Function FromReader

pkg/management/upgrade/upgrade.go:53–124

FromReader updates in place the binary of the instance manager, replacing itself with a new version with the new binary

(
	cancelFunc context.CancelFunc,
	exitedCondition concurrency.MultipleExecuted,
	typedClient client.Client,
	instance *postgres.Instance,
	r io.Reader,
)

// FromReader updates in place the binary of the instance manager, replacing itself
// with a new version with the new binary
func FromReader(
	cancelFunc context.CancelFunc,
	exitedCondition concurrency.MultipleExecuted,
	typedClient client.Client,
	instance *postgres.Instance,
	r io.Reader,
) error {
	// Create a temporary file to host the new instance manager binary
	updatedInstanceManager, err := os.CreateTemp(UploadFolder, "manager_*.new")
	if err != nil {
		return fmt.Errorf(
			"while creating a temporary file to host the new version of the instance manager: %w", err)
	}
	defer func() {
		// This code is executed only if the instance manager has not been updated, and
		// this is the only condition we have a temporary file to remove
		removeError := os.Remove(updatedInstanceManager.Name()) //nolint:gosec // path from our own temp file
		if removeError != nil {
			log.Warning("Error while removing temporary instance manager upload file",
				"name", updatedInstanceManager.Name(), "err", err)
		}
	}()

	// Read the new instance manager version
	newHash, err := downloadAndCloseInstanceManagerBinary(updatedInstanceManager, r)
	if err != nil {
		return fmt.Errorf("while reading new instance manager binary: %w", err)
	}

	// Validate the hash of this instance manager
	if err := validateInstanceManagerHash(typedClient,
		instance.GetClusterName(), instance.GetNamespaceName(),
		instance.GetArchitecture(), newHash); err != nil {
		return fmt.Errorf("while validating instance manager binary: %w", err)
	}

	log.Info("Received new version of the instance manager",
		"hashCode", newHash,
		"temporaryName", updatedInstanceManager.Name())

	// Grant the executable bit to the new file
	err = os.Chmod(updatedInstanceManager.Name(), 0o755) //nolint:gosec // path from our own temp file
	if err != nil {
		return fmt.Errorf("while granting the executable bit to the instance manager binary: %w", err)
	}

	// Replace the new instance manager with the new one
	//nolint:gosec // path from our own temp file
	if err := os.Rename(updatedInstanceManager.Name(), InstanceManagerPath); err != nil {
		return fmt.Errorf("while replacing instance manager binary: %w", err)
	}

	// We are ready to reload the instance manager
	// First we are going to cancel the context, this will trigger the shutdown of all
	// the Runnables handled by the manager.
	// Only the postgres process will not be actually killed, as the postgres lifecycle
	// manager will not kill it if InstanceManagerIsUpgrading is set to true.
	cancelFunc()