Remove support for LoadBalancerFeignClient (#324)

LoadBalancerFeignClient was removed in spring-cloud-openfeign, so this code might raise errors when used with newer spring versions

instrument-starters/opentracing-spring-cloud-feign-starter/src/main/java/io/opentracing/contrib/spring/cloud/feign/FeignContextBeanPostProcessor.java

@@ -27,20 +27,17 @@
 public class FeignContextBeanPostProcessor implements BeanPostProcessor {
 
   private Tracer tracer;
-  private BeanFactory beanFactory;
   private List<FeignSpanDecorator> spanDecorators;
 
-  FeignContextBeanPostProcessor(Tracer tracer, BeanFactory beanFactory,
-      List<FeignSpanDecorator> spanDecorators) {
+  FeignContextBeanPostProcessor(Tracer tracer, List<FeignSpanDecorator> spanDecorators) {
     this.tracer = tracer;
-    this.beanFactory = beanFactory;
     this.spanDecorators = spanDecorators;
   }
 
   @Override
   public Object postProcessBeforeInitialization(Object bean, String name) throws BeansException {
     if (bean instanceof FeignContext && !(bean instanceof TraceFeignContext)) {
-      return new TraceFeignContext(tracer, (FeignContext) bean, beanFactory, spanDecorators);
+      return new TraceFeignContext(tracer, (FeignContext) bean, spanDecorators);
     }
     return bean;
   }

instrument-starters/opentracing-spring-cloud-feign-starter/src/main/java/io/opentracing/contrib/spring/cloud/feign/FeignTracingAutoConfiguration.java

@@ -58,8 +58,8 @@ public class FeignTracingAutoConfiguration {
 
   @Bean
   @ConditionalOnClass(name = "org.springframework.cloud.openfeign.FeignContext")
-  FeignContextBeanPostProcessor feignContextBeanPostProcessor(BeanFactory beanFactory) {
-    return new FeignContextBeanPostProcessor(tracer, beanFactory, spanDecorators);
+  FeignContextBeanPostProcessor feignContextBeanPostProcessor() {
+    return new FeignContextBeanPostProcessor(tracer, spanDecorators);
   }
 
   @Configuration

instrument-starters/opentracing-spring-cloud-feign-starter/src/main/java/io/opentracing/contrib/spring/cloud/feign/TraceFeignContext.java

@@ -19,7 +19,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.springframework.beans.factory.BeanFactory;
 import org.springframework.cloud.openfeign.FeignContext;
 
 /**
@@ -30,10 +29,9 @@ class TraceFeignContext extends FeignContext {
   private final FeignContext delegate;
   private final TracedFeignBeanFactory tracedFeignBeanFactory;
 
-  TraceFeignContext(Tracer tracer, FeignContext delegate, BeanFactory beanFactory,
-                    List<FeignSpanDecorator> spanDecorators) {
+  TraceFeignContext(Tracer tracer, FeignContext delegate, List<FeignSpanDecorator> spanDecorators) {
     this.delegate = delegate;
-    this.tracedFeignBeanFactory = new TracedFeignBeanFactory(tracer, beanFactory, spanDecorators);
+    this.tracedFeignBeanFactory = new TracedFeignBeanFactory(tracer, spanDecorators);
   }
 
   @SuppressWarnings("unchecked")

instrument-starters/opentracing-spring-cloud-feign-starter/src/main/java/io/opentracing/contrib/spring/cloud/feign/TracedFeignBeanFactory.java

@@ -18,36 +18,24 @@
 import feign.opentracing.TracingClient;
 import io.opentracing.Tracer;
 import java.util.List;
-import org.springframework.beans.factory.BeanFactory;
-import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
-import org.springframework.cloud.openfeign.ribbon.CachingSpringLoadBalancerFactory;
-import org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient;
 import org.springframework.context.annotation.Lazy;
 
 class TracedFeignBeanFactory {
 
   private final Tracer tracer;
-  private final BeanFactory beanFactory;
   private final List<FeignSpanDecorator> spanDecorators;
 
-  public TracedFeignBeanFactory(Tracer tracer, BeanFactory beanFactory, @Lazy List<FeignSpanDecorator> spanDecorators) {
+  public TracedFeignBeanFactory(Tracer tracer, @Lazy List<FeignSpanDecorator> spanDecorators) {
     this.tracer = tracer;
-    this.beanFactory = beanFactory;
     this.spanDecorators = spanDecorators;
   }
 
   public Object from(Object bean) {
-    if (bean instanceof TracingClient || bean instanceof LoadBalancedTracedFeign) {
+    if (bean instanceof TracingClient) {
       return bean;
     }
 
     if (bean instanceof Client) {
-      if (bean instanceof LoadBalancerFeignClient) {
-        return new LoadBalancedTracedFeign(
-            buildTracingClient(((LoadBalancerFeignClient) bean).getDelegate(), tracer),
-            beanFactory.getBean(CachingSpringLoadBalancerFactory.class),
-            beanFactory.getBean(SpringClientFactory.class));
-      }
       return buildTracingClient((Client) bean, tracer);
     }
 
@@ -60,17 +48,4 @@ private TracingClient buildTracingClient(Client delegate, Tracer tracer) {
         .withFeignSpanDecorators(spanDecorators)
         .build();
   }
-
-  /**
-   * Needed for cast in {@link org.springframework.cloud.openfeign.FeignClientFactoryBean}
-   */
-  static class LoadBalancedTracedFeign extends LoadBalancerFeignClient {
-
-    public LoadBalancedTracedFeign(Client delegate,
-                                   CachingSpringLoadBalancerFactory lbClientFactory,
-                                   SpringClientFactory clientFactory) {
-      super(delegate, lbClientFactory, clientFactory);
-    }
-  }
-
 }