disk.go

// SPDX-FileCopyrightText: Copyright The Lima Authors
// SPDX-License-Identifier: Apache-2.0

package driverutil

import (
	"context"
	"errors"
	"fmt"
	"os"
	"path/filepath"

	"github.com/docker/go-units"
	"github.com/lima-vm/go-qcow2reader/image"

	"github.com/lima-vm/lima/v2/pkg/imgutil/proxyimgutil"
	"github.com/lima-vm/lima/v2/pkg/iso9660util"
	"github.com/lima-vm/lima/v2/pkg/limatype/filenames"
)

// EnsureDisk ensures that the diff disk exists with the specified size and format.
func EnsureDisk(ctx context.Context, instDir, diskSize string, diskImageFormat image.Type) error {
	diffDisk := filepath.Join(instDir, filenames.DiffDisk)
	if _, err := os.Stat(diffDisk); err == nil || !errors.Is(err, os.ErrNotExist) {
		// disk is already ensured
		return err
	}

	diskUtil := proxyimgutil.NewDiskUtil(ctx)

	baseDisk := filepath.Join(instDir, filenames.BaseDisk)

	diskSizeInBytes, _ := units.RAMInBytes(diskSize)
	if diskSizeInBytes == 0 {
		return nil
	}
	isBaseDiskISO, err := iso9660util.IsISO9660(baseDisk)
	if err != nil {
		return err
	}
	srcDisk := baseDisk
	if isBaseDiskISO {
		srcDisk = diffDisk

		// Create an empty data volume for the diff disk
		diffDiskF, err := os.Create(diffDisk)
		if err != nil {
			return err
		}

		if err = diffDiskF.Close(); err != nil {
			return err
		}
	}
	// Check whether to use ASIF format

	if err = diskUtil.Convert(ctx, diskImageFormat, srcDisk, diffDisk, &diskSizeInBytes, false); err != nil {
		return fmt.Errorf("failed to convert %q to a disk %q: %w", srcDisk, diffDisk, err)
	}
	return err
}