Add support for configuring Undertow's access log via the environment

This commit adds support for configuring Undertow's access log via the
environment using the following properties:

server.undertow.access-log-enabled
server.undertow.access-log-pattern
server.undertow.access-log-dir

See gh-3014

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

@@ -56,6 +56,7 @@ import org.springframework.util.StringUtils;
  * @author Stephane Nicoll
  * @author Andy Wilkinson
  * @author Ivan Sopov
+ * @author Marcos Barbero
  */
 @ConfigurationProperties(prefix = "server", ignoreUnknownFields = false)
 public class ServerProperties implements EmbeddedServletContainerCustomizer, Ordered {
@@ -578,6 +579,21 @@ public class ServerProperties implements EmbeddedServletContainerCustomizer, Ord
 
 		private Boolean directBuffers;
 
+		/**
+		 * Format pattern for access logs.
+		 */
+		private String accessLogPattern;
+
+		/**
+		 * Enable access log.
+		 */
+		private boolean accessLogEnabled = false;
+
+		/**
+		 * Undertow access log directory. If not specified a temporary directory will be used.
+		 */
+		private File accessLogDir;
+
 		public Integer getBufferSize() {
 			return this.bufferSize;
 		}
@@ -618,12 +634,39 @@ public class ServerProperties implements EmbeddedServletContainerCustomizer, Ord
 			this.directBuffers = directBuffers;
 		}
 
+		public String getAccessLogPattern() {
+			return accessLogPattern;
+		}
+
+		public void setAccessLogPattern(String accessLogPattern) {
+			this.accessLogPattern = accessLogPattern;
+		}
+
+		public boolean isAccessLogEnabled() {
+			return accessLogEnabled;
+		}
+
+		public void setAccessLogEnabled(boolean accessLogEnabled) {
+			this.accessLogEnabled = accessLogEnabled;
+		}
+
+		public File getAccessLogDir() {
+			return accessLogDir;
+		}
+
+		public void setAccessLogDir(File accessLogDir) {
+			this.accessLogDir = accessLogDir;
+		}
+
 		void customizeUndertow(UndertowEmbeddedServletContainerFactory factory) {
 			factory.setBufferSize(this.bufferSize);
 			factory.setBuffersPerRegion(this.buffersPerRegion);
 			factory.setIoThreads(this.ioThreads);
 			factory.setWorkerThreads(this.workerThreads);
 			factory.setDirectBuffers(this.directBuffers);
+			factory.setAccessLogDirectory(this.accessLogDir);
+			factory.setAccessLogPattern(this.accessLogPattern);
+			factory.setAccessLogEnabled(this.accessLogEnabled);
 		}
 
 	}

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

+server.undertow.access-log-enabled=true
+server.undertow.access-log-pattern=combined
\ No newline at end of file

spring-boot/src/main/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactory.java

@@ -32,6 +32,7 @@ import org.apache.commons.logging.LogFactory;
  *
  * @author Phillip Webb
  * @author Dave Syer
+ * @author Marcos Barbero
  */
 public abstract class AbstractEmbeddedServletContainerFactory extends
 		AbstractConfigurableEmbeddedServletContainer implements
@@ -78,6 +79,25 @@ public abstract class AbstractEmbeddedServletContainerFactory extends
 		return file;
 	}
 
+	/**
+	 * Returns the absolute temp dir for given web server.
+	 * @param prefix webserver name
+	 * @return The temp dir for given web server.
+	 */
+	protected File createTempDir(String prefix) {
+		try {
+			File tempFolder = File.createTempFile(prefix + ".", "." + getPort());
+			tempFolder.delete();
+			tempFolder.mkdir();
+			tempFolder.deleteOnExit();
+			return tempFolder;
+		}
+		catch (IOException ex) {
+			throw new EmbeddedServletContainerException(
+					String.format("Unable to create %s tempdir", prefix), ex);
+		}
+	}
+
 	private File getExplodedWarFileDocumentRoot() {
 		File file = getCodeSourceArchive();
 		if (this.logger.isDebugEnabled()) {

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/TomcatEmbeddedServletContainerFactory.java

@@ -79,6 +79,7 @@ import org.springframework.util.StringUtils;
  * @author Brock Mills
  * @author Stephane Nicoll
  * @author Andy Wilkinson
+ * @author Marcos Barbero
  * @see #setPort(int)
  * @see #setContextLifecycleListeners(Collection)
  * @see TomcatEmbeddedServletContainer
@@ -382,20 +383,6 @@ public class TomcatEmbeddedServletContainerFactory extends
 		return new TomcatEmbeddedServletContainer(tomcat, getPort() >= 0);
 	}
 
-	private File createTempDir(String prefix) {
-		try {
-			File tempFolder = File.createTempFile(prefix + ".", "." + getPort());
-			tempFolder.delete();
-			tempFolder.mkdir();
-			tempFolder.deleteOnExit();
-			return tempFolder;
-		}
-		catch (IOException ex) {
-			throw new EmbeddedServletContainerException(
-					"Unable to create Tomcat tempdir", ex);
-		}
-	}
-
 	@Override
 	public void setResourceLoader(ResourceLoader resourceLoader) {
 		this.resourceLoader = resourceLoader;

spring-boot/src/main/java/org/springframework/boot/context/embedded/undertow/UndertowEmbeddedServletContainerFactory.java

