Microservice-springcloud (eureka practice, nacos practice)

Spring system diagram

Version relationship

Version correspondence wiki

eureka practice

1 Parent project dependencies

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.6.14</version>
</parent>
<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

2 Build Eureka Server

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>

server:
  port: 8761
eureka:
  instance:
    hostname: localhost
  client:
    registerWithEureka: false
    fetchRegistry: false
    serviceUrl:
      defaultZone: 

3 Build a service provider

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

eureka:
  client:
    serviceUrl:
      defaultZone: http://127.0.0.1:8761/eureka/

spring:
  application:
    name: eureka-provider
server:
  port: 9000

4 Build consumers

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
spring:
  application:
    name: eureka-consumer
server:
  port: 9001

5 Service consumers

5.1 Use RestTemplate to make RPC calls

@Bean
@LoadBalanced
public RestTemplate restTemplate(){
    
    
    return new RestTemplate();
}

5.2 Real call

@GetMapping("/hello/{id}")
public String hello(@PathVariable String id){
    
    
    return restTemplate.getForObject("http://EUREKA-PROVIDER/hello/"+id, String.class);
}

注意：

The @LoadBalanced annotation must be added (org.springframework.cloud.client.loadbalancer)

Cluster mode:

https://cloud.tencent.com/developer/article/1730733

Naco Practice

1 First we need to install Nacos Server
and you can choose Docker, but you must pay attention to the pitfalls here and need to expose three ports:

docker run -d -p 8848:8848 -p 9848:9848  -p 9849:9849  --name nacos -e "MODE=standalone" -e NACOS_AUTH_IDENTITY_KEY=serverIdentity -e NACOS_AUTH_IDENTITY_VALUE=security -e NACOS_AUTH_TOKEN=SecretKey012345678901234567890123456789012345678901234567890123456789 nacos/nacos-server

2 Parent POM

<parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <!--这里的版本一定要对应上 和下面的spring-cloud-alibaba-dependencies里的spring boot 版本 -->
  <version>2.4.2</version>
</parent>
<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>com.alibaba.cloud</groupId>
      <artifactId>spring-cloud-alibaba-dependencies</artifactId>
      <version>2021.1</version>
      <type>pom</type>
      <scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement>

3 service providers

server:
  port: 8088
spring:
  application:
    name: ddd-provider
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

4 Serve consumers

server:
  port: 8089
  application:
    name: ddd-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848

<dependency>
       <groupId>com.alibaba.cloud</groupId>
       <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
   </dependency>
   <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-web</artifactId>
   </dependency>
   <dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-loadbalancer</artifactId>
       <version>3.0.1</version>
   </dependency>

5 The calling method is the same as above, using the load-balanced RestTemplate to make the call

Nacos configuration management

1 Parent project dependencies

 <dependencyManagement>
   <dependencies>
     <dependency>
       <groupId>com.alibaba.cloud</groupId>
       <artifactId>spring-cloud-alibaba-dependencies</artifactId>
       <version>${com.alibaba.cloud.version}</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>
     <dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-dependencies</artifactId>
       <version>${com.cloud.version}</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>
     <!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-dubbo -->
     <dependency>
       <groupId>com.alibaba.cloud</groupId>
       <artifactId>spring-cloud-starter-dubbo</artifactId>
       <version>${com.dubbo.version}</version>
     </dependency>
   </dependencies>
 </dependencyManagement>
 
 <dependencies>
   <!-- 因为在spring-cloud-dependencies里面是optional 所以这里我引入了 不引入会报错 StringUtils -->
   <dependency>
     <groupId>com.alibaba.nacos</groupId>
     <artifactId>nacos-common</artifactId>
     <version>2.1.0</version>
   </dependency>
</dependencies>

2 Specific modules, introducing dependencies

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>

3. Configure bootstrap.yml

and write application.yml above. It is said that it can also be used in higher versions, but I did not succeed. I will test it later to supplement it.

spring:
  application:
    name: nacos-dynamic-port
  cloud:
    nacos:
      config:
        server-addr:ip:8848
        file-extension: yml  #这个名字可以自定义 与 配置列表对应就行 官网也有一套命名规则
        namespace: 459c3b94-04e8-4de2-8eaa-c55f4a8de1b1 #这里需填工作空间的ID
        group: DEFAULT_GROUP

Naming rules:

Configuration list:

4 Verify that you can modify the port in nacos, then start it and find that the port you configured will take effect:

@RestController
@RefreshScope 、// 这个注解别忘了这个提供了bean刷新属性的能力
public class ConfigController {
    
    

    @Value("${server.port}")
    private int port;
    @RequestMapping("/info")
    public String get() {
    
    
        return "NacosDynamicPortController output, port: " + port;
    }
}

Modify different ports and find that info will print different ports.但是特别注意哈我们一般不用来更新端口，因为这个端口改了，但是服务还是在原端口提供服务的

Nacos extended configuration

1 The dependencies are the same as above and will not be repeated here.
2 Configuration here must be configured in bootstrap.yml.

spring:
  application:
    name: nacos-dynamic-env
  cloud:
    nacos:
      config:
        server-addr: 192.168.0.169:8848
        file-extension: properties
        namespace: 459c3b94-04e8-4de2-8eaa-c55f4a8de1b1
        group: DEFAULT_GROUP
        extension-configs[0]:
          dataId: demo
          refresh: true
          fileExtension: yml
          group : DEFAULT_GROUP
        extension-configs[1]:
          dataId: user
          refresh: true
          fileExtension: yml
          group : DEFAULT_GROUP

@RestController
@RefreshScope
public class ConfigController {
    
    
    @Value("${server.port}")
    private int port;
    @Value("${demo.val}")
    private String val;
    @Value("${demo.pwd}")
    private String pwd;
    @RequestMapping("/info")
    public String get() {
    
    
        return String.format("ConfigController output, port : {%s} val : {%s} pwd : {%s}", port, val, pwd);
    }
}

Final output: You can see that the configuration at the end of the same attribute will overwrite the previous one.

I highly recommend reading this blog post for a more detailed explanation.