Spring Cloud教程 - Ribbon自定义规则

[TFdream]

Spring Cloud Ribbon 定义了 com.netflix.loadbalancer.IRule接口，我们可以根据业务场景自定义规则。

定义完规则后有2种配置方式，第一种是通过代码配置，第二种是通过配置文件；

自定义IRule

自定义GrayReleaseRule类，继承自AbstractLoadBalancerRule，代码如下：

package io.dreamstudio.springcloud.netflix.ribbon.consumer.rule;

import com.alibaba.cloud.nacos.NacosDiscoveryProperties;
import com.alibaba.cloud.nacos.ribbon.ExtendBalancer;
import com.alibaba.cloud.nacos.ribbon.NacosServer;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.DynamicServerListLoadBalancer;
import com.netflix.loadbalancer.Server;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.CollectionUtils;

import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Collectors;

/**
 * 自定义灰度发布规则
 * 参考 com.alibaba.cloud.nacos.ribbon.NacosRule
 * @author Ricky Fung
 */
public class GrayReleaseRule extends AbstractLoadBalancerRule {
    private final Logger LOG = LoggerFactory.getLogger(this.getClass());

    public static final String GRAY_LABEL = "gray-label";

    @Autowired
    private NacosDiscoveryProperties nacosDiscoveryProperties;

    @Override
    public Server choose(Object key) {
        try {
            Map<String, String> metadata = this.nacosDiscoveryProperties.getMetadata();
            String grayLabel = metadata.get(GRAY_LABEL);

            DynamicServerListLoadBalancer loadBalancer = (DynamicServerListLoadBalancer) getLoadBalancer();
            String name = loadBalancer.getName();

            NamingService namingService = nacosDiscoveryProperties
                    .namingServiceInstance();
            List<Instance> instances = namingService.selectInstances(name, true);
            if (CollectionUtils.isEmpty(instances)) {
                LOG.warn("no instance in service {}", name);
                return null;
            }

            List<Instance> preferList = instances;
            if (StringUtils.isNotEmpty(grayLabel)) {
                //过滤相同的
                List<Instance> sameGrayInstances = instances.stream()
                        .filter(instance -> Objects.equals(grayLabel,
                                instance.getMetadata().get(GRAY_LABEL)))
                        .collect(Collectors.toList());

                if (CollectionUtils.isEmpty(sameGrayInstances)) {
                    LOG.error("满足条件的灰度服务提供者列表为空, name = {}, gray-label = {}, instances = {}",
                            name, grayLabel, instances);
                    return null;
                } else {
                    preferList = sameGrayInstances;
                }
            }

            Instance instance = ExtendBalancer.getHostByRandomWeight2(preferList);

            return new NacosServer(instance);
        } catch (Exception e) {
            LOG.error("Nacos Gray Rule error", e);
        }
        return null;
    }

    @Override
    public void initWithNiwsConfig(IClientConfig iClientConfig) {

    }

}

具体实现可以参考 spring-cloud-starter-alibaba-nacos-discovery 模块中实现的 com.alibaba.cloud.nacos.ribbon.NacosRule，其目标是 同集群调用优先。

使用自定义IRule

有两种配置方式可选。

1、注解配置

/**
 * Ribbon 自定义规则
 */
@Configuration
public class MyRuleConfig {

    @Bean
    public IRule getRule(){
        return new GrayReleaseRule();
    }

}

然后在代码中调用的地方增加以下配置：

@Configuration
@RibbonClient(name="netflix-ribbon-consumer", configuration=MyRuleConfig.class)  //name：建议写服务名称     configuration：配置类
public class CloudProviderConfig {

}

2、在配置文件中配置

分两步，首先注册我们的IRule对象，如下：

/**
 * Ribbon 自定义规则
 */
@Configuration
public class MyRuleConfig {

    @Bean
    public IRule getRule(){
        return new GrayReleaseRule();
    }

}

然后，我们在application.yml文件 增加配置，格式：``` .ribbon.```` ，

<clientName>: 
    ribbon: 
        NFLoadBalancerClassName: 配置ILoadBalancer的实现类
        NFLoadBalancerRuleClassName: 配置IRule的实现类
        NFLoadBalancerPingClassName: 配置IPing的实现类
        NFWSServerListClassName: 配置ServerList的实现类
        NIWSServerListFilterClassName: 配置ServerListFilter的实现类

本文中配置如下：

spring:
  application:
    name: netflix-ribbon-02-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 # Nacos 服务器地址

# 配置负载均衡
netflix-ribbon-02-consumer:
  ribbon:
    NFLoadBalancerRuleClassName: io.dreamstudio.springcloud.netflix.ribbon.consumer.rule.GrayReleaseRule

验证规则

首先 我们在 spring-cloud-netflix-ribbon-provider 的 application.yml文件中 增加元数据：

spring:
  application:
    name: netflix-ribbon-provider
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 # Nacos 服务器地址
        metadata:
          gray-label: gray

然后，我们将 spring-cloud-netflix-ribbon-02-consumer application.yml文件增加一个 元数据配置：

spring:
  application:
    name: netflix-ribbon-02-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 # Nacos 服务器地址
        metadata:
          gray-label: gray01

# 配置负载均衡
netflix-ribbon-02-consumer:
  ribbon:
    NFLoadBalancerRuleClassName: io.dreamstudio.springcloud.netflix.ribbon.consumer.rule.GrayReleaseRule

源码下载：https://github.com/TFdream/spring-cloud-tutorials/tree/master/spring-cloud-netflix-ribbon