Adds integration of new customizers in Brave

fixes gh-1436

Author: marcingrzejszczak

benchmarks/pom.xml

@@ -34,7 +34,7 @@
 		<maven.compiler.target>1.8</maven.compiler.target>
 		<maven.compiler.source>1.8</maven.compiler.source>
 		<spring-boot.version>2.2.0.BUILD-SNAPSHOT</spring-boot.version>
-		<brave.version>5.6.9</brave.version>
+		<brave.version>5.7.0</brave.version>
 	</properties>
 
 	<dependencyManagement>

docs/src/main/asciidoc/spring-cloud-sleuth.adoc

@@ -833,6 +833,16 @@ Running the preceding method with a value of `15` leads to setting a tag with a
 
 == Customizations
 
+=== Customizers
+
+With Brave 5.7 you have various options of providing customizers for your project. Brave ships with
+
+* `TracingCustomizer` - allows configuration plugins to collaborate on building an instance of `Tracing`.
+* `CurrentTraceContextCustomizer` - allows configuration plugins to collaborate on building an instance of `CurrentTraceContext`.
+* `ExtraFieldCustomizer` - allows configuration plugins to collaborate on building an instance of `ExtraFieldPropagation.Factory`.
+
+Sleuth will search for beans of those types and automatically apply customizations.
+
 === HTTP
 
 If a customization of client / server parsing of the HTTP related spans is required,

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/autoconfig/TraceAutoConfiguration.java

@@ -24,9 +24,12 @@
 import brave.ErrorParser;
 import brave.Tracer;
 import brave.Tracing;
+import brave.TracingCustomizer;
 import brave.handler.FinishedSpanHandler;
 import brave.propagation.B3Propagation;
 import brave.propagation.CurrentTraceContext;
+import brave.propagation.CurrentTraceContextCustomizer;
+import brave.propagation.ExtraFieldCustomizer;
 import brave.propagation.ExtraFieldPropagation;
 import brave.propagation.Propagation;
 import brave.propagation.ThreadLocalCurrentTraceContext;
@@ -87,6 +90,15 @@ public class TraceAutoConfiguration {
 	@Autowired(required = false)
 	ExtraFieldPropagation.FactoryBuilder extraFieldPropagationFactoryBuilder;
 
+	@Autowired(required = false)
+	List<TracingCustomizer> tracingCustomizers = new ArrayList<>();
+
+	@Autowired(required = false)
+	List<CurrentTraceContextCustomizer> currentTraceContextCustomizers = new ArrayList<>();
+
+	@Autowired(required = false)
+	List<ExtraFieldCustomizer> extraFieldCustomizers = new ArrayList<>();
+
 	@Bean
 	@ConditionalOnMissingBean
 	// NOTE: stable bean name as might be used outside sleuth
@@ -107,6 +119,9 @@ Tracing tracing(
 		for (FinishedSpanHandler finishedSpanHandlerFactory : this.finishedSpanHandlers) {
 			builder.addFinishedSpanHandler(finishedSpanHandlerFactory);
 		}
+		for (TracingCustomizer customizer : this.tracingCustomizers) {
+			customizer.customize(builder);
+		}
 		return builder.build();
 	}
 
@@ -160,6 +175,9 @@ Propagation.Factory sleuthPropagation(SleuthProperties sleuthProperties) {
 				factoryBuilder = factoryBuilder.addRedactedField(key);
 			}
 		}
+		for (ExtraFieldCustomizer customizer : this.extraFieldCustomizers) {
+			customizer.customize(factoryBuilder);
+		}
 		return factoryBuilder.build();
 	}
 
@@ -168,6 +186,9 @@ CurrentTraceContext sleuthCurrentTraceContext(CurrentTraceContext.Builder builde
 		for (CurrentTraceContext.ScopeDecorator scopeDecorator : this.scopeDecorators) {
 			builder.addScopeDecorator(scopeDecorator);
 		}
+		for (CurrentTraceContextCustomizer customizer : this.currentTraceContextCustomizers) {
+			customizer.customize(builder);
+		}
 		return builder.build();
 	}
 

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

@@ -16,14 +16,19 @@
 
 package org.springframework.cloud.sleuth.instrument.web;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import brave.ErrorParser;
 import brave.Tracing;
 import brave.http.HttpAdapter;
 import brave.http.HttpClientParser;
 import brave.http.HttpSampler;
 import brave.http.HttpServerParser;
 import brave.http.HttpTracing;
+import brave.http.HttpTracingCustomizer;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -51,6 +56,9 @@ public class TraceHttpAutoConfiguration {
 
 	static final int TRACING_FILTER_ORDER = Ordered.HIGHEST_PRECEDENCE + 5;
 
