Expose MongoDB's replica set name

Closes gh-20391

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoClientFactorySupport.java

@@ -68,14 +68,15 @@ public abstract class MongoClientFactorySupport<T> {
 		applyUuidRepresentation(settingsBuilder);
 		applyHostAndPort(settingsBuilder);
 		applyCredentials(settingsBuilder);
+		applyReplicaSet(settingsBuilder);
 		customize(settingsBuilder);
 		return settingsBuilder.build();
 	}
 
 	private void validateConfiguration() {
-		if (hasCustomAddress() || hasCustomCredentials()) {
+		if (hasCustomAddress() || hasCustomCredentials() || hasReplicaSet()) {
 			Assert.state(this.properties.getUri() == null,
-					"Invalid mongo configuration, either uri or host/port/credentials must be specified");
+					"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
 		}
 	}
 
@@ -109,6 +110,13 @@ public abstract class MongoClientFactorySupport<T> {
 		}
 	}
 
+	private void applyReplicaSet(Builder builder) {
+		if (hasReplicaSet()) {
+			builder.applyToClusterSettings(
+					(cluster) -> cluster.requiredReplicaSetName(this.properties.getReplicaSetName()));
+		}
+	}
+
 	private void customize(MongoClientSettings.Builder builder) {
 		for (MongoClientSettingsBuilderCustomizer customizer : this.builderCustomizers) {
 			customizer.customize(builder);
@@ -137,6 +145,10 @@ public abstract class MongoClientFactorySupport<T> {
 		return this.properties.getUsername() != null && this.properties.getPassword() != null;
 	}
 
+	private boolean hasReplicaSet() {
+		return this.properties.getReplicaSetName() != null;
+	}
+
 	private boolean hasCustomAddress() {
 		return this.properties.getHost() != null || this.properties.getPort() != null;
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/mongo/MongoProperties.java

@@ -59,7 +59,8 @@ public class MongoProperties {
 	private Integer port = null;
 
 	/**
-	 * Mongo database URI. Cannot be set with host, port and credentials.
+	 * Mongo database URI. Cannot be set with host, port, credentials and replica set
+	 * name.
 	 */
 	private String uri;
 
@@ -81,7 +82,6 @@ public class MongoProperties {
 	/**
 	 * Login user of the mongo server. Cannot be set with URI.
 	 */
-
 	private String username;
 
 	/**
@@ -89,6 +89,11 @@ public class MongoProperties {
 	 */
 	private char[] password;
 
+	/**
+	 * Required replica set name for the cluster. Cannot be set with URI.
+	 */
+	private String replicaSetName;
+
 	/**
 	 * Fully qualified name of the FieldNamingStrategy to use.
 	 */
@@ -144,6 +149,14 @@ public class MongoProperties {
 		this.password = password;
 	}
 
+	public String getReplicaSetName() {
+		return this.replicaSetName;
+	}
+
+	public void setReplicaSetName(String replicaSetName) {
+		this.replicaSetName = replicaSetName;
+	}
+
 	public Class<?> getFieldNamingStrategy() {
 		return this.fieldNamingStrategy;
 	}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoClientFactorySupportTests.java

@@ -51,9 +51,9 @@ import static org.mockito.Mockito.verify;
  */
 abstract class MongoClientFactorySupportTests<T> {
 
-	private MongoProperties properties = new MongoProperties();
+	private final MongoProperties properties = new MongoProperties();
 
-	private MockEnvironment environment = new MockEnvironment();
+	private final MockEnvironment environment = new MockEnvironment();
 
 	@Test
 	void canBindCharArrayPassword() {
@@ -128,6 +128,13 @@ abstract class MongoClientFactorySupportTests<T> {
 		assertMongoCredential(getClientSettings(client).getCredential(), "user", "secret", "test");
 	}
 
