第十一章 Spring Cloud Alibaba nacos配置中心

前言

Nacos 提供用于存储配置和其他元数据的 key/value 存储，为分布式系统中的外部化配置提供服务器端和客户端支持。使用 Spring Cloud Alibaba Nacos Config，您可以在 Nacos Server 集中管理你 Spring Cloud 应用的外部属性配置。
Spring Cloud Alibaba Nacos Config 是 Config Server 和 Client 的替代方案，客户端和服务器上的概念与 Spring Environment 和 PropertySource 有着一致的抽象，在特殊的 bootstrap 阶段，配置被加载到 Spring 环境中。当应用程序通过部署管道从开发到测试再到生产时，您可以管理这些环境之间的配置，并确保应用程序具有迁移时需要运行的所有内容。

1、Nacos配置中心配置信息

准备配置，nacos server中新建nacos-config.properties

2、项目里配置

2.1、添加依赖，配置pom.xml

<dependency>
    <groupId>com.alibaba.cloudgroupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-configartifactId>
    <version>2021.0.4.0version>
dependency>
<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-bootstrapartifactId>
dependency>

2.2、添加bootstrap.yml

spring:
  profiles:
    #开发环境dev，测试环境test，生产环境prod
    active: dev
  application:
    name: app-api-service #服务名
  cloud:
    nacos:
      config:
        server-addr: 127.0.0.1:8848
        group: DEFAULT_GROUP
        file-extension: yml #指定yaml格式的配置
        refresh-enabled: true

2.3、添加bootstrap.yml

server:
  port: 80
spring:  
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848  #Nacos server 的地址
feign:
  client:
    config:
      default:
        #建立连接所用的时间，适用于网络状况正常的情况下，两端连接所需要的时间
        ConnectTimeOut: 3000
        #指建立连接后从服务端读取到可用资源所用的时间
        ReadTimeOut: 5000
hqyj:
  address: cat

2.3.1、增加Nacos配置

备注：Data ID为：服务名-环境名称.yml

2.4、动态刷新配置验证

@RestController
@RequestMapping("/user")
//@DefaultProperties(defaultFallback = "userInfoListFallBack")
@RefreshScope
public class UserController {
    
    @Value("${hqyj.address}")
    private String url;
   
    @GetMapping("/url")
    public String url(){
        return url;
    }
}

2.5、网关与配置中心

2.5.1、添加依赖，配置pom.xml

<dependency>
    <groupId>com.alibaba.cloudgroupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-configartifactId>
dependency>
<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-bootstrapartifactId>
dependency>

2.5.2、添加bootstrap.yml文件

server:
  port: 80
spring:
  application:
    name: drp-gateway-service
  profiles:
    #开发环境dev，测试环境test，生产环境prod
    active: dev
  jackson:
    time-zone: GMT+8
  cloud:
    loadbalancer:
      ribbon:
        enabled: false
    nacos:
      discovery:
        server-addr: localhost:8848  #Nacos server 的地址
      config:
        server-addr: localhost:8848
        name: gateway-router
        namespace: public
        group: DEFAULT_GROUP
        #file-extension: json #指定yaml格式的配置
        refresh-enabled: true #支持刷新

2.5.3、Nacos添加配置

[{
    "id": "user-router",
    "order": 0,
    "predicates": [{
        "args": {
            "pattern": "/user/userInfoList/**"
        },
        "name": "Path"
    }],
    "uri": "lb://user-service"
 }  
]

2.5.4、添加类

package com.xxxx.SpringCloud.gateway.config;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.nacos.api.NacosFactory;
import com.alibaba.nacos.api.config.ConfigService;
import com.alibaba.nacos.api.config.listener.Listener;
import com.alibaba.nacos.api.exception.NacosException;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
import org.springframework.cloud.gateway.route.RouteDefinition;
import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Mono;
import javax.annotation.PostConstruct;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executor;


@RefreshScope
@Component
@Slf4j
public class DynamicRouteConfig implements ApplicationEventPublisherAware {
    /**
     * nacos 配置dataId
     */
    @Value("${config.dynamic.route.dataId:gateway-router}")
    private String dataId = "gateway-router";
    /**
     * nacos 配置group
     */
    @Value("${config.dynamic.route.group:DEFAULT_GROUP}")
    private String group = "DEFAULT_GROUP";

    /**
     * nacos 配置地址
     */
    @Value("${spring.cloud.nacos.config.server-addr}")
    private String serverAddr;

    @Autowired
    private RouteDefinitionWriter routeDefinitionWriter;

    private ApplicationEventPublisher applicationEventPublisher;

    private static final List<String> ROUTE_LIST = new ArrayList<>();

    @PostConstruct
    public void dynamicRouteByNacosListener() {
        try {
            ConfigService configService = NacosFactory.createConfigService(serverAddr);

// 程序首次启动, 并加载初始化路由配置
            String initConfigInfo = configService.getConfig(dataId, group, 5000);
            this.addAndPublishBatchRoute(initConfigInfo);

//添加监听路由变化
            configService.addListener(dataId, group, new Listener() {
                @Override
                public void receiveConfigInfo(String configInfo) {
                    clearRoute();
                    try {
                        List<RouteDefinition> gatewayRouteDefinitions = JSONObject.parseArray(configInfo, RouteDefinition.class);
                        for (RouteDefinition routeDefinition : gatewayRouteDefinitions) {
                            addRoute(routeDefinition);
                        }
                        publish();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public Executor getExecutor() {
                    return null;
                }
            });
        } catch (NacosException e) {
            e.printStackTrace();
        }
    }


    private void publish() {
        this.applicationEventPublisher.publishEvent(new RefreshRoutesEvent(this.routeDefinitionWriter));
    }

    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
        this.applicationEventPublisher = applicationEventPublisher;
    }

    /**
     * 批量 添加及发布 路由
     *
     * @param configInfo 配置文件字符串, 必须为json array格式
     */
    private void addAndPublishBatchRoute(String configInfo) {
        try {
            clearRoute();
            List<RouteDefinition> gatewayRouteDefinitions = JSONObject.parseArray(configInfo, RouteDefinition.class);
            for (RouteDefinition routeDefinition : gatewayRouteDefinitions) {
                addRoute(routeDefinition);
            }
            publish();
            log.info("Dynamic config gateway route finished. {}", JSON.toJSONString(gatewayRouteDefinitions));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 清除路由信息
     */
    private void clearRoute() {
        for (String id: ROUTE_LIST) {
            this.routeDefinitionWriter.delete(Mono.just(id)).subscribe();
        }
        ROUTE_LIST.clear();
    }

    /**
     * 添加路由
     *
     * @param definition
     */
    private void addRoute(RouteDefinition definition) {
        try {
            routeDefinitionWriter.save(Mono.just(definition)).subscribe();
            ROUTE_LIST.add(definition.getId());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}