Log file location should be evaluated just once

Using a random value for the logfile name caused
the logfile endpoint to return a 404 as the name
was resolved from the environment on every request.
This commit registers a bean for LogFile which is then
used by the logfile endpoint.

Fixes gh-17434

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/logging/LogFileWebEndpointAutoConfiguration.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.logging;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnEnabledEndpoint;
 import org.springframework.boot.actuate.logging.LogFileWebEndpoint;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
@@ -24,6 +25,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.logging.LogFile;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ConditionContext;
 import org.springframework.context.annotation.Conditional;
@@ -52,8 +54,8 @@ public class LogFileWebEndpointAutoConfiguration {
 	@Bean
 	@ConditionalOnMissingBean
 	@Conditional(LogFileCondition.class)
-	public LogFileWebEndpoint logFileWebEndpoint(Environment environment) {
+	public LogFileWebEndpoint logFileWebEndpoint(ObjectProvider<LogFile> logFile) {
-		return new LogFileWebEndpoint(environment, this.properties.getExternalFile());
+		return new LogFileWebEndpoint(logFile.getIfAvailable(), this.properties.getExternalFile());
 	}
 
 	private static class LogFileCondition extends SpringBootCondition {

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/documentation/LogFileWebEndpointDocumentationTests.java

@@ -19,6 +19,7 @@ package org.springframework.boot.actuate.autoconfigure.endpoint.web.documentatio
 import org.junit.Test;
 
 import org.springframework.boot.actuate.logging.LogFileWebEndpoint;
+import org.springframework.boot.logging.LogFile;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
@@ -56,7 +57,7 @@ public class LogFileWebEndpointDocumentationTests extends MockMvcEndpointDocumen
 
 		@Bean
 		public LogFileWebEndpoint endpoint(Environment environment) {
-			return new LogFileWebEndpoint(environment);
+			return new LogFileWebEndpoint(LogFile.get(environment), null);
 		}
 
 	}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/logging/LogFileWebEndpoint.java

@@ -25,7 +25,6 @@ import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
 import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
 import org.springframework.boot.actuate.endpoint.web.annotation.WebEndpoint;
 import org.springframework.boot.logging.LogFile;
-import org.springframework.core.env.Environment;
 import org.springframework.core.io.FileSystemResource;
 import org.springframework.core.io.Resource;
 
@@ -42,17 +41,13 @@ public class LogFileWebEndpoint {
 
 	private static final Log logger = LogFactory.getLog(LogFileWebEndpoint.class);
 
-	private final Environment environment;
-
 	private File externalFile;
 
-	public LogFileWebEndpoint(Environment environment, File externalFile) {
+	private final LogFile logFile;
-		this.environment = environment;
-		this.externalFile = externalFile;
-	}
 
-	public LogFileWebEndpoint(Environment environment) {
+	public LogFileWebEndpoint(LogFile logFile, File externalFile) {
-		this(environment, null);
+		this.externalFile = externalFile;
+		this.logFile = logFile;
 	}
 
 	@ReadOperation(produces = "text/plain; charset=UTF-8")
@@ -68,12 +63,11 @@ public class LogFileWebEndpoint {
 		if (this.externalFile != null) {
 			return new FileSystemResource(this.externalFile);
 		}
-		LogFile logFile = LogFile.get(this.environment);
+		if (this.logFile == null) {
-		if (logFile == null) {
 			logger.debug("Missing 'logging.file' or 'logging.path' properties");
 			return null;
 		}
-		return new FileSystemResource(logFile.toString());
+		return new FileSystemResource(this.logFile.toString());
 	}
 
 }

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/logging/LogFileWebEndpointTests.java

@@ -25,6 +25,7 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
+import org.springframework.boot.logging.LogFile;
 import org.springframework.core.io.Resource;
 import org.springframework.mock.env.MockEnvironment;
 import org.springframework.util.FileCopyUtils;
@@ -46,8 +47,6 @@ public class LogFileWebEndpointTests {
 
 	private final MockEnvironment environment = new MockEnvironment();
 
-	private final LogFileWebEndpoint endpoint = new LogFileWebEndpoint(this.environment);
-
 	private File logFile;
 
