auth/internal/config/config.go

package config

import (
	"log"

	"github.com/kelseyhightower/envconfig"
)

type dbConfig struct {
	Host string `envconfig:"DB_HOST"`
	Port int    `envconfig:"DB_PORT"`
}

type appConfig struct {
	Port int `envconfig:"APP_PORT"`
}

type authConfig struct {
	SecretKey string `envconfig:"SECRET_KEY"`
}

type sentryConfig struct {
	DSN string `envconfig:"SENTRY_DSN"`
}

// ...
type Config struct {
	Db     dbConfig
	App    appConfig
	Auth   authConfig
	Sentry sentryConfig
}

func NewConfig() *Config {
	c := Config{}
	err := envconfig.Process("", &c)
	if err != nil {
		log.Fatal(err.Error())
	}

	return &c
}