web-app-template/types/settings.go

package types

import (
	"web-app-template/log"
)

type Settings struct {
	Port              string
	PrometheusEnabled bool

	BaseUrl     string
	Environment string
	Smtp        *SmtpSettings
}

type SmtpSettings struct {
	Host     string
	Port     string
	User     string
	Pass     string
	FromMail string
	FromName string
}

func NewSettingsFromEnv(env func(string) string) *Settings {

	var smtp *SmtpSettings
	if env("SMTP_ENABLED") == "true" {
		smtp = &SmtpSettings{
			Host:     env("SMTP_HOST"),
			Port:     env("SMTP_PORT"),
			User:     env("SMTP_USER"),
			Pass:     env("SMTP_PASS"),
			FromMail: env("SMTP_FROM_MAIL"),
			FromName: env("SMTP_FROM_NAME"),
		}

		if smtp.Host == "" {
			log.Fatal("SMTP_HOST must be set")
		}
		if smtp.Port == "" {
			log.Fatal("SMTP_PORT must be set")
		}
		if smtp.User == "" {
			log.Fatal("SMTP_USER must be set")
		}
		if smtp.Pass == "" {
			log.Fatal("SMTP_PASS must be set")
		}
		if smtp.FromMail == "" {
			log.Fatal("SMTP_FROM_MAIL must be set")
		}
		if smtp.FromName == "" {
			log.Fatal("SMTP_FROM_NAME must be set")
		}
	}

	settings := &Settings{
		Port:              env("PORT"),
		PrometheusEnabled: env("PROMETHEUS_ENABLED") == "true",
		BaseUrl:           env("BASE_URL"),
		Environment:       env("ENVIRONMENT"),
		Smtp:              smtp,
	}

	if settings.BaseUrl == "" {
		log.Fatal("BASE_URL must be set")
	}
	if settings.Port == "" {
		log.Fatal("PORT must be set")
	}
	if settings.Environment == "" {
		log.Fatal("ENVIRONMENT must be set")
	}

	if settings.Environment == "prod" && (settings.Smtp == nil || !settings.PrometheusEnabled) {
		log.Fatal("SMTP and Prometheus must be enabled in production")
	}

	log.Info("BASE_URL is %q", settings.BaseUrl)
	log.Info("ENVIRONMENT is %q", settings.Environment)

	return settings
}