Separates GatewayTracingAutoConfiguration from GatewayMetricsAutoConfiguration

This fixes ordering and classpath problems now that boot has separate autoconfiguration classes.

Fixes gh-4006

Author: spencergibb

spring-cloud-gateway-server-webflux/src/main/java/org/springframework/cloud/gateway/config/GatewayMetricsAutoConfiguration.java

@@ -20,8 +20,6 @@
 
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.observation.ObservationRegistry;
-import io.micrometer.tracing.Tracer;
-import io.micrometer.tracing.propagation.Propagator;
 
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
@@ -35,12 +33,9 @@
 import org.springframework.boot.micrometer.metrics.autoconfigure.CompositeMeterRegistryAutoConfiguration;
 import org.springframework.boot.micrometer.metrics.autoconfigure.MetricsAutoConfiguration;
 import org.springframework.boot.micrometer.observation.autoconfigure.ObservationAutoConfiguration;
-import org.springframework.boot.micrometer.tracing.autoconfigure.MicrometerTracingAutoConfiguration;
-import org.springframework.boot.micrometer.tracing.autoconfigure.TracingProperties;
 import org.springframework.boot.webflux.autoconfigure.HttpHandlerAutoConfiguration;
 import org.springframework.cloud.gateway.filter.GatewayMetricsFilter;
 import org.springframework.cloud.gateway.filter.headers.observation.GatewayObservationConvention;
-import org.springframework.cloud.gateway.filter.headers.observation.GatewayPropagatingSenderTracingObservationHandler;
 import org.springframework.cloud.gateway.filter.headers.observation.ObservationClosingWebExceptionHandler;
 import org.springframework.cloud.gateway.filter.headers.observation.ObservedRequestHttpHeadersFilter;
 import org.springframework.cloud.gateway.filter.headers.observation.ObservedResponseHttpHeadersFilter;
@@ -62,9 +57,8 @@
 @EnableConfigurationProperties(GatewayMetricsProperties.class)
 @AutoConfigureBefore(HttpHandlerAutoConfiguration.class)
 @AutoConfigureAfter({ MetricsAutoConfiguration.class, CompositeMeterRegistryAutoConfiguration.class,
-		ObservationAutoConfiguration.class, MicrometerTracingAutoConfiguration.class })
-@ConditionalOnClass({ DispatcherHandler.class, MeterRegistry.class, MetricsAutoConfiguration.class,
-		MicrometerTracingAutoConfiguration.class })
+		ObservationAutoConfiguration.class })
+@ConditionalOnClass({ DispatcherHandler.class, MeterRegistry.class, MetricsAutoConfiguration.class })
 public class GatewayMetricsAutoConfiguration {
 
 	@Bean
@@ -133,23 +127,6 @@ ObservationClosingWebExceptionHandler observationClosingWebExceptionHandler() {
 			return new ObservationClosingWebExceptionHandler();
 		}
 
-		@Configuration(proxyBeanMethods = false)
-		@ConditionalOnClass({ Tracer.class, TracingProperties.class })
-		@ConditionalOnBean({ Tracer.class, TracingProperties.class })
-		static class GatewayTracingConfiguration {
-
-			@Bean
-			@ConditionalOnMissingBean
-			@ConditionalOnBean({ Propagator.class, TracingProperties.class })
-			@Order(Ordered.HIGHEST_PRECEDENCE + 5)
-			GatewayPropagatingSenderTracingObservationHandler gatewayPropagatingSenderTracingObservationHandler(
-					Tracer tracer, Propagator propagator, TracingProperties tracingProperties) {
-				return new GatewayPropagatingSenderTracingObservationHandler(tracer, propagator,
-						tracingProperties.getBaggage().getRemoteFields());
-			}
-
-		}
-
 	}
 
 }

spring-cloud-gateway-server-webflux/src/main/java/org/springframework/cloud/gateway/config/GatewayTracingAutoConfiguration.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2013-present 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.gateway.config;
+
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.propagation.Propagator;
+
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.micrometer.tracing.autoconfigure.MicrometerTracingAutoConfiguration;
+import org.springframework.boot.micrometer.tracing.autoconfigure.TracingProperties;
+import org.springframework.cloud.gateway.filter.headers.observation.GatewayPropagatingSenderTracingObservationHandler;
+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.web.reactive.DispatcherHandler;
+
+@Configuration(proxyBeanMethods = false)
+@ConditionalOnProperty(name = GatewayProperties.PREFIX + ".observability.enabled", matchIfMissing = true)
+@AutoConfigureAfter({ GatewayMetricsAutoConfiguration.class, MicrometerTracingAutoConfiguration.class })
+@ConditionalOnClass({ DispatcherHandler.class, Tracer.class, TracingProperties.class,
+		MicrometerTracingAutoConfiguration.class })
+public class GatewayTracingAutoConfiguration {
+
+	@Bean
+	@ConditionalOnMissingBean
+	@ConditionalOnBean({ Tracer.class, Propagator.class, TracingProperties.class })
+	@Order(Ordered.HIGHEST_PRECEDENCE + 5)
+	GatewayPropagatingSenderTracingObservationHandler gatewayPropagatingSenderTracingObservationHandler(Tracer tracer,
+			Propagator propagator, TracingProperties tracingProperties) {
+		return new GatewayPropagatingSenderTracingObservationHandler(tracer, propagator,
+				tracingProperties.getBaggage().getRemoteFields());
+	}
+
+}

spring-cloud-gateway-server-webflux/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -9,4 +9,5 @@ org.springframework.cloud.gateway.config.GatewayStreamAutoConfiguration
 org.springframework.cloud.gateway.discovery.GatewayDiscoveryClientAutoConfiguration
 org.springframework.cloud.gateway.config.SimpleUrlHandlerMappingGlobalCorsAutoConfiguration
 org.springframework.cloud.gateway.config.GatewayReactiveLoadBalancerClientAutoConfiguration
-org.springframework.cloud.gateway.config.LocalResponseCacheAutoConfiguration
+org.springframework.cloud.gateway.config.LocalResponseCacheAutoConfiguration
+org.springframework.cloud.gateway.config.GatewayTracingAutoConfiguration