Nacos是阿里巴巴开发的用于发现、配置和管理微服务。与Spring Cloud Alibaba完美结合。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是国产的,所以中文文档也很丰富。
启动配置管理
引入依赖
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
<version>2.2.5.RELEASE</version>
</dependency>
</dependencies>
<!-- SpringCloud依赖,起到管理版本的作用 -->
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>${com-alibaba-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
配置
在应用的 /src/main/resources/bootstrap.properties
配置文件中配置 Nacos Config 元数据
spring.application.name=spring-cloud-alibaba-nacos-config-example
spring.cloud.nacos.config.server-addr=127.0.0.1:8848
需要先启动Nacos,否则启动后会有些报错
完成上述两步后,应用会从 Nacos Config 中获取相应的配置,并添加在 Spring Environment 的 PropertySources 中。这里我们使用 @Value 注解来将对应的配置注入到 SampleController 的 userName 和 age 字段,并添加 @RefreshScope 打开动态刷新功能
@RefreshScope
class SampleController {
@Value("${user.name}")
String userName;
@Value("${user.age}")
int age;
}
启动 Nacos Server 并添加配置
下载Nacos
GitHub地址:https://github.com/alibaba/na...
启动 Server
进去其相对文件夹 nacos/bin,并对照操作系统实际情况执行如下命令。详情参考官方文档。
- Linux/Unix/Mac 操作系统,执行命令
sh startup.sh -m standalone
- Windows 操作系统,执行命令
cmd startup.cmd
在命令行执行如下命令,向 Nacos Server 中添加一条配置。
POST "http://127.0.0.1:8848/nacos/v1/cs/configs?dataId=nacos-config-example.properties&group=DEFAULT_GROUP&content=user.id=1%0Auser.name=james%0Auser.age=17"
启动服务发现
引入依赖
父级
<properties>
<java.version>1.8</java.version>
<com-alibaba-cloud.version>2.2.5.RELEASE</com-alibaba-cloud.version>
</properties>
<modules>
<module>nacos-discovery-consumer</module>
<module>nacos-discovery-provider</module>
</modules>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<!-- SpringCloud依赖,起到管理版本的作用 -->
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>${com-alibaba-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
consumer
<properties>
<spring-cloud-netflix.version>2.2.5.RELEASE</spring-cloud-netflix.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
<version>${spring-cloud-netflix.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<exclusions>
<exclusion>
<groupId>com.alibaba.nacos</groupId>
<artifactId>nacos-client</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.alibaba.nacos</groupId>
<artifactId>nacos-client</artifactId>
</dependency>
</dependencies>
provider
<dependencies>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.nacos</groupId>
<artifactId>nacos-client</artifactId>
</dependency>
</dependencies>
添加注解
通过 Spring Cloud 原生注解 @EnableDiscoveryClient
开启服务注册发现功能
// 开启服务注册发现功能
@SpringBootApplication
@EnableDiscoveryClient
public class NacosDiscoveryProviderApplication {
public static void main(String[] args) {
SpringApplication.run(NacosDiscoveryProviderApplication.class, args);
}
}
配置
在 application.properties
中配置 Nacos server 的地址
consumer
server.port=18083
spring.application.name=service-consumer
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
# nacos认证信息
spring.cloud.nacos.username=nacos
spring.cloud.nacos.password=nacos
provier
server.port=18082
spring.application.name=service-provider
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
# nacos认证信息
spring.cloud.nacos.username=nacos
spring.cloud.nacos.password=nacos
consumer
- config
通过 Spring Cloud 原生注解 @EnableDiscoveryClient
开启服务注册发现功能。给 RestTemplate 实例添加 @LoadBalanced
注解,开启 @LoadBalanced
与 Ribbon 的集成
@Configuration
public class NacosConfig {
@LoadBalanced
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
}
- controller
@RestController
public class TestController {
@Autowired
private RestTemplate restTemplate;
@RequestMapping(value = "/echo/{str}", method = RequestMethod.GET)
public String echo(@PathVariable String str) {
return restTemplate.getForObject("http://service-provider/echo/" + str, String.class);
}
}
provier
- controller
@RestController
public class TestController {
@RequestMapping(value = "/echo/{string}", method = RequestMethod.GET)
public String echo(@PathVariable String string) {
return "Hello Nacos Discovery " + string;
}
}
最后启动 ProviderApplication
和 ConsumerApplication
,调用 http://localhost:8080/echo/2021,返回内容为
Hello Nacos Discovery 2021`。
References
[1] Nacos Config Example: https://github.com/alibaba/sp...
[2] Nacos Spring Cloud: https://nacos.io/zh-cn/docs/q...
[3] Nacos: https://nacos.io/zh-cn/docs/q...