Tolerate actuator endpoints with the same id

Closes gh-39249

Author: mhalbritter

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/ConfigurationMetadataAnnotationProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * 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.
@@ -59,6 +59,7 @@
  * @author Kris De Volder
  * @author Jonas Keßler
  * @author Scott Frederick
+ * @author Moritz Halbritter
  * @since 1.2.0
  */
 @SupportedAnnotationTypes({ ConfigurationMetadataAnnotationProcessor.AUTO_CONFIGURATION_ANNOTATION,
@@ -291,18 +292,30 @@ private void processEndpoint(AnnotationMirror annotation, TypeElement element) {
 			return; // Can't process that endpoint
 		}
 		String endpointKey = ItemMetadata.newItemMetadataPrefix("management.endpoint.", endpointId);
-		Boolean enabledByDefault = (Boolean) elementValues.get("enableByDefault");
+		boolean enabledByDefault = (boolean) elementValues.getOrDefault("enableByDefault", true);
 		String type = this.metadataEnv.getTypeUtils().getQualifiedName(element);
-		this.metadataCollector.add(ItemMetadata.newGroup(endpointKey, type, type, null));
-		this.metadataCollector.add(ItemMetadata.newProperty(endpointKey, "enabled", Boolean.class.getName(), type, null,
-				String.format("Whether to enable the %s endpoint.", endpointId),
-				(enabledByDefault != null) ? enabledByDefault : true, null));
+		this.metadataCollector.addIfAbsent(ItemMetadata.newGroup(endpointKey, type, type, null));
+		this.metadataCollector.add(
+				ItemMetadata.newProperty(endpointKey, "enabled", Boolean.class.getName(), type, null,
+						"Whether to enable the %s endpoint.".formatted(endpointId), enabledByDefault, null),
+				(existing) -> checkEnabledValueMatchesExisting(existing, enabledByDefault, type));
 		if (hasMainReadOperation(element)) {
-			this.metadataCollector.add(ItemMetadata.newProperty(endpointKey, "cache.time-to-live",
+			this.metadataCollector.addIfAbsent(ItemMetadata.newProperty(endpointKey, "cache.time-to-live",
 					Duration.class.getName(), type, null, "Maximum time that a response can be cached.", "0ms", null));
 		}
 	}
 
+	private void checkEnabledValueMatchesExisting(ItemMetadata existing, boolean enabledByDefault, String sourceType) {
+		boolean existingDefaultValue = (boolean) existing.getDefaultValue();
+		if (enabledByDefault == existingDefaultValue) {
+			return;
+		}
+		throw new IllegalStateException(
+				"Existing property '%s' from type %s has a conflicting value. Existing value: %b, new value from type %s: %b"
+					.formatted(existing.getName(), existing.getSourceType(), existingDefaultValue, sourceType,
+							enabledByDefault));
+	}
+
 	private boolean hasMainReadOperation(TypeElement element) {
 		for (ExecutableElement method : ElementFilter.methodsIn(element.getEnclosedElements())) {
 			if (this.metadataEnv.getReadOperationAnnotation(method) != null

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/MetadataCollector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * 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.
@@ -20,6 +20,7 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Consumer;
 
 import javax.annotation.processing.ProcessingEnvironment;
 import javax.annotation.processing.RoundEnvironment;
@@ -35,6 +36,7 @@
  *
  * @author Andy Wilkinson
  * @author Kris De Volder
+ * @author Moritz Halbritter
  * @since 1.2.2
  */
 public class MetadataCollector {
@@ -76,6 +78,24 @@ public void add(ItemMetadata metadata) {
 		this.metadataItems.add(metadata);
 	}
 
+	public void add(ItemMetadata metadata, Consumer<ItemMetadata> onConflict) {
+		ItemMetadata existing = find(metadata.getName());
+		if (existing != null) {
+			onConflict.accept(existing);
+			return;
+		}
+		add(metadata);
+	}
+
+	public boolean addIfAbsent(ItemMetadata metadata) {
+		ItemMetadata existing = find(metadata.getName());
+		if (existing != null) {
+			return false;
+		}
+		add(metadata);
+		return true;
+	}
+
 	public boolean hasSimilarGroup(ItemMetadata metadata) {
 		if (!metadata.isOfItemType(ItemMetadata.ItemType.GROUP)) {
 			throw new IllegalStateException("item " + metadata + " must be a group");
@@ -105,6 +125,13 @@ public ConfigurationMetadata getMetadata() {
 		return metadata;
 	}
 
