alice.pds.demo.boltless.dev
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1package microvm
2
3import (
4 "context"
5 "crypto/sha256"
6 _ "embed"
7 "encoding/hex"
8 "encoding/json"
9 "errors"
10 "fmt"
11 "log/slog"
12 "os"
13 "os/exec"
14 "path/filepath"
15 "strconv"
16 "strings"
17 "sync"
18 "time"
19
20 "github.com/digitalocean/go-qemu/qmp"
21 "github.com/google/uuid"
22)
23
24const (
25 defaultQMPTimeout = 10 * time.Second
26 outerSlirpCIDR = "10.0.2.0/24"
27 innerSlirpNet = "10.0.3.0/24"
28 innerSlirpHost = "10.0.3.2"
29 innerSlirpDNS = "10.0.3.3"
30 innerSlirpDHCP = "10.0.3.15"
31 netnsTapName = "tap0"
32 netnsMTU = "65520"
33)
34
35type QEMUConfig struct {
36 Image ImageSpec
37 BootTimeout time.Duration
38 CID uint32
39 EnableKVM bool
40 QEMULogPath string
41 QMPPath string
42 SerialLogPath string
43 WorkDir string
44 VolumePaths map[string]string
45 VolumeBaseName string
46 Cgroup CgroupLimits
47 Dev bool
48}
49
50type QEMUVMHandle struct {
51 cid uint32
52 Process *os.Process
53 qemuLogPath string
54 QMPMon *qmp.SocketMonitor
55 QMPPath string
56 serialLogPath string
57 workDir string
58
59 qmpSocketPath string
60
61 cmd *exec.Cmd
62 done chan struct{}
63 qemuLogFile *os.File
64 cgroup *CgroupHandle
65 slirpCmd *exec.Cmd
66 slirpExit *os.File
67 waitErr error
68 waitErrMu sync.Mutex
69}
70
71type qemuRunner struct{}
72
73func (qemuRunner) Validate(spec ImageSpec, enableKVM bool) error {
74 if _, err := exec.LookPath(spec.RunnerCmd()); err != nil {
75 return fmt.Errorf("required host command %q not found in PATH: %w", spec.RunnerCmd(), err)
76 }
77 if _, err := os.Stat("/dev/vhost-vsock"); err != nil {
78 return fmt.Errorf("microvm requires /dev/vhost-vsock for vhost-vsock-device: %w", err)
79 }
80 if enableKVM {
81 if _, err := os.Stat("/dev/kvm"); err != nil {
82 return fmt.Errorf("microvm KVM was requested but /dev/kvm is not accessible: %w", err)
83 }
84 }
85 if len(spec.NetworkInterfaces) > 0 {
86 if _, err := os.Stat("/dev/net/tun"); err != nil {
87 return fmt.Errorf("microvm slirp4netns networking requires /dev/net/tun: %w", err)
88 }
89 for _, cmd := range []string{"ip", "mount", "slirp4netns", "unshare"} {
90 if _, err := exec.LookPath(cmd); err != nil {
91 return fmt.Errorf("required host command %q not found in PATH: %w", cmd, err)
92 }
93 }
94 }
95 return nil
96}
97
98func (qemuRunner) Start(ctx context.Context, cfg VMConfig, volumePaths map[string]string, logger *slog.Logger) (VMHandle, error) {
99 bootTimeout := cfg.BootTimeout
100 if bootTimeout == 0 {
101 bootTimeout = 10 * time.Second
102 }
103 return StartQEMU(ctx, QEMUConfig{
104 Image: cfg.Image,
105 BootTimeout: bootTimeout,
106 CID: cfg.CID,
107 EnableKVM: cfg.EnableKVM,
108 WorkDir: cfg.WorkDir,
109 VolumePaths: volumePaths,
110 Cgroup: cfg.Cgroup,
111 Dev: cfg.Dev,
112 }, logger)
113}
114
115// we hash the workDir to get a deterministic qmpSock path
116// since they are AF_UNIX sockets, they are bound by a 108 char long path limit...
