fix: record option groups to metadata JAR

spring-cloud-dataflow-apps-plugin/spring-cloud-dataflow-apps-metadata-plugin/src/main/java/org/springframework/cloud/dataflow/app/plugin/MetadataAggregationMojo.java

@@ -134,7 +134,7 @@ public class MetadataAggregationMojo extends AbstractMojo {
 	private final JsonMarshaller jsonMarshaller = new JsonMarshaller();
 
 	public void execute() throws MojoExecutionException {
-		Result result = new Result(gatherConfigurationMetadata(null), gatherVisibleMetadata());
+		Result result = new Result(gatherConfigurationMetadata(null), gatherVisibleMetadata(), gatherOptionGroupsMetadata());
 		produceArtifact(result);
 
 		if (storeFilteredMetadata) {
@@ -332,6 +332,46 @@ else if (properties.containsKey(SPRING_CLOUD_STREAM_FUNCTION_DEFINITION)) {
 		return visible;
 	}
 
+	/**
+	 * Read all existing option groups metadata from this project runtime dependencies and merge them in a single object.
+	 */
+	/*default*/ Properties gatherOptionGroupsMetadata() throws MojoExecutionException {
+		Properties optionGroups = new Properties();
+		try {
+			for (String path : mavenProject.getRuntimeClasspathElements()) {
+				if (Files.isDirectory(Paths.get(path))) {
+					Path optionGroupsPath = Paths.get(path, "META-INF", SPRING_CLOUD_DATAFLOW_OPTION_GROUPS_PROPERTIES);
+					File optionGroupsFile = optionGroupsPath.toFile();
+					if (optionGroupsFile.canRead()) {
+						try (InputStream is = new FileInputStream(optionGroupsFile)) {
+							Properties properties = new Properties();
+							properties.load(is);
+							getLog().debug("Loading option groups from " + path);
+							optionGroups.putAll(properties);
+						}
+					}
+				}
+				else {
+					try (ZipFile zipFile = new ZipFile(new File(path))) {
+						ZipEntry entry = zipFile.getEntry("META-INF/" + SPRING_CLOUD_DATAFLOW_OPTION_GROUPS_PROPERTIES);
+						if (entry != null) {
+							try (InputStream inputStream = zipFile.getInputStream(entry)) {
+								Properties properties = new Properties();
+								properties.load(inputStream);
+								getLog().debug("Loading option groups from " + path);
+								optionGroups.putAll(properties);
+							}
+						}
+					}
+				}
+			}
+		}
+		catch (Exception e) {
+			throw new MojoExecutionException("Exception trying to read option groups metadata from dependencies of project", e);
+		}
+		return optionGroups;
+	}
+
 	/*default*/ ConfigurationMetadata gatherConfigurationMetadata(MetadataFilter metadataFilters)
 			throws MojoExecutionException {
 		ConfigurationMetadata metadata = new ConfigurationMetadata();
@@ -502,11 +542,11 @@ private void mergeCommaDelimitedValue(Properties currentProperties, Properties n
 
 			entry = new ZipEntry("META-INF/" + SPRING_CLOUD_DATAFLOW_PORT_MAPPING_PROPERTIES);
 			jos.putNextEntry(entry);
+			result.getPortMappingProperties().store(jos, "Describes visible port mapping properties for this app");
 
 			entry = new ZipEntry("META-INF/" + SPRING_CLOUD_DATAFLOW_OPTION_GROUPS_PROPERTIES);
 			jos.putNextEntry(entry);
-
-			result.getPortMappingProperties().store(jos, "Describes visible port mapping properties for this app");
+			result.getOptionGroupsProperties().store(jos, "Describes option groups for this app");
 
 			getLog().info(String.format("Attaching %s to current project", output.getCanonicalPath()));
 			projectHelper.attachArtifact(mavenProject, output, classifier);
@@ -630,6 +670,8 @@ public String toString() {
 
 		private final Properties visible;
 
+		private final Properties optionGroups;
+
 		private Properties getPortMappingProperties() {
 			Properties portMappingProperties = new Properties();
 			visible.entrySet().stream()
@@ -638,9 +680,14 @@ private Properties getPortMappingProperties() {
 			return portMappingProperties;
 		}
 
-		private Result(ConfigurationMetadata metadata, Properties visible) {
+		private Properties getOptionGroupsProperties() {
+			return optionGroups;
+		}
+
+		Result(ConfigurationMetadata metadata, Properties visible, Properties optionGroups) {
 			this.metadata = metadata;
 			this.visible = visible;
+			this.optionGroups = optionGroups;
 		}
 	}
 }

spring-cloud-dataflow-apps-plugin/spring-cloud-dataflow-apps-metadata-plugin/src/test/java/org/springframework/cloud/dataflow/app/plugin/OptionGroupsTest.java

