --no-transfer-progress -B process-resources -Pdocs -pl docs -Dantora-maven-plugin.phase=none -Dgenerate-docs.phase=none -Dgenerate-readme.phase=none -Dgenerate-cloud-resources.phase=none -Dmaven-dependency-plugin-for-docs.phase=none -Dmaven-dependency-plugin-for-docs-classes.phase=none -DskipTests
+      command: ./mvnw --no-transfer-progress -B process-resources -Pdocs -pl docs -Dantora-maven-plugin.phase=none -Dgenerate-docs.phase=none -Dgenerate-readme.phase=none -Dgenerate-cloud-resources.phase=none -Dmaven-dependency-plugin-for-docs.phase=none -Dmaven-dependency-plugin-for-docs-classes.phase=none -DskipTests -DdisableConfigurationProperties
       local: true
     scan:
       dir: ./target/classes/antora-resources/

docs/modules/ROOT/pages/spring-cloud-netflix.adoc

@@ -116,6 +116,21 @@ eureka:
       socket-timeout: 10000
 ----
 
+You can also customise the `RequestConfig` for the underlying Apache HttpClient 5 by creating a bean of type `EurekaClientHttpRequestFactorySupplier.RequestConfigCustomizer`:
+
+[source,java,indent=0]
+----
+@Configuration
+public class RestClientConfiguration {
+
+	@Bean
+	EurekaClientHttpRequestFactorySupplier.RequestConfigCustomizer requestConfigCustomizer() {
+		return builder -> builder.setProtocolUpgradeEnabled(false);
+	}
+
+}
+----
+
 === Status Page and Health Indicator
 
 The status page and health indicators for a Eureka instance default to `/info` and `/health` respectively, which are the default locations of useful endpoints in a Spring Boot Actuator application.

docs/package.json

@@ -1,8 +1,8 @@
 {
   "dependencies": {
-    "antora": "3.2.0-alpha.6",
+    "antora": "3.2.0-alpha.8",
     "@antora/atlas-extension": "1.0.0-alpha.2",
-    "@antora/collector-extension": "1.0.0-rc.1",
+    "@antora/collector-extension": "1.0.1",
     "@asciidoctor/tabs": "1.0.0-beta.6",
     "@springio/antora-extensions": "1.14.2",
     "@springio/asciidoctor-extensions": "1.0.0-alpha.14"

docs/pom.xml

@@ -8,7 +8,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-netflix</artifactId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<packaging>jar</packaging>
@@ -21,20 +21,28 @@
 		<!-- Don't upload docs jar to central / repo.spring.io -->
 		<maven-deploy-plugin-default.phase>none</maven-deploy-plugin-default.phase>
 	</properties>
-<!-- 	<dependencies>
-		<dependency>
-			<groupId>${project.groupId}</groupId>
-			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>${project.groupId}</groupId>
-			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
-		</dependency>
-	</dependencies> -->
 	<build>
 		<sourceDirectory>src/main/asciidoc</sourceDirectory>
 	</build>
 	<profiles>
+		<profile>
+			<id>enable-configuration-properties</id>
+			<activation>
+				<property>
+					<name>!disableConfigurationProperties</name>
+				</property>
+			</activation>
+			<dependencies>
+				<dependency>
+					<groupId>${project.groupId}</groupId>
+					<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
+				</dependency>
+				<dependency>
+					<groupId>${project.groupId}</groupId>
+					<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
+				</dependency>
+			</dependencies>
+		</profile>
 		<profile>
 			<id>docs</id>
 			<build>