 	@Before
@@ -58,26 +57,29 @@ public class LogFileWebEndpointTests {
 
 	@Test
 	public void nullResponseWithoutLogFile() {
-		assertThat(this.endpoint.logFile()).isNull();
+		LogFileWebEndpoint endpoint = new LogFileWebEndpoint(null, null);
+		assertThat(endpoint.logFile()).isNull();
 	}
 
 	@Test
 	public void nullResponseWithMissingLogFile() {
 		this.environment.setProperty("logging.file", "no_test.log");
-		assertThat(this.endpoint.logFile()).isNull();
+		LogFileWebEndpoint endpoint = new LogFileWebEndpoint(LogFile.get(this.environment), null);
+		assertThat(endpoint.logFile()).isNull();
 	}
 
 	@Test
 	public void resourceResponseWithLogFile() throws Exception {
 		this.environment.setProperty("logging.file", this.logFile.getAbsolutePath());
-		Resource resource = this.endpoint.logFile();
+		LogFileWebEndpoint endpoint = new LogFileWebEndpoint(LogFile.get(this.environment), null);
+		Resource resource = endpoint.logFile();
 		assertThat(resource).isNotNull();
 		assertThat(StreamUtils.copyToString(resource.getInputStream(), StandardCharsets.UTF_8)).isEqualTo("--TEST--");
 	}
 
 	@Test
 	public void resourceResponseWithExternalLogFile() throws Exception {
-		LogFileWebEndpoint endpoint = new LogFileWebEndpoint(this.environment, this.logFile);
+		LogFileWebEndpoint endpoint = new LogFileWebEndpoint(null, this.logFile);
 		Resource resource = endpoint.logFile();
 		assertThat(resource).isNotNull();
 		assertThat(StreamUtils.copyToString(resource.getInputStream(), StandardCharsets.UTF_8)).isEqualTo("--TEST--");

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/logging/LogFileWebEndpointWebIntegrationTests.java

@@ -17,21 +17,19 @@
 package org.springframework.boot.actuate.logging;
 
 import java.io.File;
-import java.io.IOException;
 
-import org.junit.Before;
+import org.junit.ClassRule;
-import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 import org.junit.runner.RunWith;
 
 import org.springframework.boot.actuate.endpoint.web.test.WebEndpointRunners;
-import org.springframework.boot.test.util.TestPropertyValues;
+import org.springframework.boot.logging.LogFile;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.core.env.Environment;
 import org.springframework.http.MediaType;
+import org.springframework.mock.env.MockEnvironment;
 import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.util.FileCopyUtils;
 
@@ -48,32 +46,19 @@ public class LogFileWebEndpointWebIntegrationTests {
 
 	private static WebTestClient client;
 
-	@Rule
+	@ClassRule
-	public final TemporaryFolder temp = new TemporaryFolder();
+	public static final TemporaryFolder temp = new TemporaryFolder();
 
-	private File logFile;
+	private static File logFile;
-
-	@Before
-	public void setUp() throws IOException {
-		this.logFile = this.temp.newFile();
-		FileCopyUtils.copy("--TEST--".getBytes(), this.logFile);
-	}
-
-	@Test
-	public void getRequestProduces404ResponseWhenLogFileNotFound() {
-		client.get().uri("/actuator/logfile").exchange().expectStatus().isNotFound();
-	}
 
 	@Test
 	public void getRequestProducesResponseWithLogFile() {
-		TestPropertyValues.of("logging.file:" + this.logFile.getAbsolutePath()).applyTo(context);
 		client.get().uri("/actuator/logfile").exchange().expectStatus().isOk().expectHeader()
 				.contentType("text/plain; charset=UTF-8").expectBody(String.class).isEqualTo("--TEST--");
 	}
 
 	@Test
 	public void getRequestThatAcceptsTextPlainProducesResponseWithLogFile() {
-		TestPropertyValues.of("logging.file:" + this.logFile.getAbsolutePath()).applyTo(context);
 		client.get().uri("/actuator/logfile").accept(MediaType.TEXT_PLAIN).exchange().expectStatus().isOk()
 				.expectHeader().contentType("text/plain; charset=UTF-8").expectBody(String.class).isEqualTo("--TEST--");
 	}
@@ -82,8 +67,12 @@ public class LogFileWebEndpointWebIntegrationTests {
 	static class TestConfiguration {
 
