Add support for Elasticsearch Sniffer

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

@@ -19,6 +19,7 @@
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.time.Duration;
+import java.time.temporal.TemporalUnit;
 
 import org.apache.http.HttpHost;
 import org.apache.http.auth.AuthScope;
@@ -31,6 +32,8 @@
 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.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
@@ -80,6 +83,17 @@ RestClientBuilder elasticsearchRestClientBuilder(ElasticsearchRestClientProperti
 			return builder;
 		}
 
+		@Bean
+		Sniffer elasticsearchSnifferBuilder(ElasticsearchSnifferProperties properties,
+											RestClient elasticSearchRestClient) {
+			return Sniffer.builder(elasticSearchRestClient)
+					.setSniffIntervalMillis(
+							Math.toIntExact(properties.getSniffInterval().getSeconds() * 1000))
+					.setSniffAfterFailureDelayMillis(
+							Math.toIntExact(properties.getSniffFailureDelay().getSeconds() * 1000))
+					.build();
+		}
+
 		private HttpHost createHttpHost(String uri) {
 			try {
 				return createHttpHost(URI.create(uri));

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

@@ -0,0 +1,57 @@
+/*
+ * 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 org.elasticsearch.client.sniff.NodesSniffer;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ *
+ */
+@ConfigurationProperties(prefix = "spring.elasticsearch.sniff")
+public class ElasticsearchSnifferProperties {
+
+	/**
+	 * Sniffer interval
+	 */
+	private Duration sniffInterval = Duration.ofMinutes(5L);
+	/**
+	 * Sniffer failure delay.
+	 */
+	private Duration sniffFailureDelay = Duration.ofMinutes(1L);
+
+	public Duration getSniffInterval() {
+		return sniffInterval;
+	}
+
+	public void setSniffInterval(Duration sniffInterval) {
+		this.sniffInterval = sniffInterval;
+	}
+
+	public Duration getSniffFailureDelay() {
+		return sniffFailureDelay;
+	}
+
+	public void setSniffFailureDelay(Duration sniffFailureDelay) {
+		this.sniffFailureDelay = sniffFailureDelay;
+	}
+}

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

@@ -16,8 +16,10 @@
 
 package org.springframework.boot.autoconfigure.elasticsearch;
 
+import java.io.IOException;
 import java.time.Duration;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.apache.http.HttpHost;
@@ -34,6 +36,10 @@
 import org.elasticsearch.client.RestClient;
 import org.elasticsearch.client.RestClientBuilder;
 import org.elasticsearch.client.RestHighLevelClient;
+import org.elasticsearch.client.sniff.NodesSniffer;
+import org.elasticsearch.client.sniff.Sniffer;
+import org.elasticsearch.client.sniff.SnifferBuilder;
+import org.junit.Assert;
 import org.junit.jupiter.api.Test;
 import org.testcontainers.elasticsearch.ElasticsearchContainer;
 import org.testcontainers.junit.jupiter.Container;
@@ -220,6 +226,37 @@ void configureUriWithUsernameAndPasswordWhenUsernameAndPasswordPropertiesSet() {
 				});
 	}
 
+	@Test
+	void configureShouldOnlyCreateSnifferInstance() {
+		this.contextRunner.run(
+				(context) -> assertThat(context).doesNotHaveBean(RestClient.class)
+				.hasSingleBean(RestHighLevelClient.class));
+		this.contextRunner.run(
+				(context) -> assertThat(context).hasSingleBean(Sniffer.class));
+	}
+
+	@Test
+	void configureShouldHaveSnifferInstance() {
+		this.contextRunner.run(
+				(context) -> assertThat(context).doesNotHaveBean(RestClient.class)
+						.hasSingleBean(RestHighLevelClient.class));
+		this.contextRunner.run(
+				(context) -> {
+					assertThat(context).hasSingleBean(Sniffer.class);
+					Sniffer sniffer = context.getBean(Sniffer.class);
+					Assert.assertNotNull(sniffer);
+				});
+	}
+
+	@Test
+	void configureWithCustomSetIntervalProperties() {
+		this.contextRunner.withPropertyValues("spring.elasticsearch.sniff.sniffInterval=15s, " +
+				"spring.elasticsearch.sniff.sniffFailureDelay=15s").run((context) -> {
+			Sniffer sniffer = context.getBean(Sniffer.class);
+			Assert.assertNotNull(sniffer);
+			});
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class BuilderCustomizerConfiguration {