Add domain package

The domain package helps to abstract and builds a libvirt domain.

Signed-off-by: Alice Frosi <[email protected]>

Author: alicefr

go.mod

@@ -188,6 +188,7 @@ require (
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1 // indirect
 	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	libvirt.org/go/libvirtxml v1.9008.0
 	sigs.k8s.io/yaml v1.4.0 // indirect
 	tags.cncf.io/container-device-interface v0.6.2 // indirect
 )

go.sum

@@ -760,6 +760,8 @@ honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWh
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 libvirt.org/go/libvirt v1.10002.0 h1:ZFQsv1G8HE8SYhLBqaOuxze6+f00x96khLwn54aWJnI=
 libvirt.org/go/libvirt v1.10002.0/go.mod h1:1WiFE8EjZfq+FCVog+rvr1yatKbKZ9FaFMZgEqxEJqQ=
+libvirt.org/go/libvirtxml v1.9008.0 h1:xo2U9SqUsufTFtbyjiqs6oDdF329cvtRdqttWN7eojk=
+libvirt.org/go/libvirtxml v1.9008.0/go.mod h1:7Oq2BLDstLr/XtoQD8Fr3mfDNrzlI3utYKySXF2xkng=
 nullprogram.com/x/optparse v1.0.0/go.mod h1:KdyPE+Igbe0jQUrVfMqDMeJQIJZEuyV7pjYmp6pbG50=
 sigs.k8s.io/yaml v1.4.0 h1:Mk1wCc2gy/F0THH0TAp1QYyJNzRm2KCLy3o5ASXVI5E=
 sigs.k8s.io/yaml v1.4.0/go.mod h1:Ejl7/uTz7PSA4eKMyQCUTnhZYNmLIl+5c2lQPGR2BPY=

