Toml Config Value by Name (Go)

I use https://github.com/BurntSushi/toml for parsing the configuration file. Because the library use the struct type for the configuration variable, we have to access the struct fields with a dot to get a value.

config.Database.Username

But I want to do it dynamically. I want to create a function that receive a string type key and return the configuration value. So I do it with this way.

package main

import (
	"fmt"
	"os"
	"reflect"
	"strings"
	"github.com/BurntSushi/toml"
)

type tomlConfig struct {
	Database databaseInfo
	Title    string
}

type databaseInfo struct {
	Username string
	Password string
}

// Function to get struct type variable by index name
func GetField(t *tomlConfig, field string) string {
	r := reflect.ValueOf(t)
	f := reflect.Indirect(r)

	splitField := strings.Split(field, ".")
	for _, s := range splitField {
		f = f.FieldByName(strings.Title(s))
	}

	return f.String()
}

// Function to get config by string
func GetConfig(key string) string {
	var config tomlConfig
	if _, err := toml.Decode(
		`
		title = "Text title"

		[database]
		username = "root"
		password = "password"
		`, &config); err != nil {
		fmt.Println("Please check your configuration file")
		os.Exit(1)
	}

	configValue := GetField(&config, key)

	return configValue
}

func main() {
	fmt.Println(GetConfig("testKey"))
	fmt.Println(GetConfig("database.testKey"))
	fmt.Println(GetConfig("title"))
	fmt.Println(GetConfig("database.username"))
	fmt.Println(GetConfig("database.password"))
}

Result:

$ go run main.go 
<invalid Value>
<invalid Value>
Text title
root
password