+	private ItemMetadata find(String name) {
+		return this.metadataItems.stream()
+			.filter((candidate) -> name.equals(candidate.getName()))
+			.findFirst()
+			.orElse(null);
+	}
+
 	private boolean shouldBeMerged(ItemMetadata itemMetadata) {
 		String sourceType = itemMetadata.getSourceType();
 		return (sourceType != null && !deletedInCurrentBuild(sourceType) && !processedInCurrentBuild(sourceType));

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/EndpointMetadataGenerationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * 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.
@@ -27,16 +27,20 @@
 import org.springframework.boot.configurationsample.endpoint.DisabledEndpoint;
 import org.springframework.boot.configurationsample.endpoint.EnabledEndpoint;
 import org.springframework.boot.configurationsample.endpoint.SimpleEndpoint;
+import org.springframework.boot.configurationsample.endpoint.SimpleEndpoint2;
+import org.springframework.boot.configurationsample.endpoint.SimpleEndpoint3;
 import org.springframework.boot.configurationsample.endpoint.SpecificEndpoint;
 import org.springframework.boot.configurationsample.endpoint.incremental.IncrementalEndpoint;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatRuntimeException;
 
 /**
  * Metadata generation tests for Actuator endpoints.
  *
  * @author Stephane Nicoll
  * @author Scott Frederick
+ * @author Moritz Halbritter
  */
 class EndpointMetadataGenerationTests extends AbstractMetadataGenerationTests {
 
@@ -148,6 +152,24 @@ void incrementalEndpointBuildEnableSpecificEndpoint() {
 		assertThat(metadata.getItems()).hasSize(3);
 	}
 
+	@Test
+	void shouldTolerateEndpointWithSameId() {
+		ConfigurationMetadata metadata = compile(SimpleEndpoint.class, SimpleEndpoint2.class);
+		assertThat(metadata).has(Metadata.withGroup("management.endpoint.simple").fromSource(SimpleEndpoint.class));
+		assertThat(metadata).has(enabledFlag("simple", "simple", true));
+		assertThat(metadata).has(cacheTtl("simple"));
+		assertThat(metadata.getItems()).hasSize(3);
+	}
+
+	@Test
+	void shouldFailIfEndpointWithSameIdButWithConflictingEnabledByDefaultSetting() {
+		assertThatRuntimeException().isThrownBy(() -> compile(SimpleEndpoint.class, SimpleEndpoint3.class))
+			.havingRootCause()
+			.isInstanceOf(IllegalStateException.class)
+			.withMessage(
+					"Existing property 'management.endpoint.simple.enabled' from type org.springframework.boot.configurationsample.endpoint.SimpleEndpoint has a conflicting value. Existing value: true, new value from type org.springframework.boot.configurationsample.endpoint.SimpleEndpoint3: false");
+	}
+
 	private Metadata.MetadataItemCondition enabledFlag(String endpointId, String endpointSuffix, Boolean defaultValue) {
 		return Metadata.withEnabledFlag("management.endpoint." + endpointSuffix + ".enabled")
 			.withDefaultValue(defaultValue)

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/SimpleEndpoint2.java

@@ -0,0 +1,35 @@
+/*
+ * 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.configurationsample.endpoint;
+
+import org.springframework.boot.configurationsample.Endpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
+
+/**
+ * A simple endpoint with no default override, with the same id as {@link SimpleEndpoint}.
+ *
+ * @author Moritz Halbritter
+ */
+@Endpoint(id = "simple")
+public class SimpleEndpoint2 {
+
+	@ReadOperation
+	public String invoke() {
+		return "test";
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationsample/endpoint/SimpleEndpoint3.java

@@ -0,0 +1,36 @@
+/*
+ * 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.configurationsample.endpoint;
+
+import org.springframework.boot.configurationsample.Endpoint;
+import org.springframework.boot.configurationsample.ReadOperation;
+
+/**
+ * A simple endpoint with no default override, with the same id as {@link SimpleEndpoint},
+ * but not enabled by default.
+ *
+ * @author Moritz Halbritter
+ */
+@Endpoint(id = "simple", enableByDefault = false)
+public class SimpleEndpoint3 {
+
+	@ReadOperation
+	public String invoke() {
+		return "test";
+	}
+
+}