+	@Autowired(required = false)
+	List<HttpTracingCustomizer> httpTracingCustomizers = new ArrayList<>();
+
 	@Bean
 	@ConditionalOnMissingBean
 	// NOTE: stable bean name as might be used outside sleuth
@@ -60,9 +68,13 @@ HttpTracing httpTracing(Tracing tracing, SkipPatternProvider provider,
 			@Nullable @ServerSampler HttpSampler serverSampler) {
 		HttpSampler combinedSampler = combineUserProvidedSamplerWithSkipPatternSampler(
 				serverSampler, provider);
-		return HttpTracing.newBuilder(tracing).clientParser(clientParser)
-				.serverParser(serverParser).clientSampler(clientSampler)
-				.serverSampler(combinedSampler).build();
+		HttpTracing.Builder builder = HttpTracing.newBuilder(tracing)
+				.clientParser(clientParser).serverParser(serverParser)
+				.clientSampler(clientSampler).serverSampler(combinedSampler);
+		for (HttpTracingCustomizer customizer : this.httpTracingCustomizers) {
+			customizer.customize(builder);
+		}
+		return builder.build();
 	}
 
 	private HttpSampler combineUserProvidedSamplerWithSkipPatternSampler(

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/autoconfig/TraceAutoConfigurationCustomizersTests.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2013-2019 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
+ *
+ *      https://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.autoconfig;
+
+import brave.TracingCustomizer;
+import brave.http.HttpTracingCustomizer;
+import brave.propagation.CurrentTraceContextCustomizer;
+import brave.propagation.ExtraFieldCustomizer;
+import brave.sampler.Sampler;
+import org.junit.Test;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.cloud.sleuth.instrument.web.TraceHttpAutoConfiguration;
+import org.springframework.cloud.sleuth.instrument.web.TraceWebAutoConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import static org.assertj.core.api.BDDAssertions.then;
+
+public class TraceAutoConfigurationCustomizersTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+			.withPropertyValues("spring.sleuth.baggage-keys=my-baggage")
+			.withConfiguration(AutoConfigurations.of(TraceAutoConfiguration.class,
+					TraceWebAutoConfiguration.class, TraceHttpAutoConfiguration.class))
+			.withUserConfiguration(Customizers.class);
+
+	@Test
+	public void should_apply_customizers() {
+		this.contextRunner.run((context) -> {
+			Customizers bean = context.getBean(Customizers.class);
+
+			shouldApplyCustomizations(bean);
+			shouldNotOverrideTheDefaults(context);
+		});
+	}
+
+	private void shouldNotOverrideTheDefaults(AssertableApplicationContext context) {
+		then(context.getBean(Sampler.class)).isSameAs(Sampler.ALWAYS_SAMPLE);
+	}
+
+	private void shouldApplyCustomizations(Customizers bean) {
+		then(bean.tracingCustomizerApplied).isTrue();
+		then(bean.contextCustomizerApplied).isTrue();
+		then(bean.extraFieldCustomizerApplied).isTrue();
+		then(bean.httpCustomizerApplied).isTrue();
+	}
+
+	@Configuration
+	static class Customizers {
+
+		boolean tracingCustomizerApplied;
+
+		boolean contextCustomizerApplied;
+
+		boolean extraFieldCustomizerApplied;
+
+		boolean httpCustomizerApplied;
+
+		@Bean
+		TracingCustomizer sleuthTracingCustomizer() {
+			return builder -> tracingCustomizerApplied = true;
+		}
+
+		@Bean
+		CurrentTraceContextCustomizer sleuthCurrentTraceContextCustomizer() {
+			return builder -> contextCustomizerApplied = true;
+		}
+
+		@Bean
+		ExtraFieldCustomizer sleuthExtraFieldCustomizer() {
+			return builder -> extraFieldCustomizerApplied = true;
+		}
+
+		@Bean
+		HttpTracingCustomizer sleuthHttpTracingCustomizer() {
+			return builder -> httpCustomizerApplied = true;
+		}
+
+		@Bean
+		Sampler sampler() {
+			return Sampler.ALWAYS_SAMPLE;
+		}
+
+	}
+
+}

spring-cloud-sleuth-dependencies/pom.xml

@@ -31,7 +31,7 @@
 	<name>spring-cloud-sleuth-dependencies</name>
 	<description>Spring Cloud Sleuth Dependencies</description>
 	<properties>
-		<brave.version>5.6.10</brave.version>
+		<brave.version>5.7.0</brave.version>
 		<brave.opentracing.version>0.34.1</brave.opentracing.version>
 		<grpc.spring.boot.version>3.4.1</grpc.spring.boot.version>
 	</properties>