pom.xml

@@ -3,14 +3,14 @@
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>spring-cloud-netflix</artifactId>
-	<version>4.2.0</version>
+	<version>4.2.1-SNAPSHOT</version>
 	<packaging>pom</packaging>
 	<name>Spring Cloud Netflix</name>
 	<description>Spring Cloud Netflix</description>
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-build</artifactId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 		<relativePath />
 	</parent>
 	<scm>
@@ -21,8 +21,8 @@
 	</scm>
 	<properties>
 		<bintray.package>netflix</bintray.package>
-		<spring-cloud-commons.version>4.2.0</spring-cloud-commons.version>
-		<spring-cloud-config.version>4.2.0</spring-cloud-config.version>
+		<spring-cloud-commons.version>4.2.1-SNAPSHOT</spring-cloud-commons.version>
+		<spring-cloud-config.version>4.2.1-SNAPSHOT</spring-cloud-config.version>
 		<testcontainers.version>1.20.4</testcontainers.version>
 		<mockserverclient.version>5.15.0</mockserverclient.version>
 

spring-cloud-netflix-dependencies/pom.xml

@@ -5,11 +5,11 @@
 	<parent>
 		<artifactId>spring-cloud-dependencies-parent</artifactId>
 		<groupId>org.springframework.cloud</groupId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 		<relativePath/>
 	</parent>
 	<artifactId>spring-cloud-netflix-dependencies</artifactId>
-	<version>4.2.0</version>
+	<version>4.2.1-SNAPSHOT</version>
 	<packaging>pom</packaging>
 	<name>spring-cloud-netflix-dependencies</name>
 	<description>Spring Cloud Netflix Dependencies</description>

spring-cloud-netflix-eureka-client-tls-tests/pom.xml

@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-netflix</artifactId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 		<relativePath>..</relativePath> <!-- lookup parent from repository -->
 	</parent>
 	<artifactId>spring-cloud-netflix-eureka-client-tls-tests</artifactId>

spring-cloud-netflix-eureka-client-tls-tests/src/test/java/org/springframework/cloud/netflix/eureka/EurekaClientTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2024 the original author or authors.
+ * Copyright 2018-2025 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.netflix.eureka;
 
+import java.util.Collections;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.junit.jupiter.api.BeforeAll;
@@ -64,8 +66,8 @@ public class EurekaClientTests extends BaseCertTests {
 
 		@Bean
 		public RestTemplateDiscoveryClientOptionalArgs discoveryClientOptionalArgs() {
-			return new RestTemplateDiscoveryClientOptionalArgs(
-					new DefaultEurekaClientHttpRequestFactorySupplier(new RestTemplateTimeoutProperties()), null);
+			return new RestTemplateDiscoveryClientOptionalArgs(new DefaultEurekaClientHttpRequestFactorySupplier(
+					new RestTemplateTimeoutProperties(), Collections.emptySet()));
 		}
 
 	}

spring-cloud-netflix-eureka-client/pom.xml

@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-netflix</artifactId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 		<relativePath>..</relativePath> <!-- lookup parent from repository -->
 	</parent>
 	<artifactId>spring-cloud-netflix-eureka-client</artifactId>

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/config/DiscoveryClientOptionalArgsConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2024 the original author or authors.
+ * Copyright 2017-2025 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.
@@ -18,6 +18,7 @@ package org.springframework.cloud.netflix.eureka.config;
 
 import java.io.IOException;
 import java.security.GeneralSecurityException;
+import java.util.Set;
 
 import com.netflix.discovery.AbstractDiscoveryClientOptionalArgs;
 import com.netflix.discovery.shared.transport.jersey.TransportClientFactories;
@@ -94,8 +95,10 @@ public class DiscoveryClientOptionalArgsConfiguration {
 		@Bean
 		@ConditionalOnMissingBean
 		EurekaClientHttpRequestFactorySupplier defaultEurekaClientHttpRequestFactorySupplier(
-				RestTemplateTimeoutProperties restTemplateTimeoutProperties) {
-			return new DefaultEurekaClientHttpRequestFactorySupplier(restTemplateTimeoutProperties);
+				RestTemplateTimeoutProperties restTemplateTimeoutProperties,
+				Set<EurekaClientHttpRequestFactorySupplier.RequestConfigCustomizer> requestConfigCustomizers) {
+			return new DefaultEurekaClientHttpRequestFactorySupplier(restTemplateTimeoutProperties,
+					requestConfigCustomizers);
 		}
 
