Add support for Elasticsearch sniffer

Closes gh-24174

spring-boot-project/spring-boot-autoconfigure/build.gradle

@@ -76,6 +76,7 @@ dependencies {
 	optional("org.eclipse.jetty.websocket:javax-websocket-server-impl")
 	optional("org.ehcache:ehcache")
 	optional("org.elasticsearch.client:elasticsearch-rest-client")
+	optional("org.elasticsearch.client:elasticsearch-rest-client-sniffer")
 	optional("org.elasticsearch.client:elasticsearch-rest-high-level-client")
 	optional("org.flywaydb:flyway-core")
 	optional("org.freemarker:freemarker")

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/ElasticsearchRestClientAutoConfiguration.java

@@ -16,30 +16,18 @@
 
 package org.springframework.boot.autoconfigure.elasticsearch;
 
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.time.Duration;
-
-import org.apache.http.HttpHost;
-import org.apache.http.auth.AuthScope;
-import org.apache.http.auth.Credentials;
-import org.apache.http.auth.UsernamePasswordCredentials;
-import org.apache.http.client.config.RequestConfig;
-import org.apache.http.impl.client.BasicCredentialsProvider;
-import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
 import org.elasticsearch.client.RestClient;
-import org.elasticsearch.client.RestClientBuilder;
 import org.elasticsearch.client.RestHighLevelClient;
 
-import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchRestClientConfigurations.RestClientBuilderConfiguration;
+import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchRestClientConfigurations.RestClientSnifferConfiguration;
+import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchRestClientConfigurations.RestHighLevelClientConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.boot.context.properties.PropertyMapper;
-import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.util.StringUtils;
+import org.springframework.context.annotation.Import;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for Elasticsearch REST clients.
@@ -52,139 +40,8 @@ import org.springframework.util.StringUtils;
 @ConditionalOnClass(RestHighLevelClient.class)
 @ConditionalOnMissingBean(RestClient.class)
 @EnableConfigurationProperties(ElasticsearchRestClientProperties.class)
+@Import({ RestClientBuilderConfiguration.class, RestHighLevelClientConfiguration.class,
+		RestClientSnifferConfiguration.class })
 public class ElasticsearchRestClientAutoConfiguration {
 
