RestClient support

spring-boot-admin-client/src/main/java/de/codecentric/boot/admin/client/config/SpringBootAdminClientAutoConfiguration.java

@@ -30,18 +30,23 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.reactive.WebFluxProperties;
 import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletPath;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder;
+import org.springframework.boot.http.client.ClientHttpRequestFactorySettings;
 import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Lazy;
 import org.springframework.core.env.Environment;
+import org.springframework.http.client.support.BasicAuthenticationInterceptor;
+import org.springframework.web.client.RestClient;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.reactive.function.client.WebClient;
 
@@ -53,6 +58,7 @@
 import de.codecentric.boot.admin.client.registration.ReactiveRegistrationClient;
 import de.codecentric.boot.admin.client.registration.RegistrationApplicationListener;
 import de.codecentric.boot.admin.client.registration.RegistrationClient;
+import de.codecentric.boot.admin.client.registration.RestClientRegistrationClient;
 import de.codecentric.boot.admin.client.registration.ServletApplicationFactory;
 import de.codecentric.boot.admin.client.registration.metadata.CompositeMetadataContributor;
 import de.codecentric.boot.admin.client.registration.metadata.MetadataContributor;
@@ -64,8 +70,8 @@
 @Configuration(proxyBeanMethods = false)
 @ConditionalOnWebApplication
 @Conditional(SpringBootAdminClientEnabledCondition.class)
-@AutoConfigureAfter({ WebEndpointAutoConfiguration.class, RestTemplateAutoConfiguration.class,
-		WebClientAutoConfiguration.class })
+@AutoConfigureAfter({ WebEndpointAutoConfiguration.class, RestClientAutoConfiguration.class,
+		RestTemplateAutoConfiguration.class, WebClientAutoConfiguration.class })
 @EnableConfigurationProperties({ ClientProperties.class, InstanceProperties.class, ServerProperties.class,
 		ManagementServerProperties.class })
 public class SpringBootAdminClientAutoConfiguration {
@@ -153,8 +159,32 @@ public RegistrationClient registrationClient(ClientProperties client) {
 	}
 
 	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnBean(WebClient.Builder.class)
+	@ConditionalOnBean(RestClient.Builder.class)
 	@ConditionalOnMissingBean(RestTemplateBuilder.class)
+	public static class RestClientRegistrationClientConfig {
+
+		@Bean
+		@ConditionalOnMissingBean
+		public RegistrationClient registrationClient(ClientProperties client, RestClient.Builder restClientBuilder,
+				ClientHttpRequestFactoryBuilder<?> clientHttpRequestFactoryBuilder) {
+			var factorySettings = ClientHttpRequestFactorySettings.defaults()
+				.withConnectTimeout(client.getConnectTimeout())
+				.withReadTimeout(client.getReadTimeout());
+			var clientHttpRequestFactory = clientHttpRequestFactoryBuilder.build(factorySettings);
+			restClientBuilder = restClientBuilder.requestFactory(clientHttpRequestFactory);
+			if (client.getUsername() != null && client.getPassword() != null) {
+				restClientBuilder = restClientBuilder
+					.requestInterceptor(new BasicAuthenticationInterceptor(client.getUsername(), client.getPassword()));
+			}
+			var restClient = restClientBuilder.build();
+			return new RestClientRegistrationClient(restClient);
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnBean(WebClient.Builder.class)
+	@ConditionalOnMissingBean({ RestTemplateBuilder.class, RestClient.Builder.class })
 	public static class ReactiveRegistrationClientConfig {
 
 		@Bean

spring-boot-admin-client/src/main/java/de/codecentric/boot/admin/client/registration/DefaultApplicationRegistrator.java

@@ -90,11 +90,11 @@ protected boolean register(Application application, String adminUrl, boolean fir
 			if (firstAttempt) {
 				LOGGER.warn(
 						"Failed to register application as {} at spring-boot-admin ({}): {}. Further attempts are logged on DEBUG level",
-						application, this.adminUrls, ex.getMessage());
+						application, this.adminUrls, ex.getMessage(), ex);
 			}
 			else {
 				LOGGER.debug("Failed to register application as {} at spring-boot-admin ({}): {}", application,
-						this.adminUrls, ex.getMessage());
+						this.adminUrls, ex.getMessage(), ex);
 			}
 			return false;
 		}

