Initialize containers first and destroy them last

Update `TestcontainersLifecycleBeanPostProcessor` so that on
initialization of the first bean all `Container` instances are started.

With this update all `Container` beans will be started first in the
`preInstantiateSingletons` phase and destroyed last.

Closes gh-35223

spring-boot-project/spring-boot-testcontainers/src/main/java/org/springframework/boot/testcontainers/lifecycle/TestcontainersLifecycleBeanPostProcessor.java

@@ -16,6 +16,14 @@
 
 package org.springframework.boot.testcontainers.lifecycle;
 
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.testcontainers.containers.ContainerState;
 import org.testcontainers.containers.GenericContainer;
 import org.testcontainers.lifecycle.Startable;
 
@@ -27,10 +35,16 @@ import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.config.DestructionAwareBeanPostProcessor;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
+import org.springframework.core.log.LogMessage;
 
 /**
  * {@link BeanPostProcessor} to manage the lifecycle of {@link Startable startable
  * containers}.
+ * <p>
+ * As well as starting containers, this {@link BeanPostProcessor} will also ensure that
+ * all containers are started as early as possible in the
+ * {@link ConfigurableListableBeanFactory#preInstantiateSingletons() pre-instantiate
+ * singletons} phase.
  *
  * @author Phillip Webb
  * @author Stephane Nicoll
@@ -39,7 +53,11 @@ import org.springframework.core.annotation.Order;
 @Order(Ordered.LOWEST_PRECEDENCE)
 class TestcontainersLifecycleBeanPostProcessor implements DestructionAwareBeanPostProcessor {
 
-	private final ConfigurableListableBeanFactory beanFactory;
+	private static final Log logger = LogFactory.getLog(TestcontainersLifecycleBeanPostProcessor.class);
+
+	private ConfigurableListableBeanFactory beanFactory;
+
+	private AtomicBoolean initializedContainers = new AtomicBoolean();
 
 	TestcontainersLifecycleBeanPostProcessor(ConfigurableListableBeanFactory beanFactory) {
 		this.beanFactory = beanFactory;
@@ -50,9 +68,24 @@ class TestcontainersLifecycleBeanPostProcessor implements DestructionAwareBeanPo
 		if (bean instanceof Startable startable) {
 			startable.start();
 		}
+		if (this.beanFactory.isConfigurationFrozen()) {
+			initializeContainers();
+		}
 		return bean;
 	}
 
+	private void initializeContainers() {
+		if (this.initializedContainers.compareAndSet(false, true)) {
+			Set<String> beanNames = new LinkedHashSet<>();
+			beanNames.addAll(List.of(this.beanFactory.getBeanNamesForType(ContainerState.class, false, false)));
+			beanNames.addAll(List.of(this.beanFactory.getBeanNamesForType(Startable.class, false, false)));
+			for (String beanName : beanNames) {
+				logger.debug(LogMessage.format("Initializing container bean '%s'", beanName));
+				this.beanFactory.getBean(beanName);
+			}
+		}
+	}
+
 	@Override
 	public boolean requiresDestruction(Object bean) {
 		return bean instanceof Startable;

spring-boot-project/spring-boot-testcontainers/src/test/java/org/springframework/boot/testcontainers/lifecycle/TestcontainersLifecycleOrderIntegrationTests.java

@@ -0,0 +1,113 @@
+/*
+ * 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.testcontainers.lifecycle;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+import org.springframework.boot.testcontainers.lifecycle.TestcontainersLifecycleOrderIntegrationTests.AssertingSpringExtension;
+import org.springframework.boot.testcontainers.lifecycle.TestcontainersLifecycleOrderIntegrationTests.ContainerConfig;
+import org.springframework.boot.testcontainers.lifecycle.TestcontainersLifecycleOrderIntegrationTests.TestConfig;
+import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
+import org.springframework.boot.testsupport.testcontainers.RedisContainer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests for {@link TestcontainersLifecycleApplicationContextInitializer} to
+ * ensure create and destroy events happen in the correct order.
+ *
+ * @author Phillip Webb
+ */
+@ExtendWith(AssertingSpringExtension.class)
+@ContextConfiguration(classes = { TestConfig.class, ContainerConfig.class })
+@DirtiesContext
+public class TestcontainersLifecycleOrderIntegrationTests {
+
+	static List<String> events = Collections.synchronizedList(new ArrayList<>());
+
+	@Test
+	void eventsAreOrderedCorrectlyAfterStartup() {
+		assertThat(events).containsExactly("start-container", "create-bean");
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class ContainerConfig {
+
+		@Bean
+		@ServiceConnection("redis")
+		RedisContainer redisContainer() {
+			return new RedisContainer() {
+
+				@Override
+				public void start() {
+					events.add("start-container");
+					super.start();
+				}
+
+				@Override
+				public void stop() {
+					events.add("stop-container");
+					super.stop();
+				}
+
+			};
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class TestConfig {
+
+		@Bean
+		TestBean testBean() {
+			events.add("create-bean");
+			return new TestBean();
+		}
+
+	}
+
+	static class TestBean implements AutoCloseable {
+
+		@Override
+		public void close() throws Exception {
+			events.add("destroy-bean");
+		}
+
+	}
+
+	static class AssertingSpringExtension extends SpringExtension {
+
+		@Override
+		public void afterAll(ExtensionContext context) throws Exception {
+			super.afterAll(context);
+			assertThat(events).containsExactly("start-container", "create-bean", "destroy-bean", "stop-container");
+		}
+
+	}
+
+}