Allow users to provide a customizer to customize the HttpClient behav…

…ior. (spring-cloud#2413)

Fixes spring-cloud#2410

Co-authored-by: Ryan Baxter <[email protected]>

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/config/EnvironmentRepositoryConfiguration.java

@@ -62,6 +62,7 @@
 import org.springframework.cloud.config.server.environment.GoogleSecretManagerEnvironmentProperties;
 import org.springframework.cloud.config.server.environment.GoogleSecretManagerEnvironmentRepository;
 import org.springframework.cloud.config.server.environment.GoogleSecretManagerEnvironmentRepositoryFactory;
+import org.springframework.cloud.config.server.environment.HttpClient4BuilderCustomizer;
 import org.springframework.cloud.config.server.environment.HttpClientConfigurableHttpConnectionFactory;
 import org.springframework.cloud.config.server.environment.HttpClientVaultRestTemplateFactory;
 import org.springframework.cloud.config.server.environment.HttpRequestConfigTokenProvider;
@@ -184,11 +185,12 @@ public MultipleJGitEnvironmentRepositoryFactory gitEnvironmentRepositoryFactory(
 				Optional<ConfigurableHttpConnectionFactory> jgitHttpConnectionFactory,
 				Optional<TransportConfigCallback> customTransportConfigCallback,
 				Optional<GoogleCloudSourceSupport> googleCloudSourceSupport,
-				GitCredentialsProviderFactory gitCredentialsProviderFactory) {
+				GitCredentialsProviderFactory gitCredentialsProviderFactory,
+				List<HttpClient4BuilderCustomizer> customizers) {
 			final TransportConfigCallbackFactory transportConfigCallbackFactory = new TransportConfigCallbackFactory(
 					customTransportConfigCallback.orElse(null), googleCloudSourceSupport.orElse(null));
 			return new MultipleJGitEnvironmentRepositoryFactory(environment, server, jgitHttpConnectionFactory,
-					transportConfigCallbackFactory, gitCredentialsProviderFactory);
+					transportConfigCallbackFactory, gitCredentialsProviderFactory, customizers);
 		}
 
 		@Bean

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/ConfigurableHttpConnectionFactory.java

@@ -16,13 +16,21 @@
 
 package org.springframework.cloud.config.server.environment;
 
+import java.util.Collections;
+import java.util.List;
+
 import org.eclipse.jgit.transport.http.HttpConnectionFactory;
 
 /**
  * @author Dylan Roberts
  */
 public interface ConfigurableHttpConnectionFactory extends HttpConnectionFactory {
 
-	void addConfiguration(MultipleJGitEnvironmentProperties environmentProperties) throws Exception;
+	default void addConfiguration(MultipleJGitEnvironmentProperties environmentProperties) throws Exception {
+		addConfiguration(environmentProperties, Collections.EMPTY_LIST);
+	}
+
+	void addConfiguration(MultipleJGitEnvironmentProperties environmentProperties,
+			List<HttpClient4BuilderCustomizer> customizers) throws Exception;
 
 }

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/HttpClient4BuilderCustomizer.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2018-2024 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.config.server.environment;
+
+import org.apache.http.impl.client.HttpClientBuilder;
+
+/**
+ * @author Ryan Baxter
+ */
+public interface HttpClient4BuilderCustomizer {
+
+	/**
+	 * Allows for customization of the HttpClientBuilder before it is created.
+	 * @param httpClientBuilder the HttpClientBuilder to customize
+	 */
+	void customize(HttpClientBuilder httpClientBuilder);
+
+}

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/HttpClientConfigurableHttpConnectionFactory.java

@@ -54,11 +54,11 @@ public class HttpClientConfigurableHttpConnectionFactory implements Configurable
 	Map<String, HttpClientBuilder> httpClientBuildersByUri = new LinkedHashMap<>();
 
 	@Override
-	public void addConfiguration(MultipleJGitEnvironmentProperties environmentProperties)
-			throws GeneralSecurityException {
-		addHttpClient(environmentProperties);
+	public void addConfiguration(MultipleJGitEnvironmentProperties environmentProperties,
+			List<HttpClient4BuilderCustomizer> customizers) throws GeneralSecurityException {
+		addHttpClient(environmentProperties, customizers);
 		for (JGitEnvironmentProperties repo : environmentProperties.getRepos().values()) {
-			addHttpClient(repo);
+			addHttpClient(repo, customizers);
 		}
 	}
 
@@ -81,9 +81,10 @@ public HttpConnection create(URL url, Proxy proxy) throws IOException {
 		}
 	}
 
-	private void addHttpClient(JGitEnvironmentProperties properties) throws GeneralSecurityException {
+	private void addHttpClient(JGitEnvironmentProperties properties, List<HttpClient4BuilderCustomizer> customizers)
+			throws GeneralSecurityException {
 		if (properties.getUri() != null && properties.getUri().startsWith("http")) {
-			this.httpClientBuildersByUri.put(properties.getUri(), HttpClient4Support.builder(properties));
+			this.httpClientBuildersByUri.put(properties.getUri(), HttpClient4Support.builder(properties, customizers));
 		}
 	}
 

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/MultipleJGitEnvironmentRepositoryFactory.java

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.config.server.environment;
 
+import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 
 import io.micrometer.observation.ObservationRegistry;
@@ -42,6 +44,8 @@ public class MultipleJGitEnvironmentRepositoryFactory
 
 	private final GitCredentialsProviderFactory gitCredentialsProviderFactory;
 