 		@Bean
@@ -189,8 +192,10 @@ public class DiscoveryClientOptionalArgsConfiguration {
 		@Bean
 		@ConditionalOnMissingBean
 		EurekaClientHttpRequestFactorySupplier defaultEurekaClientHttpRequestFactorySupplier(
-				RestClientTimeoutProperties restClientTimeoutProperties) {
-			return new DefaultEurekaClientHttpRequestFactorySupplier(restClientTimeoutProperties);
+				RestClientTimeoutProperties restClientTimeoutProperties,
+				Set<EurekaClientHttpRequestFactorySupplier.RequestConfigCustomizer> requestConfigCustomizers) {
+			return new DefaultEurekaClientHttpRequestFactorySupplier(restClientTimeoutProperties,
+					requestConfigCustomizers);
 		}
 
 		@Bean

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/config/EurekaConfigServerBootstrapConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2024 the original author or authors.
+ * Copyright 2013-2025 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.netflix.eureka.config;
 
+import java.util.Set;
+
 import com.netflix.discovery.EurekaClientConfig;
 import com.netflix.discovery.shared.transport.EurekaHttpClient;
 
@@ -54,7 +56,7 @@ import org.springframework.web.client.RestTemplate;
 import org.springframework.web.reactive.function.client.WebClient;
 
 /**
- * Bootstrap configuration for config client that wants to lookup the config server via
+ * Bootstrap configuration for config client that wants to look the config server up via
  * discovery.
  *
  * @author Dave Syer
@@ -103,8 +105,10 @@ public class EurekaConfigServerBootstrapConfiguration {
 		@Bean
 		@ConditionalOnMissingBean
 		EurekaClientHttpRequestFactorySupplier defaultEurekaClientHttpRequestFactorySupplier(
-				RestTemplateTimeoutProperties restTemplateTimeoutProperties) {
-			return new DefaultEurekaClientHttpRequestFactorySupplier(restTemplateTimeoutProperties);
+				RestTemplateTimeoutProperties restTemplateTimeoutProperties,
+				Set<EurekaClientHttpRequestFactorySupplier.RequestConfigCustomizer> requestConfigCustomizers) {
+			return new DefaultEurekaClientHttpRequestFactorySupplier(restTemplateTimeoutProperties,
+					requestConfigCustomizers);
 		}
 
 		/**
@@ -174,8 +178,10 @@ public class EurekaConfigServerBootstrapConfiguration {
 		@Bean
 		@ConditionalOnMissingBean
 		EurekaClientHttpRequestFactorySupplier defaultEurekaClientHttpRequestFactorySupplier(
-				RestClientTimeoutProperties restClientTimeoutProperties) {
-			return new DefaultEurekaClientHttpRequestFactorySupplier(restClientTimeoutProperties);
+				RestClientTimeoutProperties restClientTimeoutProperties,
+				Set<EurekaClientHttpRequestFactorySupplier.RequestConfigCustomizer> requestConfigCustomizers) {
+			return new DefaultEurekaClientHttpRequestFactorySupplier(restClientTimeoutProperties,
+					requestConfigCustomizers);
 		}
 
 		static class OnRestClientPresentAndEnabledCondition extends AllNestedConditions {

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/config/EurekaConfigServerBootstrapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2024 the original author or authors.
+ * Copyright 2013-2025 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.
@@ -61,7 +61,8 @@ public class EurekaConfigServerBootstrapper implements BootstrapRegistryInitiali
 			EurekaHttpClient httpClient = new RestClientTransportClientFactory(
 					context.getOrElse(TlsProperties.class, null),
 					context.getOrElse(EurekaClientHttpRequestFactorySupplier.class,
-							new DefaultEurekaClientHttpRequestFactorySupplier(new RestClientTimeoutProperties())))
+							new DefaultEurekaClientHttpRequestFactorySupplier(new RestClientTimeoutProperties(),
+									Collections.emptySet())))
 				.newClient(HostnameBasedUrlRandomizer.randomEndpoint(config, getPropertyResolver(context)));
 			return new EurekaConfigServerInstanceProvider(httpClient, config)::getInstances;
 		});

