Merge pull request #1596 from AkihiroSuda/vz-make-qemu-img-optional

vz: drop dependency on qemu-img

Author: AkihiroSuda

cmd/limactl/stop.go

@@ -133,18 +133,21 @@ func stopInstanceForcibly(inst *store.Instance) {
 		logrus.Info("The host agent process seems already stopped")
 	}
 
-	logrus.Infof("Removing *.pid *.sock under %q", inst.Dir)
+	suffixesToBeRemoved := []string{".pid", ".sock", ".tmp"}
+	logrus.Infof("Removing %s under %q", inst.Dir, strings.ReplaceAll(strings.Join(suffixesToBeRemoved, " "), ".", "*."))
 	fi, err := os.ReadDir(inst.Dir)
 	if err != nil {
 		logrus.Error(err)
 		return
 	}
 	for _, f := range fi {
 		path := filepath.Join(inst.Dir, f.Name())
-		if strings.HasSuffix(path, ".pid") || strings.HasSuffix(path, ".sock") {
-			logrus.Infof("Removing %q", path)
-			if err := os.Remove(path); err != nil {
-				logrus.Error(err)
+		for _, suffix := range suffixesToBeRemoved {
+			if strings.HasSuffix(path, suffix) {
+				logrus.Infof("Removing %q", path)
+				if err := os.Remove(path); err != nil {
+					logrus.Error(err)
+				}
 			}
 		}
 	}

go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/google/go-cmp v0.5.9
 	github.com/gorilla/mux v1.8.0
 	github.com/hashicorp/go-multierror v1.1.1
+	github.com/lima-vm/go-qcow2reader v0.1.1
 	github.com/lima-vm/sshocker v0.3.2
 	github.com/lithammer/dedent v1.1.0
 	github.com/mattn/go-isatty v0.0.19

go.sum

@@ -177,6 +177,8 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/leodido/go-urn v1.2.0 h1:hpXL4XnriNwQ/ABnpepYM/1vCLWNDfUNts8dX3xTG6Y=
+github.com/lima-vm/go-qcow2reader v0.1.1 h1:UegxTAU4usoSzKLDqhbaNmmV4Ec4qhQO11QYeLLy7Jc=
+github.com/lima-vm/go-qcow2reader v0.1.1/go.mod h1:e3p29BzLT8hNh4jbLezdFAHU4eBijf0bm5GilStCRKE=
 github.com/lima-vm/sshocker v0.3.2 h1:o0WqVzcpt6mzVCuqtS3N3O8kwTx6X4SLr4h7YaRISuE=
 github.com/lima-vm/sshocker v0.3.2/go.mod h1:9SWN6wob210VM6oJkkzvWQOlHSp/rQLB+0fSEc92zig=
 github.com/linuxkit/virtsock v0.0.0-20220523201153-1a23e78aa7a2 h1:DZMFueDbfz6PNc1GwDRA8+6lBx1TB9UnxDQliCqR73Y=