pkg/vm/domain/domain.go

@@ -0,0 +1,242 @@
+package domain
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os/exec"
+
+	"github.com/sirupsen/logrus"
+	"libvirt.org/go/libvirtxml"
+)
+
+type DomainOption func(d *libvirtxml.Domain)
+
+const (
+	MemoryMemfd            = "memfd"
+	MemoryAccessModeShared = "shared"
+)
+
+type DiskDriverType string
+
+func (d DiskDriverType) String() string {
+	return string(d)
+}
+
+const (
+	DiskDriverQCOW2 DiskDriverType = "qcow2"
+	DiskDriverRaw   DiskDriverType = "raw"
+)
+
+type DiskBus string
+
+func (b DiskBus) String() string {
+	return string(b)
+}
+
+const (
+	DiskBusSCSI   DiskBus = "scsi"
+	DiskBusVirtio DiskBus = "virtio"
+)
+
+func NewDomain(opts ...DomainOption) *libvirtxml.Domain {
+	domain := &libvirtxml.Domain{}
+	for _, f := range opts {
+		f(domain)
+	}
+
+	return domain
+}
+
+func WithName(name string) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		d.Name = name
+	}
+}
+
+func WithMemory(memory uint) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		d.Memory = &libvirtxml.DomainMemory{
+			Value: memory,
+			Unit:  "MiB",
+		}
+	}
+}
+
+func WithMemoryBackingForVirtiofs() DomainOption {
+	return func(d *libvirtxml.Domain) {
+		d.MemoryBacking = &libvirtxml.DomainMemoryBacking{
+			MemorySource: &libvirtxml.DomainMemorySource{Type: MemoryMemfd},
+			MemoryAccess: &libvirtxml.DomainMemoryAccess{Mode: MemoryAccessModeShared},
+		}
+	}
+}
+
+func WithCPUHostModel() DomainOption {
+	return func(d *libvirtxml.Domain) {
+		d.CPU = &libvirtxml.DomainCPU{
+			Mode: "host-model",
+		}
+	}
+}
+
+func WithVCPUs(cpus uint) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		d.VCPU = &libvirtxml.DomainVCPU{Value: cpus}
+	}
+}
+
+func allocateDevices(d *libvirtxml.Domain) {
+	if d.Devices == nil {
+		d.Devices = &libvirtxml.DomainDeviceList{}
+	}
+}
+
+func WithFilesystem(source, target string) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		allocateDevices(d)
+		d.Devices.Filesystems = append(d.Devices.Filesystems, libvirtxml.DomainFilesystem{
+			Driver: &libvirtxml.DomainFilesystemDriver{
+				Type: "virtiofs",
+			},
+			Source: &libvirtxml.DomainFilesystemSource{
+				Mount: &libvirtxml.DomainFilesystemSourceMount{
+					Dir: source,
+				},
+			},
+			Target: &libvirtxml.DomainFilesystemTarget{
+				Dir: target,
+			},
+		})
+	}
+}
+
+func WithDisk(path, serial, dev string, diskType DiskDriverType, bus DiskBus) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		allocateDevices(d)
+		d.Devices.Disks = append(d.Devices.Disks, libvirtxml.DomainDisk{
+			Device: "disk",
+			Driver: &libvirtxml.DomainDiskDriver{
+				Name: "qemu",
+				Type: diskType.String(),
+			},
+			Source: &libvirtxml.DomainDiskSource{
+				File: &libvirtxml.DomainDiskSourceFile{
+					File: path,
+				},
+			},
+			Target: &libvirtxml.DomainDiskTarget{
+				Bus: bus.String(),
+				Dev: dev,
+			},
+			Serial: serial,
+		})
+	}
+}
+
+func WithSerialConsole() DomainOption {
+	return func(d *libvirtxml.Domain) {
+		allocateDevices(d)
+		d.Devices.Consoles = append(d.Devices.Consoles, libvirtxml.DomainConsole{
+			Source: &libvirtxml.DomainChardevSource{Pty: &libvirtxml.DomainChardevSourcePty{}},
+			Target: &libvirtxml.DomainConsoleTarget{
+				Type: "serial",
+			},
+		})
+
+	}
+}
+
+func WithInterface(mac, model string) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		allocateDevices(d)
+		d.Devices.Interfaces = append(d.Devices.Interfaces, libvirtxml.DomainInterface{
+			Source: &libvirtxml.DomainInterfaceSource{
+				User: &libvirtxml.DomainInterfaceSourceUser{},
+			},
+			MAC: &libvirtxml.DomainInterfaceMAC{
+				Address: mac,
+			},
+			Model: &libvirtxml.DomainInterfaceModel{
+				Type: model,
+			},
+		})
+	}
+}
+
+func WithVSOCK(cid uint) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		allocateDevices(d)
+		d.Devices.VSock = &libvirtxml.DomainVSock{
+			Model: "virtio",
+			CID: &libvirtxml.DomainVSockCID{
+				Address: fmt.Sprintf("%d", cid),
+			},
+		}
+	}
+}
+
+func WithUUID(uuid string) DomainOption {
+	return func(d *libvirtxml.Domain) {
+		d.UUID = uuid
+	}
+}
+
+func WithKVM() DomainOption {
+	return func(d *libvirtxml.Domain) {
+		d.Type = "kvm"
+	}
+}
+
+func WithOS() DomainOption {
+	// TODO: fix this for multiarch
+	return func(d *libvirtxml.Domain) {
+		d.OS = &libvirtxml.DomainOS{
+			Type: &libvirtxml.DomainOSType{
+				Arch:    "x86_64",
+				Machine: "q35",
+				Type:    "hvm",
+			},
+		}
+	}
+}
+
+type diskInfo struct {
+	Format      string `json:"format"`
+	BackingFile string `json:"backing-filename"`
+	ActualSize  int64  `json:"actual-size"`
+	VirtualSize int64  `json:"virtual-size"`
+}
+
+func GetDiskInfo(imagePath string) (DiskDriverType, error) {
+	path, err := exec.LookPath("qemu-img")
+	if err != nil {
+		return "", fmt.Errorf("qemu-img not found: %v\n", err)
+	}
+
+	args := []string{"info", imagePath, "--output", "json"}
+	cmd := exec.Command(path, args...)
+	logrus.Debugf("Execute: %s", cmd.String())
+	stderr, err := cmd.StderrPipe()
+	if err != nil {
+		return "", fmt.Errorf("failed to get stderr for qemu-img command: %v", err)
+	}
+	out, err := cmd.Output()
+	if err != nil {
+		errout, _ := io.ReadAll(stderr)
+		return "", fmt.Errorf("failed to invoke qemu-img: %v: %s", err, errout)
+	}
+	info := &diskInfo{}
+	err = json.Unmarshal(out, info)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse disk info: %v", err)
+	}
+	switch info.Format {
+	case "qcow2":
+		return DiskDriverQCOW2, nil
+	case "raw":
+		return DiskDriverRaw, nil
+	default:
+		return "", fmt.Errorf("Unsupported format: %s", info.Format)
+	}
+}