Go语言项目中使用Viper获取配置信息详解

go 1.20
github.com/spf13/viper v1.18.2

go mod init github.com/rengmo/practicego

go get github.com/spf13/viper

redis:
  host: localhost
  port: 6379
  user:     # 本地redis的用户名为空
  password: abc123
  db: 0

package config

import (
	"fmt"

	"github.com/spf13/viper"
)

func init() {
	// 设置配置文件的名字
	viper.SetConfigName("dev")
	// 设置文件的格式
	viper.SetConfigType("yaml")
	// 设置查找配置文件的路径为当前路径 . 表示项目的工作目录，也就是main.go同级的那个目录
	viper.AddConfigPath("./config")

	// 读取配置文件中的数据到viper中
	err := viper.ReadInConfig()
	if err != nil {
		panic(err)
	}
	// 从viper中获取配置数据
	redisPort := viper.Get("redis.port")
	fmt.Printf("redisPort: %v \n", redisPort) // 打印结果：redisPort: 6379 
}

package main

import (
	_ "github.com/rengmo/practicego/infrastructure"
)

func main() {

}

	// 设置配置文件的名字
	viper.SetConfigName("dev")
	// 设置文件的格式
	viper.SetConfigType("yaml")
	// 设置查找配置文件的路径为当前路径 . 表示项目的工作目录，也就是main.go同级的那个目录
	viper.AddConfigPath("./config")

// 设置配置文件的路径
viper.SetConfigFile("./config/dev.yaml")

func init() {
  ...
	var config *Config
	err = viper.Unmarshal(&config)
	if err != nil {
		panic(err)
	}
	redisConfig := config.Redis
	fmt.Printf("redisConfig %+v\n", redisConfig) 
  // 打印的结果：redisConfig {Host:localhost Port:6379 User: Password:abc123 DB:0}
}

type Config struct {
	Redis RedisConfig
}

type RedisConfig struct {
	Host     string
	Port     int
	User     string
	Password string
	DB       int
}

Redis:
  Host: localhost
  Port: 6379

// AutomaticEnv makes Viper check if environment variables match any of the existing keys
// (config, default or flags). If matching env vars are found, they are loaded into Viper.
func AutomaticEnv() { v.AutomaticEnv() }

	viper.AutomaticEnv()
	env := viper.Get("env")
	fmt.Println("env: ", env) // env:  <nil>

	viper.SetDefault("env", "DEV")
	viper.AutomaticEnv()
	env := viper.Get("env")
	fmt.Println("env: ", env) // env:  DEV

func (v *Viper) BindEnv(input ...string) error {
	if len(input) == 0 {
		return fmt.Errorf("missing key to bind to")
	}

	key := strings.ToLower(input[0])

	if len(input) == 1 {
		v.env[key] = append(v.env[key], v.mergeWithEnvPrefix(key))
	} else {
		v.env[key] = append(v.env[key], input[1:]...)
	}

	return nil
}

	viper.BindEnv("env", "DEV")
	viper.AutomaticEnv()
	env := viper.Get("env")
	fmt.Println("env: ", env) // env:  PROD

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Launch Package",
            "type": "go",
            "request": "launch",
            "mode": "auto",
            "program": "${workspaceFolder}",
            "env": {
                "env": "PROD"
            }
        }
    ]
}

mysql:
  host: localhost
  port: 3306
  user: root
  password: 666666Aa_
  db_name: practicego

type Config struct {
	Redis    RedisConfig
	MySQL    MySQLConfig
	Priority string
}

type MySQLConfig struct {
	Host     string
	Port     int
	User     string
	Password string
	DBName   string `mapstructure:"db_name"`
}

func init() {
	viper.SetConfigFile("./config/dev.yaml")
	err := viper.ReadInConfig()
	if err != nil {
		panic(err)
	}
  
  var config *Config
	err = viper.Unmarshal(&config)
	if err != nil {
		panic(err)
	}
  
  mysqlConfig := config.MySQL
	fmt.Printf("mysqlConfig %+v\n", mysqlConfig)
}