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/http/DefaultEurekaClientHttpRequestFactorySupplier.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2024 the original author or authors.
+ * Copyright 2013-2025 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.
@@ -16,11 +16,14 @@
 
 package org.springframework.cloud.netflix.eureka.http;
 
+import java.util.Collections;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;
 
+import org.apache.hc.client5.http.config.ConnectionConfig;
 import org.apache.hc.client5.http.config.RequestConfig;
 import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
 import org.apache.hc.client5.http.impl.classic.HttpClientBuilder;
@@ -50,9 +53,12 @@ public class DefaultEurekaClientHttpRequestFactorySupplier implements EurekaClie
 
 	private final TimeoutProperties timeoutProperties;
 
+	// TODO: switch to final after removing deprecated interfaces
+	private Set<RequestConfigCustomizer> requestConfigCustomizers = Collections.emptySet();
+
 	/**
 	 * @deprecated in favour of
-	 * {@link DefaultEurekaClientHttpRequestFactorySupplier#DefaultEurekaClientHttpRequestFactorySupplier(TimeoutProperties)}
+	 * {@link DefaultEurekaClientHttpRequestFactorySupplier#DefaultEurekaClientHttpRequestFactorySupplier(TimeoutProperties, Set)}
 	 */
 	@Deprecated(forRemoval = true)
 	public DefaultEurekaClientHttpRequestFactorySupplier() {
@@ -61,17 +67,28 @@ public class DefaultEurekaClientHttpRequestFactorySupplier implements EurekaClie
 
 	/**
 	 * @deprecated in favour of
-	 * {@link DefaultEurekaClientHttpRequestFactorySupplier#DefaultEurekaClientHttpRequestFactorySupplier(TimeoutProperties)}
+	 * {@link DefaultEurekaClientHttpRequestFactorySupplier#DefaultEurekaClientHttpRequestFactorySupplier(TimeoutProperties, Set)}
 	 */
 	@Deprecated(forRemoval = true)
 	public DefaultEurekaClientHttpRequestFactorySupplier(RestTemplateTimeoutProperties timeoutProperties) {
 		this.timeoutProperties = timeoutProperties;
 	}
 
+	/**
+	 * @deprecated in favour of
+	 * {@link DefaultEurekaClientHttpRequestFactorySupplier#DefaultEurekaClientHttpRequestFactorySupplier(TimeoutProperties, Set)}
+	 */
+	@Deprecated(forRemoval = true)
 	public DefaultEurekaClientHttpRequestFactorySupplier(TimeoutProperties timeoutProperties) {
 		this.timeoutProperties = timeoutProperties;
 	}
 
+	public DefaultEurekaClientHttpRequestFactorySupplier(TimeoutProperties timeoutProperties,
+			Set<RequestConfigCustomizer> requestConfigCustomizers) {
+		this.timeoutProperties = timeoutProperties;
+		this.requestConfigCustomizers = requestConfigCustomizers;
+	}
+
 	@Override
 	public ClientHttpRequestFactory get(SSLContext sslContext, @Nullable HostnameVerifier hostnameVerifier) {
 		HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
@@ -79,9 +96,7 @@ public class DefaultEurekaClientHttpRequestFactorySupplier implements EurekaClie
 			httpClientBuilder
 				.setConnectionManager(buildConnectionManager(sslContext, hostnameVerifier, timeoutProperties));
 		}
-		if (timeoutProperties != null) {
-			httpClientBuilder.setDefaultRequestConfig(buildRequestConfig());
-		}
+		httpClientBuilder.setDefaultRequestConfig(buildRequestConfig());
 
