Spring Nacos

参考:

spring官网

https://spring.io/projects/spring-cloud-alibaba
nacos

https://nacos.io/en-us/

课程开场白

首先学习配置管理

搞清楚什么是配置中心

nacos 是配置中心的实现方案
服务发现
服务治理
首先通过一个快速入门程序学习nacos的配置中心的搭建方案

这里建议参考官方

https://spring-cloud-alibaba-group.github.io/github-pages/2021/en-us/index.html#_spring_cloud_alibaba_rocketmq_binder
第五章节会将nacos的最佳应用
第三和第四是基础
第五章是重点

nacos功能

服务发现
服务健康检查
配置管理
DNS服务
服务和元数据管理

配置中心介绍

配置文件信息使用nacos保存用于它自身启动或运行需要的信息。

相当于spring consul的功能。

配置中心
- 发布修改配置
- 获取最新配置
- 配置更新通知后获取最新配置
  
  对于类似于连接池需要配置

安装

下载

https://github.com/alibaba/nacos/releases/download/2.1.0/nacos-server-2.1.0.tar.gz
- 历史版本
- https://github.com/alibaba/nacos/releases

启动

https://nacos.io/en-us/docs/quick-start.html

#Linux/Unix/Mac
#Run the following command to start(standalone means non-cluster mode):

sh startup.sh -m standalone
#Shutdown
sh shutdown.sh

默认端口是8848

各服务位置

Service registration 注册服务

1	curl -X POST 'http://192.168.86.100:8848/nacos/v1/ns/instance?serviceName=nacos.naming.serviceName&ip=20.18.7.10&port=8080'

Service discovery 发现服务

1	curl -X GET 'http://192.168.86.100:8848/nacos/v1/ns/instance/list?serviceName=nacos.naming.serviceName'

Publish config 发布配置

1	curl -X POST "http://192.168.86.100:8848/nacos/v1/cs/configs?dataId=nacos.cfg.dataId&group=test&content=helloWorld"

Get config 获取配置

1	curl -X GET "http://192.168.86.100:8848/nacos/v1/cs/configs?dataId=nacos.cfg.dataId&group=test"

发布配置

使用mysql数据库对nacos进行持久化

执行nacos的数据文件创建他的数据库。

https://nacos.io/zh-cn/docs/deployment.html 部署模式参考

1
2
3

#[root@java-study ~]# find -name nacos-mysql.sql
# 默认nacos-mysql数据文件在这
./nacos/conf/nacos-mysql.sql

创建nacos_config数据库

修改配置文件

#*************** Config Module Related Configurations ***************#
### If use MySQL as datasource:
spring.datasource.platform=mysql

### Count of DB:
# db.num=1

### Connect URL of DB:
db.num=1
db.url.0=jdbc:mysql://192.168.86.1:4306/nacos_config?characterEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true&useUnicode=true&useSSL=false&serverTimezone=UTC
db.user.0=root
db.password.0=123456

这里使用本地的数据库一直再出问题

有三种可能:

本地登陆数据库不适用密码- 这个应该解决了。
其次就是无法正确的获得数据。
mariadb版本问题(切换到86.1就解决了问题)

log

Caused by: java.lang.IllegalStateException: No DataSource set
        at org.springframework.util.Assert.state(Assert.java:73)
        at org.springframework.jdbc.support.JdbcAccessor.obtainDataSource(JdbcAccessor.java:77)
        at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:371)
        at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:452)
        at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:462)
        at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:473)
        at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:480)
        at com.alibaba.nacos.config.server.service.repository.extrnal.ExternalStoragePersistServiceImpl.findConfigMaxId(ExternalStoragePersistServiceImpl.java:674)
        at com.alibaba.nacos.config.server.service.dump.processor.DumpAllProcessor.process(DumpAllProcessor.java:51)
        at com.alibaba.nacos.config.server.service.dump.DumpService.dumpConfigInfo(DumpService.java:282)
        at com.alibaba.nacos.config.server.service.dump.DumpService.dumpOperate(DumpService.java:195)
        ... 61 common frames omitted

配置管理使用DEMO

编写一个入门程序

发布一个配置

点击这里来发布一个配置

编写一个程序来获取配置

编写一个可以运行的spring boot程序

创建一个NacosConfiguration类

package org.akachi.demo.nacos.product.configuration;

import com.alibaba.nacos.api.annotation.NacosProperties;
import com.alibaba.nacos.spring.context.annotation.config.EnableNacosConfig;
import com.alibaba.nacos.spring.context.annotation.config.NacosPropertySource;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Configuration;

