Make PID and application version available in the environment

Adds the following new properties:

- spring.application.pid
- spring.application.version

Refactors the ResourceBanner and the structured logging support to use
the new properties.

Closes gh-41604

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/SpringBootContextLoaderTests.java

@@ -160,11 +160,11 @@ void propertySourceOrdering() {
 			.stream()
 			.map(PropertySource::getName)
 			.collect(Collectors.toCollection(ArrayList::new));
-		String last = names.remove(names.size() - 1);
+		String configResource = names.remove(names.size() - 2);
 		assertThat(names).containsExactly("configurationProperties", "Inlined Test Properties", "commandLineArgs",
 				"servletConfigInitParams", "servletContextInitParams", "systemProperties", "systemEnvironment",
-				"random");
-		assertThat(last).startsWith("Config resource");
+				"random", "applicationInfo");
+		assertThat(configResource).startsWith("Config resource");
 	}
 
 	@Test

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/ApplicationInfoPropertySource.java

@@ -0,0 +1,77 @@
+/*
+ * 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;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.boot.system.ApplicationPid;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.MapPropertySource;
+import org.springframework.core.env.MutablePropertySources;
+import org.springframework.core.env.PropertySource;
+import org.springframework.util.StringUtils;
+
+/**
+ * {@link PropertySource} which provides information about the application, like the
+ * process ID (PID) or the version.
+ *
+ * @author Moritz Halbritter
+ */
+class ApplicationInfoPropertySource extends MapPropertySource {
+
+	static final String NAME = "applicationInfo";
+
+	ApplicationInfoPropertySource(Class<?> mainClass) {
+		super(NAME, getProperties(readVersion(mainClass)));
+	}
+
+	ApplicationInfoPropertySource(String applicationVersion) {
+		super(NAME, getProperties(applicationVersion));
+	}
+
+	private static Map<String, Object> getProperties(String applicationVersion) {
+		Map<String, Object> result = new HashMap<>();
+		if (StringUtils.hasText(applicationVersion)) {
+			result.put("spring.application.version", applicationVersion);
+		}
+		ApplicationPid applicationPid = new ApplicationPid();
+		if (applicationPid.isAvailable()) {
+			result.put("spring.application.pid", applicationPid.toLong());
+		}
+		return result;
+	}
+
+	private static String readVersion(Class<?> applicationClass) {
+		Package sourcePackage = (applicationClass != null) ? applicationClass.getPackage() : null;
+		return (sourcePackage != null) ? sourcePackage.getImplementationVersion() : null;
+	}
+
+	/**
+	 * Moves the {@link ApplicationInfoPropertySource} to the end of the environment's
+	 * property sources.
+	 * @param environment the environment
+	 */
+	static void moveToEnd(ConfigurableEnvironment environment) {
+		MutablePropertySources propertySources = environment.getPropertySources();
+		PropertySource<?> propertySource = propertySources.remove(NAME);
+		if (propertySource != null) {
+			propertySources.addLast(propertySource);
+		}
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/ResourceBanner.java

@@ -47,6 +47,7 @@
  * @author Vedran Pavic
  * @author Toshiaki Maki
  * @author Krzysztof Krason
+ * @author Moritz Halbritter
  * @since 1.2.0
  */
 public class ResourceBanner implements Banner {
@@ -91,7 +92,7 @@ protected List<PropertyResolver> getPropertyResolvers(Environment environment, C
 		}
 		sources.addLast(getTitleSource(sourceClass));
 		sources.addLast(getAnsiSource());
-		sources.addLast(getVersionSource(sourceClass));
+		sources.addLast(getVersionSource(sourceClass, environment));
 		List<PropertyResolver> resolvers = new ArrayList<>();
 		resolvers.add(new PropertySourcesPropertyResolver(sources));
 		return resolvers;
@@ -119,12 +120,15 @@ private AnsiPropertySource getAnsiSource() {
 		return new AnsiPropertySource("ansi", true);
 	}
 
