// Buildqcow2 creates a qcow2 image using qemu-img, qemu-nbd, fdisk, mkfs.ext4,
// cp, and extlinux.
func Buildqcow2(buildPath string, c vmconfig.Config) error {
targetName := strings.Split(filepath.Base(c.Path), ".")[0]
log.Debugln("using target name:", targetName)
err := nbd.Modprobe()
if err != nil {
return err
}
wd, err := os.Getwd()
if err != nil {
return err
}
// Final qcow2 target
targetqcow2 := fmt.Sprintf("%v/%v.qcow2", wd, targetName)
// Temporary file for building qcow2 file, will be renamed to targetqcow2
tmpqcow2 := fmt.Sprintf("%v/%v.qcow2.tmp", wd, targetName)
err = createQcow2(tmpqcow2, *f_qcowsize)
if err != nil {
return err
}
// Cleanup our temporary building file
defer func() {
// Check if file exists
if _, err := os.Stat(tmpqcow2); err == nil {
if err = os.Remove(tmpqcow2); err != nil {
log.Errorln(err)
}
}
}()
dev, err := nbd.ConnectImage(tmpqcow2)
if err != nil {
return err
}
// Disconnect from the nbd device
defer func() {
if err := nbd.DisconnectDevice(dev); err != nil {
log.Errorln(err)
}
}()
err = partitionQcow2(dev)
if err != nil {
return err
}
err = formatQcow2(dev + "p1")
if err != nil {
return err
}
mountPath, err := mountQcow2(dev + "p1")
if err != nil {
return err
}
err = copyQcow2(buildPath, mountPath)
if err != nil {
err2 := umountQcow2(mountPath)
if err2 != nil {
log.Errorln(err2)
}
return err
}
err = extlinux(mountPath)
if err != nil {
err2 := umountQcow2(mountPath)
if err2 != nil {
log.Errorln(err2)
}
return err
}
err = umountQcow2(mountPath)
if err != nil {
return err
}
err = extlinuxMBR(dev, *f_mbr)
if err != nil {
return err
}
return os.Rename(tmpqcow2, targetqcow2)
}
func (inject *injectData) run() (string, error) {
if inject.err != nil {
return "", inject.err
}
// create the new img
p := process("qemu-img")
cmd := exec.Command(p, "create", "-f", "qcow2", "-b", inject.srcImg, inject.dstImg)
log.Debug("creating sub image with: %v", cmd)
result, err := cmd.CombinedOutput()
if err != nil {
return "", fmt.Errorf("%v\n%v", string(result[:]), err)
}
// create a tmp mount point
mntDir, err := ioutil.TempDir(*f_base, "dstImg")
if err != nil {
return "", err
}
log.Debug("temporary mount point: %v", mntDir)
inject.nbdPath, err = nbd.ConnectImage(inject.dstImg)
if err != nil {
return "", err
}
defer vmInjectCleanup(mntDir, inject.nbdPath)
time.Sleep(100 * time.Millisecond) // give time to create partitions
// decide on a partition
if inject.partition == "" {
_, err = os.Stat(inject.nbdPath + "p1")
if err != nil {
return "", errors.New("no partitions found")
}
_, err = os.Stat(inject.nbdPath + "p2")
if err == nil {
return "", errors.New("please specify a partition; multiple found")
}
inject.partition = "1"
}
// mount new img
p = process("mount")
cmd = exec.Command(p, "-w", inject.nbdPath+"p"+inject.partition, mntDir)
result, err = cmd.CombinedOutput()
if err != nil {
// check that ntfs-3g is installed
p = process("ntfs-3g")
cmd = exec.Command(p, "--version")
_, err = cmd.CombinedOutput()
if err != nil {
log.Error("ntfs-3g not found, ntfs images unwriteable")
}
// mount with ntfs-3g
p = process("mount")
cmd = exec.Command(p, "-o", "ntfs-3g", inject.nbdPath+"p"+inject.partition, mntDir)
result, err = cmd.CombinedOutput()
if err != nil {
log.Error("failed to mount partition")
return "", fmt.Errorf("%v\n%v", string(result[:]), err)
}
}
// copy files/folders into mntDir
p = process("cp")
for _, pair := range inject.pairs {
dir := filepath.Dir(filepath.Join(mntDir, pair.dst))
os.MkdirAll(dir, 0775)
cmd = exec.Command(p, "-fr", pair.src, mntDir+"/"+pair.dst)
result, err = cmd.CombinedOutput()
if err != nil {
return "", fmt.Errorf("%v\n%v", string(result[:]), err)
}
}
return inject.dstImg, nil
}
// diskInject injects files into a disk image. dst/partition specify the image
// and the partition number, pairs is the dst, src filepaths. options can be
// used to supply mount arguments.
func diskInject(dst, partition string, pairs map[string]string, options []string) error {
// Load nbd
if err := nbd.Modprobe(); err != nil {
return err
}
// create a tmp mount point
mntDir, err := ioutil.TempDir(*f_base, "dstImg")
if err != nil {
return err
}
log.Debug("temporary mount point: %v", mntDir)
nbdPath, err := nbd.ConnectImage(dst)
if err != nil {
return err
}
defer diskInjectCleanup(mntDir, nbdPath)
time.Sleep(100 * time.Millisecond) // give time to create partitions
// decide on a partition
if partition == "" {
_, err = os.Stat(nbdPath + "p1")
if err != nil {
return errors.New("no partitions found")
}
_, err = os.Stat(nbdPath + "p2")
if err == nil {
return errors.New("please specify a partition; multiple found")
}
partition = "1"
}
// mount new img
var path string
if partition == "none" {
path = nbdPath
} else {
path = nbdPath + "p" + partition
}
// we use mount(8), because the mount syscall (mount(2)) requires we
// populate the fstype field, which we don't know
args := []string{"mount"}
if len(options) != 0 {
args = append(args, options...)
args = append(args, path, mntDir)
} else {
args = []string{"mount", "-w", path, mntDir}
}
log.Debug("mount args: %v", args)
_, err = processWrapper(args...)
if err != nil {
// check that ntfs-3g is installed
_, err = processWrapper("ntfs-3g", "--version")
if err != nil {
log.Error("ntfs-3g not found, ntfs images unwriteable")
}
// mount with ntfs-3g
out, err := processWrapper("mount", "-o", "ntfs-3g", path, mntDir)
if err != nil {
log.Error("failed to mount partition")
return fmt.Errorf("%v: %v", out, err)
}
}
// copy files/folders into mntDir
for dst, src := range pairs {
dir := filepath.Dir(filepath.Join(mntDir, dst))
os.MkdirAll(dir, 0775)
out, err := processWrapper("cp", "-fr", src, filepath.Join(mntDir, dst))
if err != nil {
return fmt.Errorf("%v: %v", out, err)
}
}
return nil
}