pkg/nativeimgutil/nativeimgutil.go

@@ -0,0 +1,154 @@
+// Package nativeimgutil provides image utilities that do not depend on `qemu-img` binary.
+package nativeimgutil
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/containerd/continuity/fs"
+	"github.com/lima-vm/go-qcow2reader"
+	"github.com/lima-vm/go-qcow2reader/image/qcow2"
+	"github.com/lima-vm/go-qcow2reader/image/raw"
+	"github.com/lima-vm/lima/pkg/osutil"
+	"github.com/sirupsen/logrus"
+)
+
+// ConvertToRaw converts a source disk into a raw disk.
+// source and dest may be same.
+// ConvertToRaw is a NOP if source == dest, and no resizing is needed.
+func ConvertToRaw(source, dest string, size *int64, allowSourceWithBackingFile bool) error {
+	srcF, err := os.Open(source)
+	if err != nil {
+		return err
+	}
+	defer srcF.Close()
+	srcImg, err := qcow2reader.Open(srcF)
+	if err != nil {
+		return fmt.Errorf("failed to detect the format of %q: %w", source, err)
+	}
+	if size != nil && *size < srcImg.Size() {
+		return fmt.Errorf("specified size %d is smaller than the original image size (%d) of %q", *size, srcImg.Size(), source)
+	}
+	switch t := srcImg.Type(); t {
+	case raw.Type:
+		if err = srcF.Close(); err != nil {
+			return err
+		}
+		return convertRawToRaw(source, dest, size)
+	case qcow2.Type:
+		if !allowSourceWithBackingFile {
+			q, ok := srcImg.(*qcow2.Qcow2)
+			if !ok {
+				return fmt.Errorf("unexpected qcow2 image %T", srcImg)
+			}
+			if q.BackingFile != "" {
+				return fmt.Errorf("qcow2 image %q has an unexpected backing file: %q", source, q.BackingFile)
+			}
+		}
+	default:
+		logrus.Warnf("image %q has an unexpected format: %q", source, t)
+	}
+	if err = srcImg.Readable(); err != nil {
+		return fmt.Errorf("image %q is not readable: %w", source, err)
+	}
+
+	// Create a tmp file because source and dest can be same.
+	destTmpF, err := os.CreateTemp(filepath.Dir(dest), filepath.Base(dest)+".lima-*.tmp")
+	if err != nil {
+		return err
+	}
+	destTmp := destTmpF.Name()
+	defer os.RemoveAll(destTmp)
+	defer destTmpF.Close()
+
+	// Copy
+	srcImgR := io.NewSectionReader(srcImg, 0, srcImg.Size())
+	const bufSize = 1024 * 1024
+	if copied, err := copySparse(destTmpF, srcImgR, bufSize); err != nil {
+		return fmt.Errorf("failed to call copySparse(), bufSize=%d, copied=%d: %w", bufSize, copied, err)
+	}
+
+	// Resize
+	if size != nil {
+		if err = MakeSparse(destTmpF, *size); err != nil {
+			return err
+		}
+	}
+	if err = destTmpF.Close(); err != nil {
+		return err
+	}
+
+	// Rename destTmp into dest
+	if err = os.RemoveAll(dest); err != nil {
+		return err
+	}
+	return os.Rename(destTmp, dest)
+}
+
+func convertRawToRaw(source, dest string, size *int64) error {
+	if source != dest {
+		// continuity attempts clonefile
+		if err := fs.CopyFile(dest, source); err != nil {
+			return fmt.Errorf("failed to copy %q into %q: %w", source, dest, err)
+		}
+	}
+	if size != nil {
+		destF, err := os.OpenFile(dest, os.O_RDWR, 0644)
+		if err != nil {
+			return err
+		}
+		if err = MakeSparse(destF, *size); err != nil {
+			_ = destF.Close()
+			return err
+		}
+		return destF.Close()
+	}
+	return nil
+}
+
+func copySparse(w *os.File, r io.Reader, bufSize int64) (int64, error) {
+	var n int64
+	zeroBuf := make([]byte, bufSize)
+	buf := make([]byte, bufSize)
+	var eof bool
+	for !eof {
+		rN, rErr := r.Read(buf)
+		if rErr != nil {
+			eof = errors.Is(rErr, io.EOF)
+			if !eof {
+				return n, fmt.Errorf("failed to read: %w", rErr)
+			}
+		}
+		// TODO: qcow2reader should have a method to notify whether buf is zero
+		if bytes.Equal(buf, zeroBuf) {
+			if _, sErr := w.Seek(int64(rN), io.SeekCurrent); sErr != nil {
+				return n, fmt.Errorf("failed seek: %w", sErr)
+			}
+			// no need to ftruncate here
+			n += int64(rN)
+		} else {
+			wN, wErr := w.Write(buf)
+			if wN > 0 {
+				n += int64(wN)
+			}
+			if wErr != nil {
+				return n, fmt.Errorf("failed to read: %w", wErr)
+			}
+			if wN != rN {
+				return n, fmt.Errorf("read %d, but wrote %d bytes", rN, wN)
+			}
+		}
+	}
+	return n, nil
+}
+
+func MakeSparse(f *os.File, n int64) error {
+	if _, err := f.Seek(n, io.SeekStart); err != nil {
+		return err
+	}
+	return osutil.Ftruncate(int(f.Fd()), n)
+}

pkg/osutil/osutil_unix.go

@@ -0,0 +1,9 @@
+//go:build !windows
+
+package osutil
+
+import "golang.org/x/sys/unix"
+
+func Ftruncate(fd int, length int64) (err error) {
+	return unix.Ftruncate(fd, length)
+}

pkg/osutil/osutil_windows.go

@@ -29,3 +29,7 @@ type Signal int
 func SysKill(pid int, sig Signal) error {
 	return fmt.Errorf("unimplemented")
 }
+
+func Ftruncate(fd int, length int64) (err error) {
+	return fmt.Errorf("unimplemented")
+}

pkg/store/disk.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/lima-vm/go-qcow2reader"
 	"github.com/lima-vm/lima/pkg/qemu/imgutil"
 	"github.com/lima-vm/lima/pkg/store/filenames"
 )
@@ -36,11 +37,10 @@ func InspectDisk(diskName string) (*Disk, error) {
 		return nil, err
 	}
 
