Allow testcontainer beans to also contribute properties

Allow `Container` bean definitions to inject a `DynamicPropertyRegistry`
so that they can contribute environment properties.

Closes gh-35201

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

@@ -1047,6 +1047,21 @@ You can now launch `TestMyApplication` as you would any regular Java `main` meth
 
 
 
+
+[[features.testing.testcontainers.at-development-time.dynamic-properties]]
+===== Contributing Dynamic Properties at Development Time
+If you want to contribute dynamic properties at development time from your `Container` `@Bean` methods, you can do so by injecting a `DynamicPropertyRegistry`.
+This works in a similar way to the <<features#features.testing.testcontainers.dynamic-properties,`@DynamicPropertySource` annotation>> that you can use in your tests.
+It allows you to add properties that will become available once your container has started.
+
+A typical configuration would look like this:
+
+include::code:MyContainersConfiguration[]
+
+NOTE: Using a `@ServiceConnection` is recommended whenever possible, however, dynamic properties can be a useful fallback for technologies that don't yet have `@ServiceConnection` support.
+
+
+
 [[features.testing.utilities]]
 === Test Utilities
 A few test utility classes that are generally useful when testing your application are packaged as part of `spring-boot`.

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/features/testing/testcontainers/atdevelopmenttime/dynamicproperties/MyContainersConfiguration.java

@@ -0,0 +1,36 @@
+/*
+ * 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.features.testing.testcontainers.atdevelopmenttime.dynamicproperties;
+
+import org.testcontainers.containers.MongoDBContainer;
+
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.test.context.DynamicPropertyRegistry;
+
+@TestConfiguration(proxyBeanMethods = false)
+public class MyContainersConfiguration {
+
+	@Bean
+	public MongoDBContainer monogDbContainer(DynamicPropertyRegistry properties) {
+		MongoDBContainer container = new MongoDBContainer("mongo:5.0");
+		properties.add("spring.data.mongodb.host", container::getHost);
+		properties.add("spring.data.mongodb.port", container::getFirstMappedPort);
+		return container;
+	}
+
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/features/testing/testcontainers/atdevelopmenttime/dynamicproperties/MyContainersConfiguration.kt

@@ -0,0 +1,35 @@
+/*
+ * 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.features.testing.testcontainers.atdevelopmenttime.dynamicproperties
+
+import org.springframework.boot.test.context.TestConfiguration
+import org.springframework.context.annotation.Bean;
+import org.springframework.test.context.DynamicPropertyRegistry
+import org.testcontainers.containers.MongoDBContainer
+
+@TestConfiguration(proxyBeanMethods = false)
+class MyContainersConfiguration {
+
+	@Bean
+	fun monogDbContainer(properties: DynamicPropertyRegistry): MongoDBContainer {
+		var container = MongoDBContainer("mongo:5.0")
+		properties.add("spring.data.mongodb.host", container::getHost);
+		properties.add("spring.data.mongodb.port", container::getFirstMappedPort);
+		return container
+	}
+
+}