一、Nacos介绍

Nacos（Naming and Configuration Service）是一款阿里巴巴开源的动态服务发现、配置管理和服务管理平台。它提供了注册中心、配置中心和元数据管理等功能，帮助开发者轻松实现服务的注册、发现和配置管理。

本文介绍的所有代码存放位置：[./src/nacos/nacos.go]#(./src/nacos/nacos.go)

二、Nacos安装

下载nacos
shell
```
https://nacos.io/download/nacos-server
```
环境检查配置
运行nacos的要求如下：
- Java环境
  64 bit JDK 1.8+；
- 环境要求
单机环境运行（开发使用）
shell
```
startup.cmd -m standalone
```
nacos控制台页面
浏览器打开http://127.0.0.1:8848/nacos,即可进入Nacos控制台页面。

三、Nacos 服务注册&发现

引入包

shell

go get -u github.com/nacos-group/nacos-sdk-go/v2

创建服务注册&发现客户端

package server

import (
    "bytes"
    "encoding/json"
    "log"
    "strconv"
    "strings"

    "github.com/nacos-group/nacos-sdk-go/v2/clients"
    "github.com/nacos-group/nacos-sdk-go/v2/clients/config_client"
    "github.com/nacos-group/nacos-sdk-go/v2/clients/naming_client"
    "github.com/nacos-group/nacos-sdk-go/v2/common/constant"
    "github.com/nacos-group/nacos-sdk-go/v2/model"
    "github.com/nacos-group/nacos-sdk-go/v2/vo"
    "github.com/spf13/viper"
)

func getNacosServerUrl() []string {
    nacosUrlSclice := make([]string, 0)
    nacosUrl := viper.GetString("nacos.server")
    if strings.Contains(nacosUrl, ";") {
        nacosUrlSclice = strings.Split(nacosUrl, ";")
    } else {
        nacosUrlSclice = append(nacosUrlSclice, nacosUrl)
    }
    return nacosUrlSclice
}

func getNacosConfig() (constant.ClientConfig, []constant.ServerConfig) {
    // 创建clientConfig
    clientConfig := constant.ClientConfig{
        TimeoutMs:           5000,
        NotLoadCacheAtStart: true,
        LogDir:              "/tmp/nacos/log",
        CacheDir:            "/tmp/nacos/cache",
        LogLevel:            "warn",
    }

    // 至少一个ServerConfig
    serverConfigs := make([]constant.ServerConfig, 0)
    for _, addr := range getNacosServerUrl() {
        ipPort := strings.Split(addr, ":")
        if len(ipPort) != 2 {
            continue
        }
        port, _ := strconv.Atoi(ipPort[1])
        serverConfigs = append(serverConfigs, constant.ServerConfig{
            IpAddr:      ipPort[0],
            ContextPath: "/nacos",
            Port:        uint64(port),
        })
    }
    return clientConfig, serverConfigs
}

// GetNacosNamingClient 获取Nacos服务发现客户端
func GetNacosNamingClient() (naming_client.INamingClient, error) {
    clientConfig, serverConfigs := getNacosConfig()
    // 创建服务发现客户端
    return clients.CreateNamingClient(map[string]interface{}{
        "serverConfigs": serverConfigs,
        "clientConfig":  clientConfig,
    })
}

注册服务至nacos

func RegisterService2Nacos(ip string, port uint64, endpoint string, metadata map[string]string) (bool, error) {
    client, err := GetNacosNamingClient()
    if err != nil {
        return false, err
    }

    return client.RegisterInstance(vo.RegisterInstanceParam{
        Ip:          ip,
        Port:        port,
        ServiceName: endpoint,
        Weight:      10,
        Enable:      true,
        Healthy:     true,
        Ephemeral:   true,
        Metadata:    metadata,
        GroupName:   endpoint,
    })
}

从nacos中注销服务

func UnRegisterService2Nacos(ip string, port uint64, endpoint string) (bool, error) {
    client, err := GetNacosNamingClient()
    if err != nil {
        return false, err
    }

    return client.DeregisterInstance(vo.DeregisterInstanceParam{
        Ip:          ip,
        Port:        port,
        ServiceName: endpoint,
        Ephemeral:   true,
        GroupName:   endpoint,
    })
}

从nacos中获取健康可用的服务

func GetServiceNacos(endpoint string) ([]model.Instance, error) {
    client, err := GetNacosNamingClient()
    if err != nil {
        return nil, err
    }
    return client.SelectInstances(vo.SelectInstancesParam{
        ServiceName: endpoint,
        GroupName:   endpoint,
        HealthyOnly: true,
    })
}

监听nacos中的服务

func SubscribeServiceNacos(endpoint string, callback func(services []model.Instance, err error)) error {
    client, err := GetNacosNamingClient()
    if err != nil {
        return err
    }
    param := &vo.SubscribeParam{
        ServiceName:       endpoint,
        GroupName:         endpoint,
        SubscribeCallback: callback,
    }
    return client.Subscribe(param)
}

取消监听nacos中的服务

func UnSubscribeServiceNacos(endpoint string, callback func(services []model.Instance, err error)) error {
    client, err := GetNacosNamingClient()
    if err != nil {
        return err
    }
    return client.Unsubscribe(&vo.SubscribeParam{
        ServiceName:       endpoint,
        GroupName:         endpoint,
        SubscribeCallback: callback,
    })
}

