alibaba-nacos之config、discovery

Nacos 致力于帮助您发现、配置和管理微服务。Nacos 提供了一组简单易用的特性集，帮助您快速实现动态服务发现、服务配置、服务元数据及流量管理。

nacos的官网地址：https://nacos.io/zh-cn/docs/what-is-nacos.html

nacos的server的启动，以及支持mysql存储，可以参考官网的快速启动

1.config

pom中引入jar包，Spring cloud不同版本，引入不同的version

<!-- nacos -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            <version>0.1.1.RELEASE</version>
        </dependency>

bootstrap.properties配置文件

spring.cloud.nacos.config.server-addr=127.0.0.1:8848
spring.cloud.nacos.config.file-extension=yml
spring.application.name=yunlian-truck-ucenter
spring.cloud.nacos.config.namespace=598429e8-6c07-4ee3-b96e-ac242c40a382
spring.cloud.nacos.config.group=truck-impc
#spring.profiles.active=local

active namespace可以在程序启动时，放入启动参数中，namespace可以作为dev,test,prod等环境隔离

 

添加数据到nacos服务器，post数据

@RefreshScope 支持动态更新配置文件中数据，无需重启服务

原理是客户端通过每隔30秒http去服务器请求，加入到服务器到队列，服务器会在29.5秒时处理数据，如果此时服务器上的配置更改了，则从队列中取出客户端，进行实时返回数据

详细参考：http://www.javashuo.com/article/p-szknmkuj-ek.html

                  http://www.javashuo.com/article/p-afbzdqwl-eo.html

@RestController
@IgnoreUserToken
@RefreshScope
public class NacosTestController {

    @Value("${ucenter.nacos.test}")
    private String test ;

    @GetMapping("/config")
    public String config(){
        return test ;
    }
}

多个项目共享同一配置的情况，例如开发环境多个应用都引用了mysql的配置，仅在0.2.0的版本以上支持

spring.cloud.nacos.config.server-addr=127.0.0.1:8848

# 0.2.1.RELEASE \u4EE5\u4E0A\u652F\u6301\u591A\u4E2A\u914D\u7F6E\uFF0C\u6587\u6863\uFF1Ahttps://github.com/spring-cloud-incubator/spring-cloud-alibaba/wiki/Nacos-config

# Nacos \u63A7\u5236\u53F0\u6DFB\u52A0\u914D\u7F6E\uFF1A
#   Data ID\uFF1Aapp.properties
#   Group\uFF1Amulti-data-ids
#   \u914D\u7F6E\u5185\u5BB9\uFF1Aapp.user.cache=false
spring.cloud.nacos.config.ext-config[0].data-id=app.properties
spring.cloud.nacos.config.ext-config[0].group=multi-data-ids
spring.cloud.nacos.config.ext-config[0].refresh=true

# 1. \u672C\u5730\u5B89\u88C5 MySQL
# 2. Nacos \u63A7\u5236\u53F0\u6DFB\u52A0\u914D\u7F6E\uFF1A
#   Data ID\uFF1Adatasource.properties
#   Group\uFF1Amulti-data-ids
#   \u914D\u7F6E\u5185\u5BB9\u793A\u4F8B\uFF1A
#       spring.datasource.url=jdbc:mysql://localhost:3306/test?useSSL=false
#       spring.datasource.username=root
#       spring.datasource.password=root
#       spring.datasource.initial-size=10
#       spring.datasource.max-active=20
spring.cloud.nacos.config.ext-config[1].data-id=datasource.properties
spring.cloud.nacos.config.ext-config[1].group=multi-data-ids

# 1. \u672C\u5730\u5B89\u88C5 Redis
# 2. Nacos \u63A7\u5236\u53F0\u6DFB\u52A0\u914D\u7F6E\uFF1A
#   Data ID\uFF1Aredis.properties
#   Group\uFF1Amulti-data-ids
#   \u914D\u7F6E\u5185\u5BB9\u793A\u4F8B\uFF1A
#       spring.redis.host=localhost
#       spring.redis.password=20190101
#       spring.redis.timeout=5000
#       spring.redis.max-idle=5
#       spring.redis.max-active=10
#       spring.redis.max-wait=3000
#       spring.redis.test-on-borrow=false
spring.cloud.nacos.config.ext-config[2].data-id=redis.properties
spring.cloud.nacos.config.ext-config[2].group=multi-data-ids

 

2.discovery

pom properties

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    <version>0.1.1.RELEASE</version>
</dependency>

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

discovery与eureka都是实现服务注册发现，需要去掉eureka的jar包解决 single bean问题

Field registration in org.springframework.cloud.client.serviceregistry.ServiceRegistryAutoConfiguration$ServiceRegistryEndpointConfiguration required a single bean, but 2 were found:
    - eurekaRegistration: defined by method 'eurekaRegistration' in class path resource [org/springframework/cloud/netflix/eureka/EurekaClientAutoConfiguration.class]
    - nacosRegistration: defined by method 'nacosRegistration' in class path resource [org/springframework/cloud/alibaba/nacos/NacosDiscoveryAutoConfiguration.class]

另外一个错误：

Caused by: java.lang.NoSuchMethodError: org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.<init>(Lorg/springframework/cloud/client/serviceregistry/ServiceRegistry;Lorg/springframework/cloud/client/serviceregistry/AutoServiceRegistrationProperties;)V
	at org.springframework.cloud.alibaba.nacos.registry.NacosAutoServiceRegistration.<init>(NacosAutoServiceRegistration.java:43)
	at org.springframework.cloud.alibaba.nacos.NacosDiscoveryAutoConfiguration.nacosAutoServiceRegistration(NacosDiscoveryAutoConfiguration.java:62)

由于NacosAutoServiceRegistration中代码super(serviceRegistry, autoServiceRegistrationProperties);是引用的spring-cloud-commons 2.0版本以上才有的方法，导致0.1.X版本的discovery启动会上述报错。这与spring cloud的对应版本的commons的包的版本冲突

public class NacosAutoServiceRegistration
		extends AbstractAutoServiceRegistration<NacosRegistration> {
	private static final Logger LOGGER = LoggerFactory
			.getLogger(NacosAutoServiceRegistration.class);

	@Autowired
	private NacosRegistration registration;

	public NacosAutoServiceRegistration(
			ServiceRegistry<NacosRegistration> serviceRegistry,
			AutoServiceRegistrationProperties autoServiceRegistrationProperties,
			NacosRegistration registration) {
		super(serviceRegistry, autoServiceRegistrationProperties);
		this.registration = registration;
	}

 

 

综上：

如果使用nacos，建议还是使用0.2.x的版本，这样也就是要求Spring cloud是2.0的版本