Support image building with Gradle and war packaging

This commit updates the Gradle image building task to support building
images from executable and non-executable war files.

Fixes gh-23825

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/asciidoc/packaging-oci-image.adoc

 [[build-image]]
 == Packaging OCI Images
-The plugin can create an https://github.com/opencontainers/image-spec[OCI image] from an executable jar file using https://buildpacks.io[Cloud Native Buildpacks] (CNB).
+The plugin can create an https://github.com/opencontainers/image-spec[OCI image] from a jar or war file using https://buildpacks.io[Cloud Native Buildpacks] (CNB).
 Images can be built using the `bootBuildImage` task.
 
 NOTE: For security reasons, images build and run as non-root users.
 See the {buildpacks-reference}/reference/spec/platform-api/#users[CNB specification] for more details.
 
-The task is automatically created when the `java` plugin is applied and is an instance of {boot-build-image-javadoc}[`BootBuildImage`].
-
-NOTE: The `bootBuildImage` task is not supported with projects using <<packaging-executable-wars, war packaging>>.
+The task is automatically created when the `java` or `war` plugin is applied and is an instance of {boot-build-image-javadoc}[`BootBuildImage`].
 
 NOTE: The `bootBuildImage` task can not be used with a <<packaging-executable-configuring-launch-script, fully executable Spring Boot archive>> that includes a launch script.
 Disable launch script configuration in the `bootJar` task when building a jar file that is intended to be used with `bootBuildImage`.

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/JavaPluginAction.java

@@ -123,7 +123,7 @@ final class JavaPluginAction implements PluginApplicationAction {
 		project.getTasks().register(SpringBootPlugin.BOOT_BUILD_IMAGE_TASK_NAME, BootBuildImage.class, (buildImage) -> {
 			buildImage.setDescription("Builds an OCI image of the application using the output of the bootJar task");
 			buildImage.setGroup(BasePlugin.BUILD_GROUP);
-			buildImage.getJar().set(bootJar.get().getArchiveFile());
+			buildImage.getArchiveFile().set(bootJar.get().getArchiveFile());
 			buildImage.getTargetJavaVersion().set(javaPluginConvention(project).getTargetCompatibility());
 		});
 	}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/WarPluginAction.java

 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -22,7 +22,6 @@ import org.gradle.api.Project;
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.artifacts.ConfigurationContainer;
 import org.gradle.api.file.FileCollection;
-import org.gradle.api.file.RegularFile;
 import org.gradle.api.internal.artifacts.dsl.LazyPublishArtifact;
 import org.gradle.api.plugins.BasePlugin;
 import org.gradle.api.plugins.WarPlugin;
@@ -56,8 +55,8 @@ class WarPluginAction implements PluginApplicationAction {
 	@Override
 	public void execute(Project project) {
 		disableWarTask(project);
-		disableBootBuildImageTask(project);
 		TaskProvider<BootWar> bootWar = configureBootWarTask(project);
+		configureBootBuildImageTask(project, bootWar);
 		configureArtifactPublication(bootWar);
 	}
 
@@ -65,11 +64,6 @@ class WarPluginAction implements PluginApplicationAction {
 		project.getTasks().named(WarPlugin.WAR_TASK_NAME).configure((war) -> war.setEnabled(false));
 	}
 
-	private void disableBootBuildImageTask(Project project) {
-		project.getTasks().named(SpringBootPlugin.BOOT_BUILD_IMAGE_TASK_NAME, BootBuildImage.class)
-				.configure((buildImage) -> buildImage.getJar().set((RegularFile) null));
-	}
-
 	private TaskProvider<BootWar> configureBootWarTask(Project project) {
 		Configuration developmentOnly = project.getConfigurations()
 				.getByName(SpringBootPlugin.DEVELOPMENT_ONLY_CONFIGURATION_NAME);
@@ -103,6 +97,11 @@ class WarPluginAction implements PluginApplicationAction {
 		return configurations.getByName(WarPlugin.PROVIDED_RUNTIME_CONFIGURATION_NAME);
 	}
 