+	@Test
+	void replicaSetCanBeCustomized() {
+		this.properties.setReplicaSetName("test");
+		T client = createMongoClient();
+		assertThat(getClientSettings(client).getClusterSettings().getRequiredReplicaSetName()).isEqualTo("test");
+	}
+
 	@Test
 	void databaseCanBeCustomized() {
 		this.properties.setDatabase("foo");
@@ -193,7 +200,15 @@ abstract class MongoClientFactorySupportTests<T> {
 		this.properties.setUsername("user");
 		this.properties.setPassword("secret".toCharArray());
 		assertThatIllegalStateException().isThrownBy(this::createMongoClient).withMessageContaining(
-				"Invalid mongo configuration, either uri or host/port/credentials must be specified");
+				"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
+	}
+
+	@Test
+	void uriCannotBeSetWithReplicaSetName() {
+		this.properties.setUri("mongodb://127.0.0.1:1234/mydb");
+		this.properties.setReplicaSetName("test");
+		assertThatIllegalStateException().isThrownBy(this::createMongoClient).withMessageContaining(
+				"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
 	}
 
 	@Test
@@ -202,7 +217,7 @@ abstract class MongoClientFactorySupportTests<T> {
 		this.properties.setHost("localhost");
 		this.properties.setPort(4567);
 		assertThatIllegalStateException().isThrownBy(this::createMongoClient).withMessageContaining(
-				"Invalid mongo configuration, either uri or host/port/credentials must be specified");
+				"Invalid mongo configuration, either uri or host/port/credentials/replicaSet must be specified");
 	}
 
 	@Test
@@ -265,6 +280,10 @@ abstract class MongoClientFactorySupportTests<T> {
 		assertThat(properties.isAutoIndexCreation()).isTrue();
 	}
 
+	private List<ServerAddress> getAllAddresses(T client) {
+		return getClientSettings(client).getClusterSettings().getHosts();
+	}
+
 	protected T createMongoClient() {
 		return createMongoClient(this.properties, this.environment, null, null);
 	}
@@ -283,8 +302,6 @@ abstract class MongoClientFactorySupportTests<T> {
 
 	protected abstract MongoClientSettings getClientSettings(T client);
 
-	protected abstract List<ServerAddress> getAllAddresses(T client);
-
 	protected void assertServerAddress(ServerAddress serverAddress, String expectedHost, int expectedPort) {
 		assertThat(serverAddress.getHost()).isEqualTo(expectedHost);
 		assertThat(serverAddress.getPort()).isEqualTo(expectedPort);

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoClientFactoryTests.java

@@ -19,7 +19,6 @@ package org.springframework.boot.autoconfigure.mongo;
 import java.util.List;
 
 import com.mongodb.MongoClientSettings;
-import com.mongodb.ServerAddress;
 import com.mongodb.client.MongoClient;
 
 import org.springframework.core.env.Environment;
@@ -42,11 +41,6 @@ class MongoClientFactoryTests extends MongoClientFactorySupportTests<MongoClient
 		return new MongoClientFactory(properties, environment, customizers).createMongoClient(settings);
 	}
 
-	@Override
-	protected List<ServerAddress> getAllAddresses(MongoClient client) {
-		return client.getClusterDescription().getClusterSettings().getHosts();
-	}
-
 	@Override
 	protected MongoClientSettings getClientSettings(MongoClient client) {
 		return (MongoClientSettings) ReflectionTestUtils.getField(client, "settings");

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/ReactiveMongoClientFactoryTests.java

@@ -19,8 +19,6 @@ package org.springframework.boot.autoconfigure.mongo;
 import java.util.List;
 
 import com.mongodb.MongoClientSettings;
-import com.mongodb.ServerAddress;
-import com.mongodb.connection.ClusterSettings;
 import com.mongodb.internal.async.client.AsyncMongoClient;
 import com.mongodb.reactivestreams.client.MongoClient;
 
@@ -42,13 +40,6 @@ class ReactiveMongoClientFactoryTests extends MongoClientFactorySupportTests<Mon
 		return new ReactiveMongoClientFactory(properties, environment, customizers).createMongoClient(settings);
 	}
 
-	@Override
-	protected List<ServerAddress> getAllAddresses(MongoClient client) {
-		MongoClientSettings settings = getClientSettings(client);
-		ClusterSettings clusterSettings = settings.getClusterSettings();
-		return clusterSettings.getHosts();
-	}
-
 	@Override
 	protected MongoClientSettings getClientSettings(MongoClient client) {
 		AsyncMongoClient wrapped = (AsyncMongoClient) ReflectionTestUtils.getField(client, "wrapped");