四、Nacos 服务配置管理

创建配置管理客户端

package server

import (
    "bytes"
    "encoding/json"
    "log"
    "strconv"
    "strings"

    "github.com/nacos-group/nacos-sdk-go/v2/clients"
    "github.com/nacos-group/nacos-sdk-go/v2/clients/config_client"
    "github.com/nacos-group/nacos-sdk-go/v2/clients/naming_client"
    "github.com/nacos-group/nacos-sdk-go/v2/common/constant"
    "github.com/nacos-group/nacos-sdk-go/v2/model"
    "github.com/nacos-group/nacos-sdk-go/v2/vo"
    "github.com/spf13/viper"
)

func getNacosServerUrl() []string {
    nacosUrlSclice := make([]string, 0)
    nacosUrl := viper.GetString("nacos.server")
    if strings.Contains(nacosUrl, ";") {
        nacosUrlSclice = strings.Split(nacosUrl, ";")
    } else {
        nacosUrlSclice = append(nacosUrlSclice, nacosUrl)
    }
    return nacosUrlSclice
}

func getNacosConfig() (constant.ClientConfig, []constant.ServerConfig) {
    // 创建clientConfig
    clientConfig := constant.ClientConfig{
        TimeoutMs:           5000,
        NotLoadCacheAtStart: true,
        LogDir:              "/tmp/nacos/log",
        CacheDir:            "/tmp/nacos/cache",
        LogLevel:            "warn",
    }

    // 至少一个ServerConfig
    serverConfigs := make([]constant.ServerConfig, 0)
    for _, addr := range getNacosServerUrl() {
        ipPort := strings.Split(addr, ":")
        if len(ipPort) != 2 {
            continue
        }
        port, _ := strconv.Atoi(ipPort[1])
        serverConfigs = append(serverConfigs, constant.ServerConfig{
            IpAddr:      ipPort[0],
            ContextPath: "/nacos",
            Port:        uint64(port),
        })
    }
    return clientConfig, serverConfigs
}

// GetNacosConfigClient 获取Nacos动态配置客户端
func GetNacosConfigClient() (config_client.IConfigClient, error) {
    clientConfig, serverConfigs := getNacosConfig()
    // 创建服务发现客户端
    return clients.CreateConfigClient(map[string]interface{}{
        "serverConfigs": serverConfigs,
        "clientConfig":  clientConfig,
    })
}

获取nacos中的配置

func GetConfigByNacos(endpoint string) (string, error) {
    client, err := GetNacosConfigClient()
    if err != nil {
        return "", err
    }
    content, err := client.GetConfig(vo.ConfigParam{
        DataId: endpoint,
        Group:  endpoint})
    return content, nil
}

发送配置文件至nacos

func PublicConfig2Nacos(endpoint string, metadata map[string]string) (bool, error) {
    client, err := GetNacosConfigClient()
    if err != nil {
        return false, err
    }
    dataBytes, err := json.Marshal(metadata)
    if err != nil {
        return false, err
    }
    return client.PublishConfig(vo.ConfigParam{
        DataId:  endpoint,
        Group:   endpoint,
        Content: string(dataBytes),
    })
}

删除nacos中的配置文件

func DeleteConfigByNacos(endpoint string) (bool, error) {
    client, err := GetNacosConfigClient()
    if err != nil {
        return false, err
    }
    return client.DeleteConfig(vo.ConfigParam{
        DataId: endpoint,
        Group:  endpoint,
    })
}

监听nacos中文件变化

func ListenConfigByNacos(endpoint string, callback func(namespace, group, dataId, data string)) error {
    client, err := GetNacosConfigClient()
    if err != nil {
        return err
    }
    return client.ListenConfig(vo.ConfigParam{
        DataId:   endpoint,
        Group:    endpoint,
        OnChange: callback,
    })
}

取消监听nacos中文件变化

func UnListenConfigByNacos(endpoint string) error {
    client, err := GetNacosConfigClient()
    if err != nil {
        return err
    }
    return client.CancelListenConfig(vo.ConfigParam{
        DataId: endpoint,
        Group:  endpoint,
    })
}

五、Nacos服务配置监听更新demo

func InitNacosDynamicConfig(endpoint string) {
    config, err := GetConfigByNacos(endpoint)
    if err != nil {
        log.Println("fetch remote config failed：", err.Error())
        panic(err)
    }
    err = viper.ReadConfig(bytes.NewBufferString(config))
    if err != nil {
        log.Println("parse remote config failed：", err.Error())
        panic(err)
    }

    err = ListenConfigByNacos(endpoint, func(namespace, group, dataId, data string) {
        log.Printf("listen config change: namespace: %s, group: %s, dataId: %s, data: \n%s\n", namespace, group, dataId, data)
        err := viper.ReadConfig(bytes.NewBufferString(data))
        if err != nil {
            log.Println("parse remote new config failed：", err.Error())
            panic(err)
        }
    })
    if err != nil {
        log.Println("listen remote config failed：", err.Error())
        panic(err)
    }
}

一、Nacos介绍 ​

二、Nacos安装 ​

三、Nacos 服务注册&发现 ​

四、Nacos 服务配置管理 ​

五、Nacos服务配置监听更新demo ​

一、Nacos介绍

二、Nacos安装

三、Nacos 服务注册&发现

四、Nacos 服务配置管理

五、Nacos服务配置监听更新demo