Introduce docker-test plugin for running tests that require Docker

See gh-41228

buildSrc/build.gradle

@@ -93,6 +93,10 @@ gradlePlugin {
 			id = "org.springframework.boot.deployed"
 			implementationClass = "org.springframework.boot.build.DeployedPlugin"
 		}
+		dockerTestPlugin {
+			id = "org.springframework.boot.docker-test"
+			implementationClass = "org.springframework.boot.build.test.DockerTestPlugin"
+		}
 		integrationTestPlugin {
 			id = "org.springframework.boot.integration-test"
 			implementationClass = "org.springframework.boot.build.test.IntegrationTestPlugin"

buildSrc/src/main/java/org/springframework/boot/build/mavenplugin/MavenPluginPlugin.java

@@ -87,6 +87,7 @@ import org.xml.sax.SAXException;
 
 import org.springframework.boot.build.DeployedPlugin;
 import org.springframework.boot.build.MavenRepositoryPlugin;
+import org.springframework.boot.build.test.DockerTestPlugin;
 import org.springframework.boot.build.test.IntegrationTestPlugin;
 import org.springframework.core.CollectionFactory;
 import org.springframework.util.Assert;
@@ -138,11 +139,15 @@ public class MavenPluginPlugin implements Plugin<Project> {
 			.set(new File(project.getBuildDir(), "runtime-classpath-repository"));
 		project.getDependencies()
 			.components((components) -> components.all(MavenRepositoryComponentMetadataRule.class));
-		Sync task = project.getTasks().create("populateIntTestMavenRepository", Sync.class);
-		task.setDestinationDir(new File(project.getBuildDir(), "int-test-maven-repository"));
+		Sync task = project.getTasks().create("populateTestMavenRepository", Sync.class);
+		task.setDestinationDir(new File(project.getBuildDir(), "test-maven-repository"));
 		task.with(copyIntTestMavenRepositoryFiles(project, runtimeClasspathMavenRepository));
 		task.dependsOn(project.getTasks().getByName(MavenRepositoryPlugin.PUBLISH_TO_PROJECT_REPOSITORY_TASK_NAME));
 		project.getTasks().getByName(IntegrationTestPlugin.INT_TEST_TASK_NAME).dependsOn(task);
+		project.getPlugins()
+			.withType(DockerTestPlugin.class)
+			.all((dockerTestPlugin) -> project.getTasks()
+				.named(DockerTestPlugin.DOCKER_TEST_TASK_NAME, (dockerTest) -> dockerTest.dependsOn(task)));
 	}
 
 	private CopySpec copyIntTestMavenRepositoryFiles(Project project,

buildSrc/src/main/java/org/springframework/boot/build/test/DockerTestBuildService.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2012-2024 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.build.test;
+
+import org.gradle.api.Project;
+import org.gradle.api.provider.Provider;
+import org.gradle.api.services.BuildService;
+import org.gradle.api.services.BuildServiceParameters;
+
+/**
+ * Build service for Docker-based tests. Configured to only allow serial execution,
+ * thereby ensuring that Docker-based tests do not run in parallel.
+ *
+ * @author Andy Wilkinson
+ */
+abstract class DockerTestBuildService implements BuildService<BuildServiceParameters.None> {
+
+	static Provider<DockerTestBuildService> registerIfNecessary(Project project) {
+		return project.getGradle()
+			.getSharedServices()
+			.registerIfAbsent("dockerTest", DockerTestBuildService.class, (spec) -> spec.getMaxParallelUsages().set(1));
+	}
+
+}