 		@Bean
-		public LogFileWebEndpoint logFileEndpoint(Environment environment) {
+		public LogFileWebEndpoint logFileEndpoint() throws Exception {
-			return new LogFileWebEndpoint(environment);
+			logFile = temp.newFile();
+			FileCopyUtils.copy("--TEST--".getBytes(), logFile);
+			MockEnvironment environment = new MockEnvironment();
+			environment.setProperty("logging.file", logFile.getAbsolutePath());
+			return new LogFileWebEndpoint(LogFile.get(environment), null);
 		}
 
 	}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/logging/LoggingApplicationListener.java

@@ -121,6 +121,11 @@ public class LoggingApplicationListener implements GenericApplicationListener {
 	 */
 	public static final String LOGGING_SYSTEM_BEAN_NAME = "springBootLoggingSystem";
 
+	/**
+	 * The name of the {@link LogFile} bean.
+	 */
+	public static final String LOGFILE_BEAN_NAME = "springBootLogFile";
+
 	private static final Map<String, List<String>> DEFAULT_GROUP_LOGGERS;
 	static {
 		MultiValueMap<String, String> loggers = new LinkedMultiValueMap<>();
@@ -160,6 +165,8 @@ public class LoggingApplicationListener implements GenericApplicationListener {
 
 	private LoggingSystem loggingSystem;
 
+	private LogFile logFile;
+
 	private int order = DEFAULT_ORDER;
 
 	private boolean parseArgs = true;
@@ -224,6 +231,9 @@ public class LoggingApplicationListener implements GenericApplicationListener {
 		if (!beanFactory.containsBean(LOGGING_SYSTEM_BEAN_NAME)) {
 			beanFactory.registerSingleton(LOGGING_SYSTEM_BEAN_NAME, this.loggingSystem);
 		}
+		if (this.logFile != null && !beanFactory.containsBean(LOGFILE_BEAN_NAME)) {
+			beanFactory.registerSingleton(LOGFILE_BEAN_NAME, this.logFile);
+		}
 	}
 
 	private void onContextClosedEvent() {
@@ -246,12 +256,12 @@ public class LoggingApplicationListener implements GenericApplicationListener {
 	 */
 	protected void initialize(ConfigurableEnvironment environment, ClassLoader classLoader) {
 		new LoggingSystemProperties(environment).apply();
-		LogFile logFile = LogFile.get(environment);
+		this.logFile = LogFile.get(environment);
-		if (logFile != null) {
+		if (this.logFile != null) {
-			logFile.applyToSystemProperties();
+			this.logFile.applyToSystemProperties();
 		}
 		initializeEarlyLoggingLevel(environment);
-		initializeSystem(environment, this.loggingSystem, logFile);
+		initializeSystem(environment, this.loggingSystem, this.logFile);
 		initializeFinalLoggingLevels(environment, this.loggingSystem);
 		registerShutdownHookIfNecessary(environment, this.loggingSystem);
 	}

spring-boot-samples/spring-boot-sample-actuator/src/test/java/sample/actuator/EndpointsPropertiesSampleActuatorApplicationTests.java

@@ -66,6 +66,13 @@ public class EndpointsPropertiesSampleActuatorApplicationTests {
 		assertThat(entity.getBody()).contains("\"hello\":\"world\"");
 	}
 
+	@Test
+	public void logfileWithRandomName() {
+		ResponseEntity<String> entity = this.restTemplate.withBasicAuth("user", getPassword())
+				.getForEntity("/admin/logfile", String.class);
+		assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.OK);
+	}
+
 	private String getPassword() {
 		return "password";
 	}

spring-boot-samples/spring-boot-sample-actuator/src/test/resources/application-endpoints.properties

@@ -1,3 +1,5 @@
 server.error.path: /oops
 management.endpoint.health.show-details: always
 management.endpoints.web.base-path: /admin
+logging.file=./target/${spring.application.instance_id}.log
+spring.application.instance_id=${random.value}