-	private MapPropertySource getVersionSource(Class<?> sourceClass) {
-		return new MapPropertySource("version", getVersionsMap(sourceClass));
+	private MapPropertySource getVersionSource(Class<?> sourceClass, Environment environment) {
+		return new MapPropertySource("version", getVersionsMap(sourceClass, environment));
 	}
 
-	private Map<String, Object> getVersionsMap(Class<?> sourceClass) {
+	private Map<String, Object> getVersionsMap(Class<?> sourceClass, Environment environment) {
 		String appVersion = getApplicationVersion(sourceClass);
+		if (appVersion == null) {
+			appVersion = getApplicationVersion(environment);
+		}
 		String bootVersion = getBootVersion();
 		Map<String, Object> versions = new HashMap<>();
 		versions.put("application.version", getVersionString(appVersion, false));
@@ -134,9 +138,19 @@ private Map<String, Object> getVersionsMap(Class<?> sourceClass) {
 		return versions;
 	}
 
+	/**
+	 * Returns the application version.
+	 * @param sourceClass the source class
+	 * @return the application version or {@code null} if unknown
+	 * @deprecated since 3.4.0 for removal in 3.6.0
+	 */
+	@Deprecated(since = "3.4.0", forRemoval = true)
 	protected String getApplicationVersion(Class<?> sourceClass) {
-		Package sourcePackage = (sourceClass != null) ? sourceClass.getPackage() : null;
-		return (sourcePackage != null) ? sourcePackage.getImplementationVersion() : null;
+		return null;
+	}
+
+	private String getApplicationVersion(Environment environment) {
+		return environment.getProperty("spring.application.version");
 	}
 
 	protected String getBootVersion() {

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplication.java

@@ -368,6 +368,7 @@ private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners
 		configureEnvironment(environment, applicationArguments.getSourceArgs());
 		ConfigurationPropertySources.attach(environment);
 		listeners.environmentPrepared(bootstrapContext, environment);
+		ApplicationInfoPropertySource.moveToEnd(environment);
 		DefaultPropertiesPropertySource.moveToEnd(environment);
 		Assert.state(!environment.containsProperty("spring.main.environment-prefix"),
 				"Environment prefix cannot be set via properties.");
@@ -539,6 +540,7 @@ protected void configurePropertySources(ConfigurableEnvironment environment, Str
 				sources.addFirst(new SimpleCommandLinePropertySource(args));
 			}
 		}
+		environment.getPropertySources().addLast(new ApplicationInfoPropertySource(this.mainApplicationClass));
 	}
 
 	/**

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/ElasticCommonSchemaStructuredLogFormatter.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.logging.log4j2;
 
+import java.util.Objects;
+
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.impl.ThrowableProxy;
@@ -28,7 +30,7 @@
 import org.springframework.boot.logging.structured.ElasticCommonSchemaService;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
-import org.springframework.boot.system.ApplicationPid;
+import org.springframework.core.env.Environment;
 import org.springframework.util.ObjectUtils;
 
 /**
@@ -40,17 +42,17 @@
  */
 class ElasticCommonSchemaStructuredLogFormatter extends JsonWriterStructuredLogFormatter<LogEvent> {
 
-	ElasticCommonSchemaStructuredLogFormatter(ApplicationPid pid, ElasticCommonSchemaService service) {
-		super((members) -> jsonMembers(pid, service, members));
+	ElasticCommonSchemaStructuredLogFormatter(Environment environment) {
+		super((members) -> jsonMembers(environment, members));
 	}
 
-	private static void jsonMembers(ApplicationPid pid, ElasticCommonSchemaService service,
-			JsonWriter.Members<LogEvent> members) {
+	private static void jsonMembers(Environment environment, JsonWriter.Members<LogEvent> members) {
 		members.add("@timestamp", LogEvent::getInstant).as(ElasticCommonSchemaStructuredLogFormatter::asTimestamp);
 		members.add("log.level", LogEvent::getLevel).as(Level::name);
-		members.add("process.pid", pid).when(ApplicationPid::isAvailable).as(ApplicationPid::toLong);
+		members.add("process.pid", environment.getProperty("spring.application.pid", Long.class))
+			.when(Objects::nonNull);
 		members.add("process.thread.name", LogEvent::getThreadName);
-		service.jsonMembers(members);
+		ElasticCommonSchemaService.get(environment).jsonMembers(members);
 		members.add("log.logger", LogEvent::getLoggerName);
 		members.add("message", LogEvent::getMessage).as(Message::getFormattedMessage);
 		members.from(LogEvent::getContextData)