@@ -19,6 +19,10 @@ package org.springframework.boot.context.embedded.undertow;
 import io.undertow.Undertow;
 import io.undertow.Undertow.Builder;
 import io.undertow.UndertowMessages;
+import io.undertow.server.HandlerWrapper;
+import io.undertow.server.HttpHandler;
+import io.undertow.server.handlers.accesslog.AccessLogHandler;
+import io.undertow.server.handlers.accesslog.DefaultAccessLogReceiver;
 import io.undertow.server.handlers.resource.ClassPathResourceManager;
 import io.undertow.server.handlers.resource.FileResourceManager;
 import io.undertow.server.handlers.resource.Resource;
@@ -69,8 +73,11 @@ import org.springframework.context.ResourceLoaderAware;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.util.Assert;
 import org.springframework.util.ResourceUtils;
+import org.xnio.OptionMap;
 import org.xnio.Options;
 import org.xnio.SslClientAuthMode;
+import org.xnio.XnioWorker;
+import org.xnio.Xnio;
 
 /**
  * {@link EmbeddedServletContainerFactory} that can be used to create
@@ -81,6 +88,7 @@ import org.xnio.SslClientAuthMode;
  *
  * @author Ivan Sopov
  * @author Andy Wilkinson
+ * @author Marcos Barbero
  * @since 1.2.0
  * @see UndertowEmbeddedServletContainer
  */
@@ -105,6 +113,12 @@ public class UndertowEmbeddedServletContainerFactory extends
 
 	private Boolean directBuffers;
 
+	private File accessLogDirectory;
+
+	private String accessLogPattern;
+
+	private boolean accessLogEnabled = false;
+
 	/**
 	 * Create a new {@link UndertowEmbeddedServletContainerFactory} instance.
 	 */
@@ -337,6 +351,9 @@ public class UndertowEmbeddedServletContainerFactory extends
 		for (UndertowDeploymentInfoCustomizer customizer : this.deploymentInfoCustomizers) {
 			customizer.customize(deployment);
 		}
+		if (isAccessLogEnabled()) {
+			configureAccessLog(deployment);
+		}
 		DeploymentManager manager = Servlets.defaultContainer().addDeployment(deployment);
 		manager.deploy();
 		SessionManager sessionManager = manager.getDeployment().getSessionManager();
@@ -345,6 +362,51 @@ public class UndertowEmbeddedServletContainerFactory extends
 		return manager;
 	}
 
+	private void configureAccessLog(DeploymentInfo deploymentInfo) {
+		deploymentInfo.addInitialHandlerChainWrapper(new HandlerWrapper() {
+			@Override
+			public HttpHandler wrap(HttpHandler handler) {
+				try {
+					String formatString = (accessLogPattern != null) ? accessLogPattern
+							: "common";
+					DefaultAccessLogReceiver accessLogReceiver = new DefaultAccessLogReceiver(
+							createWorker(), getLogsDir(), "access_log");
+					return new AccessLogHandler(handler, accessLogReceiver, formatString,
+							Undertow.class.getClassLoader());
+				}
+				catch (IOException ex) {
+					throw new IllegalStateException(ex);
+				}
+			}
+		});
+	}
+
+	private XnioWorker createWorker() throws IOException {
+		Xnio xnio = Xnio.getInstance(Undertow.class.getClassLoader());
+		OptionMap.Builder builder = OptionMap.builder();
+		if(this.ioThreads != null && this.ioThreads > 0) {
+			builder.set(Options.WORKER_IO_THREADS, ioThreads);
+		}
+		if(this.workerThreads != null && this.workerThreads > 0) {
+			builder.set(Options.WORKER_TASK_CORE_THREADS, workerThreads);
+			builder.set(Options.WORKER_TASK_MAX_THREADS, workerThreads);
+		}
+		return xnio.createWorker(builder.getMap());
+	}
+
+	private File getLogsDir() {
+		File logsDir;
+		if (accessLogDirectory != null) {
+			logsDir = accessLogDirectory;
+			if (!logsDir.isDirectory() && !logsDir.mkdirs()) {
+				throw new IllegalStateException("Failed to create logs dir '" + logsDir + "'");
+			}
+		} else {
+			logsDir = createTempDir("undertow");
+		}
+		return logsDir;
+	}
+
 	private void registerServletContainerInitializerToDriveServletContextInitializers(
 			DeploymentInfo deployment, ServletContextInitializer... initializers) {
 		ServletContextInitializer[] mergedInitializers = mergeInitializers(initializers);
@@ -442,6 +504,22 @@ public class UndertowEmbeddedServletContainerFactory extends
 		this.directBuffers = directBuffers;
 	}
 
+	public void setAccessLogDirectory(File accessLogDirectory) {
+		this.accessLogDirectory = accessLogDirectory;
+	}
+
+	public void setAccessLogPattern(String accessLogPattern) {
+		this.accessLogPattern = accessLogPattern;
+	}
+
+	public void setAccessLogEnabled(boolean accessLogEnabled) {
+		this.accessLogEnabled = accessLogEnabled;
+	}
+
+	public boolean isAccessLogEnabled() {
+		return accessLogEnabled;
+	}
+
 	/**
 	 * Undertow {@link ResourceManager} for JAR resources.
 	 */