Updates sample decisions upon context refresh (#751)

fixes #747

spring-cloud-sleuth-stream/pom.xml

@@ -28,6 +28,11 @@
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-commons</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-context</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-aop</artifactId>

spring-cloud-sleuth-stream/src/main/java/org/springframework/cloud/sleuth/stream/SleuthStreamAutoConfiguration.java

@@ -24,6 +24,7 @@ import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.ServerProperties;
@@ -31,6 +32,7 @@ import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.client.serviceregistry.Registration;
 import org.springframework.cloud.commons.util.InetUtils;
+import org.springframework.cloud.context.config.annotation.RefreshScope;
 import org.springframework.cloud.sleuth.Sampler;
 import org.springframework.cloud.sleuth.SpanAdjuster;
 import org.springframework.cloud.sleuth.autoconfig.TraceAutoConfiguration;
@@ -71,10 +73,25 @@ public class SleuthStreamAutoConfiguration {
 
 	@Autowired(required = false) List<SpanAdjuster> spanAdjusters = new ArrayList<>();
 
-	@Bean
-	@ConditionalOnMissingBean
-	public Sampler defaultTraceSampler(SamplerProperties config) {
-		return new PercentageBasedSampler(config);
+	@Configuration
+	@ConditionalOnClass(RefreshScope.class)
+	protected static class RefreshScopedPercentageBasedSamplerConfiguration {
+		@Bean
+		@RefreshScope
+		@ConditionalOnMissingBean
+		public Sampler defaultTraceSampler(SamplerProperties config) {
+			return new PercentageBasedSampler(config);
+		}
+	}
+
+	@Configuration
+	@ConditionalOnMissingClass("org.springframework.cloud.context.config.annotation.RefreshScope")
+	protected static class NonRefreshScopePercentageBasedSamplerConfiguration {
+		@Bean
+		@ConditionalOnMissingBean
+		public Sampler defaultTraceSampler(SamplerProperties config) {
+			return new PercentageBasedSampler(config);
+		}
 	}
 
 	@Bean

spring-cloud-sleuth-zipkin/pom.xml

@@ -45,6 +45,11 @@
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-commons</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-context</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-actuator</artifactId>

spring-cloud-sleuth-zipkin/src/main/java/org/springframework/cloud/sleuth/zipkin/ZipkinAutoConfiguration.java

@@ -35,6 +35,7 @@ import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.client.serviceregistry.Registration;
 import org.springframework.cloud.commons.util.InetUtils;
+import org.springframework.cloud.context.config.annotation.RefreshScope;
 import org.springframework.cloud.sleuth.Sampler;
 import org.springframework.cloud.sleuth.SpanAdjuster;
 import org.springframework.cloud.sleuth.SpanReporter;
@@ -136,10 +137,25 @@ public class ZipkinAutoConfiguration {
 		return new DefaultZipkinRestTemplateCustomizer(zipkinProperties);
 	}
 
-	@Bean
-	@ConditionalOnMissingBean
-	public Sampler defaultTraceSampler(SamplerProperties config) {
-		return new PercentageBasedSampler(config);
+	@Configuration
+	@ConditionalOnClass(RefreshScope.class)
+	protected static class RefreshScopedPercentageBasedSamplerConfiguration {
+		@Bean
+		@RefreshScope
+		@ConditionalOnMissingBean
+		public Sampler defaultTraceSampler(SamplerProperties config) {
+			return new PercentageBasedSampler(config);
+		}
+	}
+
+	@Configuration
+	@ConditionalOnMissingClass("org.springframework.cloud.context.config.annotation.RefreshScope")
+	protected static class NonRefreshScopePercentageBasedSamplerConfiguration {
+		@Bean
+		@ConditionalOnMissingBean
+		public Sampler defaultTraceSampler(SamplerProperties config) {
+			return new PercentageBasedSampler(config);
+		}
 	}
 
 	@Bean

spring-cloud-sleuth-zipkin2/pom.xml

@@ -45,6 +45,11 @@
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-commons</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-context</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-actuator</artifactId>

spring-cloud-sleuth-zipkin2/src/main/java/org/springframework/cloud/sleuth/zipkin2/ZipkinAutoConfiguration.java

@@ -19,15 +19,18 @@ package org.springframework.cloud.sleuth.zipkin2;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.client.serviceregistry.Registration;
 import org.springframework.cloud.commons.util.InetUtils;
+import org.springframework.cloud.context.config.annotation.RefreshScope;
 import org.springframework.cloud.sleuth.Sampler;
 import org.springframework.cloud.sleuth.SpanAdjuster;
 import org.springframework.cloud.sleuth.SpanReporter;
@@ -95,10 +98,25 @@ public class ZipkinAutoConfiguration {
 		return new DefaultZipkinRestTemplateCustomizer(zipkinProperties);
 	}
 
-	@Bean
-	@ConditionalOnMissingBean
-	public Sampler defaultTraceSampler(SamplerProperties config) {
-		return new PercentageBasedSampler(config);
+	@Configuration
+	@ConditionalOnClass(RefreshScope.class)
+	protected static class RefreshScopedPercentageBasedSamplerConfiguration {
+		@Bean
+		@RefreshScope
+		@ConditionalOnMissingBean
+		public Sampler defaultTraceSampler(SamplerProperties config) {
+			return new PercentageBasedSampler(config);
+		}
+	}
+
+	@Configuration
+	@ConditionalOnMissingClass("org.springframework.cloud.context.config.annotation.RefreshScope")
+	protected static class NonRefreshScopePercentageBasedSamplerConfiguration {
+		@Bean
+		@ConditionalOnMissingBean
+		public Sampler defaultTraceSampler(SamplerProperties config) {
+			return new PercentageBasedSampler(config);
+		}
 	}
 
 	@Bean