viper

设置和读取值

package main

import (
  "fmt"

  "github.com/spf13/viper"
)

func main() {
  viper.SetDefault("name", "张三")
  viper.Set("name", "李四")

  fmt.Println(viper.Get("name")) // 李四
}

写配置文件

package main

import (
  "github.com/spf13/viper"
)

func main() {
  viper.Set("Server", "Server")
  type ServerConfig struct {
    Addr string `json:"addr"`
    Port string `json:"port"`
  }

  var serverConfig = ServerConfig{
    Addr: "localhost",
    Port: "8080",
  }
  viper.SetDefault("ServerConfig", serverConfig)

  viper.SetConfigType("json")
  viper.WriteConfigAs("config.json")
}

{
  "server": "Server",
  "serverconfig": {
    "addr": "localhost",
    "port": "8080"
  }
}

读取配置文件

package main

import (
  "fmt"

  "github.com/spf13/viper"
)

func main() {
  viper.SetConfigType("yaml")
  viper.SetConfigFile("config.yaml")

  err := viper.ReadInConfig()
  if err != nil {
    panic(err)
    return
  }

  fmt.Println(viper.Get("app"))

  fmt.Println(viper.Get("server.port"))

  type Config struct {
    App string `json:"mapstructure:app"`
  }

  var config Config
  err = viper.Unmarshal(&config)
  if err != nil {
    panic(err)
    return
  }

  fmt.Println(config)
}

监控配置文件变化

package main

import (
  "fmt"

  "github.com/fsnotify/fsnotify"
  "github.com/spf13/viper"
)

func main() {
  viper.SetConfigType("yaml")
  viper.SetConfigFile("config.yaml")

  viper.WatchConfig()
  viper.OnConfigChange(func(e fsnotify.Event) {
    // name是文件名，op是变化的类型:WRITE
    fmt.Println("Config file changed:", e.Name, e.Op)
  })

  select {}
}

读取系统环境变量

package main

import (
  "fmt"

  "github.com/spf13/viper"
)

func main() {
  viper.AutomaticEnv()
  viper.SetEnvPrefix("")

  fmt.Println(viper.Get("GOPATH"))
}

Linux下使用echo $GOPATH命令查看。

获取命令行参数

package main

import (
  "fmt"

  "github.com/spf13/pflag"
  "github.com/spf13/viper"
)

func main() {
  var ip string
  var port int
  pflag.StringVar(&ip, "ip", "localhost", "ip address")
  pflag.IntVar(&port, "port", 3000, "port number")
  pflag.Parse()

  viper.BindPFlags(pflag.CommandLine)

  fmt.Println(viper.Get("ip"))
}

运行: go run main.go --ip 127.0.0.1 --port 8080

读取远程配置

etcd

package main

import (
  "fmt"

  "github.com/spf13/viper"
  _ "github.com/spf13/viper/remote"
)

func main() {
  viper.AddRemoteProvider("etcd3", "http://127.0.0.1:2379", "config/dev")
  viper.SetConfigType("json")

  err := viper.ReadRemoteConfig()
  if err != nil {
    panic(err)
  }

  fmt.Println(viper.Get("addr"))
}