Enable the configuration of arbitrary Elasticsearch client properties

Previously, only a handful of properties could be set when
auto-configuring an Elasticsearch client. This commit introduces support
for configuring arbitrary properties using the
spring.data.elasticsearch.properties prefix. For example,
client.transport.sniff can be configured using
spring.data.elasticsearch.properties.client.transport.sniff.

Closes gh-1838

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

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.elasticsearch;
 
+import java.util.Properties;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.elasticsearch.client.Client;
@@ -75,8 +77,9 @@ public class ElasticsearchAutoConfiguration implements DisposableBean {
 	}
 
 	private Client createNodeClient() throws Exception {
-		ImmutableSettings.Builder settings = ImmutableSettings.settingsBuilder().put(
-				"http.enabled", String.valueOf(false));
+		ImmutableSettings.Builder settings = ImmutableSettings.settingsBuilder()
+				.put("http.enabled", String.valueOf(false))
+				.put(this.properties.getProperties());
 		Node node = new NodeBuilder().settings(settings)
 				.clusterName(this.properties.getClusterName()).local(true).node();
 		this.releasable = node;
@@ -85,15 +88,21 @@ public class ElasticsearchAutoConfiguration implements DisposableBean {
 
 	private Client createTransportClient() throws Exception {
 		TransportClientFactoryBean factory = new TransportClientFactoryBean();
-		factory.setClusterName(this.properties.getClusterName());
 		factory.setClusterNodes(this.properties.getClusterNodes());
-		factory.setClientTransportSniff(this.properties.getClientTransportSniff());
+		factory.setProperties(createProperties());
 		factory.afterPropertiesSet();
 		TransportClient client = factory.getObject();
 		this.releasable = client;
 		return client;
 	}
 
+	private Properties createProperties() {
+		Properties properties = new Properties();
+		properties.put("cluster.name", this.properties.getClusterName());
+		properties.putAll(this.properties.getProperties());
+		return properties;
+	}
+
 	@Override
 	public void destroy() throws Exception {
 		if (this.releasable != null) {

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

@@ -16,6 +16,9 @@
 
 package org.springframework.boot.autoconfigure.elasticsearch;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 /**
@@ -40,9 +43,9 @@ public class ElasticsearchProperties {
 	private String clusterNodes;
 
 	/**
-	 * Allow the client to sniff for other members of the cluster.
+	 * Additional properties used to configure the client
 	 */
-	private boolean clientTransportSniff = true;
+	private Map<String, String> properties = new HashMap<String, String>();
 
 	public String getClusterName() {
 		return this.clusterName;
@@ -60,12 +63,12 @@ public class ElasticsearchProperties {
 		this.clusterNodes = clusterNodes;
 	}
 
-	public boolean getClientTransportSniff() {
-		return this.clientTransportSniff;
+	public Map<String, String> getProperties() {
+		return this.properties;
 	}
 
-	public void setClientTransportSniff(boolean clientTransportSniff) {
-		this.clientTransportSniff = clientTransportSniff;
+	public void setProperties(Map<String, String> properties) {
+		this.properties = properties;
 	}
 
 }

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

@@ -27,7 +27,9 @@ import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfigurati
 import org.springframework.boot.test.EnvironmentTestUtils;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
+import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.is;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 
@@ -52,11 +54,16 @@ public class ElasticsearchAutoConfigurationTests {
 
 	@Test
 	public void createNodeClient() {
-		this.context = new AnnotationConfigApplicationContext(
-				PropertyPlaceholderAutoConfiguration.class,
+		this.context = new AnnotationConfigApplicationContext();
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.data.elasticsearch.properties.foo.bar:baz");
+		this.context.register(PropertyPlaceholderAutoConfiguration.class,
 				ElasticsearchAutoConfiguration.class);
+		this.context.refresh();
 		assertEquals(1, this.context.getBeanNamesForType(Client.class).length);
-		assertThat(this.context.getBean(Client.class), instanceOf(NodeClient.class));
+		Client client = this.context.getBean(Client.class);
+		assertThat(client, instanceOf(NodeClient.class));
+		assertThat(((NodeClient) client).settings().get("foo.bar"), is(equalTo("baz")));
 	}
 
 	@Test

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -349,9 +349,9 @@ content into your application; rather pick only the properties that you need.
 	spring.data.solr.repositories.enabled=true # if spring data repository support is enabled
 
 	# ELASTICSEARCH ({sc-spring-boot-autoconfigure}/elasticsearch/ElasticsearchProperties.{sc-ext}[ElasticsearchProperties])
-	spring.data.elasticsearch.client-transport-sniff=true # Allow the client to sniff for other members of the cluster
 	spring.data.elasticsearch.cluster-name= # The cluster name (defaults to elasticsearch)
 	spring.data.elasticsearch.cluster-nodes= # The address(es) of the server node (comma-separated; if not specified starts a client node)
+	spring.data.elasticsearch.properties.*= # Additional properties used to configure the client
 	spring.data.elasticsearch.repositories.enabled=true # if spring data repository support is enabled
 
 	# DATA REST ({spring-data-rest-javadoc}/core/config/RepositoryRestConfiguration.{dc-ext}[RepositoryRestConfiguration])