Create installation VM and run bootc install inside a VM using rootless podman

pkg/vm/installvm.go

@@ -0,0 +1,187 @@
+package vm
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"math/rand"
+
+	"github.com/containers/podman-bootc/pkg/vm/domain"
+	"github.com/google/uuid"
+	"github.com/opencontainers/runtime-tools/filepath"
+	"github.com/sirupsen/logrus"
+	"libvirt.org/go/libvirt"
+	"libvirt.org/go/libvirtxml"
+)
+
+const (
+	CIDInstallVM = 3
+	VSOCKPort    = 1234
+)
+
+const VMImage = "quay.io/containers/bootc-vm:latest"
+
+const (
+	mac    = "52:54:00:0b:dd:1e"
+	imodel = "e1000"
+)
+
+const (
+	ContainerStoragePath = "/usr/lib/bootc/container_storage"
+	ConfigDir            = "/usr/lib/bootc/config"
+	OutputDir            = "/usr/lib/bootc/output"
+	SocketDir            = "/run/podman"
+	LibvirtSocketDir     = "/run/libvirt"
+	BootcDir             = "/bootc-data"
+)
+const (
+	RootTarget            = "root"
+	StorageVirtiofsTarget = "storage"
+	ConfigVirtiofsTarget  = "config"
+	OutputVirtiofsTarget  = "output"
+)
+
+const cmdline = "console=ttyS0 rootfstype=virtiofs root=root rw init=/sbin/init panic=1"
+
+const VNCPort int = 5959
+// The virtiofs wrapper helps to launch virtiofs with the correct flags inside a container
+const VsfdWrapperPath = "/usr/local/bin/virtiofsd-wrapper"
+
+type InstallOptions struct {
+	OutputImage  string
+	OutputFormat domain.DiskDriverType
+	Root         bool
+	Kernel       string
+	Initrd       string
+}
+
+type InstallVM struct {
+	libvirtURI string
+	socket     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(path string, opts InstallOptions) *InstallVM {
+	mode := "session"
+	if opts.Root {
+		mode = "system"
+	}
+	uri := fmt.Sprintf("qemu:///%s?socket=%s", mode, path)
+	name := "bootc-" + RandomString(5)
+	return &InstallVM{
+		domain:     name,
+		libvirtURI: uri,
+		opts:       opts,
+		socket:     path,
+	}
+}
+
+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(filepath.Join(OutputDir, vm.opts.OutputImage), "output", "vda", vm.opts.OutputFormat, domain.DiskBusVirtio),
+		domain.WithFilesystem(BootcDir, RootTarget, VsfdWrapperPath),
+		domain.WithFilesystem(ContainerStoragePath, StorageVirtiofsTarget, VsfdWrapperPath),
+		domain.WithFilesystem(ConfigDir, ConfigVirtiofsTarget, VsfdWrapperPath),
+		domain.WithFilesystem(OutputDir, OutputVirtiofsTarget, VsfdWrapperPath),
+		domain.WithDirectBoot(vm.opts.Kernel, vm.opts.Initrd, cmdline),
+		domain.WithVNC(VNCPort),
+		domain.WIthFeatures(),
+	)
+}
+
+func waitForSocket(path string, timeout time.Duration, interval time.Duration) error {
+	logrus.Debugf("Wait for socket %s", path)
+	start := time.Now()
+
+	for {
+		_, err := os.Stat(path)
+		if err == nil {
+			return nil
+		}
+		if !os.IsNotExist(err) {
+			return fmt.Errorf("error checking file: %w", err)
+		}
+
+		if time.Since(start) > timeout {
+			break
+		}
+		time.Sleep(interval)
+	}
+
+	return fmt.Errorf("timeout waiting for file: " + path)
+}
+
+func (vm *InstallVM) Run() error {
+	if err := waitForSocket(vm.socket, 2*time.Minute, 1*time.Second); err != nil {
+		return err
+	}
+	domainXML, err := vm.newDomain().Marshal()
+	if err != nil {
+		return err
+	}
+	logrus.Debugf("XML: %s", domainXML)
+	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.Warningf("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
+}