Support for Virt driver

This is a driver based on libvirt.org, for remote hypervisors.

Requires "virsh" to be installed. Currently only shows version.

Signed-off-by: Anders F Björklund <[email protected]>

Author: afbjorklund

examples/experimental/virt.yaml

@@ -0,0 +1,13 @@
+# A template to run ubuntu using vmType: virt instead of qemu (Default)
+vmType: "virt"
+
+images:
+- location: "https://cloud-images.ubuntu.com/releases/22.04/release/ubuntu-22.04-server-cloudimg-amd64.img"
+  arch: "x86_64"
+- location: "https://cloud-images.ubuntu.com/releases/22.04/release/ubuntu-22.04-server-cloudimg-arm64.img"
+  arch: "aarch64"
+
+mounts:
+- location: "~"
+- location: "/tmp/lima"
+  writable: true

pkg/driverutil/driverutil.go

@@ -2,13 +2,17 @@ package driverutil
 
 import (
 	"github.com/lima-vm/lima/pkg/limayaml"
+	"github.com/lima-vm/lima/pkg/virt"
 	"github.com/lima-vm/lima/pkg/vz"
 	"github.com/lima-vm/lima/pkg/wsl2"
 )
 
 // Drivers returns the available drivers.
 func Drivers() []string {
 	drivers := []string{limayaml.QEMU}
+	if virt.Enabled {
+		drivers = append(drivers, limayaml.VIRT)
+	}
 	if vz.Enabled {
 		drivers = append(drivers, limayaml.VZ)
 	}

pkg/driverutil/instance.go

@@ -4,12 +4,16 @@ import (
 	"github.com/lima-vm/lima/pkg/driver"
 	"github.com/lima-vm/lima/pkg/limayaml"
 	"github.com/lima-vm/lima/pkg/qemu"
+	"github.com/lima-vm/lima/pkg/virt"
 	"github.com/lima-vm/lima/pkg/vz"
 	"github.com/lima-vm/lima/pkg/wsl2"
 )
 
 func CreateTargetDriverInstance(base *driver.BaseDriver) driver.Driver {
 	limaDriver := base.Yaml.VMType
+	if *limaDriver == limayaml.VIRT {
+		return virt.New(base)
+	}
 	if *limaDriver == limayaml.VZ {
 		return vz.New(base)
 	}

pkg/limayaml/defaults.go

@@ -848,6 +848,8 @@ func NewArch(arch string) Arch {
 
 func NewVMType(driver string) VMType {
 	switch driver {
+	case "virt":
+		return VIRT
 	case "vz":
 		return VZ
 	case "qemu":

pkg/limayaml/limayaml.go

@@ -62,6 +62,7 @@ const (
 	WSLMount MountType = "wsl2"
 
 	QEMU VMType = "qemu"
+	VIRT VMType = "virt"
 	VZ   VMType = "vz"
 	WSL2 VMType = "wsl2"
 )

pkg/limayaml/validate.go

@@ -61,8 +61,10 @@ func Validate(y LimaYAML, warn bool) error {
 		if !IsNativeArch(*y.Arch) {
 			return fmt.Errorf("field `arch` must be %q for VZ; got %q", NewArch(runtime.GOARCH), *y.Arch)
 		}
+	case VIRT:
+		// NOP
 	default:
-		return fmt.Errorf("field `vmType` must be %q, %q, %q; got %q", QEMU, VZ, WSL2, *y.VMType)
+		return fmt.Errorf("field `vmType` must be %q, %q, %q, %q; got %q", QEMU, VIRT, VZ, WSL2, *y.VMType)
 	}
 
 	if len(y.Images) == 0 {

pkg/virt/disk.go

@@ -0,0 +1,49 @@
+package virt
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+
+	"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/store/filenames"
+)
+
+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
+		return err
+	}
+
+	baseDisk := filepath.Join(driver.Instance.Dir, filenames.BaseDisk)
+	if _, err := os.Stat(baseDisk); errors.Is(err, os.ErrNotExist) {
+		var ensuredBaseDisk bool
+		errs := make([]error, len(driver.Yaml.Images))
+		for i, f := range driver.Yaml.Images {
+			if _, err := fileutils.DownloadFile(baseDisk, f.File, true, "the image", *driver.Yaml.Arch); err != nil {
+				errs[i] = err
+				continue
+			}
+			ensuredBaseDisk = true
+			break
+		}
+		if !ensuredBaseDisk {
+			return fileutils.Errors(errs)
+		}
+	}
+	diskSize, _ := units.RAMInBytes(*driver.Yaml.Disk)
+	if diskSize == 0 {
+		return nil
+	}
+	isBaseDiskISO, err := iso9660util.IsISO9660(baseDisk)
+	if err != nil {
+		return err
+	}
+	_ = isBaseDiskISO
+	// TODO
+	return nil
+}

pkg/virt/virt.go

@@ -0,0 +1,20 @@
+package virt
+
+import (
+	"fmt"
+	"os/exec"
+	"regexp"
+)
+
+func Version() (string, error) {
+	out, err := exec.Command("virsh", "version").Output()
+	if err != nil {
+		return "", err
+	}
+	re := regexp.MustCompile("Using library: libvirt (.*)")
+	m := re.FindStringSubmatch(string(out))
+	if m == nil {
+		return "", fmt.Errorf("can't find libvirt version")
+	}
+	return m[1], nil
+}

pkg/virt/virt_driver.go

@@ -0,0 +1,47 @@
+package virt
+
+import (
+	"context"
+	"os/exec"
+
+	"github.com/lima-vm/lima/pkg/driver"
+	"github.com/sirupsen/logrus"
+)
+
+const Enabled = true
+
+type LimaVirtDriver struct {
+	*driver.BaseDriver
+}
+
+func New(driver *driver.BaseDriver) *LimaVirtDriver {
+	return &LimaVirtDriver{
+		BaseDriver: driver,
+	}
+}
+
+func (l *LimaVirtDriver) Validate() error {
+	if _, err := exec.LookPath("virsh"); err != nil {
+		return err
+	}
+
+	v, err := Version()
+	if err != nil {
+		return err
+	}
+	logrus.Infof("Version: %s", v)
+
+	return nil
+}
+
+func (l *LimaVirtDriver) CreateDisk() error {
+	return EnsureDisk(l.BaseDriver)
+}
+
+func (l *LimaVirtDriver) Start(_ context.Context) (chan error, error) {
+	return nil, errors.New("TODO")
+}
+
+func (l *LimaVirtDriver) Stop(_ context.Context) error {
+	return nil
+}