-	info, err := imgutil.GetInfo(dataDisk)
+	disk.Size, err = inspectDiskSize(dataDisk)
 	if err != nil {
 		return nil, err
 	}
-	disk.Size = info.VSize
 
 	instDir, err := os.Readlink(filepath.Join(diskDir, filenames.InUseBy))
 	if err != nil {
@@ -57,6 +57,34 @@ func InspectDisk(diskName string) (*Disk, error) {
 	return disk, nil
 }
 
+// inspectDiskSize attempts to inspect the disk size by itself,
+// and falls back to inspectDiskSizeWithQemuImg on an error.
+func inspectDiskSize(fName string) (int64, error) {
+	f, err := os.Open(fName)
+	if err != nil {
+		return inspectDiskSizeWithQemuImg(fName)
+	}
+	defer f.Close()
+	img, err := qcow2reader.Open(f)
+	if err != nil {
+		return inspectDiskSizeWithQemuImg(fName)
+	}
+	sz := img.Size()
+	if sz < 0 {
+		return inspectDiskSizeWithQemuImg(fName)
+	}
+	return sz, nil
+}
+
+// inspectDiskSizeWithQemuImg invokes `qemu-img` binary to inspect the disk size.
+func inspectDiskSizeWithQemuImg(fName string) (int64, error) {
+	info, err := imgutil.GetInfo(fName)
+	if err != nil {
+		return -1, err
+	}
+	return info.VSize, nil
+}
+
 func (d *Disk) Lock(instanceDir string) error {
 	inUseBy := filepath.Join(d.Dir, filenames.InUseBy)
 	return os.Symlink(instanceDir, inUseBy)

pkg/vz/disk.go

@@ -4,20 +4,18 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"os/exec"
 	"path/filepath"
-	"strconv"
 
 	"github.com/docker/go-units"
 	"github.com/lima-vm/lima/pkg/driver"
 	"github.com/lima-vm/lima/pkg/fileutils"
 	"github.com/lima-vm/lima/pkg/iso9660util"
-	"github.com/lima-vm/lima/pkg/qemu/imgutil"
+	"github.com/lima-vm/lima/pkg/nativeimgutil"
 	"github.com/lima-vm/lima/pkg/store/filenames"
+	"github.com/sirupsen/logrus"
 )
 
 func EnsureDisk(driver *driver.BaseDriver) error {
-
 	diffDisk := filepath.Join(driver.Instance.Dir, filenames.DiffDisk)
 	if _, err := os.Stat(diffDisk); err == nil || !errors.Is(err, os.ErrNotExist) {
 		// disk is already ensured
@@ -44,32 +42,25 @@ func EnsureDisk(driver *driver.BaseDriver) error {
 	if diskSize == 0 {
 		return nil
 	}
-	//TODO - Break qemu dependency
 	isBaseDiskISO, err := iso9660util.IsISO9660(baseDisk)
 	if err != nil {
 		return err
 	}
-	baseDiskInfo, err := imgutil.GetInfo(baseDisk)
-	if err != nil {
-		return fmt.Errorf("failed to get the information of base disk %q: %w", baseDisk, err)
-	}
-	if err = imgutil.AcceptableAsBasedisk(baseDiskInfo); err != nil {
-		return fmt.Errorf("file %q is not acceptable as the base disk: %w", baseDisk, err)
-	}
-	if baseDiskInfo.Format == "" {
-		return fmt.Errorf("failed to inspect the format of %q", baseDisk)
-	}
-	args := []string{"create", "-f", "qcow2"}
-	if !isBaseDiskISO {
-		args = append(args, "-F", baseDiskInfo.Format, "-b", baseDisk)
-	}
-	args = append(args, diffDisk, strconv.Itoa(int(diskSize)))
-	cmd := exec.Command("qemu-img", args...)
-	if out, err := cmd.CombinedOutput(); err != nil {
-		return fmt.Errorf("failed to run %v: %q: %w", cmd.Args, string(out), err)
+	if isBaseDiskISO {
+		// Create an empty data volume (sparse)
+		diffDiskF, err := os.Create(diffDisk)
+		if err != nil {
+			return err
+		}
+		if err = nativeimgutil.MakeSparse(diffDiskF, diskSize); err != nil {
+			diffDiskF.Close()
+			return err
+		}
+		return diffDiskF.Close()
 	}
-	if err = imgutil.ConvertToRaw(diffDisk, diffDisk); err != nil {
-		return fmt.Errorf("cannot convert qcow2 to raw for vz driver")
+	logrus.Infof("Converting %q to a raw disk %q (size=%d)", baseDisk, diffDisk, diskSize)
+	if err = nativeimgutil.ConvertToRaw(baseDisk, diffDisk, &diskSize, false); err != nil {
+		return fmt.Errorf("failed to convert %q to a raw disk %q (size=%d): %w", baseDisk, diffDisk, diskSize, err)
 	}
-	return nil
+	return err
 }