-	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnMissingBean(RestClientBuilder.class)
-	static class RestClientBuilderConfiguration {
-
-		@Bean
-		RestClientBuilderCustomizer defaultRestClientBuilderCustomizer(ElasticsearchRestClientProperties properties) {
-			return new DefaultRestClientBuilderCustomizer(properties);
-		}
-
-		@Bean
-		RestClientBuilder elasticsearchRestClientBuilder(ElasticsearchRestClientProperties properties,
-				ObjectProvider<RestClientBuilderCustomizer> builderCustomizers) {
-			HttpHost[] hosts = properties.getUris().stream().map(this::createHttpHost).toArray(HttpHost[]::new);
-			RestClientBuilder builder = RestClient.builder(hosts);
-			builder.setHttpClientConfigCallback((httpClientBuilder) -> {
-				builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(httpClientBuilder));
-				return httpClientBuilder;
-			});
-			builder.setRequestConfigCallback((requestConfigBuilder) -> {
-				builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(requestConfigBuilder));
-				return requestConfigBuilder;
-			});
-			builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(builder));
-			return builder;
-		}
-
-		private HttpHost createHttpHost(String uri) {
-			try {
-				return createHttpHost(URI.create(uri));
-			}
-			catch (IllegalArgumentException ex) {
-				return HttpHost.create(uri);
-			}
-		}
-
-		private HttpHost createHttpHost(URI uri) {
-			if (!StringUtils.hasLength(uri.getUserInfo())) {
-				return HttpHost.create(uri.toString());
-			}
-			try {
-				return HttpHost.create(new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(),
-						uri.getQuery(), uri.getFragment()).toString());
-			}
-			catch (URISyntaxException ex) {
-				throw new IllegalStateException(ex);
-			}
-		}
-
-	}
-
-	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnMissingBean(RestHighLevelClient.class)
-	static class RestHighLevelClientConfiguration {
-
-		@Bean
-		RestHighLevelClient elasticsearchRestHighLevelClient(RestClientBuilder restClientBuilder) {
-			return new RestHighLevelClient(restClientBuilder);
-		}
-
-	}
-
-	static class DefaultRestClientBuilderCustomizer implements RestClientBuilderCustomizer {
-
-		private static final PropertyMapper map = PropertyMapper.get();
-
-		private final ElasticsearchRestClientProperties properties;
-
-		DefaultRestClientBuilderCustomizer(ElasticsearchRestClientProperties properties) {
-			this.properties = properties;
-		}
-
-		@Override
-		public void customize(RestClientBuilder builder) {
-		}
-
-		@Override
-		public void customize(HttpAsyncClientBuilder builder) {
-			builder.setDefaultCredentialsProvider(new PropertiesCredentialsProvider(this.properties));
-		}
-
-		@Override
-		public void customize(RequestConfig.Builder builder) {
-			map.from(this.properties::getConnectionTimeout).whenNonNull().asInt(Duration::toMillis)
-					.to(builder::setConnectTimeout);
-			map.from(this.properties::getReadTimeout).whenNonNull().asInt(Duration::toMillis)
-					.to(builder::setSocketTimeout);
-		}
-
-	}
-
-	private static class PropertiesCredentialsProvider extends BasicCredentialsProvider {
-
-		PropertiesCredentialsProvider(ElasticsearchRestClientProperties properties) {
-			if (StringUtils.hasText(properties.getUsername())) {
-				Credentials credentials = new UsernamePasswordCredentials(properties.getUsername(),
-						properties.getPassword());
-				setCredentials(AuthScope.ANY, credentials);
-			}
-			properties.getUris().stream().map(this::toUri).filter(this::hasUserInfo)
-					.forEach(this::addUserInfoCredentials);
-		}
-
-		private URI toUri(String uri) {
-			try {
-				return URI.create(uri);
-			}
-			catch (IllegalArgumentException ex) {
-				return null;
-			}
-		}
-
-		private boolean hasUserInfo(URI uri) {
-			return uri != null && StringUtils.hasLength(uri.getUserInfo());
-		}
-
-		private void addUserInfoCredentials(URI uri) {
-			AuthScope authScope = new AuthScope(uri.getHost(), uri.getPort());
-			Credentials credentials = createUserInfoCredentials(uri.getUserInfo());
-			setCredentials(authScope, credentials);
-		}
-
-		private Credentials createUserInfoCredentials(String userInfo) {
-			int delimiter = userInfo.indexOf(":");
-			if (delimiter == -1) {
-				return new UsernamePasswordCredentials(userInfo, null);
-			}
-			String username = userInfo.substring(0, delimiter);
-			String password = userInfo.substring(delimiter + 1);
-			return new UsernamePasswordCredentials(username, password);
-		}
-
-	}
-
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/ElasticsearchRestClientConfigurations.java

