digamos que você tenha um frontend rodando no seu navegador em `http://localhost:8080`, e seu JavaScript esteja tentando se comunicar com um backend rodando em `http://localhost` (como não especificamos uma porta, o navegador assumirá a porta padrão `80`).

Portanto, o navegador enviará uma requisição HTTP `OPTIONS` ao backend `:80`, e se o backend enviar os cabeçalhos apropriados autorizando a comunicação a partir dessa origem diferente (`http://localhost:8080`), então o navegador `:8080`...

Browser unter `http://localhost:8080` läuft, und dessen JavaScript versucht, mit einem Backend zu kommunizieren, das unter `http://localhost` läuft (da wir keinen Port angegeben haben, geht der Browser vom Default-Port `80` aus).

Dann wird der Browser ein HTTP-`OPTIONS`-<abbr title="Request – Anfrage: Daten, die der Client zum Server sendet">Request</abbr> an das `:80`-Backend senden, und wenn das Backend die entsprechenden Header sendet, die die Kommunikation von diesem anderen Origin (`...

  The API Server will no longer proxy non-101 responses for upgrade requests. This could break proxied backends (such as an extension API server) that respond to upgrade requests with a non-101 response code. ([#92941](https://github.com/kubernetes/kubernetes/pull/92941), [@tallclair](https://github.com/tallclair)) [SIG API Machinery]
 

	ErrUnsupportedBackend = newErrFn(
		"Unable to write to the backend",
		"Please ensure your drive supports O_DIRECT",
		"",
	)

	ErrUnableToWriteInBackend = newErrFn(
		"Unable to write to the backend",
		"Please ensure MinIO binary has write permissions for the backend",
		`Verify if MinIO binary is running as the same user who has write permissions for the backend`,
	)

	ErrPortAlreadyInUse = newErrFn(

		// Init and run test on ErasureSD backend with signature v4.
		{serverType: "ErasureSD", signer: signerV4},
		// Init and run test on ErasureSD backend, with tls enabled.
		{serverType: "ErasureSD", signer: signerV4, secure: true},
		// Init and run test on Erasure backend.
		{serverType: "Erasure", signer: signerV4},
		// Init and run test on ErasureSet backend.
		{serverType: "ErasureSet", signer: signerV4},
	}

* Migrations **Alembic**.
* **CORS** (partage des ressources entre origines multiples, ou *Cross Origin Resource Sharing*).
* *Worker* **Celery** pouvant importer et utiliser les modèles et le code du reste du backend.

* **Alembic** migration.
* **CORS** (Cross Origin Resource Sharing).
* **Celery** worker'ları ile backend içerisinden seçilen işleri çalıştırabilirsiniz.

	clusterDriveMetrics, err := c.clusterDriveMetrics.Get()
	if err != nil {
		metricsLogIf(ctx, err)
	} else {
		m.Set(configStandardParity, float64(clusterDriveMetrics.storageInfo.Backend.StandardSCParity))
		m.Set(configRRSParity, float64(clusterDriveMetrics.storageInfo.Backend.RRSCParity))
	}

	return nil

// errCorruptedFormat - corrupted format.
var errCorruptedFormat = StorageErr("corrupted format")

// errCorruptedBackend - corrupted backend.
var errCorruptedBackend = StorageErr("corrupted backend")

// errUnformattedDisk - unformatted disk found.
var errUnformattedDisk = StorageErr("unformatted drive found")

// errInconsistentDisk - inconsistent disk found.

		return "", fmt.Errorf(`found backend type %s, expected %s or %s - to migrate to a supported backend visit https://docs.min.io/community/minio-object-store/operations/deployments/baremetal-migrate-fs-gateway.html`, meta.Format, formatBackendErasure, formatBackendErasureSingle)
	}
	// Erasure backend found, proceed to detect version.
	format := &formatErasureVersionDetect{}