Go语言实现配置热加载的方法分享

service:
    server:
          env: dev
          host: 127.0.0.1
          port: 9902

package global
import (
 "context"
 "path"
)
type Config struct {
 Conf struct {
    FilePath       string
    LastModifyTime int64
 }
 ctx    context.Context
 cancel context.CancelFunc
}
func NewConfig() (*Config, error) {
 conf := new(Config)
 conf.ctx, conf.cancel = context.WithCancel(context.Background())
 conf.Conf.FilePath = path.Join("./config", "api.yaml")
 APIconfig = conf.loadRoute()
 go conf.reload() //开启协程监听routeNotify
 go func() {
    for {
       select {
       case lastModifyTime, ok := <-routeNotify:
          if !ok {
             return
          }
          conf.Conf.LastModifyTime = lastModifyTime
          route := routeAtomic.Load().(*APIConf)
          if route != nil {
             APIconfig = route
          }
       }
    }
 }()
 return conf, nil
}
func (c *Config) Stop() {
 c.cancel()
}

go conf.reload()

package global
import (
   "fmt"
   "gopkg.in/yaml.v3"
   "io/ioutil"
   "os"
   "sync/atomic"
   "time"
)
const (
   CheckInterval = 5 * time.Second
)
var (
   routeAtomic atomic.Value //原子性，解决并发问题
   routeNotify = make(chan int64) //channel 放入timestamp
)
func (c *Config) reload() {
   ticker := time.NewTicker(CheckInterval)
   defer ticker.Stop()
   for {
      select {
      case <-c.ctx.Done():
         close(routeNotify)
         return
      case <-ticker.C:
         if f, err := os.Stat(c.Route.FilePath); err != nil {
            fmt.Println(err)
         } else if f.ModTime().Unix() != c.Route.LastModifyTime {
            if c.Route.LastModifyTime == 0 {
               c.Route.LastModifyTime = f.ModTime().Unix()
            } else {
               routeAtomic.Store(c.loadConfig())
               routeNotify <- f.ModTime().Unix()
               fmt.Println("配置文件发生变化")
            }
         }
      }
   }
}
func (c *Config) loadConfig() *APIConf {
   if fp, err := ioutil.ReadFile(c.Route.FilePath); err != nil {
      fmt.Println(err)
      return nil
   } else {
      route := new(APIConf)
      if err := yaml.Unmarshal(fp, &route); err != nil {
         return nil
      }
      return route
   }
}

package global
var (
   APIconfig = new(APIConf)
)

package global
type ServiceConf struct {
   Server struct {
      Env  string `yaml:"env"` 
      Host string `yaml:"host"`
      Port string  `yaml:"port"`
   } `yaml:"server"`
}
type APIConf struct { 
   Service ServiceConf `yaml:"service"`
}

package main
import (
   "dyconfig/global"
   "fmt"
   "github.com/gin-gonic/gin"
)
func main() {
   if conf, err := global.NewConfig(); err != nil { // 初始化配置
      fmt.Println(err)
   } else {
      defer conf.Stop()
   }
   gin.SetMode(gin.DebugMode)
   r := gin.Default()
   r.GET("/ping", func(context *gin.Context) {
      fmt.Println("当前host是: ", global.APIconfig.Service.Server.Host)
      fmt.Println("当前port是: ", global.APIconfig.Service.Server.Port)
      context.JSON(
         200, gin.H{
            "host": global.APIconfig.Service.Server.Host,
            "port": &global.APIconfig.Service.Server.Port,
         })
   })
   port := global.APIconfig.Service.Server.Port
   fmt.Println("当前host是: ", global.APIconfig.Service.Server.Host)
   fmt.Println("当前port是: ", global.APIconfig.Service.Server.Port)
   port = ":" + port
   _ = r.Run(port)
}