@@ -0,0 +1,204 @@
+/*
+ * Copyright 2012-2020 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.boot.autoconfigure.elasticsearch;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.time.Duration;
+
+import org.apache.http.HttpHost;
+import org.apache.http.auth.AuthScope;
+import org.apache.http.auth.Credentials;
+import org.apache.http.auth.UsernamePasswordCredentials;
+import org.apache.http.client.config.RequestConfig;
+import org.apache.http.impl.client.BasicCredentialsProvider;
+import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
+import org.elasticsearch.client.RestClient;
+import org.elasticsearch.client.RestClientBuilder;
+import org.elasticsearch.client.RestHighLevelClient;
+import org.elasticsearch.client.sniff.Sniffer;
+import org.elasticsearch.client.sniff.SnifferBuilder;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
+import org.springframework.boot.context.properties.PropertyMapper;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.util.StringUtils;
+
+/**
+ * Elasticsearch rest client configurations.
+ *
+ * @author Stephane Nicoll
+ */
+class ElasticsearchRestClientConfigurations {
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(RestClientBuilder.class)
+	static class RestClientBuilderConfiguration {
+
+		@Bean
+		RestClientBuilderCustomizer defaultRestClientBuilderCustomizer(ElasticsearchRestClientProperties properties) {
+			return new DefaultRestClientBuilderCustomizer(properties);
+		}
+
+		@Bean
+		RestClientBuilder elasticsearchRestClientBuilder(ElasticsearchRestClientProperties properties,
+				ObjectProvider<RestClientBuilderCustomizer> builderCustomizers) {
+			HttpHost[] hosts = properties.getUris().stream().map(this::createHttpHost).toArray(HttpHost[]::new);
+			RestClientBuilder builder = RestClient.builder(hosts);
+			builder.setHttpClientConfigCallback((httpClientBuilder) -> {
+				builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(httpClientBuilder));
+				return httpClientBuilder;
+			});
+			builder.setRequestConfigCallback((requestConfigBuilder) -> {
+				builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(requestConfigBuilder));
+				return requestConfigBuilder;
+			});
+			builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(builder));
+			return builder;
+		}
+
+		private HttpHost createHttpHost(String uri) {
+			try {
+				return createHttpHost(URI.create(uri));
+			}
+			catch (IllegalArgumentException ex) {
+				return HttpHost.create(uri);
+			}
+		}
+
+		private HttpHost createHttpHost(URI uri) {
+			if (!StringUtils.hasLength(uri.getUserInfo())) {
+				return HttpHost.create(uri.toString());
+			}
+			try {
+				return HttpHost.create(new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(),
+						uri.getQuery(), uri.getFragment()).toString());
+			}
+			catch (URISyntaxException ex) {
+				throw new IllegalStateException(ex);
+			}
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(RestHighLevelClient.class)
+	static class RestHighLevelClientConfiguration {
+
+		@Bean
+		RestHighLevelClient elasticsearchRestHighLevelClient(RestClientBuilder restClientBuilder) {
+			return new RestHighLevelClient(restClientBuilder);
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass(Sniffer.class)
+	@ConditionalOnSingleCandidate(RestHighLevelClient.class)
+	static class RestClientSnifferConfiguration {
+
+		@Bean
+		@ConditionalOnMissingBean
+		Sniffer elasticsearchSniffer(RestHighLevelClient client, ElasticsearchRestClientProperties properties) {
+			SnifferBuilder builder = Sniffer.builder(client.getLowLevelClient());
+			PropertyMapper get = PropertyMapper.get().alwaysApplyingWhenNonNull();
+			get.from(properties.getSniffer().getInterval()).asInt(Duration::toMillis)
+					.to(builder::setSniffIntervalMillis);
+			get.from(properties.getSniffer().getDelayAfterFailure()).asInt(Duration::toMillis)
+					.to(builder::setSniffAfterFailureDelayMillis);
+			return builder.build();
+		}
+
+	}
+
+	static class DefaultRestClientBuilderCustomizer implements RestClientBuilderCustomizer {
+
+		private static final PropertyMapper map = PropertyMapper.get();
+
+		private final ElasticsearchRestClientProperties properties;
+
+		DefaultRestClientBuilderCustomizer(ElasticsearchRestClientProperties properties) {
+			this.properties = properties;
+		}
+
+		@Override
+		public void customize(RestClientBuilder builder) {
+		}
+
+		@Override
+		public void customize(HttpAsyncClientBuilder builder) {
+			builder.setDefaultCredentialsProvider(new PropertiesCredentialsProvider(this.properties));
+		}
+
+		@Override
+		public void customize(RequestConfig.Builder builder) {
+			map.from(this.properties::getConnectionTimeout).whenNonNull().asInt(Duration::toMillis)
+					.to(builder::setConnectTimeout);
+			map.from(this.properties::getReadTimeout).whenNonNull().asInt(Duration::toMillis)
+					.to(builder::setSocketTimeout);
+		}
+
+	}
+
+	private static class PropertiesCredentialsProvider extends BasicCredentialsProvider {
+
+		PropertiesCredentialsProvider(ElasticsearchRestClientProperties properties) {
+			if (StringUtils.hasText(properties.getUsername())) {
+				Credentials credentials = new UsernamePasswordCredentials(properties.getUsername(),
+						properties.getPassword());
+				setCredentials(AuthScope.ANY, credentials);
+			}
+			properties.getUris().stream().map(this::toUri).filter(this::hasUserInfo)
+					.forEach(this::addUserInfoCredentials);
+		}
+
+		private URI toUri(String uri) {
+			try {
+				return URI.create(uri);
+			}
+			catch (IllegalArgumentException ex) {
+				return null;
+			}
+		}
+
+		private boolean hasUserInfo(URI uri) {
+			return uri != null && StringUtils.hasLength(uri.getUserInfo());
+		}
+
+		private void addUserInfoCredentials(URI uri) {
+			AuthScope authScope = new AuthScope(uri.getHost(), uri.getPort());
+			Credentials credentials = createUserInfoCredentials(uri.getUserInfo());
+			setCredentials(authScope, credentials);
+		}
+
+		private Credentials createUserInfoCredentials(String userInfo) {
+			int delimiter = userInfo.indexOf(":");
+			if (delimiter == -1) {
+				return new UsernamePasswordCredentials(userInfo, null);
+			}
+			String username = userInfo.substring(0, delimiter);
+			String password = userInfo.substring(delimiter + 1);
+			return new UsernamePasswordCredentials(username, password);
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/ElasticsearchRestClientProperties.java