+	private void configureBootBuildImageTask(Project project, TaskProvider<BootWar> bootWar) {
+		project.getTasks().named(SpringBootPlugin.BOOT_BUILD_IMAGE_TASK_NAME, BootBuildImage.class)
+				.configure((buildImage) -> buildImage.getArchiveFile().set(bootWar.get().getArchiveFile()));
+	}
+
 	private void configureArtifactPublication(TaskProvider<BootWar> bootWar) {
 		LazyPublishArtifact artifact = new LazyPublishArtifact(bootWar);
 		this.singlePublishedArtifact.addCandidate(artifact);

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImage.java

@@ -68,7 +68,7 @@ public class BootBuildImage extends DefaultTask {
 
 	private final Property<String> projectVersion;
 
-	private RegularFileProperty jar;
+	private RegularFileProperty archiveFile;
 
 	private Property<JavaVersion> targetJavaVersion;
 
@@ -95,7 +95,7 @@ public class BootBuildImage extends DefaultTask {
 	private final DockerSpec docker = new DockerSpec();
 
 	public BootBuildImage() {
-		this.jar = getProject().getObjects().fileProperty();
+		this.archiveFile = getProject().getObjects().fileProperty();
 		this.targetJavaVersion = getProject().getObjects().property(JavaVersion.class);
 		this.projectName = getProject().getName();
 		this.projectVersion = getProject().getObjects().property(String.class);
@@ -106,13 +106,22 @@ public class BootBuildImage extends DefaultTask {
 	}
 
 	/**
-	 * Returns the property for the jar file from which the image will be built.
-	 * @return the jar property
+	 * Returns the property for the archive file from which the image will be built.
+	 * @return the archive file property
+	 */
+	@Input
+	public RegularFileProperty getArchiveFile() {
+		return this.archiveFile;
+	}
+
+	/**
+	 * Returns the property for the archive file from which the image will be built.
+	 * @return the archive file property
+	 * @deprecated since 2.5.0 in favor of {@link #getArchiveFile()}
 	 */
 	@Input
-	@Optional
 	public RegularFileProperty getJar() {
-		return this.jar;
+		return this.archiveFile;
 	}
 
 	/**
@@ -396,17 +405,14 @@ public class BootBuildImage extends DefaultTask {
 
 	@TaskAction
 	void buildImage() throws DockerEngineException, IOException {
-		if (!this.jar.isPresent()) {
-			throw new GradleException("Executable jar file required for building image");
-		}
-		BuildRequest request = createRequest();
 		Builder builder = new Builder(this.docker.asDockerConfiguration());
+		BuildRequest request = createRequest();
 		builder.build(request);
 	}
 
 	BuildRequest createRequest() {
 		return customize(BuildRequest.of(determineImageReference(),
-				(owner) -> new ZipFileTarArchive(this.jar.get().getAsFile(), owner)));
+				(owner) -> new ZipFileTarArchive(this.archiveFile.get().getAsFile(), owner)));
 	}
 
