Add support for Ribbon loadbalancing in RestTemplate via an…

pom.xml

@@ -210,7 +210,7 @@
         <eureka.version>1.1.135</eureka.version>
         <feign.version>6.1.2</feign.version>
         <hystrix.version>1.4.0-RC4</hystrix.version>
-        <ribbon.version>0.3.12</ribbon.version>
+        <ribbon.version>0.3.13</ribbon.version>
         <turbine.version>0.4</turbine.version>
         <zuul.version>1.0.24</zuul.version>
     </properties>

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/client/ClientAutoConfiguration.java

+package org.springframework.cloud.client;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Spencer Gibb
+ * TODO: move org.springframework.cloud.client to a spring-cloud-common project
+ */
+@Configuration
+@EnableConfigurationProperties
+@ConditionalOnExpression("${spring.cloud.client.enabled:true}")
+public class ClientAutoConfiguration {
+
+    @Bean
+    @ConditionalOnMissingBean(ClientProperties.class)
+    public ClientProperties clientProperties() {
+        return new ClientProperties();
+    }
+
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/client/ClientProperties.java

+package org.springframework.cloud.client;
+
+import lombok.Data;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+import java.util.List;
+
+/**
+ * @author Spencer Gibb
+ */
+@Data
+@ConfigurationProperties("spring.cloud.client")
+public class ClientProperties {
+    private List<String> serviceIds;
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/eureka/EurekaClientAutoConfiguration.java

@@ -19,6 +19,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.cloud.client.ClientProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
@@ -47,4 +48,9 @@ public class EurekaClientAutoConfiguration {
 		return new EurekaInstanceConfigBean();
 	}
 
+    @Bean
+    @ConditionalOnMissingBean(EurekaRibbonInitializer.class)
+    public EurekaRibbonInitializer eurekaRibbonInitializer(ClientProperties clientProperties) {
+        return new EurekaRibbonInitializer(clientProperties);
+    }
 }

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/eureka/EurekaRibbonInitializer.java

+package org.springframework.cloud.netflix.eureka;
+
+import com.netflix.config.ConfigurationManager;
+import com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList;
+import org.springframework.cloud.client.ClientProperties;
+
+/**
+ * @author Spencer Gibb
+ */
+public class EurekaRibbonInitializer {
+
+    public EurekaRibbonInitializer(ClientProperties clientProperties) {
+        if (clientProperties.getServiceIds() != null) {
+            for (String serviceId : clientProperties.getServiceIds()) {
+                setServiceListClassAndVIP(serviceId);
+            }
+        }
+    }
+
+    public static void setServiceListClassAndVIP(String serviceId) {
+        setProp(serviceId, "NIWSServerListClassName", DiscoveryEnabledNIWSServerList.class.getName());
+        setProp(serviceId, "DeploymentContextBasedVipAddresses", serviceId); //FIXME: what should this be?
+    }
+
+    private static void setProp(String serviceId, String suffix, String value) {
+        ConfigurationManager.getConfigInstance().setProperty(serviceId + ".ribbon." + suffix, value);
+    }
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/FeignConfigurer.java

 package org.springframework.cloud.netflix.feign;
 
-import com.netflix.config.ConfigurationManager;
-import com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList;
 import feign.Contract;
 import feign.Feign;
 import feign.Logger;
@@ -50,16 +48,7 @@ public class FeignConfigurer {
 
     protected <T> T loadBalance(Feign.Builder builder, Class<T> type, String schemeName) {
         String name = URI.create(schemeName).getHost();
-        setServiceListClassAndVIP(name);
         return builder.target(LoadBalancingTarget.create(type, schemeName));
     }
 