buildSrc/src/main/java/org/springframework/boot/build/test/DockerTestPlugin.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2012-2024 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.build.test;
+
+import org.gradle.api.Plugin;
+import org.gradle.api.Project;
+import org.gradle.api.plugins.JavaPlugin;
+import org.gradle.api.plugins.JavaPluginExtension;
+import org.gradle.api.provider.Provider;
+import org.gradle.api.services.BuildService;
+import org.gradle.api.tasks.SourceSet;
+import org.gradle.api.tasks.SourceSetContainer;
+import org.gradle.api.tasks.testing.Test;
+import org.gradle.language.base.plugins.LifecycleBasePlugin;
+import org.gradle.plugins.ide.eclipse.EclipsePlugin;
+import org.gradle.plugins.ide.eclipse.model.EclipseModel;
+
+/**
+ * Plugin for Docker-based tests. Creates a {@link SourceSet source set}, {@link Test
+ * test} task, and {@link BuildService shared service} named {@code dockerTest}. The build
+ * service is configured to only allow serial usage and the {@code dockerTest} task is
+ * configured to use the build service. In a parallel build, this ensures that only a
+ * single {@code dockerTest} task can run at any given time.
+ *
+ * @author Andy Wilkinson
+ */
+public class DockerTestPlugin implements Plugin<Project> {
+
+	/**
+	 * Name of the {@code dockerTest} task.
+	 */
+	public static String DOCKER_TEST_TASK_NAME = "dockerTest";
+
+	/**
+	 * Name of the {@code dockerTest} source set.
+	 */
+	public static String DOCKER_TEST_SOURCE_SET_NAME = "dockerTest";
+
+	/**
+	 * Name of the {@code dockerTest} shared service.
+	 */
+	public static String DOCKER_TEST_SERVICE_NAME = "dockerTest";
+
+	@Override
+	public void apply(Project project) {
+		project.getPlugins().withType(JavaPlugin.class, (javaPlugin) -> configureDockerTesting(project));
+	}
+
+	private void configureDockerTesting(Project project) {
+		Provider<DockerTestBuildService> buildService = DockerTestBuildService.registerIfNecessary(project);
+		SourceSet dockerTestSourceSet = createSourceSet(project);
+		Provider<Test> dockerTest = createTestTask(project, dockerTestSourceSet, buildService);
+		project.getTasks().getByName(LifecycleBasePlugin.CHECK_TASK_NAME).dependsOn(dockerTest);
+		project.getPlugins().withType(EclipsePlugin.class, (eclipsePlugin) -> {
+			EclipseModel eclipse = project.getExtensions().getByType(EclipseModel.class);
+			eclipse.classpath((classpath) -> classpath.getPlusConfigurations()
+				.add(project.getConfigurations()
+					.getByName(dockerTestSourceSet.getRuntimeClasspathConfigurationName())));
+		});
+	}
+
+	private SourceSet createSourceSet(Project project) {
+		SourceSetContainer sourceSets = project.getExtensions().getByType(JavaPluginExtension.class).getSourceSets();
+		SourceSet dockerTestSourceSet = sourceSets.create(DOCKER_TEST_SOURCE_SET_NAME);
+		SourceSet main = sourceSets.getByName(SourceSet.MAIN_SOURCE_SET_NAME);
+		SourceSet test = sourceSets.getByName(SourceSet.TEST_SOURCE_SET_NAME);
+		dockerTestSourceSet.setCompileClasspath(dockerTestSourceSet.getCompileClasspath()
+			.plus(main.getOutput())
+			.plus(main.getCompileClasspath())
+			.plus(test.getOutput()));
+		dockerTestSourceSet.setRuntimeClasspath(dockerTestSourceSet.getRuntimeClasspath()
+			.plus(main.getOutput())
+			.plus(main.getRuntimeClasspath())
+			.plus(test.getOutput()));
+		project.getPlugins().withType(IntegrationTestPlugin.class, (integrationTestPlugin) -> {
+			SourceSet intTest = sourceSets.getByName(IntegrationTestPlugin.INT_TEST_SOURCE_SET_NAME);
+			dockerTestSourceSet
+				.setCompileClasspath(dockerTestSourceSet.getCompileClasspath().plus(intTest.getOutput()));
+			dockerTestSourceSet
+				.setRuntimeClasspath(dockerTestSourceSet.getRuntimeClasspath().plus(intTest.getOutput()));
+		});
+		return dockerTestSourceSet;
+	}
+
+	private Provider<Test> createTestTask(Project project, SourceSet dockerTestSourceSet,
+			Provider<DockerTestBuildService> buildService) {
+		Provider<Test> dockerTest = project.getTasks().register(DOCKER_TEST_TASK_NAME, Test.class, (task) -> {
+			task.usesService(buildService);
+			task.setGroup(LifecycleBasePlugin.VERIFICATION_GROUP);
+			task.setDescription("Runs Docker-based tests.");
+			task.setTestClassesDirs(dockerTestSourceSet.getOutput().getClassesDirs());
+			task.setClasspath(dockerTestSourceSet.getRuntimeClasspath());
+			task.shouldRunAfter(JavaPlugin.TEST_TASK_NAME);
+		});
+		return dockerTest;
+	}
+
+}

src/checkstyle/checkstyle-suppressions.xml

@@ -59,6 +59,8 @@
 	<suppress files="[\\/]spring-boot-smoke-tests[\\/]spring-boot-smoke-test-testng[\\/]" checks="SpringJUnit5" />
 	<suppress files="[\\/]spring-boot-test-support[\\/]" checks="SpringJavadoc" message="\@since" />
 	<suppress files="[\\/]spring-boot-gradle-test-support[\\/]" checks="SpringJavadoc" message="\@since" />
+	<suppress files="[\\/]src[\\/]dockerTest[\\/]java[\\/]" checks="JavadocPackage" />
+	<suppress files="[\\/]src[\\/]dockerTest[\\/]java[\\/]" checks="SpringJavadoc" message="\@since" />
 	<suppress files="[\\/]src[\\/]intTest[\\/]java[\\/]" checks="JavadocPackage" />
 	<suppress files="[\\/]src[\\/]intTest[\\/]java[\\/]" checks="SpringJavadoc" message="\@since" />
 	<suppress files="[\\/]src[\\/]systemTest[\\/]java[\\/]" checks="JavadocPackage" />