117func qmpSocketPath(workDir string) string {
118 base := filepath.Dir(workDir)
119 if workDir == "" {
120 base = os.TempDir()
121 }
122 sum := sha256.Sum256([]byte(workDir))
123 return filepath.Join(base, hex.EncodeToString(sum[:8])+".qmp.sock")
124}
125
126func StartQEMU(ctx context.Context, cfg QEMUConfig, logger *slog.Logger) (VMHandle, error) {
127 if logger == nil {
128 logger = slog.Default()
129 }
130
131 workDir := cfg.WorkDir
132
133 handle := &QEMUVMHandle{
134 workDir: workDir,
135 }
136
137 var ok bool
138 defer func() {
139 if !ok {
140 if detail := VMCrashLog(handle); detail != "" {
141 logger.Error("microVM failed to start", "cid", handle.cid, "detail", detail)
142 }
143 _ = handle.Close()
144 }
145 }()
146
147 cid := cfg.CID
148 if cid == 0 {
149 var err error
150 cid, err = AllocateCID()
151 if err != nil {
152 return nil, err
153 }
154 }
155 if cid < minGuestCID {
156 return nil, fmt.Errorf("guest CID must be >= %d", minGuestCID)
157 }
158 handle.cid = cid
159
160 volumePaths := cfg.VolumePaths
161
162 qemuLogPath := cfg.QEMULogPath
163 if qemuLogPath == "" {
164 qemuLogPath = filepath.Join(workDir, "qemu.log")
165 }
166 qemuLogFile, err := createParentedFile(qemuLogPath)
167 if err != nil {
168 return nil, err
169 }
170 handle.qemuLogPath = qemuLogPath
171 handle.qemuLogFile = qemuLogFile
172
173 serialLogPath := cfg.SerialLogPath
174 if serialLogPath == "" {
175 serialLogPath = filepath.Join(workDir, "serial.log")
176 }
177 if err := os.MkdirAll(filepath.Dir(serialLogPath), 0o755); err != nil {
178 return nil, fmt.Errorf("create serial log directory: %w", err)
179 }
180 handle.serialLogPath = serialLogPath
181
182 qmpPath := cfg.QMPPath
183 if qmpPath == "" {
184 qmpPath = qmpSocketPath(workDir)
185 handle.qmpSocketPath = qmpPath
186 }
187 handle.QMPPath = qmpPath
188
189 qemuCmd := cfg.Image.RunnerCmd()
190 qemuBinary, err := exec.LookPath(qemuCmd)
191 if err != nil {
192 return nil, fmt.Errorf("%s command not found in PATH: %w", qemuCmd, err)
193 }
194
195 args, err := qemuArgs(qemuArgsConfig{
196 Image: cfg.Image,
197 CID: cid,
198 EnableKVM: cfg.EnableKVM,
199 QMPPath: qmpPath,
200 SerialLogPath: serialLogPath,
201 VolumePaths: volumePaths,
202 })
203 if err != nil {
204 return nil, err
205 }
206
207 cmd, slirpNet, err := qemuCommand(ctx, qemuBinary, args, cfg.Image, workDir, cfg.Dev)
208 if err != nil {
209 return nil, err
210 }
211 cmd.Env = append(os.Environ(), "TMPDIR="+workDir)
212 cmd.Stdout = qemuLogFile
213 cmd.Stderr = qemuLogFile
214
215 cgroup, err := prepareCgroup(cfg.Cgroup, logger)
216 if err != nil {
217 return nil, err
218 }
219 handle.cgroup = cgroup
220
221 logger.Info("starting qemu microvm", "cid", cid, "workDir", workDir, "serialLog", serialLogPath, "qmp", qmpPath)
222 if err := cmd.Start(); err != nil {
223 return nil, fmt.Errorf("starting qemu: %w", err)
224 }
225 handle.cmd = cmd
226 handle.Process = cmd.Process
227 handle.done = make(chan struct{})
228 go func() {
229 err := cmd.Wait()
230 handle.waitErrMu.Lock()
231 handle.waitErr = err
232 handle.waitErrMu.Unlock()
233 close(handle.done)
234 }()
235
236 if err := cgroup.AddProcess(cmd.Process.Pid, logger); err != nil {
237 return nil, err
238 }
239
240 if slirpNet != nil {
241 handle.slirpCmd, handle.slirpExit, err = slirpNet.Start(ctx, qemuLogFile, logger)
242 if err != nil {
243 return nil, err
244 }
245 if handle.slirpCmd != nil && handle.slirpCmd.Process != nil {
246 if err := cgroup.AddProcess(handle.slirpCmd.Process.Pid, logger); err != nil {
247 return nil, err
248 }
249 }
250 }
251
252 qmpTimeout := cfg.BootTimeout
253 if qmpTimeout == 0 {