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/StructuredLogLayout.java

@@ -30,11 +30,9 @@
 import org.apache.logging.log4j.core.layout.AbstractStringLayout;
 
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
-import org.springframework.boot.logging.structured.ElasticCommonSchemaService;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatterFactory;
 import org.springframework.boot.logging.structured.StructuredLogFormatterFactory.CommonFormatters;
-import org.springframework.boot.system.ApplicationPid;
 import org.springframework.core.env.Environment;
 import org.springframework.util.Assert;
 
@@ -106,8 +104,7 @@ public StructuredLogLayout build() {
 		private void addCommonFormatters(CommonFormatters<LogEvent> commonFormatters) {
 			commonFormatters.add(CommonStructuredLogFormat.ELASTIC_COMMON_SCHEMA,
 					(instantiator) -> new ElasticCommonSchemaStructuredLogFormatter(
-							instantiator.getArg(ApplicationPid.class),
-							instantiator.getArg(ElasticCommonSchemaService.class)));
+							instantiator.getArg(Environment.class)));
 			commonFormatters.add(CommonStructuredLogFormat.LOGSTASH,
 					(instantiator) -> new LogstashStructuredLogFormatter());
 		}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/ElasticCommonSchemaStructuredLogFormatter.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.logging.logback;
 
+import java.util.Objects;
+
 import ch.qos.logback.classic.pattern.ThrowableProxyConverter;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.classic.spi.IThrowableProxy;
@@ -27,7 +29,7 @@
 import org.springframework.boot.logging.structured.ElasticCommonSchemaService;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
-import org.springframework.boot.system.ApplicationPid;
+import org.springframework.core.env.Environment;
 
 /**
  * Logback {@link StructuredLogFormatter} for
@@ -41,18 +43,19 @@ class ElasticCommonSchemaStructuredLogFormatter extends JsonWriterStructuredLogF
 	private static final PairExtractor<KeyValuePair> keyValuePairExtractor = PairExtractor.of((pair) -> pair.key,
 			(pair) -> pair.value);
 
-	ElasticCommonSchemaStructuredLogFormatter(ApplicationPid pid, ElasticCommonSchemaService service,
+	ElasticCommonSchemaStructuredLogFormatter(Environment environment,
 			ThrowableProxyConverter throwableProxyConverter) {
-		super((members) -> jsonMembers(pid, service, throwableProxyConverter, members));
+		super((members) -> jsonMembers(environment, throwableProxyConverter, members));
 	}
 
-	private static void jsonMembers(ApplicationPid pid, ElasticCommonSchemaService service,
-			ThrowableProxyConverter throwableProxyConverter, JsonWriter.Members<ILoggingEvent> members) {
+	private static void jsonMembers(Environment environment, ThrowableProxyConverter throwableProxyConverter,
+			JsonWriter.Members<ILoggingEvent> members) {
 		members.add("@timestamp", ILoggingEvent::getInstant);
 		members.add("log.level", ILoggingEvent::getLevel);
-		members.add("process.pid", pid).when(ApplicationPid::isAvailable).as(ApplicationPid::toLong);
+		members.add("process.pid", environment.getProperty("spring.application.pid", Long.class))
+			.when(Objects::nonNull);
 		members.add("process.thread.name", ILoggingEvent::getThreadName);
-		service.jsonMembers(members);
+		ElasticCommonSchemaService.get(environment).jsonMembers(members);
 		members.add("log.logger", ILoggingEvent::getLoggerName);
 		members.add("message", ILoggingEvent::getFormattedMessage);
 		members.addMapEntries(ILoggingEvent::getMDCPropertyMap);

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/StructuredLogEncoder.java

@@ -25,11 +25,9 @@
 import ch.qos.logback.core.encoder.EncoderBase;
 
