Using spf13/viper like node-config

viper-like-node-config.go

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/spf13/viper"
)

// Load reads in configurations from config files and environment variables
// It uses the following order to override configurations:
// 1. .default.env, 2. .$env.env, 3. .local.env, 4. environment variables
func Load(env, configFolderPath string) error {
	viper.SetConfigName(".default")
	viper.SetConfigType("env")
	viper.AddConfigPath(configFolderPath)

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

	if env != "" {
		env = strings.ToLower(env)
		viper.SetConfigName(fmt.Sprintf(".%s", env))
		viper.MergeInConfig()
	}

	viper.SetConfigName(".local")
	viper.MergeInConfig()

	viper.AutomaticEnv()

	return nil
}

func main() {
	s := viper.Get("key")
	fmt.Println(s)
}