@@ -57,6 +57,8 @@ public class ElasticsearchRestClientProperties {
 	 */
 	private Duration readTimeout = Duration.ofSeconds(30);
 
+	private final Sniffer sniffer = new Sniffer();
+
 	public List<String> getUris() {
 		return this.uris;
 	}
@@ -97,4 +99,38 @@ public class ElasticsearchRestClientProperties {
 		this.readTimeout = readTimeout;
 	}
 
+	public Sniffer getSniffer() {
+		return this.sniffer;
+	}
+
+	public static class Sniffer {
+
+		/**
+		 * Interval between consecutive ordinary sniff executions.
+		 */
+		private Duration interval = Duration.ofMinutes(5);
+
+		/**
+		 * Delay of a sniff execution scheduled after a failure.
+		 */
+		private Duration delayAfterFailure = Duration.ofMinutes(1);
+
+		public Duration getInterval() {
+			return this.interval;
+		}
+
+		public void setInterval(Duration interval) {
+			this.interval = interval;
+		}
+
+		public Duration getDelayAfterFailure() {
+			return this.delayAfterFailure;
+		}
+
+		public void setDelayAfterFailure(Duration delayAfterFailure) {
+			this.delayAfterFailure = delayAfterFailure;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/elasticsearch/ElasticsearchRestClientAutoConfigurationTests.java

@@ -34,12 +34,14 @@ import org.elasticsearch.client.RequestOptions;
 import org.elasticsearch.client.RestClient;
 import org.elasticsearch.client.RestClientBuilder;
 import org.elasticsearch.client.RestHighLevelClient;
+import org.elasticsearch.client.sniff.Sniffer;
 import org.junit.jupiter.api.Test;
 import org.testcontainers.elasticsearch.ElasticsearchContainer;
 import org.testcontainers.junit.jupiter.Container;
 import org.testcontainers.junit.jupiter.Testcontainers;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.testsupport.testcontainers.DockerImageNames;
 import org.springframework.context.annotation.Bean;
@@ -47,6 +49,7 @@ import org.springframework.context.annotation.Configuration;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verifyNoInteractions;
 
