$ MYAPP_NAME=test go run main.go                                               
&{Name:}

package main

import (
	"fmt"
	"strings"

	"github.com/iamolegga/enviper"
	"github.com/spf13/viper"
)

type Config struct {
	Name string `mapstructure:"name,omitempty"`
}

func main() {
	e := enviper.New(viper.New())
	e.SetEnvPrefix("MYAPP")
	e.AddConfigPath("/etc/myapp")
	e.SetConfigName("app")

	config := &Config{}
	if err := e.Unmarshal(config); err != nil {
		panic(err)
	}

	fmt.Printf("%+v\n", config)
}