go_example1.go

package config

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

type Config struct {
    Port   string `mapstructure:"PORT"`
    DBHost string `mapstructure:"DB_HOST"`
    DBUser string `mapstructure:"DB_USER"`
    DBPass string `mapstructure:"DB_PASS"`
    DBName string `mapstructure:"DB_NAME"`
    DBPort string `mapstructure:"DB_PORT"`
}

func LoadConfig() (c Config, err error) {
    viper.AddConfigPath("./")
    viper.SetConfigName(".env")
    viper.SetConfigType("env")
    viper.AutomaticEnv()

    err = viper.ReadInConfig()

    if err != nil {
        return
    }

    err = viper.Unmarshal(&c)

    return
}