library-buildConfig.go

func BuildConfig(filename ...string) (*AppConfig, error) {
	if len(filename) == 1 {
		return buildConfigFromFile(filename[0])
	} else {
		return BuildConfigWithoutFile()
	}
}

func buildConfigFromFile(filename string) (*AppConfig, error) {

	var ac AppConfig
	file, err := ioutil.ReadFile(filename)
	if err != nil {
		return nil, errors.Wrap(err, "read error")
	}
	err = yaml.Unmarshal(file, &ac)

	if err != nil {
		return nil, errors.Wrap(err, "unmarshal")
	}
	fmt.Println("appConfig:", ac)
	return &ac, nil
}