254 qmpTimeout = defaultQMPTimeout
255 }
256 qmpCtx, cancelQMP := context.WithTimeout(ctx, qmpTimeout)
257 defer cancelQMP()
258 if err := handle.waitForQMP(qmpCtx, qmpTimeout); err != nil {
259 return nil, err
260 }
261
262 status, err := handle.waitForQMPRunning(qmpCtx, qmpTimeout)
263 if err != nil {
264 return nil, err
265 }
266 logger.Info("qemu microvm running", "cid", cid, "status", status)
267
268 ok = true
269 return handle, nil
270}
271
272func (h *QEMUVMHandle) Wait() error {
273 if h == nil || h.done == nil {
274 return nil
275 }
276 <-h.done
277 h.waitErrMu.Lock()
278 defer h.waitErrMu.Unlock()
279 return h.waitErr
280}
281
282func (h *QEMUVMHandle) WaitContext(ctx context.Context) error {
283 if h == nil || h.done == nil {
284 return nil
285 }
286 select {
287 case <-h.done:
288 h.waitErrMu.Lock()
289 defer h.waitErrMu.Unlock()
290 return h.waitErr
291 case <-ctx.Done():
292 return ctx.Err()
293 }
294}
295
296func (h *QEMUVMHandle) Kill() error {
297 if h == nil || h.Process == nil {
298 return nil
299 }
300 return h.Process.Kill()
301}
302
303func (h *QEMUVMHandle) Shutdown(ctx context.Context) error {
304 if h == nil {
305 return nil
306 }
307 if h.QMPMon != nil {
308 if err := h.QMPSystemPowerdown(); err != nil {
309 // dead qmp socket means qemu exited concurrently so we wait
310 select {
311 case <-h.done:
312 return nil
313 case <-ctx.Done():
314 return err
315 }
316 }
317 }
318 if h.done == nil {
319 return nil
320 }
321 select {
322 case <-h.done:
323 return h.Wait()
324 case <-ctx.Done():
325 _ = h.Kill()
326 _ = h.Wait()
327 return ctx.Err()
328 }
329}
330
331func (h *QEMUVMHandle) Close() error {
332 if h == nil {
333 return nil
334 }
335
336 var closeErr error
337 if h.QMPMon != nil {
338 closeErr = errors.Join(closeErr, h.QMPMon.Disconnect())
339 h.QMPMon = nil
340 }
341 if h.Process != nil {
342 _ = h.Process.Kill()
343 _ = h.Wait()
344 }
345 if h.slirpExit != nil {
346 _ = h.slirpExit.Close()
347 h.slirpExit = nil
348 }
349 if h.slirpCmd != nil && h.slirpCmd.Process != nil {
350 _ = h.slirpCmd.Process.Kill()
351 _ = h.slirpCmd.Wait()
352 h.slirpCmd = nil
353 }
354 if h.qemuLogFile != nil {
355 closeErr = errors.Join(closeErr, h.qemuLogFile.Close())
356 h.qemuLogFile = nil
357 }
358 if h.cgroup != nil {
359 closeErr = errors.Join(closeErr, h.cgroup.Close())
360 h.cgroup = nil
361 }
362 if h.qmpSocketPath != "" {
363 if err := os.Remove(h.qmpSocketPath); err != nil && !os.IsNotExist(err) {
364 closeErr = errors.Join(closeErr, err)
365 }
366 h.qmpSocketPath = ""
367 }
368 return closeErr
369}
370
371func (h *QEMUVMHandle) QMPRun(command qmp.Command) ([]byte, error) {
372 if h == nil || h.QMPMon == nil {
373 return nil, fmt.Errorf("qmp monitor is not connected")
374 }
375 data, err := json.Marshal(command)
376 if err != nil {
377 return nil, err
378 }
379 return h.QMPMon.Run(data)
380}
381
382func (h *QEMUVMHandle) QMPQueryStatus() (string, error) {
383 raw, err := h.QMPRun(qmp.Command{Execute: "query-status"})
384 if err != nil {
385 return "", fmt.Errorf("qmp query-status failed: %w", err)
386 }
387
388 var resp struct {
389 Return *struct {
390 Status string `json:"status"`
391 } `json:"return"`
392 }
393 if err := json.Unmarshal(raw, &resp); err != nil {
394 return "", fmt.Errorf("qmp query-status parse %q: %w", raw, err)
395 }
396 if resp.Return == nil {
397 return "", fmt.Errorf("qmp query-status missing return: %s", raw)
398 }
399 if resp.Return.Status == "" {
400 return "", fmt.Errorf("qmp query-status missing return.status: %s", raw)
401 }
402 return resp.Return.Status, nil
403}
404
405func (h *QEMUVMHandle) waitForQMPRunning(ctx context.Context, timeout time.Duration) (string, error) {