 		CloseableHttpClient httpClient = httpClientBuilder.build();
 		HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
@@ -90,7 +105,7 @@ public class DefaultEurekaClientHttpRequestFactorySupplier implements EurekaClie
 	}
 
 	private HttpClientConnectionManager buildConnectionManager(SSLContext sslContext, HostnameVerifier hostnameVerifier,
-			TimeoutProperties restTemplateTimeoutProperties) {
+			TimeoutProperties timeoutProperties) {
 		PoolingHttpClientConnectionManagerBuilder connectionManagerBuilder = PoolingHttpClientConnectionManagerBuilder
 			.create();
 		SSLConnectionSocketFactoryBuilder sslConnectionSocketFactoryBuilder = SSLConnectionSocketFactoryBuilder
@@ -102,20 +117,25 @@ public class DefaultEurekaClientHttpRequestFactorySupplier implements EurekaClie
 			sslConnectionSocketFactoryBuilder.setHostnameVerifier(hostnameVerifier);
 		}
 		connectionManagerBuilder.setSSLSocketFactory(sslConnectionSocketFactoryBuilder.build());
-		if (restTemplateTimeoutProperties != null) {
+		if (timeoutProperties != null) {
 			connectionManagerBuilder.setDefaultSocketConfig(SocketConfig.custom()
-				.setSoTimeout(Timeout.of(restTemplateTimeoutProperties.getSocketTimeout(), TimeUnit.MILLISECONDS))
+				.setSoTimeout(Timeout.of(timeoutProperties.getSocketTimeout(), TimeUnit.MILLISECONDS))
+				.build());
+			connectionManagerBuilder.setDefaultConnectionConfig(ConnectionConfig.custom()
+				.setConnectTimeout(Timeout.of(timeoutProperties.getConnectTimeout(), TimeUnit.MILLISECONDS))
 				.build());
 		}
 		return connectionManagerBuilder.build();
 	}
 
 	private RequestConfig buildRequestConfig() {
-		return RequestConfig.custom()
-			.setConnectTimeout(Timeout.of(timeoutProperties.getConnectTimeout(), TimeUnit.MILLISECONDS))
-			.setConnectionRequestTimeout(
-					Timeout.of(timeoutProperties.getConnectRequestTimeout(), TimeUnit.MILLISECONDS))
-			.build();
+		RequestConfig.Builder requestConfigBuilder = RequestConfig.custom();
+		if (timeoutProperties != null) {
+			requestConfigBuilder.setConnectionRequestTimeout(
+					Timeout.of(timeoutProperties.getConnectRequestTimeout(), TimeUnit.MILLISECONDS));
+		}
+		requestConfigCustomizers.forEach(customizer -> customizer.customize(requestConfigBuilder));
+		return requestConfigBuilder.build();
 	}
 
 }

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/http/EurekaClientHttpRequestFactorySupplier.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2022 the original author or authors.
+ * Copyright 2013-2025 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.
@@ -19,6 +19,8 @@ package org.springframework.cloud.netflix.eureka.http;
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;
 
+import org.apache.hc.client5.http.config.RequestConfig;
+
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.lang.Nullable;
 
@@ -38,4 +40,17 @@ public interface EurekaClientHttpRequestFactorySupplier {
 	 */
 	ClientHttpRequestFactory get(SSLContext sslContext, @Nullable HostnameVerifier hostnameVerifier);
 
+	/**
+	 * Allows customising the {@link RequestConfig} of the underlying Apache HC5 instance.
+	 *
+	 * @author Olga Maciaszek-Sharma
+	 * @since 4.2.1
+	 */
+	@FunctionalInterface
+	interface RequestConfigCustomizer {
+
+		void customize(RequestConfig.Builder builder);
+
+	}
+
 }

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/http/EurekaServerMockApplication.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2022 the original author or authors.
+ * Copyright 2017-2025 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.
@@ -31,6 +31,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
@@ -45,6 +46,7 @@ import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.PutMapping;
 import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.ResponseStatus;
@@ -59,6 +61,7 @@ import static org.springframework.util.Assert.isTrue;
  *
  * @author Daniel Lavoie
  * @author Wonchul Heo
+ * @author Olga Maciaszek-Sharma
  */
 @Configuration(proxyBeanMethods = false)
 @RestController
@@ -172,7 +175,11 @@ public class EurekaServerMockApplication {
 	}
 