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
-import org.springframework.boot.logging.structured.ElasticCommonSchemaService;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatterFactory;
 import org.springframework.boot.logging.structured.StructuredLogFormatterFactory.CommonFormatters;
-import org.springframework.boot.system.ApplicationPid;
 import org.springframework.boot.util.Instantiator.AvailableParameters;
 import org.springframework.core.env.Environment;
 import org.springframework.util.Assert;
@@ -82,9 +80,7 @@ private void addAvailableParameters(AvailableParameters availableParameters) {
 
 	private void addCommonFormatters(CommonFormatters<ILoggingEvent> commonFormatters) {
 		commonFormatters.add(CommonStructuredLogFormat.ELASTIC_COMMON_SCHEMA,
-				(instantiator) -> new ElasticCommonSchemaStructuredLogFormatter(
-						instantiator.getArg(ApplicationPid.class),
-						instantiator.getArg(ElasticCommonSchemaService.class),
+				(instantiator) -> new ElasticCommonSchemaStructuredLogFormatter(instantiator.getArg(Environment.class),
 						instantiator.getArg(ThrowableProxyConverter.class)));
 		commonFormatters.add(CommonStructuredLogFormat.LOGSTASH, (instantiator) -> new LogstashStructuredLogFormatter(
 				instantiator.getArg(ThrowableProxyConverter.class)));

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/structured/ElasticCommonSchemaService.java

@@ -38,7 +38,8 @@ public record ElasticCommonSchemaService(String name, String version, String env
 
 	private ElasticCommonSchemaService withDefaults(Environment environment) {
 		String name = withFallbackProperty(environment, this.name, "spring.application.name");
-		return new ElasticCommonSchemaService(name, this.version, this.environment, this.nodeName);
+		String version = withFallbackProperty(environment, this.version, "spring.application.version");
+		return new ElasticCommonSchemaService(name, version, this.environment, this.nodeName);
 	}
 
 	private String withFallbackProperty(Environment environment, String value, String property) {

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/structured/StructuredLogFormatter.java

@@ -20,7 +20,6 @@
 
 import ch.qos.logback.classic.pattern.ThrowableProxyConverter;
 
-import org.springframework.boot.system.ApplicationPid;
 import org.springframework.core.env.Environment;
 
 /**
@@ -29,8 +28,6 @@
  * Implementing classes can declare the following parameter types in the constructor:
  * <ul>
  * <li>{@link Environment}</li>
- * <li>{@link ApplicationPid}</li>
- * <li>{@link ElasticCommonSchemaService}</li>
  * </ul>
  * When using Logback, implementing classes can also use the following parameter types in
  * the constructor:

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/structured/StructuredLogFormatterFactory.java

@@ -21,7 +21,6 @@
 import java.util.TreeMap;
 import java.util.function.Consumer;
 
-import org.springframework.boot.system.ApplicationPid;
 import org.springframework.boot.util.Instantiator;
 import org.springframework.boot.util.Instantiator.AvailableParameters;
 import org.springframework.boot.util.Instantiator.FailureHandler;
@@ -68,9 +67,6 @@ public StructuredLogFormatterFactory(Class<E> logEventType, Environment environm
 		this.logEventType = logEventType;
 		this.instantiator = new Instantiator<>(StructuredLogFormatter.class, (allAvailableParameters) -> {
 			allAvailableParameters.add(Environment.class, environment);
-			allAvailableParameters.add(ApplicationPid.class, (type) -> new ApplicationPid());
-			allAvailableParameters.add(ElasticCommonSchemaService.class,
-					(type) -> ElasticCommonSchemaService.get(environment));
 			if (availableParameters != null) {
 				availableParameters.accept(allAvailableParameters);
 			}

spring-boot-project/spring-boot/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -285,6 +285,11 @@
       "sourceType": "org.springframework.boot.context.ContextIdApplicationContextInitializer",
       "description": "Application name."
     },
+    {
+      "name": "spring.application.version",
+      "type": "java.lang.String",
+      "description": "Application version (defaults to 'Implementation-Version' from the manifest)."
+    },
     {
       "name": "spring.banner.charset",
       "type": "java.nio.charset.Charset",