Fixing TraceFilter order (#382)

after making TraceFilter process different dispatch types we've introduced a bug related to filter ordering. TraceFilter was registered with a default ordering which is of lowest precedence.

With this change we ensure that the ordering of TraceFilter is fixed.

Fixes #380

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/TraceFilter.java

@@ -65,13 +65,15 @@ import org.springframework.web.util.UrlPathHelper;
  * @see TraceKeys
  * @see TraceWebAutoConfiguration#traceFilter
  */
-@Order(Ordered.HIGHEST_PRECEDENCE + 5)
+@Order(TraceFilter.ORDER)
 public class TraceFilter extends GenericFilterBean {
 
 	private static final Log log = LogFactory.getLog(MethodHandles.lookup().lookupClass());
 
 	private static final String HTTP_COMPONENT = "http";
 
+	protected static final int ORDER = Ordered.HIGHEST_PRECEDENCE + 5;
+
 	protected static final String TRACE_REQUEST_ATTR = TraceFilter.class.getName()
 			+ ".TRACE";
 

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/TraceWebAutoConfiguration.java

@@ -15,8 +15,8 @@
  */
 package org.springframework.cloud.sleuth.instrument.web;
 
-import javax.servlet.http.HttpServletRequest;
 import java.util.regex.Pattern;
+import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.annotation.Value;
@@ -90,6 +90,7 @@ public class TraceWebAutoConfiguration {
 			HttpTraceKeysInjector httpTraceKeysInjector, TraceFilter traceFilter) {
 		FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(traceFilter);
 		filterRegistrationBean.setDispatcherTypes(ASYNC, ERROR, FORWARD, INCLUDE, REQUEST);
+		filterRegistrationBean.setOrder(TraceFilter.ORDER);
 		return filterRegistrationBean;
 	}
 

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/web/TraceFilterWebIntegrationMultipleFiltersTests.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright 2013-2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.sleuth.instrument.web;
+
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicReference;
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.context.embedded.FilterRegistrationBean;
+import org.springframework.boot.test.SpringApplicationConfiguration;
+import org.springframework.boot.test.WebIntegrationTest;
+import org.springframework.cloud.sleuth.Sampler;
+import org.springframework.cloud.sleuth.Span;
+import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.cloud.sleuth.sampler.AlwaysSampler;
+import org.springframework.cloud.sleuth.trace.TestSpanContextHolder;
+import org.springframework.cloud.sleuth.util.ExceptionUtils;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
+import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.web.client.DefaultResponseErrorHandler;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.filter.GenericFilterBean;
+
+import static org.springframework.cloud.sleuth.assertions.SleuthAssertions.then;
+
+/**
+ * @author Marcin Grzejszczak
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@WebIntegrationTest({ "server.port=0" })
+@SpringApplicationConfiguration(classes = { TraceFilterWebIntegrationMultipleFiltersTests.Config.class })
+public class TraceFilterWebIntegrationMultipleFiltersTests {
+
+	@Autowired Tracer tracer;
+	@Autowired RestTemplate restTemplate;
+	@Autowired Environment environment;
+	@Autowired MyFilter myFilter;
+
+	@Before
+	@After
+	public void cleanup() {
+		ExceptionUtils.setFail(true);
+		TestSpanContextHolder.removeCurrentSpan();
+	}
+
+	@Test
+	public void should_register_trace_filter_before_the_custom_filter() {
+		this.restTemplate.getForObject("http://localhost:" + port() + "/", String.class);
+
+		then(this.tracer.getCurrentSpan()).isNull();
+		then(this.myFilter.getSpan().get()).isNotNull();
+		then(ExceptionUtils.getLastException()).isNull();
+	}
+
+	private int port() {
+		return this.environment.getProperty("local.server.port", Integer.class);
+	}
+
+	@EnableAutoConfiguration
+	@Configuration
+	public static class Config {
+
+		@Bean Sampler alwaysSampler() {
+			return new AlwaysSampler();
+		}
+
+
+		@Bean RestTemplate restTemplate() {
+			RestTemplate restTemplate = new RestTemplate();
+			restTemplate.setErrorHandler(new DefaultResponseErrorHandler() {
+				@Override public void handleError(ClientHttpResponse response)
+						throws IOException {
+				}
+			});
+			return restTemplate;
+		}
+
+		@Bean MyFilter myFilter(Tracer tracer) {
+			return new MyFilter(tracer);
+		}
+
+		@Bean FilterRegistrationBean registrationBean(MyFilter myFilter) {
+			FilterRegistrationBean bean = new FilterRegistrationBean();
+			bean.setFilter(myFilter);
+			bean.setOrder(0);
+			return bean;
+		}
+	}
+
+	static class MyFilter extends GenericFilterBean {
+
+		AtomicReference<Span> span = new AtomicReference<>();
+
+		private final Tracer tracer;
+
+		MyFilter(Tracer tracer) {
+			this.tracer = tracer;
+		}
+
+		@Override public void doFilter(ServletRequest request, ServletResponse response,
+				FilterChain chain) throws IOException, ServletException {
+			Span currentSpan = tracer.getCurrentSpan();
+			this.span.set(currentSpan);
+		}
+
+		public AtomicReference<Span> getSpan() {
+			return span;
+		}
+	}
+}