406 statusCtx, cancel := context.WithTimeout(ctx, timeout)
407 defer cancel()
408
409 ticker := time.NewTicker(25 * time.Millisecond)
410 defer ticker.Stop()
411
412 var lastStatus string
413 var lastErr error
414
415 for {
416 status, err := h.QMPQueryStatus()
417 if err != nil {
418 lastErr = err
419 } else {
420 lastErr = nil
421 lastStatus = status
422
423 switch status {
424 case "running":
425 return status, nil
426 case "shutdown", "internal-error", "io-error", "guest-panicked":
427 return "", fmt.Errorf("qemu guest entered unhealthy state before running (status: %s)", status)
428 }
429 }
430
431 select {
432 case <-statusCtx.Done():
433 if lastErr != nil {
434 return "", fmt.Errorf("qemu guest did not reach running state (last status: %s): %w", lastStatus, errors.Join(statusCtx.Err(), lastErr))
435 }
436 return "", fmt.Errorf("qemu guest did not reach running state (last status: %s): %w", lastStatus, statusCtx.Err())
437 case <-h.done:
438 return "", fmt.Errorf("qemu exited before reaching running state: %w", h.Wait())
439 case <-ticker.C:
440 }
441 }
442}
443
444func (h *QEMUVMHandle) QMPSystemPowerdown() error {
445 _, err := h.QMPRun(qmp.Command{Execute: "system_powerdown"})
446 return err
447}
448
449func (h *QEMUVMHandle) Logs() VMLogs {
450 if h == nil {
451 return VMLogs{}
452 }
453 return VMLogs{
454 Serial: h.serialLogPath,
455 Extra: map[string]string{
456 "qemu": h.qemuLogPath,
457 },
458 }
459}
460
461func (h *QEMUVMHandle) CID() uint32 {
462 if h == nil {
463 return 0
464 }
465 return h.cid
466}
467
468func (h *QEMUVMHandle) WorkDir() string {
469 if h == nil {
470 return ""
471 }
472 return h.workDir
473}
474
475func (h *QEMUVMHandle) OOMKilled() bool {
476 if h == nil {
477 return false
478 }
479 return h.cgroup.OOMKilled()
480}
481
482func (h *QEMUVMHandle) waitForQMP(ctx context.Context, timeout time.Duration) error {
483 qmpCtx, cancel := context.WithTimeout(ctx, timeout)
484 defer cancel()
485
486 var lastErr error
487 for {
488 mon, err := qmp.NewSocketMonitor("unix", h.QMPPath, 2*time.Second)
489 if err == nil {
490 if err = mon.Connect(); err == nil {
491 h.QMPMon = mon
492 return nil
493 }
494 _ = mon.Disconnect()
495 }
496 lastErr = err
497
498 select {
499 case <-qmpCtx.Done():
500 return fmt.Errorf("qmp connect timeout: %w", lastErr)
501 case <-h.done:
502 return fmt.Errorf("qemu exited before qmp was ready: %w", h.Wait())
503 case <-time.After(25 * time.Millisecond):
504 }
505 }
506}
507
508func qemuCommand(
509 ctx context.Context,
510 qemuBinary string,
511 args []string,
512 spec ImageSpec,
513 workDir string,
514 dev bool,
515) (*exec.Cmd, *slirpNamespace, error) {
516 if len(spec.NetworkInterfaces) == 0 {
517 return exec.CommandContext(ctx, qemuBinary, args...), nil, nil
518 }
519
520 ipPath, err := exec.LookPath("ip")
521 if err != nil {
522 return nil, nil, fmt.Errorf("ip command not found in PATH: %w", err)
523 }
524 mountPath, err := exec.LookPath("mount")
525 if err != nil {
526 return nil, nil, fmt.Errorf("mount command not found in PATH: %w", err)
527 }
528 unsharePath, err := exec.LookPath("unshare")
529 if err != nil {
530 return nil, nil, fmt.Errorf("unshare command not found in PATH: %w", err)
531 }
532
533 pidFile, resolvPath, wrapperPath, err := prepareQEMUNetnsFiles(workDir, dev)
534 if err != nil {
535 return nil, nil, err
536 }
537
538 cmdArgs := append([]string{
539 "--user",
540 "--map-root-user",
541 "--net",
542 "--mount",
543 "--propagation", "private",
544 "--",
545 wrapperPath,
546 pidFile,
547 ipPath,
548 mountPath,
549 resolvPath,
550 qemuBinary,
551 }, args...)
