vm: create installation VM

The installation VM is a temporary VM used for running privleged command
using rootless podman. This VM uses the vm image build with make image.
It has already pre configured the local podman, the proxy and the
required directories for bootc.

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

Author: alicefr

pkg/vm/installvm.go

@@ -0,0 +1,137 @@
+package vm
+
+import (
+	"fmt"
+
+	"math/rand"
+
+	"github.com/containers/podman-bootc/pkg/vm/domain"
+	"github.com/google/uuid"
+	"github.com/sirupsen/logrus"
+	"libvirt.org/go/libvirt"
+	"libvirt.org/go/libvirtxml"
+)
+
+const (
+	CIDInstallVM = 3
+	VSOCKPort    = 1234
+)
+const (
+	mac    = "52:54:00:0b:dd:1e"
+	imodel = "e1000"
+)
+
+const (
+	StorageVirtiofsTarget = "storage"
+	ConfigVirtiofsTarget  = "config"
+	OutputVirtiofsTarget  = "output"
+)
+
+type InstallOptions struct {
+	DiskImage            string
+	OutputImage          string
+	InputFormat          domain.DiskDriverType
+	OutputFormat         domain.DiskDriverType
+	ContainerStoragePath string
+	ConfigPath           string
+	OutputPath           string
+	Root                 bool
+}
+
+type InstallVM struct {
+	libvirtURI string
+	domain     string
+	opts       InstallOptions
+}
+
+const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOQRSTUVWXYZ0123456789"
+
+func RandomString(n int) string {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = letterBytes[rand.Intn(len(letterBytes))]
+	}
+	return string(b)
+}
+
+func NewInstallVM(opts InstallOptions) *InstallVM {
+	uri := "qemu:///session"
+	if opts.Root {
+		uri = "qemu:///system"
+	}
+	name := "bootc-" + RandomString(5)
+	return &InstallVM{
+		domain:     name,
+		libvirtURI: uri,
+		opts:       opts,
+	}
+}
+
+func (vm *InstallVM) newDomain() *libvirtxml.Domain {
+	return domain.NewDomain(
+		domain.WithName(vm.domain),
+		domain.WithUUID(uuid.New().String()),
+		domain.WithKVM(),
+		domain.WithOS(),
+		domain.WithMemory(2048),
+		domain.WithMemoryBackingForVirtiofs(),
+		domain.WithCPUHostModel(),
+		domain.WithVCPUs(2),
+		domain.WithSerialConsole(),
+		domain.WithVSOCK(CIDInstallVM),
+		domain.WithInterface(mac, imodel),
+		domain.WithDisk(vm.opts.DiskImage, "input", "vda", vm.opts.InputFormat, domain.DiskBusVirtio),
+		domain.WithDisk(vm.opts.OutputImage, "output", "vdb", vm.opts.OutputFormat, domain.DiskBusVirtio),
+		domain.WithFilesystem(vm.opts.ContainerStoragePath, StorageVirtiofsTarget),
+		domain.WithFilesystem(vm.opts.ConfigPath, ConfigVirtiofsTarget),
+		domain.WithFilesystem(vm.opts.OutputPath, OutputVirtiofsTarget),
+	)
+}
+
+func (vm *InstallVM) Run() error {
+	domainXML, err := vm.newDomain().Marshal()
+	if err != nil {
+		return err
+	}
+	conn, err := libvirt.NewConnect(vm.libvirtURI)
+	if err != nil {
+		return err
+	}
+	_, err = conn.DomainDefineXMLFlags(domainXML, libvirt.DOMAIN_DEFINE_VALIDATE)
+	if err != nil {
+		return fmt.Errorf("unable to define virtual machine domain: %w", err)
+	}
+	dom, err := conn.LookupDomainByName(vm.domain)
+	if err != nil {
+		return err
+	}
+	defer dom.Free()
+	err = dom.Create()
+	if err != nil {
+		return fmt.Errorf("Failed to start domain: %v", err)
+	}
+	logrus.Debugf("Domain %s started successfully.", vm.domain)
+
+	return nil
+}
+
+func (vm *InstallVM) Stop() error {
+	conn, err := libvirt.NewConnect(vm.libvirtURI)
+	if err != nil {
+		return err
+	}
+	dom, err := conn.LookupDomainByName(vm.domain)
+	if err != nil {
+		return err
+	}
+	defer dom.Free()
+	if err := dom.Destroy(); err != nil {
+		logrus.Warning("Failed to destroy the domain %s, maybe already stopped: %v", vm.domain, err)
+	}
+	if err := dom.Undefine(); err != nil {
+		return fmt.Errorf("Undefine failed: %v", err)
+	}
+	logrus.Debugf("Domain %s stopped and deleted successfully", vm.domain)
+
+	return nil
+}