"github.com/spf13/viper"包可用于解析json,toml,yaml,命令参数,环境变量,远程配置，一次初始化，全局调用。

========== ========== ========== ========== ==========

package main

import (
	"fmt"
	"github.com/spf13/viper"
	"log"
	"strings"
	"time"
)

const config = `
app:
  isprod: true
  logger: file
redis:
  mastername: failover
  username: root
  password: test
  db: 1
  sentineladdrs:
    - 127.0.0.1:26379
    - 127.0.0.2:26379
    - 127.0.0.3:26379
  sentinelusername: root
  sentinelpassword: test
  cert: |
    -----BEGIN CERTIFICATE-----
    -----END CERTIFICATE-----
  key: |
    -----BEGIN RSA PRIVATE KEY-----
    -----END RSA PRIVATE KEY-----
  ca: |
    -----BEGIN CERTIFICATE-----
    -----END CERTIFICATE-----
  idletimeout: 1h2m3s4ms5us6ns
timerange:
  begin: 2022-01-01T00:00:00+08:00
  end: 2022-12-31T23:59:59+08:00
` //配置内容或写入到conf.yaml文件

func main() {
	viper.SetConfigType("yaml") //文本语言
	//viper.SetConfigName("conf")                  //文件名称(不含后缀)
	//viper.AddConfigPath(".")                     //搜索目录
	//if err := viper.ReadInConfig(); err != nil { //读入到viper包私有的map[string]any类型变量中
	//	log.Fatal("viper.ReadInConfig error", err)
	//}
	if err := viper.ReadConfig(strings.NewReader(config)); err != nil { //或从io.Reader读取
		log.Fatal("viper.ReadConfig error", err)
	}

	//直接从内存中读取配置，viper包会进行断言和解析，当不存在时返回零值。
	fmt.Println(viper.GetBool("app.isprod"))                 //true
	fmt.Println(viper.GetString("app.logger"))               //file
	fmt.Println(viper.GetInt("redis.db"))                    //1
	fmt.Println(viper.GetStringSlice("redis.sentineladdrs")) //[127.0.0.1:26379 127.0.0.2:26379 127.0.0.3:26379]
	fmt.Println(viper.GetDuration("redis.idletimeout"))      //1h2m3.004005006s Duration支持的最大单位是h
	fmt.Println(viper.GetTime("timerange.end"))              //2022-12-31 23:59:59 +0800 CST

	//解析到结构体中，后续每次从结构体读取，不需要再进行断言和解析，性能更优。
	var cfg struct {
		App struct {
			IsProd bool
			Logger string
		}
		Redis struct {
			MasterName       string
			Username         string
			Password         string
			DB               int
			SentinelAddrs    []string
			SentinelUsername string
			SentinelPassword string
			Cert             string
			Key              string
			Ca               string
			IdleTimeout      time.Duration
		}
		TimeRange struct {
			Begin time.Time
			End   time.Time
		}
	}
	if err := viper.Unmarshal(&cfg); err != nil {
		log.Fatal("viper.Unmarshal error: ", err)
	}
	fmt.Println(cfg.App.IsProd)          //true
	fmt.Println(cfg.App.Logger)          //file
	fmt.Println(cfg.Redis.DB)            //1
	fmt.Println(cfg.Redis.SentinelAddrs) //[127.0.0.1:26379 127.0.0.2:26379 127.0.0.3:26379]
	fmt.Println(cfg.Redis.IdleTimeout)   //1h2m3.004005006s
	fmt.Println(cfg.TimeRange.End)       //2022-12-31 23:59:59 +0800 CST
}