/**
 * @Author akachi
 * @Email zsts@hotmail.com
 * @Date 2022/6/7 14:55
 */
@Configuration
@EnableNacosConfig(globalProperties =
@NacosProperties(serverAddr = "192.168.86.100:8848")
)
@NacosPropertySource(dataId = "nacos-product-demo", autoRefreshed = true)
public class NacosConfiguration {
}

创建一个Controller作为验证

package org.akachi.demo.nacos.product.controller;

import com.alibaba.nacos.api.config.annotation.NacosValue;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 * @Author akachi
 * @Email zsts@hotmail.com
 * @Date 2022/6/7 15:00
 */
@Controller
@RequestMapping("config")
public class ConfigController {
    @NacosValue(value = "${useLocalCache:false}", autoRefreshed = true)
    private boolean useLocalCache;

    @GetMapping(value = "/get")
    @ResponseBody
    public boolean get() {
        return useLocalCache;
    }
}

调用 GET http://localhost:18880/config/get

如果返回true则为成功

服务发现DEMO

demo

创建controller

package org.akachi.demo.nacos.product.controller;

import com.alibaba.nacos.api.annotation.NacosInjected;
import com.alibaba.nacos.api.config.annotation.NacosValue;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

/**
 * @Author akachi
 * @Email zsts@hotmail.com
 * @Date 2022/6/7 16:03
 */

@Controller
@RequestMapping("discovery")
public class DiscoveryController {

    @NacosInjected
    private NamingService namingService;

    @ResponseBody
    @GetMapping
    public List<Instance> get(@RequestParam String serviceName) throws NacosException {
        return namingService.getAllInstances(serviceName);
    }
}

创建service在服务器上执行

curl -X POST 'http://127.0.0.1:8848/nacos/v1/ns/instance?serviceName=nacos-product-demo&ip=192.168.86.1&port=18880'
调用

http://localhost:18880/discovery?serviceName=nacos-product-demo

nacos配置文件模型

通常我们使用namespace进行不同环境的隔离，group作为不同系统的文件隔离

如图:

新建命名空间namespace

@EnableNacosConfig(
        globalProperties =@NacosProperties(
                serverAddr = "192.168.86.100:8848",
                namespace = "sdf"
        )
)

在调用EnableNacosConfig注解时需要在globalProperties中加入sdf来确定使用的配置文件的namespace

不同namespace之间可以克隆

注册服务

这个教材太蠢了还不如看看官方示例操

base pom

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>


    <groupId>org.akachi</groupId>
    <artifactId>nacos-demo</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>nacos-provider</module>
        <module>nacos-consumer</module>
    </modules>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <spring-boot.version>2.0.4.RELEASE</spring-boot.version>
        <spring-cloud.version>Finchley.RELEASE</spring-cloud.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
                <version>0.2.2.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba.nacos</groupId>
                <artifactId>nacos-client</artifactId>
                <version>1.1.0</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

nacos-provider pom

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>nacos-demo</artifactId>
        <groupId>org.akachi</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>nacos-provider</artifactId>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.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>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

ProviderApplication

启动程序和controller都在这

package org.akachi.nacos.provider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

/**
 * @Author akachi
 * @Email zsts@hotmail.com
 * @Date 2022/6/8 15:56
 */
@SpringBootApplication
@EnableDiscoveryClient
public class ProviderApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProviderApplication.class, args);
    }
    @RestController
    class EchoController {
        @RequestMapping(value = "/echo/{string}", method = RequestMethod.GET)
        public String echo(@PathVariable String string) {
            return "Hello Nacos Discovery " + string;
        }
    }
}

application.yml的配置

server:
  port: 33030

spring:
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.86.100:8848
  application:
    name: service-provider

使用openfeign相互调用服务

yml

server:
  port: 33130
spring:
  application:
    name: service-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 192.168.86.100:8848

RemoteClient

```yml
package org.akachi.nacos.consumer.service;

import org.akachi.nacos.consumer.service.hystrix.RemoteHystrix;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

/**
- @Author akachi
- @Email zsts@hotmail.com
- @Date 2022/6/8 17:24
- /
  //http://service-provider/echo/" + str
  @FeignClient(name = “service-provider”,fallback = RemoteHystrix.class)
  public interface RemoteClient {
  
  @GetMapping(“/echo/{string}”)
  String helloNacos(@PathVariable(“string”) String string);
  }