storage/config/config.go

package config

import (
	"log"
	"os"
	"time"

	"github.com/joho/godotenv"
)

var (
	Mode    string
	Host    string
	BaseURL string

	AdminPassword string

	MonitorScriptsDir   string
	MonitorCacheTimeout time.Duration
)

func loadEnv(key string, defaultValue ...string) string {
	env, present := os.LookupEnv(key)

	if len(defaultValue) > 0 && !present {
		env = defaultValue[0]
	}

	log.Printf("Env variable %s = %q", key, env)
	return env
}

func parseEnv[T any](key, defaultValue string, parseFunc func(string) (T, error)) T {
	env := loadEnv(key, defaultValue)

	v, err := parseFunc(env)
	if err != nil {
		v, err = parseFunc(defaultValue)
		if err != nil {
			log.Fatalf("Unable to parse default value %q to type %T", defaultValue, v)
		}
	}

	log.Printf(`Env variable %s parsed from %q to %T of value %v`, key, env, v, v)
	return v
}

func init() {
	// Setup logger
	log.SetFlags(log.Lshortfile | log.Ltime | log.Ldate)

	// Load Config
	godotenv.Load()

	Mode = loadEnv("MODE", "development")
	Host = loadEnv("HOST", ":4000")
	BaseURL = loadEnv("HOST", "http://localhost:4000")

	AdminPassword = loadEnv("ADMIN_PASSWORD", "secret")

	MonitorScriptsDir = loadEnv("MONITOR_SCRIPTS_DIR", "./scripts")
	MonitorCacheTimeout = parseEnv("MONITOR_CACHE_TIMEOUT", "5s", time.ParseDuration)
}