现代微服务配置中心与服务发现完全指南 2026：Nacos vs Consul vs etcd 选型 + 动态灰度 + 生产容灾

1
# 启动容器
2
docker compose up -d
3

4
# 默认初始账号密码：nacos / nacos (首次登录后强制修改密码)

1
package main
2

3
import (
4
  "encoding/json"
5
  "fmt"
6
  "sync"
7
  "time"
8

9
  "github.com/nacos-group/nacos-sdk-go/v2/clients"
10
  "github.com/nacos-group/nacos-sdk-go/v2/common/constant"
11
  "github.com/nacos-group/nacos-sdk-go/v2/vo"
12
)
13

14
// AppDynamicConfig 业务动态配置结构体
15
type AppDynamicConfig struct {
16
  EnableVipDiscount bool    `json:"enable_vip_discount"`
17
  DiscountRate      float64 `json:"discount_rate"`
18
  MaxConnectionPool int     `json:"max_connection_pool"`
19
}
20

21
// ConfigManager 线程安全的配置管理器单例
22
type ConfigManager struct {
23
  rwLock sync.RWMutex
24
  config AppDynamicConfig
25
}
26

27
var globalConfig ConfigManager
28

29
func (m *ConfigManager) Get() AppDynamicConfig {
30
  m.rwLock.RLock()
31
  defer m.rwLock.RUnlock()
32
  return m.config
33
}
34

35
func (m *ConfigManager) Update(newCfg AppDynamicConfig) {
36
  m.rwLock.Lock()
37
  defer m.rwLock.Unlock()
38
  m.config = newCfg
39
}
40

41
func main() {
42
  // 1. 配置 Nacos 服务端与客户端参数
43
  serverConfigs := []constant.ServerConfig{
44
    *constant.NewServerConfig("127.0.0.1", 8848),
45
  }
46

47
  clientConfig := *constant.NewClientConfig(
48
    constant.WithNamespaceId("public"), // 命名空间
49
    constant.WithTimeoutMs(5000),
50
    constant.WithNotLoadCacheAtStart(false), // 开启启动自动加载本地磁盘缓存
51
    constant.WithLogDir("/tmp/nacos/log"),
52
    constant.WithCacheDir("/tmp/nacos/cache"), // 二级容灾：本地快照存储目录
53
    constant.WithLogLevel("info"),
54
  )
55

56
  // 2. 创建配置客户端
57
  configClient, err := clients.NewConfigClient(
58
    vo.NacosClientParam{
59
      ClientConfig:  &clientConfig,
60
      ServerConfigs: serverConfigs,
61
    },
62
  )
63
  if err != nil {
64
    panic(fmt.Sprintf("Failed to create nacos client: %v", err))
65
  }
66

67
  dataId := "order-service.json"
68
  group := "PROD_GROUP"
69

70
  // 3. 初始同步获取配置
71
  content, err := configClient.GetConfig(vo.ConfigParam{
72
    DataId: dataId,
73
    Group:  group,
74
  })
75
  if err != nil {
76
    fmt.Printf("⚠️ Failed to get initial config from Nacos, using default fallback: %v\n", err)
77
    globalConfig.Update(AppDynamicConfig{
78
      EnableVipDiscount: false,
79
      DiscountRate:      1.0,
80
      MaxConnectionPool: 50,
81
    })
82
  } else {
83
    var initCfg AppDynamicConfig
84
    if err := json.Unmarshal([]byte(content), &initCfg); err == nil {
85
      globalConfig.Update(initCfg)
86
      fmt.Printf("✅ Initial config loaded from Nacos successfully: %+v\n", initCfg)
87
    }
88
  }
89

90
  // 4. 注册异步动态监听器 (长连秒级热推)
91
  err = configClient.ListenConfig(vo.ConfigParam{
92
    DataId: dataId,
93
    Group:  group,
94
    OnChange: func(namespace, group, dataId, data string) {
95
      fmt.Println("\n⚡ [Nacos Push] Detected remote configuration change!")
96
      var newCfg AppDynamicConfig
97
      if err := json.Unmarshal([]byte(data), &newCfg); err != nil {
98
        fmt.Printf("❌ Failed to parse new config JSON: %v\n", err)
99
        return
100
      }
101
      globalConfig.Update(newCfg)
102
      fmt.Printf("🎉 Dynamic configuration updated in-memory: %+v\n", newCfg)
103
    },
104
  })
105
  if err != nil {
106
    panic(fmt.Sprintf("Failed to listen config: %v", err))
107
  }
108

109
  // 5. 模拟业务持续读取动态配置
110
  for i := 0; i < 5; i++ {
111
    cur := globalConfig.Get()
112
    fmt.Printf("[Business Loop] VIP Discount: %v, Rate: %.2f, Pool: %d\n",
113
      cur.EnableVipDiscount, cur.DiscountRate, cur.MaxConnectionPool)
114
    time.Sleep(3 * time.Second)
115
  }
116
}