物联网架构成长之路(51)-Nacos微服务配置中心、服务注册服务发现

0.前言

　　之前练习微服务是用Eureka，最近发现BladeX是用的Nacos，发现Nacos还比较简单实用。所以练习一下这个，为物联网V2版本积累经验。

1. 下载、安装、启动

　　下载Nacos

https://github.com/alibaba/nacos/releases
https://nacos.io/zh-cn/docs/quick-start.html

　　解压启动

　　访问http://127.0.0.1:8848/nacos/index.html
　　默认帐号密码 nacos/nacos

2. Nacos作为配置中心

　　参考官方文档，实现nacos-config

https://github.com/alibaba/spring-cloud-alibaba/blob/master/spring-cloud-alibaba-docs/src/main/asciidoc/nacos-config.adoc

　　注意，springcloud使用配置中心，那么配置文件是对应的 bootstrap.properties

bootstrap.properties

spring.cloud.nacos.config.server-addr=127.0.0.1:8848
spring.cloud.nacos.config.prefix=example
spring.profiles.active=demo
spring.cloud.nacos.config.file-extension=properties

# ${prefix}-${spring.profile.active}.${file-extension}
# example-demo.properties

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wunaozai.demo</groupId>
    <artifactId>NacosConfig</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>NacosConfig</name>
    <description>Nacos配置中心</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud-alibaba.version>2.2.0.RELEASE</spring-cloud-alibaba.version>
        <maven-jar-plugin.version>3.0.0</maven-jar-plugin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>15.0</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <repositories>
        <repository>
            <id>maven-ali</id>
            <url>http://maven.aliyun.com/nexus/content/groups/public//</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>true</enabled>
                <updatePolicy>always</updatePolicy>
                <checksumPolicy>fail</checksumPolicy>
            </snapshots>
        </repository>
    </repositories>
    
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

NacosConfigApplication.java

package com.wunaozai.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class NacosConfigApplication {

    public static void main(String[] args) {
        ConfigurableApplicationContext context = 
                SpringApplication.run(NacosConfigApplication.class, args);
        String username = context.getEnvironment().getProperty("user.name");
        String userage  = context.getEnvironment().getProperty("user.age");
        System.out.println("user.name=" + username + "  " + "user.age=" + userage);
    }

}

NacosController.java

package com.wunaozai.demo.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RefreshScope
@RestController
@RequestMapping(value="/nacos")
public class NacosController {

    @Value("${str:---}")
    private String str;
    
    @RequestMapping(value="/get")
    public String get() {
        return str;
    }
}

然后在nacos管理界面上配置如下信息

user.name=demo
user.age=99
server.port=9988
str=wunaozai

配置后，启动NacosConfig服务，并访问浏览器，效果如下。

 修改nacos上的配置文件后，保存。程序会自动更新配置。

3. Nacos作为服务中心，服务注册与服务发现

3.1 服务提供者Provider

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wunaozai.demo</groupId>
    <artifactId>NacosDiscoveryProvider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>NacosDiscoveryProvider</name>
    <description>Nacos服务发现与注册</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud-alibaba.version>2.2.0.RELEASE</spring-cloud-alibaba.version>
        <maven-jar-plugin.version>3.0.0</maven-jar-plugin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <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-actuator</artifactId> 
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>15.0</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.properites

server.port=8081
spring.application.name=nacos-provider
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

NacosProviderController.java

package com.wunaozai.demo;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping(value="/provider")
public class NacosProviderController {

    @RequestMapping(value="/echo")
    public String echo(String str) {
        return "Hello Nacos Discovery: " + str;
    }
}

NacosDiscoveryProviderApplication.java

package com.wunaozai.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class NacosDiscoveryProviderApplication {

    public static void main(String[] args) {
        SpringApplication.run(NacosDiscoveryProviderApplication.class, args);
    }

}

3.2 服务消费者Consumer

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wunaozai.demo</groupId>
    <artifactId>NacosDiscoveryConsumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>NacosDiscoveryConsumer</name>
    <description>Nacos服务注册与发现</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud-alibaba.version>2.2.0.RELEASE</spring-cloud-alibaba.version>
        <maven-jar-plugin.version>3.0.0</maven-jar-plugin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>15.0</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.properites

server.port=8083
spring.application.name=nacos-consumer
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

BeanConfig.java

package com.wunaozai.demo.config;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;

@Component
public class BeanConfig {

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

NacosConsumerController.java

package com.wunaozai.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
@RequestMapping(value="/consumer")
public class NacosConsumerController {

    @Autowired
    private RestTemplate restTemplate;
    
    @GetMapping(value="/echo")
    public String getProviderEcho(String msg) {
        return restTemplate.getForObject("http://nacos-provider/provider/echo?str=" + msg, String.class);
    }
}

NacosDiscoveryConsumerApplication.java

package com.wunaozai.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class NacosDiscoveryConsumerApplication {

    public static void main(String[] args) {
        SpringApplication.run(NacosDiscoveryConsumerApplication.class, args);
    }

}

浏览器访问结果

Nacos管理界面

参考资料：

　　https://github.com/alibaba/spring-cloud-alibaba/blob/master/spring-cloud-alibaba-docs/src/main/asciidoc/nacos-config.adoc
　　https://github.com/alibaba/spring-cloud-alibaba/blob/master/spring-cloud-alibaba-docs/src/main/asciidoc/nacos-discovery.adoc
　　https://www.jianshu.com/p/3e13272a9c84

附件代码下载: https://files.cnblogs.com/files/wunaozai/IoT-51-Nacos.zip

本文地址：https://www.cnblogs.com/wunaozai/p/12378485.html
本系列目录： https://www.cnblogs.com/wunaozai/p/8067577.html
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