 	@GetMapping("/apps/{appName}")
-	public Application getApplication(@PathVariable String appName) {
+	public Application getApplication(@PathVariable String appName, @RequestHeader HttpHeaders headers) {
+		// Used to verify that RequestConfig customizer has taken effect
+		if (appName.equals("upgrade") && !headers.containsKey("upgrade")) {
+			throw new RuntimeException("No upgrade header found");
+		}
 		return new Application();
 	}
 

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/http/RestClientEurekaHttpClientTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2024 the original author or authors.
+ * Copyright 2017-2025 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.
@@ -16,11 +16,15 @@
 
 package org.springframework.cloud.netflix.eureka.http;
 
+import java.util.Collections;
 import java.util.Optional;
+import java.util.Set;
 
 import com.netflix.appinfo.providers.EurekaConfigBasedInstanceInfoProvider;
 import com.netflix.discovery.shared.resolver.DefaultEndpoint;
+import com.netflix.discovery.shared.transport.EurekaHttpClient;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
@@ -32,6 +36,8 @@ import org.springframework.cloud.netflix.eureka.RestClientTimeoutProperties;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.web.client.RestClient;
 
+import static org.assertj.core.api.AssertionsForClassTypes.assertThatExceptionOfType;
+
 /**
  * Tests for {@link RestClientEurekaHttpClient}.
  *
@@ -53,13 +59,9 @@ class RestClientEurekaHttpClientTests extends AbstractEurekaHttpClientTests {
 
 	@BeforeEach
 	void setup() {
-		eurekaHttpClient = new RestClientTransportClientFactory(Optional.empty(), Optional.empty(),
-				new DefaultEurekaClientHttpRequestFactorySupplier(new RestClientTimeoutProperties()),
-				RestClient::builder)
-			.newClient(new DefaultEndpoint(serviceUrl));
+		eurekaHttpClient = buildEurekaHttpClient();
 
 		EurekaInstanceConfigBean config = new EurekaInstanceConfigBean(inetUtils);
-
 		String appname = "customapp";
 		config.setIpAddress("127.0.0.1");
 		config.setHostname("localhost");
@@ -73,4 +75,22 @@ class RestClientEurekaHttpClientTests extends AbstractEurekaHttpClientTests {
 		info = new EurekaConfigBasedInstanceInfoProvider(config).get();
 	}
 
+	private EurekaHttpClient buildEurekaHttpClient() {
+		return buildEurekaHttpClient(Collections.emptySet());
+	}
+
+	@Test
+	void shouldCustomiseHttpClientRequestConfig() {
+		eurekaHttpClient = buildEurekaHttpClient(Set.of(builder -> builder.setProtocolUpgradeEnabled(false)));
+		assertThatExceptionOfType(RuntimeException.class).isThrownBy(() -> eurekaHttpClient.getApplication("upgrade"));
+	}
+
+	private EurekaHttpClient buildEurekaHttpClient(
+			Set<EurekaClientHttpRequestFactorySupplier.RequestConfigCustomizer> customizers) {
+		return new RestClientTransportClientFactory(Optional.empty(), Optional.empty(),
+				new DefaultEurekaClientHttpRequestFactorySupplier(new RestClientTimeoutProperties(), customizers),
+				RestClient::builder)
+			.newClient(new DefaultEndpoint(serviceUrl));
+	}
+
 }

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/http/RestClientTransportClientFactoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2024 the original author or authors.
+ * Copyright 2017-2025 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.cloud.netflix.eureka.http;
 
+import java.util.Collections;
 import java.util.Optional;
 
 import com.netflix.discovery.shared.resolver.DefaultEndpoint;
@@ -42,7 +43,8 @@ class RestClientTransportClientFactoryTests {
 	@BeforeEach
 	void setup() {
 		transportClientFactory = new RestClientTransportClientFactory(Optional.empty(), Optional.empty(),
-				new DefaultEurekaClientHttpRequestFactorySupplier(new RestClientTimeoutProperties()),
+				new DefaultEurekaClientHttpRequestFactorySupplier(new RestClientTimeoutProperties(),
+						Collections.emptySet()),
 				RestClient::builder);
 	}
 

spring-cloud-netflix-eureka-server/pom.xml

@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-netflix</artifactId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 		<relativePath>..</relativePath> <!-- lookup parent from repository -->
 	</parent>
 	<artifactId>spring-cloud-netflix-eureka-server</artifactId>

