Expose Tomcat AccessLog Max days property

See spring-projectsgh-15954

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

@@ -609,6 +609,19 @@ public static class Accesslog {
 			 */
 			private boolean buffered = true;
 
+			/**
+			 * The number of days to retain the access log files before they are removed.
+			 */
+			private int maxDays = -1;
+
+			public int getMaxDays() {
+				return this.maxDays;
+			}
+
+			public void setMaxDays(int maxDays) {
+				this.maxDays = maxDays;
+			}
+
 			public boolean isEnabled() {
 				return this.enabled;
 			}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizer.java

@@ -263,6 +263,7 @@ private void customizeAccessLog(ConfigurableTomcatWebServerFactory factory) {
 				tomcatProperties.getAccesslog().isRequestAttributesEnabled());
 		valve.setRotatable(tomcatProperties.getAccesslog().isRotate());
 		valve.setBuffered(tomcatProperties.getAccesslog().isBuffered());
+		valve.setMaxDays(tomcatProperties.getAccesslog().getMaxDays());
 		factory.addEngineValves(valve);
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizerTests.java

@@ -325,6 +325,23 @@ public void accessLogIsDisabledByDefault() {
 		assertThat(factory.getEngineValves()).isEmpty();
 	}
 
+	@Test
+	public void accessLogSetMaxDays() {
+		bind("server.tomcat.accesslog.enabled=true",
+				"server.tomcat.accesslog.max-days=20");
+		TomcatServletWebServerFactory factory = customizeAndGetFactory();
+		assertThat(((AccessLogValve) factory.getEngineValves().iterator().next())
+				.getMaxDays()).isEqualTo(20);
+	}
+
+	@Test
+	public void accessLogDefaultMaxDays() {
+		bind("server.tomcat.accesslog.enabled=true");
+		TomcatServletWebServerFactory factory = customizeAndGetFactory();
+		assertThat(((AccessLogValve) factory.getEngineValves().iterator().next())
+				.getMaxDays()).isEqualTo(-1);
+	}
+
 	private void bind(String... inlinedProperties) {
 		TestPropertySourceUtils.addInlinedPropertiesToEnvironment(this.environment,
 				inlinedProperties);

spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix/application-properties.adoc

@@ -255,6 +255,7 @@ content into your application. Rather, pick only the properties that you need.
 	server.tomcat.accesslog.directory=logs # Directory in which log files are created. Can be absolute or relative to the Tomcat base dir.
 	server.tomcat.accesslog.enabled=false # Enable access log.
 	server.tomcat.accesslog.file-date-format=.yyyy-MM-dd # Date format to place in the log file name.
+	server.tomcat.accesslog.max-days=-1#The number of days to retain the access log files before they are removed.
 	server.tomcat.accesslog.pattern=common # Format pattern for access logs.
 	server.tomcat.accesslog.prefix=access_log # Log file name prefix.
 	server.tomcat.accesslog.rename-on-rotate=false # Whether to defer inclusion of the date stamp in the file name until rotate time.