 /**
  * Tests for {@link ElasticsearchRestClientAutoConfiguration}.
@@ -220,6 +223,52 @@ class ElasticsearchRestClientAutoConfigurationTests {
 				});
 	}
 
+	@Test
+	void configureWithoutSnifferLibraryShouldNotCreateSniffer() {
+		this.contextRunner.withClassLoader(new FilteredClassLoader("org.elasticsearch.client.sniff"))
+				.run((context) -> assertThat(context).hasSingleBean(RestHighLevelClient.class)
+						.doesNotHaveBean(Sniffer.class));
+	}
+
+	@Test
+	void configureShouldCreateSnifferUsingRestHighLevelClient() {
+		this.contextRunner.run((context) -> {
+			assertThat(context).hasSingleBean(Sniffer.class);
+			assertThat(context.getBean(Sniffer.class)).hasFieldOrPropertyWithValue("restClient",
+					context.getBean(RestHighLevelClient.class).getLowLevelClient());
+			// Validate shutdown order as the sniffer must be shutdown before the client
+			assertThat(context.getBeanFactory().getDependentBeans("elasticsearchRestHighLevelClient"))
+					.contains("elasticsearchSniffer");
+		});
+	}
+
+	@Test
+	void configureWithCustomSnifferSettings() {
+		this.contextRunner.withPropertyValues("spring.elasticsearch.rest.sniffer.interval=180s",
+				"spring.elasticsearch.rest.sniffer.delay-after-failure=30s").run((context) -> {
+					assertThat(context).hasSingleBean(Sniffer.class);
+					Sniffer sniffer = context.getBean(Sniffer.class);
+					assertThat(sniffer).hasFieldOrPropertyWithValue("sniffIntervalMillis",
+							Duration.ofMinutes(3).toMillis());
+					assertThat(sniffer).hasFieldOrPropertyWithValue("sniffAfterFailureDelayMillis",
+							Duration.ofSeconds(30).toMillis());
+				});
+	}
+
+	@Test
+	void configureWhenCustomSnifferShouldBackOff() {
+		Sniffer customSniffer = mock(Sniffer.class);
+		this.contextRunner.withBean(Sniffer.class, () -> customSniffer)
+				.withPropertyValues("spring.elasticsearch.rest.sniffer.interval=180s",
+						"spring.elasticsearch.rest.sniffer.delay-after-failure=30s")
+				.run((context) -> {
+					assertThat(context).hasSingleBean(Sniffer.class);
+					Sniffer sniffer = context.getBean(Sniffer.class);
+					assertThat(sniffer).isSameAs(customSniffer);
+					verifyNoInteractions(customSniffer);
+				});
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class BuilderCustomizerConfiguration {
 

spring-boot-project/spring-boot-docs/src/docs/asciidoc/spring-boot-features.adoc

@@ -4983,6 +4983,19 @@ To take full control over the registration, define a `RestClientBuilder` bean.
 
 TIP: If your application needs access to a "Low Level" `RestClient`, you can get it by calling `client.getLowLevelClient()` on the auto-configured `RestHighLevelClient`.
 
+Additionally, if `elasticsearch-rest-client-sniffer` is on the classpath, a `Sniffer` is auto-configured to automatically discover nodes from a running Elasticsearch cluster and set them to the `RestHighLevelClient` bean.
+You can further tune how `Sniffer` is configured, as shown in the following example:
+
+[source,yaml,indent=0,configprops,configblocks]
+----
+	spring:
+	  elasticsearch:
+	    rest:
+          sniffer:
+            interval: 10m
+            delay-after-failure: 30s
+----
+
 
 
 [[boot-features-connecting-to-elasticsearch-reactive-rest]]