Customize the Buildpacks builder when using kafka-streams

If kafka-streams is selected, the builder is set to 'paketobuildpacks/builder-jammy-base:latest'.

Closes gh-1695

start-site/src/main/java/io/spring/start/site/extension/dependency/springkafka/SpringKafkaProjectGenerationConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -17,6 +17,9 @@
 package io.spring.start.site.extension.dependency.springkafka;
 
 import io.spring.initializr.generator.buildsystem.Build;
+import io.spring.initializr.generator.buildsystem.gradle.GradleBuildSystem;
+import io.spring.initializr.generator.buildsystem.maven.MavenBuildSystem;
+import io.spring.initializr.generator.condition.ConditionalOnBuildSystem;
 import io.spring.initializr.generator.condition.ConditionalOnRequestedDependency;
 import io.spring.initializr.generator.project.ProjectDescription;
 import io.spring.initializr.generator.project.ProjectGenerationConfiguration;
@@ -33,6 +36,7 @@
  *
  * @author Stephane Nicoll
  * @author Eddú Meléndez
+ * @author Moritz Halbritter
  */
 @ProjectGenerationConfiguration
 class SpringKafkaProjectGenerationConfiguration {
@@ -73,6 +77,27 @@ ServiceConnectionsCustomizer kafkaServiceConnectionsCustomizer(Build build, Dock
 		};
 	}
 
+	@Bean
+	@ConditionalOnRequestedDependency("kafka-streams")
+	@ConditionalOnBuildSystem(MavenBuildSystem.ID)
+	SpringKafkaStreamsMavenBuildCustomizer springKafkaStreamsMavenBuildCustomizer() {
+		return new SpringKafkaStreamsMavenBuildCustomizer();
+	}
+
+	@Bean
+	@ConditionalOnRequestedDependency("kafka-streams")
+	@ConditionalOnBuildSystem(id = GradleBuildSystem.ID, dialect = GradleBuildSystem.DIALECT_GROOVY)
+	SpringKafkaStreamsGradleBuildCustomizer springKafkaStreamsGradleBuildCustomizer() {
+		return new SpringKafkaStreamsGradleBuildCustomizer('\'');
+	}
+
+	@Bean
+	@ConditionalOnRequestedDependency("kafka-streams")
+	@ConditionalOnBuildSystem(id = GradleBuildSystem.ID, dialect = GradleBuildSystem.DIALECT_KOTLIN)
+	SpringKafkaStreamsGradleBuildCustomizer springKafkaStreamsGradleKotlinBuildCustomizer() {
+		return new SpringKafkaStreamsGradleBuildCustomizer('\"');
+	}
+
 	private boolean isKafkaEnabled(Build build) {
 		return build.dependencies().has("kafka") || build.dependencies().has("kafka-streams");
 	}

start-site/src/main/java/io/spring/start/site/extension/dependency/springkafka/SpringKafkaStreamsGradleBuildCustomizer.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2012-2025 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 io.spring.start.site.extension.dependency.springkafka;
+
+import io.spring.initializr.generator.buildsystem.gradle.GradleBuild;
+import io.spring.initializr.generator.spring.build.BuildCustomizer;
+
+/**
+ * {@link BuildCustomizer} for Gradle builds to configure the buildpack builder.
+ *
+ * @author Moritz Halbritter
+ */
+class SpringKafkaStreamsGradleBuildCustomizer implements BuildCustomizer<GradleBuild> {
+
+	private static final String BUILDER = "paketobuildpacks/builder-jammy-base:latest";
+
+	private final char quote;
+
+	SpringKafkaStreamsGradleBuildCustomizer(char quote) {
+		this.quote = quote;
+	}
+
+	@Override
+	public void customize(GradleBuild build) {
+		build.tasks()
+			.customize("bootBuildImage",
+					(bootBuildImage) -> bootBuildImage.attribute("builder", this.quote + BUILDER + this.quote));
+	}
+
+}

start-site/src/main/java/io/spring/start/site/extension/dependency/springkafka/SpringKafkaStreamsMavenBuildCustomizer.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2012-2025 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 io.spring.start.site.extension.dependency.springkafka;
+
+import io.spring.initializr.generator.buildsystem.maven.MavenBuild;
+import io.spring.initializr.generator.spring.build.BuildCustomizer;
+
+/**
+ * {@link BuildCustomizer} for Maven builds to configure the buildpack builder.
+ *
+ * @author Moritz Halbritter
+ */
+class SpringKafkaStreamsMavenBuildCustomizer implements BuildCustomizer<MavenBuild> {
+
+	private static final String BUILDER = "paketobuildpacks/builder-jammy-base:latest";
+
+	@Override
+	public void customize(MavenBuild build) {
+		build.plugins()
+			.add("org.springframework.boot", "spring-boot-maven-plugin", (plugin) -> plugin.configuration(
+					(configuration) -> configuration.configure("image", (image) -> image.add("builder", BUILDER))));
+	}
+
+}

start-site/src/test/java/io/spring/start/site/extension/dependency/springkafka/SpringKafkaProjectGenerationConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -28,6 +28,7 @@
  *
  * @author Wonwoo Lee
  * @author Stephane Nicoll
+ * @author Moritz Halbritter
  */
 class SpringKafkaProjectGenerationConfigurationTests extends AbstractExtensionTests {
 
@@ -49,4 +50,40 @@ void springKafkaTestIsNotAddedWithoutKafka() {
 			.hasDependenciesSize(2);
 	}
 
+	@Test
+	void customizesBuildpacksBuilderWhenUsingMavenAndKafkaStreams() {
+		ProjectRequest request = createProjectRequest("kafka-streams");
+		assertThat(mavenPom(request)).containsIgnoringWhitespaces("""
+				<plugin>
+					<groupId>org.springframework.boot</groupId>
+					<artifactId>spring-boot-maven-plugin</artifactId>
+					<configuration>
+						<image>
+							<builder>paketobuildpacks/builder-jammy-base:latest</builder>
+						</image>
+					</configuration>
+				</plugin>
+				""");
+	}
+
+	@Test
+	void customizesBuildpacksBuilderWhenUsingGradleGroovyAndKafkaStreams() {
+		ProjectRequest request = createProjectRequest("kafka-streams");
+		assertThat(gradleBuild(request)).containsIgnoringWhitespaces("""
+				tasks.named('bootBuildImage') {
+					builder = 'paketobuildpacks/builder-jammy-base:latest'
+				}
+				""");
+	}
+
+	@Test
+	void customizesBuildpacksBuilderWhenUsingGradleKotlinAndKafkaStreams() {
+		ProjectRequest request = createProjectRequest("kafka-streams");
+		assertThat(gradleKotlinDslBuild(request)).containsIgnoringWhitespaces("""
+				tasks.bootBuildImage {
+				    builder = "paketobuildpacks/builder-jammy-base:latest"
+				}
+				""");
+	}
+
 }