scaffold-goweb/internal/config/config.go

package config

import (
	"io"
	"io/ioutil"
	"time"

	"github.com/pkg/errors"

	"github.com/caarlos0/env/v6"
	"gopkg.in/yaml.v2"
)

type Config struct {
	Debug bool       `yaml:"debug" env:"DEBUG"`
	HTTP  HTTPConfig `yaml:"http"`
}

// NewFromFile retrieves the configuration from the given file
func NewFromFile(filepath string) (*Config, error) {
	config := NewDefault()

	data, err := ioutil.ReadFile(filepath)
	if err != nil {
		return nil, errors.Wrapf(err, "could not read file '%s'", filepath)
	}

	if err := yaml.Unmarshal(data, config); err != nil {
		return nil, errors.Wrapf(err, "could not unmarshal configuration")
	}

	return config, nil
}

type HTTPConfig struct {
	Address                 string `yaml:"address" env:"HTTP_ADDRESS"`
	CookieAuthenticationKey string `yaml:"cookieAuthenticationKey" env:"HTTP_COOKIE_AUTHENTICATION_KEY"`
	CookieEncryptionKey     string `yaml:"cookieEncryptionKey" env:"HTTP_COOKIE_ENCRYPTION_KEY"`
	CookieMaxAge            int    `yaml:"cookieMaxAge" env:"HTTP_COOKIE_MAX_AGE"`
	TemplateDir             string `yaml:"templateDir" env:"HTTP_TEMPLATE_DIR"`
	PublicDir               string `yaml:"publicDir" env:"HTTP_PUBLIC_DIR"`
}

func NewDumpDefault() *Config {
	config := NewDefault()
	return config
}

func NewDefault() *Config {
	return &Config{
		Debug: false,
		HTTP: HTTPConfig{
			Address:                 ":3000",
			CookieAuthenticationKey: "",
			CookieEncryptionKey:     "",
			CookieMaxAge:            int((time.Hour * 1).Seconds()), // 1 hour
			TemplateDir:             "template",
			PublicDir:               "public",
		},
	}
}

func Dump(config *Config, w io.Writer) error {
	data, err := yaml.Marshal(config)
	if err != nil {
		return errors.Wrap(err, "could not dump config")
	}

	if _, err := w.Write(data); err != nil {
		return err
	}

	return nil
}

func WithEnvironment(conf *Config) error {
	if err := env.Parse(conf); err != nil {
		return err
	}

	return nil
}