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

@@ -71,12 +71,18 @@ public class EurekaInstanceMonitor implements SmartApplicationListener {
 
 	@Override
 	public void onApplicationEvent(ApplicationEvent event) {
-		final Map<Tags, Long> aggregatedCounts = instanceRegistry.getApplications()
+		executor.execute(() -> {
+			Map<Tags, Long> aggregatedCounts = collectAggregatedCounts();
+			registerMetrics(aggregatedCounts);
+		});
+	}
+
+	private Map<Tags, Long> collectAggregatedCounts() {
+		return instanceRegistry.getApplications()
 			.getRegisteredApplications()
 			.stream()
 			.flatMap(application -> application.getInstances().stream())
 			.collect(Collectors.groupingBy(tagProvider::eurekaInstanceTags, Collectors.counting()));
-		executor.execute(() -> registerMetrics(aggregatedCounts));
 	}
 
 	private void registerMetrics(Map<Tags, Long> aggregatedCounts) {

spring-cloud-netflix-eureka-server/src/test/java/org/springframework/cloud/netflix/eureka/server/EurekaInstanceMonitorTests.java

@@ -30,7 +30,9 @@ import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.cloud.netflix.eureka.server.metrics.EurekaInstanceMonitor;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.web.bind.annotation.RestController;
 
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.awaitility.Awaitility.await;
@@ -158,7 +160,8 @@ class EurekaInstanceMonitorTests {
 	}
 
 	private void assertEurekaInstance(Map<Tags, Long> meterRegistryCounts) {
-		await().atMost(5, SECONDS)
+		await().pollDelay(5, MILLISECONDS)
+			.atMost(5, SECONDS)
 			.pollInterval(fibonacci())
 			.untilAsserted(() -> meterRegistryCounts.forEach((tags,
 					count) -> assertThat((long) meterRegistry.get("eureka.server.instances").tags(tags).gauge().value())
@@ -168,6 +171,7 @@ class EurekaInstanceMonitorTests {
 	@Configuration(proxyBeanMethods = false)
 	@EnableAutoConfiguration
 	@EnableEurekaServer
+	@RestController
 	protected static class Application {
 
 	}

spring-cloud-netflix-eureka-server/src/test/java/org/springframework/cloud/netflix/eureka/server/EurekaInstanceMonitorWithCustomTagsProviderTests.java

@@ -32,6 +32,7 @@ import org.springframework.cloud.netflix.eureka.server.metrics.EurekaInstanceTag
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.awaitility.Awaitility.await;
@@ -89,7 +90,8 @@ class EurekaInstanceMonitorWithCustomTagsProviderTests {
 	}
 
 	private void assertEurekaInstance(Map<Tags, Long> meterRegistryCounts) {
-		await().atMost(5, SECONDS)
+		await().pollDelay(5, MILLISECONDS)
+			.atMost(6, SECONDS)
 			.pollInterval(fibonacci())
 			.untilAsserted(() -> meterRegistryCounts.forEach((tags,
 					count) -> assertThat((long) meterRegistry.get("eureka.server.instances").tags(tags).gauge().value())

spring-cloud-starter-netflix-eureka-client/pom.xml

@@ -4,7 +4,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-netflix</artifactId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 	</parent>
 	<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
 	<name>Spring Cloud Starter Netflix Eureka Client</name>

spring-cloud-starter-netflix-eureka-server/pom.xml

@@ -3,7 +3,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-netflix</artifactId>
-		<version>4.2.0</version>
+		<version>4.2.1-SNAPSHOT</version>
 	</parent>
 	<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
 	<name>Spring Cloud Starter Netflix Eureka Server</name>