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devexamples

Load Environment Variables Into Config

Read configuration from environment variables with typed parsing and defaults, validating required fields at startup rather than at first use.

GoConfig Management

Code

snippet
package config

import (
	"fmt"
	"os"
	"strconv"
)

type Config struct {
	Port        int
	DatabaseURL string
	Debug       bool
}

func Load() (Config, error) {
	databaseURL := os.Getenv("DATABASE_URL")
	if databaseURL == "" {
		return Config{}, fmt.Errorf("DATABASE_URL is required")
	}
	port, err := strconv.Atoi(getEnv("PORT", "8080"))
	if err != nil {
		return Config{}, fmt.Errorf("PORT must be a number: %w", err)
	}
	return Config{
		Port:        port,
		DatabaseURL: databaseURL,
		Debug:       getEnv("DEBUG", "false") == "true",
	}, nil
}

func getEnv(key, fallback string) string {
	if value, ok := os.LookupEnv(key); ok {
		return value
	}
	return fallback
}

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