directory/internal/config/config.go

package config

import (
	"fmt"

	"github.com/rs/zerolog"
	"github.com/spf13/viper"
	"go.uber.org/fx"
	"sneak.berlin/go/directory/internal/globals"
	"sneak.berlin/go/directory/internal/logger"

	// spooky action at a distance!
	// this populates the environment
	// from a ./.env file automatically
	// for development configuration.
	// .env contents should be things like
	// `DBURL=postgres://user:pass@.../`
	// (without the backticks, of course)
	_ "github.com/joho/godotenv/autoload"
)

type ConfigParams struct {
	fx.In
	Globals *globals.Globals
	Logger  *logger.Logger
}

type Config struct {
	DBDSN            string
	Debug            bool
	MaintenanceMode  bool
	DevelopmentMode  bool
	DevAdminUsername string
	DevAdminPassword string
	MetricsPassword  string
	MetricsUsername  string
	Port             int
	SentryDSN        string
	params           *ConfigParams
	log              *zerolog.Logger
}

func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
	log := params.Logger.Get()
	name := params.Globals.Appname

	viper.SetConfigName(name)
	viper.SetConfigType("yaml")
	// path to look for the config file in:
	viper.AddConfigPath(fmt.Sprintf("/etc/%s", name))
	// call multiple times to add many search paths:
	viper.AddConfigPath(fmt.Sprintf("$HOME/.config/%s", name))
	// viper.SetEnvPrefix(strings.ToUpper(s.appname))
	viper.AutomaticEnv()

	viper.SetDefault("DEBUG", "false")
	viper.SetDefault("MAINTENANCE_MODE", "false")
	viper.SetDefault("DEVELOPMENT_MODE", "false")
	viper.SetDefault("DEV_ADMIN_USERNAME", "")
	viper.SetDefault("DEV_ADMIN_PASSWORD", "")
	viper.SetDefault("PORT", "8080")
	viper.SetDefault("DB_DSN", "")
	viper.SetDefault("SENTRY_DSN", "")
	viper.SetDefault("METRICS_USERNAME", "")
	viper.SetDefault("METRICS_PASSWORD", "")

	if err := viper.ReadInConfig(); err != nil {
		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
			// Config file not found; ignore error if desired
		} else {
			// Config file was found but another error was produced
			log.Panic().
				Err(err).
				Msg("config file malformed")
		}
	}

	s := &Config{
		DBDSN:            viper.GetString("DB_DSN"),
		Debug:            viper.GetBool("debug"),
		Port:             viper.GetInt("PORT"),
		SentryDSN:        viper.GetString("SENTRY_DSN"),
		MaintenanceMode:  viper.GetBool("MAINTENANCE_MODE"),
		DevelopmentMode:  viper.GetBool("DEVELOPMENT_MODE"),
		DevAdminUsername: viper.GetString("DEV_ADMIN_USERNAME"),
		DevAdminPassword: viper.GetString("DEV_ADMIN_PASSWORD"),
		MetricsUsername:  viper.GetString("METRICS_USERNAME"),
		MetricsPassword:  viper.GetString("METRICS_PASSWORD"),
		log:              log,
		params:           &params,
	}

	if s.Debug {
		params.Logger.EnableDebugLogging()
		s.log = params.Logger.Get()
	}

	return s, nil
}