-    public static void setServiceListClassAndVIP(String serviceId) {
-        setProp(serviceId, "NIWSServerListClassName", DiscoveryEnabledNIWSServerList.class.getName());
-        setProp(serviceId, "DeploymentContextBasedVipAddresses", serviceId); //FIXME: what should this be?
-    }
-
-    private static void setProp(String serviceId, String suffix, String value) {
-        ConfigurationManager.getConfigInstance().setProperty(serviceId + ".ribbon." + suffix, value);
-    }
 }

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/ribbon/RibbonAutoConfiguration.java

+package org.springframework.cloud.netflix.ribbon;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration;
+import org.springframework.cloud.netflix.eureka.EurekaRibbonInitializer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.client.ClientHttpRequestInterceptor;
+import org.springframework.web.client.RestTemplate;
+
+import javax.annotation.PostConstruct;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author Spencer Gibb
+ */
+@Configuration
+@AutoConfigureAfter(EurekaClientAutoConfiguration.class)
+public class RibbonAutoConfiguration {
+
+    //TODO: why doesn't @AutoConfigureAfter(EurekaClientAutoConfiguration.class) do what the following does for order?
+    @Autowired
+    EurekaRibbonInitializer eurekaRibbonInitializer;
+
+    @Bean
+    @ConditionalOnMissingBean(RestTemplate.class)
+    public RestTemplate restTemplate() {
+        return new RestTemplate();
+    }
+
+    @Bean
+    public RibbonInterceptor ribbonInterceptor() {
+        return new RibbonInterceptor();
+    }
+
+    @PostConstruct
+    public void init() {
+        List<ClientHttpRequestInterceptor> list = new ArrayList<>();
+        list.add(ribbonInterceptor());
+        restTemplate().setInterceptors(list);
+    }
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/ribbon/RibbonInterceptor.java

+package org.springframework.cloud.netflix.ribbon;
+
+import com.netflix.client.ClientFactory;
+import com.netflix.loadbalancer.ILoadBalancer;
+import com.netflix.loadbalancer.Server;
+import org.springframework.http.HttpRequest;
+import org.springframework.http.client.ClientHttpRequestExecution;
+import org.springframework.http.client.ClientHttpRequestInterceptor;
+import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.http.client.support.HttpRequestWrapper;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import java.io.IOException;
+import java.net.URI;
+
+/**
+ * @author Spencer Gibb
+ */
+public class RibbonInterceptor implements ClientHttpRequestInterceptor {
+    @Override
+    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
+        HttpRequestWrapper wrapper = new HttpRequestWrapper(request) {
+            @Override
+            public URI getURI() {
+                URI originalUri = super.getURI();
+                String serviceName = originalUri.getHost();
+                ILoadBalancer loadBalancer = ClientFactory.getNamedLoadBalancer(serviceName);
+                Server server = loadBalancer.chooseServer(null);
+                if (server == null) {
+                    throw new IllegalStateException("Unable to locate ILoadBalancer for service: "+ serviceName);
+                }
+                URI uri = UriComponentsBuilder.fromUri(originalUri)
+                        .host(server.getHost())
+                        .port(server.getPort())
+                        .build()
+                        .toUri();
+                return uri;
+            }
+        };
+        return execution.execute(wrapper, body);
+    }
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/RibbonRoutingFilter.java

 package org.springframework.cloud.netflix.zuul.filters.route;
 
-import static org.springframework.cloud.netflix.feign.FeignConfigurer.setServiceListClassAndVIP;
+import static org.springframework.cloud.netflix.eureka.EurekaRibbonInitializer.setServiceListClassAndVIP;
 
 import java.io.IOException;
 import java.io.InputStream;

spring-cloud-netflix-core/src/main/resources/META-INF/spring.factories

 org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+org.springframework.cloud.client.ClientAutoConfiguration,\
 org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration,\
 org.springframework.cloud.netflix.feign.FeignAutoConfiguration,\
 org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration,\
+org.springframework.cloud.netflix.ribbon.RibbonAutoConfiguration,\
 org.springframework.cloud.netflix.servo.ServoMetricsAutoConfiguration
\ No newline at end of file