Create service connections from Testcontainers-managed containers

Building upon the auto-configuration support for service connections,
this commit adds support for deriving connection details from a
Testcontainers-managed container. Several service-specific
annotations have been introduced. These annotations can be used on a
container field to indicate that it is a source of the details for
a service connection.

See gh-34658

Co-Authored-By: Phillip Webb <pwebb@vmware.com>
Co-Authored-By: Mortitz Halbritter <mkammerer@vmware.com>

spring-boot-project/spring-boot-docs/src/docs/asciidoc/howto/testing.adoc

@@ -29,11 +29,46 @@ Testcontainers can be used in a Spring Boot test as follows:
 include::code:vanilla/MyIntegrationTests[]
 
 This will start up a docker container running Neo4j (if Docker is running locally) before any of the tests are run.
-In most cases, you will need to configure the application using details from the running container, such as container IP or port.
+In most cases, you will need to configure the application to connect to the service running in the container.
 
-This can be done with a static `@DynamicPropertySource` method that allows adding dynamic property values to the Spring Environment.
 
-include::code:dynamicproperties/MyIntegrationTests[]
+[[howto.testing.testcontainers.service-connections]]
+==== Service Connections
+A service connection is a connection to any remote service.
+Spring Boot's auto-configuration can consume the details of a service connection and use them to establish a connection to a remote service.
+When doing so, the connection details take precedence over any connection-related configuration properties.
+
+When using Testcontainers, connection details can be automatically created for a service running in a container by annotating the container field in the test class.
+
+include::code:MyIntegrationTests[]
+
+Thanks to `@Neo4jServiceConnection`, the above configuration allows Neo4j-related beans in the application to communicate with Neo4j running inside the Testcontainers-managed Docker container.
+This is done by automatically defining a `Neo4jConnectionDetails` bean which is then used by the Neo4j auto-configuration, overriding any connection-related configuration properties.
+
+The following service connection annotations are provided by `spring-boot-test-autoconfigure`:
+
+- `@CassandraServiceConnection`
+- `@CouchbaseServiceConnection`
+- `@ElasticsearchServiceConnection`
+- `@InfluxDbServiceConnection`
+- `@JdbcServiceConnection`
+- `@KafkaServiceConnection`
+- `@MongoServiceConnection`
+- `@Neo4jServiceConnection`
+- `@R2dbcServiceConnection`
+- `@RabbitServiceConnection`
+- `@RedisServiceConnection`
+
+As with the earlier `@Neo4jConnectionDetails` example, each can be used on a container field. Doing so will automatically configure the application to connect to the service running in the container.
+
+
+
+[[howto.testing.testcontainers.dynamic-properties]]
+==== Dynamic Properties
+A slightly more verbose but also more flexible alternative to service connections is `@DynamicPropertySource`.
+A static `@DynamicPropertySource` method allows adding dynamic property values to the Spring Environment.
+
+include::code:/MyIntegrationTests[]
 
 The above configuration allows Neo4j-related beans in the application to communicate with Neo4j running inside the Testcontainers-managed Docker container.
 

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/howto/testing/testcontainers/serviceconnections/MyIntegrationTests.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012-2023 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.docs.howto.testing.testcontainers.serviceconnections;
+
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.Neo4jContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import org.springframework.boot.test.autoconfigure.neo4j.Neo4jServiceConnection;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+@Testcontainers
+class MyIntegrationTests {
+
+	@Container
+	@Neo4jServiceConnection
+	static Neo4jContainer<?> neo4j = new Neo4jContainer<>("neo4j:4.2");
+
+	@Test
+	void myTest() {
+		// ...
+	}
+
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/howto/testing/testcontainers/serviceconnections/MyIntegrationTests.kt

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2012-2023 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.docs.howto.testing.testcontainers.serviceconnection
+
+import org.junit.jupiter.api.Test
+import org.springframework.boot.test.autoconfigure.neo4j.Neo4jServiceConnection;
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.test.context.DynamicPropertyRegistry
+import org.springframework.test.context.DynamicPropertySource
+import org.testcontainers.containers.Neo4jContainer
+import org.testcontainers.junit.jupiter.Container
+import org.testcontainers.junit.jupiter.Testcontainers
+
+@SpringBootTest
+@Testcontainers
+internal class MyIntegrationTests {
+
+	@Test
+	fun myTest() {
+		// ...
+	}
+
+	companion object {
+
+		@Container
+		@Neo4jServiceConnection
+		var neo4j: Neo4jContainer<*> = Neo4jContainer<Nothing>("neo4j:4.2")
+
+	}
+
+}