552
553 cmd := exec.CommandContext(ctx, unsharePath, cmdArgs...)
554
555 return cmd, &slirpNamespace{
556 spec: spec,
557 pidFile: pidFile,
558 dev: dev,
559 }, nil
560}
561
562func prepareQEMUNetnsFiles(workDir string, dev bool) (pidFile, resolvPath, wrapperPath string, err error) {
563 pidFile = filepath.Join(workDir, "qemu-netns.pid")
564 resolvPath = filepath.Join(workDir, "qemu-netns-resolv.conf")
565 wrapperPath = filepath.Join(workDir, "qemu-netns-wrapper")
566
567 // the guest resolves through shuttle on 127.0.0.1. keep qemu's slirp DNS
568 // pointed at an unroutable local resolver inside this network namespace so
569 // direct guest queries to 10.0.3.3 don't bypass the shuttle dns policy.
570 if err := os.WriteFile(resolvPath, []byte("nameserver 127.0.0.1\n"), 0o644); err != nil {
571 return "", "", "", fmt.Errorf("write qemu network namespace resolv.conf: %w", err)
572 }
573
574 if err := writeNetnsWrapper(wrapperPath, dev); err != nil {
575 return "", "", "", fmt.Errorf("write qemu network namespace wrapper: %w", err)
576 }
577
578 return pidFile, resolvPath, wrapperPath, nil
579}
580
581type qemuArgsConfig struct {
582 Image ImageSpec
583 CID uint32
584 EnableKVM bool
585 QMPPath string
586 SerialLogPath string
587 VolumePaths map[string]string
588}
589
590func qemuArgs(cfg qemuArgsConfig) ([]string, error) {
591 uuid := uuid.New()
592
593 b := newArgBuilder(64)
594
595 addQEMUMachineArgs(&b, cfg, uuid)
596 addQEMUStoreArgs(&b, cfg)
597
598 if cfg.EnableKVM {
599 addQEMUKVMArgs(&b, cfg.Image)
600 }
601
602 if err := addQEMUVolumeArgs(&b, cfg); err != nil {
603 return nil, err
604 }
605
606 if err := addQEMUNetworkArgs(&b, cfg.Image.NetworkInterfaces); err != nil {
607 return nil, err
608 }
609
610 b.Optf("-device", "vhost-vsock-device,guest-cid=%d", cfg.CID)
611
612 if len(cfg.Image.RunnerConfig.ExtraArgs) > 0 {
613 b.Add(cfg.Image.RunnerConfig.ExtraArgs...)
614 }
615
616 return b.Args(), nil
617}
618
619func addQEMUMachineArgs(b *argBuilder, cfg qemuArgsConfig, uuid uuid.UUID) {
620 if cfg.Image.RunnerConfig.Machine != "" {
621 b.Opt("-M", cfg.Image.RunnerConfig.Machine)
622 }
623 b.Optf("-m", "%dM", cfg.Image.MemoryMiB)
624 b.Opt("-smp", strconv.Itoa(cfg.Image.VCPUs))
625
626 b.Add(
627 "-nodefaults",
628 "-no-user-config",
629 "-no-reboot",
630 )
631
632 b.Opt("-kernel", cfg.Image.Kernel)
633 b.Opt("-initrd", cfg.Image.Initrd)
634
635 b.Opt("-device", "virtio-rng-device")
636
637 b.Optf("-smbios", "type=1,uuid=%s", uuid)
638 b.Opt("-serial", "file:"+cfg.SerialLogPath)
639
640 // use virtio console if requsted. this is faster than the serial UART logging
641 // because serial has a higher cost when being accesssed. we still have to
642 // support serial itself for early kernel boot but thats OK.
