gh-1331 defaulting 404 response metrics to "unkownPath" when no matching handler can be found

Fixes gh-1331, Fixes gh-1333

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

@@ -37,6 +37,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
+import org.springframework.http.HttpStatus;
 import org.springframework.util.StopWatch;
 import org.springframework.web.filter.OncePerRequestFilter;
 import org.springframework.web.servlet.HandlerMapping;
@@ -56,6 +57,7 @@ import org.springframework.web.util.UrlPathHelper;
 public class MetricFilterAutoConfiguration {
 
 	private static final int UNDEFINED_HTTP_STATUS = 999;
+	private static final String UNKNOWN_PATH_SUFFIX = "/unknownPath";
 
 	@Autowired
 	private CounterService counterService;
@@ -91,6 +93,10 @@ public class MetricFilterAutoConfiguration {
 				{
 					suffix = request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE).toString().replaceAll("[{}]", "-");
 				}
+				else if(getStatus(response) == HttpStatus.NOT_FOUND.value())
+				{
+					suffix=UNKNOWN_PATH_SUFFIX;
+				}
 				String gaugeKey = getKey("response" + suffix);
 				MetricFilterAutoConfiguration.this.gaugeService.submit(gaugeKey,
 						stopWatch.getTotalTimeMillis());

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

@@ -22,6 +22,7 @@ import static org.mockito.BDDMockito.willAnswer;
 import static org.mockito.Matchers.anyDouble;
 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;
@@ -37,11 +38,15 @@ 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.http.HttpStatus;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.bind.annotation.PathVariable;
 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;
 
 /**
@@ -89,6 +94,39 @@ public class MetricFilterAutoConfigurationTests {
 				anyDouble());
 		context.close();
 	}
+	
+	@Test
+	public void recordsKnown404HttpInteractionsAsSingleMetricWithPathAndTemplateVariable() throws Exception {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				Config.class, MetricFilterAutoConfiguration.class);
+		Filter filter = context.getBean(Filter.class);
+		MockMvc mvc = MockMvcBuilders.standaloneSetup(new MetricFilterTestController()).addFilter(filter).build();
+		mvc.perform(get("/knownPath/foo"))
+		.andExpect(status().isNotFound());
+		
+		verify(context.getBean(CounterService.class)).increment("status.404.knownPath.-someVariable-");
+		verify(context.getBean(GaugeService.class)).submit(eq("response.knownPath.-someVariable-"),
+				anyDouble());
+		context.close();
+	}
+	
+	@Test
+	public void records404HttpInteractionsAsSingleMetric() throws Exception {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				Config.class, MetricFilterAutoConfiguration.class);
+		Filter filter = context.getBean(Filter.class);
+		MockMvc mvc = MockMvcBuilders.standaloneSetup(new MetricFilterTestController()).addFilter(filter).build();
+		mvc.perform(get("/unknownPath/1"))
+		.andExpect(status().isNotFound());
+		
+		mvc.perform(get("/unknownPath/2"))
+		.andExpect(status().isNotFound());
+		
+		verify(context.getBean(CounterService.class), times(2)).increment("status.404.unknownPath");
+		verify(context.getBean(GaugeService.class), times(2)).submit(eq("response.unknownPath"),
+				anyDouble());
+		context.close();
+	}
 
 	@Test
 	public void skipsFilterIfMissingServices() throws Exception {
@@ -121,7 +159,15 @@ class MetricFilterTestController
 {
 	
 	@RequestMapping("templateVarTest/{someVariable}")
-	public String testTemplateVariableResolution(String someVariable)
+	public String testTemplateVariableResolution(@PathVariable String someVariable)
+	{
+		return someVariable;
+	}
+	
+	@RequestMapping("knownPath/{someVariable}")
+	@ResponseStatus(HttpStatus.NOT_FOUND)
+	@ResponseBody
+	public String testKnownPathWith404Response(@PathVariable String someVariable)
 	{
 		return someVariable;
 	}