@@ -0,0 +1,139 @@
+/*
+ * Copyright 2018-2025 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 org.springframework.cloud.dataflow.app.plugin;
+
+import java.io.File;
+import java.io.InputStream;
+import java.util.Properties;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+
+import org.apache.maven.project.MavenProject;
+import org.apache.maven.project.MavenProjectHelper;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.boot.configurationprocessor.metadata.ConfigurationMetadata;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.springframework.cloud.dataflow.app.plugin.MetadataAggregationMojo.CONFIGURATION_PROPERTIES_INBOUND_PORTS;
+import static org.springframework.cloud.dataflow.app.plugin.MetadataAggregationMojo.SPRING_CLOUD_DATAFLOW_OPTION_GROUPS_PROPERTIES;
+
+/**
+ * @author Max Brauer
+ */
+class OptionGroupsTest {
+
+	@TempDir
+	File tempDir;
+
+	@Test
+	void shouldWriteOptionGroupsToMetadataJar() throws Exception {
+		MetadataAggregationMojo mojo = new MetadataAggregationMojo();
+		MavenProject project = createMockMavenProject();
+		setField(mojo, "mavenProject", project);
+		setField(mojo, "projectHelper", mock(MavenProjectHelper.class));
+		setField(mojo, "classifier", "metadata");
+
+		ConfigurationMetadata metadata = new ConfigurationMetadata();
+
+		Properties ports = new Properties(); // no ports
+
+		Properties optionGroups = new Properties();
+		optionGroups.setProperty("com.vmware.tanzu.dataflow.configuration-properties.option-groups.common", "prop1,prop2,prop3");
+		optionGroups.setProperty("com.vmware.tanzu.dataflow.configuration-properties.option-groups.readers.filereader", "reader.prop1,reader.prop2");
+		optionGroups.setProperty("com.vmware.tanzu.dataflow.configuration-properties.option-groups.writers.filewriter", "writer.prop1,writer.prop2,writer.prop3");
+
+		MetadataAggregationMojo.Result result = new MetadataAggregationMojo.Result(metadata, ports, optionGroups);
+
+		mojo.produceArtifact(result);
+
+		File output = new File(tempDir, "target/test-artifact-1.0.0-SNAPSHOT-metadata.jar");
+		assertThat(output).exists();
+
+		try (ZipFile zipFile = new ZipFile(output)) {
+			ZipEntry optionGroupsEntry = zipFile.getEntry("META-INF/" + SPRING_CLOUD_DATAFLOW_OPTION_GROUPS_PROPERTIES);
+			assertThat(optionGroupsEntry).isNotNull();
+
+			Properties optionGroupsProps = new Properties();
+			try (InputStream is = zipFile.getInputStream(optionGroupsEntry)) {
+				optionGroupsProps.load(is);
+			}
+			assertThat(optionGroupsProps)
+					.as("Option groups file should contain option groups properties")
+					.containsKey("com.vmware.tanzu.dataflow.configuration-properties.option-groups.common")
+					.containsKey("com.vmware.tanzu.dataflow.configuration-properties.option-groups.readers.filereader")
+					.containsKey("com.vmware.tanzu.dataflow.configuration-properties.option-groups.writers.filewriter");
+			assertThat(optionGroupsProps.getProperty("com.vmware.tanzu.dataflow.configuration-properties.option-groups.common"))
+					.isEqualTo("prop1,prop2,prop3");
+		}
+	}
+
+	@Test
+	void shouldWriteEmptyOptionGroupsToMetadataJar() throws Exception {
+		MetadataAggregationMojo mojo = new MetadataAggregationMojo();
+		MavenProject project = createMockMavenProject();
+		setField(mojo, "mavenProject", project);
+		setField(mojo, "projectHelper", mock(MavenProjectHelper.class));
+		setField(mojo, "classifier", "metadata");
+
+		ConfigurationMetadata metadata = new ConfigurationMetadata();
+
+		Properties ports = new Properties(); // no ports
+		Properties optionGroups = new Properties(); // no option groups
+
+		MetadataAggregationMojo.Result result = new MetadataAggregationMojo.Result(metadata, ports, optionGroups);
+
+		mojo.produceArtifact(result);
+
+		File output = new File(tempDir, "target/test-artifact-1.0.0-SNAPSHOT-metadata.jar");
+		assertThat(output).exists();
+
+		try (ZipFile zipFile = new ZipFile(output)) {
+			ZipEntry optionGroupsEntry = zipFile.getEntry("META-INF/" + SPRING_CLOUD_DATAFLOW_OPTION_GROUPS_PROPERTIES);
+			assertThat(optionGroupsEntry)
+					.as("Option groups file should exist even when empty")
+					.isNotNull();
+
+			Properties optionGroupsProps = new Properties();
+			try (InputStream is = zipFile.getInputStream(optionGroupsEntry)) {
+				optionGroupsProps.load(is);
+			}
+			assertThat(optionGroupsProps)
+					.as("Option groups should be empty when no groups provided")
+					.isEmpty();
+		}
+	}
+
+	private MavenProject createMockMavenProject() {
+		MavenProject project = mock(MavenProject.class);
+		File targetDir = new File(tempDir, "target");
+		targetDir.mkdirs();
+		when(project.getBasedir()).thenReturn(tempDir);
+		when(project.getArtifactId()).thenReturn("test-artifact");
+		when(project.getVersion()).thenReturn("1.0.0-SNAPSHOT");
+		return project;
+	}
+
+	private void setField(Object target, String fieldName, Object value) throws Exception {
+		java.lang.reflect.Field field = target.getClass().getDeclaredField(fieldName);
+		field.setAccessible(true);
+		field.set(target, value);
+	}
+}