643 if cfg.Image.RunnerConfig.Console == "hvc0" {
644 b.Optf("-chardev", "file,id=virtiocon0,path=%s,append=on", cfg.SerialLogPath)
645 b.Add("-device", "virtio-serial-device")
646 b.Opt("-device", "virtconsole,chardev=virtiocon0")
647 }
648 b.Opt("-display", "none")
649 b.Opt("-monitor", "none")
650 b.Opt("-append", cfg.Image.BootArgs)
651
652 b.Opt("-sandbox", "on")
653 b.Optf("-qmp", "unix:%s,server,nowait", cfg.QMPPath)
654}
655
656func addQEMUStoreArgs(b *argBuilder, cfg qemuArgsConfig) {
657 drive := newOptionBuilder(8)
658 drive.KV("id", "store")
659 drive.KV("format", "raw")
660 drive.Add("read-only=on")
661 drive.KV("file", cfg.Image.StoreDisk)
662 drive.Add("if=none")
663 drive.Add("aio=io_uring")
664
665 b.Opt("-drive", drive.String())
666 b.Opt("-device", "virtio-blk-device,drive=store")
667}
668
669func addQEMUKVMArgs(b *argBuilder, image ImageSpec) {
670 b.Flag("-enable-kvm")
671 if image.RunnerConfig.CPU != "" {
672 b.Opt("-cpu", image.RunnerConfig.CPU)
673 }
674 b.Opt("-device", "i8042")
675}
676
677func addQEMUVolumeArgs(b *argBuilder, cfg qemuArgsConfig) error {
678 for index, volume := range cfg.Image.Volumes {
679 path := cfg.VolumePaths[volume.Image]
680 if path == "" {
681 return fmt.Errorf("missing prepared path for volume %q", volume.Image)
682 }
683
684 driveID := fmt.Sprintf("volume%d", index)
685
686 drive := newOptionBuilder(10)
687 drive.KV("id", driveID)
688 drive.KV("format", "raw")
689 drive.Add("read-only=off")
690 drive.KV("file", path)
691 drive.Add("if=none")
692 drive.Add("aio=io_uring")
693 drive.Add("discard=unmap")
694 drive.Add("cache=none")
695
696 b.Opt("-drive", drive.String())
697 b.Optf("-device", "virtio-blk-device,drive=%s", driveID)
698 }
699
700 return nil
701}
702
703func addQEMUNetworkArgs(b *argBuilder, interfaces []NetworkInterface) error {
704 for _, networkInterface := range interfaces {
705 if networkInterface.Type != "slirp4netns" {
706 return fmt.Errorf("unsupported microvm network interface type %q", networkInterface.Type)
707 }
708
709 netdevOpts := newOptionBuilder(6)
710 netdevOpts.Add("user")
711 netdevOpts.KV("id", networkInterface.ID)
712 netdevOpts.KV("net", innerSlirpNet)
713 netdevOpts.KV("host", innerSlirpHost)
714 netdevOpts.KV("dns", innerSlirpDNS)
715 netdevOpts.KV("dhcpstart", innerSlirpDHCP)
716
717 b.Opt("-netdev", netdevOpts.String())
718 b.Optf(
719 "-device", "virtio-net-device,netdev=%s,mac=%s",
720 networkInterface.ID, networkInterface.MAC,
721 )
722 }
723
724 return nil
725}
726
727func waitForPIDFile(ctx context.Context, path string) (string, error) {
728 waitCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
729 defer cancel()
730
731 ticker := time.NewTicker(25 * time.Millisecond)
732 defer ticker.Stop()
733
734 for {
735 data, err := os.ReadFile(path)
736 if err == nil {
737 pid := strings.TrimSpace(string(data))
738 if pid != "" {
739 return pid, nil
740 }
741 } else if !errors.Is(err, os.ErrNotExist) {
742 return "", fmt.Errorf("read qemu network namespace pid: %w", err)
743 }
744
745 select {
746 case <-waitCtx.Done():
747 return "", fmt.Errorf("waiting for qemu network namespace pid: %w", waitCtx.Err())
748 case <-ticker.C:
749 }
750 }
751}