+	private final List<HttpClient4BuilderCustomizer> customizers;
+
 	@Deprecated
 	public MultipleJGitEnvironmentRepositoryFactory(ConfigurableEnvironment environment, ConfigServerProperties server,
 			TransportConfigCallbackFactory transportConfigCallbackFactory) {
@@ -61,19 +65,29 @@ public MultipleJGitEnvironmentRepositoryFactory(ConfigurableEnvironment environm
 			Optional<ConfigurableHttpConnectionFactory> connectionFactory,
 			TransportConfigCallbackFactory transportConfigCallbackFactory,
 			GitCredentialsProviderFactory gitCredentialsProviderFactory) {
+		this(environment, server, connectionFactory, transportConfigCallbackFactory, gitCredentialsProviderFactory,
+				Collections.EMPTY_LIST);
+	}
+
+	public MultipleJGitEnvironmentRepositoryFactory(ConfigurableEnvironment environment, ConfigServerProperties server,
+			Optional<ConfigurableHttpConnectionFactory> connectionFactory,
+			TransportConfigCallbackFactory transportConfigCallbackFactory,
+			GitCredentialsProviderFactory gitCredentialsProviderFactory,
+			List<HttpClient4BuilderCustomizer> customizers) {
 		this.environment = environment;
 		this.server = server;
 		this.connectionFactory = connectionFactory;
 		this.transportConfigCallbackFactory = transportConfigCallbackFactory;
 		this.gitCredentialsProviderFactory = gitCredentialsProviderFactory;
+		this.customizers = customizers;
 	}
 
 	@Override
 	public MultipleJGitEnvironmentRepository build(MultipleJGitEnvironmentProperties environmentProperties)
 			throws Exception {
 		if (this.connectionFactory.isPresent()) {
 			HttpTransport.setConnectionFactory(this.connectionFactory.get());
-			this.connectionFactory.get().addConfiguration(environmentProperties);
+			this.connectionFactory.get().addConfiguration(environmentProperties, this.customizers);
 		}
 
 		MultipleJGitEnvironmentRepository repository = new MultipleJGitEnvironmentRepository(this.environment,

spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/support/HttpClient4Support.java

@@ -18,6 +18,8 @@
 
 import java.net.ProxySelector;
 import java.security.GeneralSecurityException;
+import java.util.Collections;
+import java.util.List;
 
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
@@ -34,6 +36,7 @@
 import org.apache.http.protocol.HttpContext;
 import org.apache.http.ssl.SSLContextBuilder;
 
+import org.springframework.cloud.config.server.environment.HttpClient4BuilderCustomizer;
 import org.springframework.cloud.config.server.proxy.ProxyHostProperties;
 import org.springframework.util.CollectionUtils;
 
@@ -48,6 +51,11 @@ private HttpClient4Support() {
 
 	public static HttpClientBuilder builder(HttpEnvironmentRepositoryProperties environmentProperties)
 			throws GeneralSecurityException {
+		return builder(environmentProperties, Collections.EMPTY_LIST);
+	}
+
+	public static HttpClientBuilder builder(HttpEnvironmentRepositoryProperties environmentProperties,
+			List<HttpClient4BuilderCustomizer> customizers) throws GeneralSecurityException {
 		SSLContextBuilder sslContextBuilder = new SSLContextBuilder();
 		HttpClientBuilder httpClientBuilder = HttpClients.custom();
 
@@ -78,8 +86,10 @@ public static HttpClientBuilder builder(HttpEnvironmentRepositoryProperties envi
 		httpClientBuilder.disableRedirectHandling();
 
 		int timeout = environmentProperties.getTimeout() * 1000;
-		return httpClientBuilder.setSSLContext(sslContextBuilder.build()).setDefaultRequestConfig(
+		httpClientBuilder.setSSLContext(sslContextBuilder.build()).setDefaultRequestConfig(
 				RequestConfig.custom().setSocketTimeout(timeout).setConnectTimeout(timeout).build());
+		customizers.forEach(customizer -> customizer.customize(httpClientBuilder));
+		return httpClientBuilder;
 	}
 
 	static class SchemeBasedRoutePlanner4 extends DefaultRoutePlanner {

spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/environment/HttpClientConfigurableHttpConnectionFactoryTest.java

@@ -31,6 +31,10 @@
 import org.springframework.util.ReflectionUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
 public class HttpClientConfigurableHttpConnectionFactoryTest {
 
@@ -69,6 +73,23 @@ public void matchingUrl() throws Exception {
 		assertThat(actualHttpClientBuilder).isSameAs(expectedHttpClientBuilder);
 	}
 
+	@Test
+	public void customizeHttpClient() throws Exception {
+		String url = "http://localhost/test.git";
+		MultipleJGitEnvironmentProperties properties = new MultipleJGitEnvironmentProperties();
+		properties.setUri(url);
+		HttpClient4BuilderCustomizer customizer = mock(HttpClient4BuilderCustomizer.class);
+		this.connectionFactory.addConfiguration(properties, List.of(customizer));
+
+		HttpConnection actualConnection = this.connectionFactory.create(new URL(url));
+
+		HttpClientBuilder expectedHttpClientBuilder = this.connectionFactory.httpClientBuildersByUri.values().stream()
+				.findFirst().get();
+		HttpClientBuilder actualHttpClientBuilder = getActualHttpClientBuilder(actualConnection);
+		assertThat(actualHttpClientBuilder).isSameAs(expectedHttpClientBuilder);
+		verify(customizer, times(1)).customize(any(HttpClientBuilder.class));
+	}
+
 	@Test
 	public void longerUrl() throws Exception {
 		MultipleJGitEnvironmentProperties properties = new MultipleJGitEnvironmentProperties();