spring-boot-admin-client/src/main/java/de/codecentric/boot/admin/client/registration/RestClientRegistrationClient.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2014-2024 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 de.codecentric.boot.admin.client.registration;
+
+import java.util.Collections;
+import java.util.Map;
+
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.web.client.RestClient;
+
+public class RestClientRegistrationClient implements RegistrationClient {
+
+	private static final ParameterizedTypeReference<Map<String, Object>> RESPONSE_TYPE = new ParameterizedTypeReference<>() {
+	};
+
+	private final RestClient restClient;
+
+	public RestClientRegistrationClient(RestClient restClient) {
+		this.restClient = restClient;
+	}
+
+	@Override
+	public String register(String adminUrl, Application application) {
+		Map<String, Object> response = this.restClient.post()
+			.uri(adminUrl)
+			.headers(this::setRequestHeaders)
+			.body(application)
+			.retrieve()
+			.body(RESPONSE_TYPE);
+		return response.get("id").toString();
+	}
+
+	@Override
+	public void deregister(String adminUrl, String id) {
+		this.restClient.delete().uri(adminUrl + '/' + id).retrieve().toBodilessEntity();
+	}
+
+	protected void setRequestHeaders(HttpHeaders headers) {
+		headers.setContentType(MediaType.APPLICATION_JSON);
+		headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
+	}
+
+}

spring-boot-admin-client/src/test/java/de/codecentric/boot/admin/client/config/ClientPropertiesTest.java

@@ -53,7 +53,7 @@ public void should_default_autoDeregister_to_true() {
 	}
 
 	@Test
-	public void should_return_all_admiUrls() {
+	public void should_return_all_adminUrls() {
 		ClientProperties clientProperties = new ClientProperties();
 		clientProperties.setApiPath("register");
 		clientProperties.setUrl(new String[] { "http://first", "http://second" });

spring-boot-admin-client/src/test/java/de/codecentric/boot/admin/client/config/SpringBootAdminClientAutoConfigurationTest.java

@@ -22,6 +22,9 @@
 import org.springframework.boot.actuate.autoconfigure.endpoint.EndpointAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.endpoint.web.WebEndpointAutoConfiguration;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.http.client.HttpClientAutoConfiguration;
+import org.springframework.boot.autoconfigure.logging.ConditionEvaluationReportLoggingListener;
+import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.reactive.WebFluxProperties;
 import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration;
@@ -34,6 +37,7 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.web.client.RestClient;
 import org.springframework.web.client.RestTemplate;
 
 import de.codecentric.boot.admin.client.registration.ApplicationRegistrator;
@@ -113,6 +117,32 @@ public void blockingClientInBlockingEnvironment() {
 			});
 	}
 
+	@Test
+	public void restClientRegistrationClientInBlockingEnvironment() {
+		WebApplicationContextRunner webApplicationContextRunner = new WebApplicationContextRunner().withConfiguration(
+				AutoConfigurations.of(EndpointAutoConfiguration.class, WebEndpointAutoConfiguration.class,
+						DispatcherServletAutoConfiguration.class, HttpClientAutoConfiguration.class,
+						RestClientAutoConfiguration.class, SpringBootAdminClientAutoConfiguration.class));
+
+		webApplicationContextRunner
+			.withPropertyValues("spring.boot.admin.client.url:http://localhost:8081",
+					"spring.boot.admin.client.connectTimeout=1337", "spring.boot.admin.client.readTimeout=42")
+			.withInitializer(new ConditionEvaluationReportLoggingListener())
+			.run((context) -> {
+				RegistrationClient registrationClient = context.getBean(RegistrationClient.class);
+				RestClient restClient = (RestClient) ReflectionTestUtils.getField(registrationClient, "restClient");
+				assertThat(restClient).isNotNull();
+
+				ClientHttpRequestFactory requestFactory = (ClientHttpRequestFactory) ReflectionTestUtils
+					.getField(restClient, "clientRequestFactory");
+
+				Integer connectTimeout = (Integer) ReflectionTestUtils.getField(requestFactory, "connectTimeout");
+				assertThat(connectTimeout).isEqualTo(1337);
+				Duration readTimeout = (Duration) ReflectionTestUtils.getField(requestFactory, "readTimeout");
+				assertThat(readTimeout).isEqualTo(Duration.ofMillis(42));
+			});
+	}
+
 	@Test
 	public void customBlockingClientInReactiveEnvironment() {
 		ReactiveWebApplicationContextRunner reactiveContextRunner = new ReactiveWebApplicationContextRunner()

spring-boot-admin-client/src/test/java/de/codecentric/boot/admin/client/registration/RestClientRegistrationClientTest.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2014-2024 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 de.codecentric.boot.admin.client.registration;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.springframework.web.client.RestClient;
+
+public class RestClientRegistrationClientTest extends AbstractRegistrationClientTest {
+
+	@BeforeEach
+	public void setUp() {
+		super.setUp(new RestClientRegistrationClient(RestClient.create()));
+	}
+
+}