 	private ImageReference determineImageReference() {

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImageIntegrationTests.java

@@ -79,6 +79,47 @@ class BootBuildImageIntegrationTests {
 		}
 	}
 
+	@TestTemplate
+	void buildsImageWithWarPackaging() throws IOException {
+		writeMainClass();
+		writeLongNameResource();
+		BuildResult result = this.gradleBuild.build("bootBuildImage", "-PapplyWarPlugin",
+				"--pullPolicy=IF_NOT_PRESENT");
+		String projectName = this.gradleBuild.getProjectDir().getName();
+		assertThat(result.task(":bootBuildImage").getOutcome()).isEqualTo(TaskOutcome.SUCCESS);
+		assertThat(result.getOutput()).contains("docker.io/library/" + projectName);
+		File buildLibs = new File(this.gradleBuild.getProjectDir(), "build/libs");
+		assertThat(buildLibs.listFiles())
+				.containsExactly(new File(buildLibs, this.gradleBuild.getProjectDir().getName() + ".war"));
+		ImageReference imageReference = ImageReference.of(ImageName.of(projectName));
+		try (GenericContainer<?> container = new GenericContainer<>(imageReference.toString())) {
+			container.waitingFor(Wait.forLogMessage("Launched\\n", 1)).start();
+		}
+		finally {
+			new DockerApi().image().remove(imageReference, false);
+		}
+	}
+
+	@TestTemplate
+	void buildsImageWithWarPackagingAndJarConfiguration() throws IOException {
+		writeMainClass();
+		writeLongNameResource();
+		BuildResult result = this.gradleBuild.build("bootBuildImage", "--pullPolicy=IF_NOT_PRESENT");
+		String projectName = this.gradleBuild.getProjectDir().getName();
+		assertThat(result.task(":bootBuildImage").getOutcome()).isEqualTo(TaskOutcome.SUCCESS);
+		assertThat(result.getOutput()).contains("docker.io/library/" + projectName);
+		File buildLibs = new File(this.gradleBuild.getProjectDir(), "build/libs");
+		assertThat(buildLibs.listFiles())
+				.containsExactly(new File(buildLibs, this.gradleBuild.getProjectDir().getName() + ".war"));
+		ImageReference imageReference = ImageReference.of(ImageName.of(projectName));
+		try (GenericContainer<?> container = new GenericContainer<>(imageReference.toString())) {
+			container.waitingFor(Wait.forLogMessage("Launched\\n", 1)).start();
+		}
+		finally {
+			new DockerApi().image().remove(imageReference, false);
+		}
+	}
+
 	@TestTemplate
 	void buildsImageWithCustomName() throws IOException {
 		writeMainClass();
@@ -267,15 +308,6 @@ class BootBuildImageIntegrationTests {
 		assertThat(result.getOutput()).contains("requires docker.publishRegistry");
 	}
 
-	@TestTemplate
-	void failsWithWarPackaging() throws IOException {
-		writeMainClass();
-		writeLongNameResource();
-		BuildResult result = this.gradleBuild.buildAndFail("bootBuildImage", "-PapplyWarPlugin");
-		assertThat(result.task(":bootBuildImage").getOutcome()).isEqualTo(TaskOutcome.FAILED);
-		assertThat(result.getOutput()).contains("Executable jar file required for building image");
-	}
-
 	@TestTemplate
 	void failsWithBuildpackNotInBuilder() throws IOException {
 		writeMainClass();
@@ -285,26 +317,6 @@ class BootBuildImageIntegrationTests {
 		assertThat(result.getOutput()).contains("'urn:cnb:builder:example/does-not-exist:0.0.1' not found in builder");
 	}
 
-	@TestTemplate
-	void buildsImageWithWarPackagingAndJarConfiguration() throws IOException {
-		writeMainClass();
-		writeLongNameResource();
-		BuildResult result = this.gradleBuild.build("bootBuildImage", "--pullPolicy=IF_NOT_PRESENT");
-		String projectName = this.gradleBuild.getProjectDir().getName();
-		assertThat(result.task(":bootBuildImage").getOutcome()).isEqualTo(TaskOutcome.SUCCESS);
-		assertThat(result.getOutput()).contains("docker.io/library/" + projectName);
-		File buildLibs = new File(this.gradleBuild.getProjectDir(), "build/libs");
-		assertThat(buildLibs.listFiles())
-				.containsExactly(new File(buildLibs, this.gradleBuild.getProjectDir().getName() + ".war"));
-		ImageReference imageReference = ImageReference.of(ImageName.of(projectName));
-		try (GenericContainer<?> container = new GenericContainer<>(imageReference.toString())) {
-			container.waitingFor(Wait.forLogMessage("Launched\\n", 1)).start();
-		}
-		finally {
-			new DockerApi().image().remove(imageReference, false);
-		}
-	}
-
 	private void writeMainClass() throws IOException {
 		File examplePackage = new File(this.gradleBuild.getProjectDir(), "src/main/java/example");
 		examplePackage.mkdirs();