From 240b112ac361412b74574c0842d84448085ead1a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=8D=A1=E5=B0=94?= <xy0615@163.com>
Date: Wed, 1 Jun 2022 21:23:58 +0800
Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0=20'pigx-common/pigx-common-g?=
 =?UTF-8?q?ateway/src/main/java/com/pig4cloud/pigx/common/gateway/rule/Ver?=
 =?UTF-8?q?sionGrayLoadBalancer.java'?=
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增加灰度路由支持nacos权重分配获取服务实例的功能
1.修复原灰度路由存在的一个bug:
原逻辑会返回带有版本号的服务实例，这些带版本号的服务按照道理应该暂时不提供公测功能
2.增加了一个功能：支持原nacos提供的权重功能
---
 .../gateway/rule/VersionGrayLoadBalancer.java | 53 ++++++++++++++-----
 1 file changed, 40 insertions(+), 13 deletions(-)

diff --git a/pigx-common/pigx-common-gateway/src/main/java/com/pig4cloud/pigx/common/gateway/rule/VersionGrayLoadBalancer.java b/pigx-common/pigx-common-gateway/src/main/java/com/pig4cloud/pigx/common/gateway/rule/VersionGrayLoadBalancer.java
index 6c42fc9a8..45c152e21 100644
--- a/pigx-common/pigx-common-gateway/src/main/java/com/pig4cloud/pigx/common/gateway/rule/VersionGrayLoadBalancer.java
+++ b/pigx-common/pigx-common-gateway/src/main/java/com/pig4cloud/pigx/common/gateway/rule/VersionGrayLoadBalancer.java
@@ -19,8 +19,9 @@ package com.pig4cloud.pigx.common.gateway.rule;
 
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.map.MapUtil;
-import cn.hutool.core.util.RandomUtil;
-import cn.hutool.core.util.StrUtil;
+import cn.hutool.core.text.CharSequenceUtil;
+import com.alibaba.nacos.client.naming.utils.Chooser;
+import com.alibaba.nacos.client.naming.utils.Pair;
 import com.pig4cloud.pigx.common.core.constant.CommonConstants;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -29,6 +30,7 @@ import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.gateway.support.NotFoundException;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -36,7 +38,7 @@ import java.util.stream.Collectors;
  * @author lengleng
  * @date 2020/1/12
  * <p>
- * 基于客户端版本号灰度路由
+ * 基于客户端版本号灰度路由，增加基于nacos权重获取服务
  */
 @Slf4j
 @RequiredArgsConstructor
@@ -48,36 +50,61 @@ public class VersionGrayLoadBalancer implements GrayLoadBalancer {
 	 * 根据serviceId 筛选可用服务
 	 * @param serviceId 服务ID
 	 * @param request 当前请求
-	 * @return
+	 * @return 服务实例：ServiceInstance
 	 */
 	@Override
 	public ServiceInstance choose(String serviceId, ServerHttpRequest request) {
 		List<ServiceInstance> instances = discoveryClient.getInstances(serviceId);
-
 		// 注册中心无实例 抛出异常
 		if (CollUtil.isEmpty(instances)) {
 			log.warn("No instance available for {}", serviceId);
 			throw new NotFoundException("No instance available for " + serviceId);
 		}
-
 		// 获取请求version，无则随机返回可用实例
 		String reqVersion = request.getHeaders().getFirst(CommonConstants.VERSION);
-		if (StrUtil.isBlank(reqVersion)) {
-			return instances.get(RandomUtil.randomInt(instances.size()));
+		if (CharSequenceUtil.isBlank(reqVersion)) {
+			//过滤出不含VERSION实例
+			List<ServiceInstance> versionInstanceList = instances.stream()
+					.filter(instance -> !instance.getMetadata().containsKey(CommonConstants.VERSION))
+					.collect(Collectors.toList());
+			if(CollUtil.isEmpty(versionInstanceList)){
+				//根据权重获取实例
+				return randomByWeight(instances);
+			}
+			//根据权重获取实例
+			return randomByWeight(versionInstanceList);
 		}
-
 		// 遍历可以实例元数据，若匹配则返回此实例
 		List<ServiceInstance> availableList = instances.stream()
 				.filter(instance -> reqVersion
 						.equalsIgnoreCase(MapUtil.getStr(instance.getMetadata(), CommonConstants.VERSION)))
 				.collect(Collectors.toList());
-
 		if (CollUtil.isEmpty(availableList)) {
-			return instances.get(RandomUtil.randomInt(instances.size()));
+			//根据权重获取实例
+			return randomByWeight(instances);
 		}
+		//根据权重获取实例
+		return randomByWeight(availableList);
+	}
 
-		return availableList.get(RandomUtil.randomInt(availableList.size()));
-
+	/**
+	 * 根据nacos设置的权重返回实例
+	 * @param serviceInstances 服务实例集合
+	 * @return 服务实例：ServiceInstance
+	 */
+	protected ServiceInstance randomByWeight(final List<ServiceInstance> serviceInstances){
+		if(serviceInstances.size()==1){
+			return serviceInstances.get(0);
+		}else {
+			List<Pair<ServiceInstance>> hostsWithWeight = new ArrayList<>();
+			for (ServiceInstance serviceInstance : serviceInstances) {
+				if ("true".equals(serviceInstance.getMetadata().getOrDefault("nacos.healthy","true"))) {
+					hostsWithWeight.add(new Pair<>(serviceInstance, Double.parseDouble(serviceInstance.getMetadata().getOrDefault("nacos.weight","1"))));
+				}
+			}
+			Chooser<String, ServiceInstance> vipChooser = new Chooser<>("www.taobao.com",hostsWithWeight);
+			return vipChooser.randomWithWeight();
+		}
 	}
 
 }