Add 3xx redirects to the "unmapped" class of requests for metrics

When Spring Security sends 302 responses to a login page we don't get
any information about the request matching in Spring MVC. Consequently
apps can end up with a lot of counter.status.302.* metrics (where
"*" can be whatever the user sent).

This change treats 3xx the same as 4xx (if it is unmapped it just gets
added to a metric called "unmapped" instead of using the actual request
path).

Fixes gh-2563

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/MetricFilterAutoConfiguration.java

@@ -27,6 +27,7 @@ import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.web.filter.OncePerRequestFilter;
@@ -45,6 +46,7 @@ import org.springframework.web.servlet.HandlerMapping;
 @ConditionalOnClass({ Servlet.class, ServletRegistration.class,
 		OncePerRequestFilter.class, HandlerMapping.class })
 @AutoConfigureAfter(MetricRepositoryAutoConfiguration.class)
+@ConditionalOnProperty(name="endpoints.metrics.filter.enabled", matchIfMissing=true)
 public class MetricFilterAutoConfiguration {
 
 	@Autowired

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/MetricsFilter.java

@@ -99,6 +99,9 @@ final class MetricsFilter extends OncePerRequestFilter {
 		if (is4xxClientError(status)) {
 			return UNKNOWN_PATH_SUFFIX;
 		}
+		if (is3xxRedirection(status)) {
+			return UNKNOWN_PATH_SUFFIX;
+		}
 		return path;
 	}
 
@@ -126,6 +129,15 @@ final class MetricsFilter extends OncePerRequestFilter {
 		}
 	}
 
+	private boolean is3xxRedirection(int status) {
+		try {
+			return HttpStatus.valueOf(status).is3xxRedirection();
+		}
+		catch (Exception ex) {
+			return false;
+		}
+	}
+
 	private String getKey(String string) {
 		// graphite compatible metric names
 		String value = string.replace("/", ".");

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/autoconfigure/MetricFilterAutoConfigurationTests.java

@@ -16,8 +16,26 @@
 
 package org.springframework.boot.actuate.autoconfigure;
 
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
+import static org.mockito.BDDMockito.willAnswer;
+import static org.mockito.BDDMockito.willThrow;
+import static org.mockito.Matchers.anyDouble;
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import java.io.IOException;
+
 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 
 import org.junit.Test;
 import org.mockito.invocation.InvocationOnMock;
@@ -27,9 +45,11 @@ import org.springframework.boot.actuate.metrics.GaugeService;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.annotation.Order;
 import org.springframework.http.HttpStatus;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.stereotype.Component;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -37,21 +57,9 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.filter.OncePerRequestFilter;
 import org.springframework.web.util.NestedServletException;
 
-import static org.hamcrest.Matchers.equalTo;
-import static org.junit.Assert.assertThat;
-import static org.mockito.BDDMockito.willAnswer;
-import static org.mockito.BDDMockito.willThrow;
-import static org.mockito.Matchers.anyDouble;
-import static org.mockito.Matchers.anyString;
-import static org.mockito.Matchers.eq;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
-
 /**
  * Tests for {@link MetricFilterAutoConfiguration}.
  *
@@ -130,6 +138,23 @@ public class MetricFilterAutoConfigurationTests {
 		context.close();
 	}
 
+	@Test
+	public void records302HttpInteractionsAsSingleMetric() throws Exception {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				Config.class, MetricFilterAutoConfiguration.class, RedirectFilter.class);
+		MetricsFilter filter = context.getBean(MetricsFilter.class);
+		MockMvc mvc = MockMvcBuilders.standaloneSetup(new MetricFilterTestController())
+				.addFilter(filter).addFilter(context.getBean(RedirectFilter.class))
+				.build();
+		mvc.perform(get("/unknownPath/1")).andExpect(status().is3xxRedirection());
+		mvc.perform(get("/unknownPath/2")).andExpect(status().is3xxRedirection());
+		verify(context.getBean(CounterService.class), times(2)).increment(
+				"status.302.unmapped");
+		verify(context.getBean(GaugeService.class), times(2)).submit(
+				eq("response.unmapped"), anyDouble());
+		context.close();
+	}
+
 	@Test
 	public void skipsFilterIfMissingServices() throws Exception {
 		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
@@ -214,4 +239,19 @@ public class MetricFilterAutoConfigurationTests {
 		}
 	}
 
+	@Component
+	@Order(0)
+	public static class RedirectFilter extends OncePerRequestFilter {
+
+		@Override
+		protected void doFilterInternal(HttpServletRequest request,
+				HttpServletResponse response, FilterChain chain) throws ServletException,
+				IOException {
+			// send redirect before filter chain is executed, like Spring Security sending
+			// us back to a login page
+			response.sendRedirect("http://example.com");
+		}
+
+	}
+
 }

spring-boot-samples/spring-boot-sample-web-secure/pom.xml

@@ -19,6 +19,10 @@
 		<main.basedir>${basedir}/../..</main.basedir>
 	</properties>
 	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-security</artifactId>