Add experimental Void guest workflow and vsock agent

Make iterating on a Firecracker-friendly Void guest practical without replacing the Debian default image path.

Add local Void rootfs build/register/verify plumbing, a language-agnostic dev package baseline, and guest SSH/work-disk hardening so new images use the runtime bundle key, keep a normal root bash environment, and repair stale nested /root layouts on restart.

Replace the guest PING/PONG responder with an HTTP /healthz agent over vsock, rename the runtime bundle and config surface from ping helper to agent while still accepting the legacy keys, and route the post-SSH reminder through the new vm.health path.

Validated with GOCACHE=/tmp/banger-gocache go test ./..., make build, bash -n customize.sh make-rootfs-void.sh, and git diff --check.
This commit is contained in:
Thales Maciel 2026-03-19 14:51:25 -03:00
parent c8d9a122f9
commit 3ed78fdcfc
No known key found for this signature in database
GPG key ID: 33112E6833C34679
42 changed files with 2222 additions and 388 deletions

View file

@ -2,6 +2,10 @@ package daemon
import (
"context"
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"errors"
"fmt"
"net"
@ -253,7 +257,7 @@ func TestSetVMRejectsStoppedOnlyChangesForRunningVM(t *testing.T) {
}
}
func TestPingVMReturnsAliveForRunningGuest(t *testing.T) {
func TestHealthVMReturnsHealthyForRunningGuest(t *testing.T) {
t.Parallel()
ctx := context.Background()
@ -296,16 +300,24 @@ func TestPingVMReturnsAliveForRunningGuest(t *testing.T) {
serverDone <- err
return
}
n, err = conn.Read(buf)
if err != nil {
serverDone <- err
reqBuf := make([]byte, 0, 512)
reqBuf = append(reqBuf, buf[:0]...)
for {
n, err = conn.Read(buf)
if err != nil {
serverDone <- err
return
}
reqBuf = append(reqBuf, buf[:n]...)
if strings.Contains(string(reqBuf), "\r\n\r\n") {
break
}
}
if got := string(reqBuf); !strings.Contains(got, "GET /healthz HTTP/1.1\r\n") {
serverDone <- fmt.Errorf("unexpected health payload %q", got)
return
}
if got := string(buf[:n]); got != "PING\n" {
serverDone <- fmt.Errorf("unexpected ping payload %q", got)
return
}
_, err = conn.Write([]byte("PONG\n"))
_, err = conn.Write([]byte("HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: 15\r\n\r\n{\"status\":\"ok\"}"))
serverDone <- err
}()
@ -326,12 +338,12 @@ func TestPingVMReturnsAliveForRunningGuest(t *testing.T) {
},
}
d := &Daemon{store: db, runner: runner}
result, err := d.PingVM(ctx, vm.Name)
result, err := d.HealthVM(ctx, vm.Name)
if err != nil {
t.Fatalf("PingVM: %v", err)
t.Fatalf("HealthVM: %v", err)
}
if !result.Alive || result.Name != vm.Name {
t.Fatalf("PingVM result = %+v, want alive %s", result, vm.Name)
if !result.Healthy || result.Name != vm.Name {
t.Fatalf("HealthVM result = %+v, want healthy %s", result, vm.Name)
}
runner.assertExhausted()
if err := <-serverDone; err != nil {
@ -339,7 +351,65 @@ func TestPingVMReturnsAliveForRunningGuest(t *testing.T) {
}
}
func TestPingVMReturnsFalseForStoppedVM(t *testing.T) {
func TestPingVMAliasReturnsAliveForHealthyVM(t *testing.T) {
t.Parallel()
ctx := context.Background()
db := openDaemonStore(t)
apiSock := filepath.Join(t.TempDir(), "fc.sock")
fake := startFakeFirecrackerProcess(t, apiSock)
t.Cleanup(func() {
_ = fake.Process.Kill()
_ = fake.Wait()
})
vsockSock := filepath.Join(t.TempDir(), "fc.vsock")
listener, err := net.Listen("unix", vsockSock)
if err != nil {
t.Fatalf("listen vsock: %v", err)
}
t.Cleanup(func() {
_ = listener.Close()
_ = os.Remove(vsockSock)
})
go func() {
conn, err := listener.Accept()
if err != nil {
return
}
defer conn.Close()
buf := make([]byte, 512)
_, _ = conn.Read(buf)
_, _ = conn.Write([]byte("OK 1\n"))
_, _ = conn.Read(buf)
_, _ = conn.Write([]byte("HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: 15\r\n\r\n{\"status\":\"ok\"}"))
}()
vm := testVM("healthy-ping", "image-healthy", "172.16.0.42")
vm.State = model.VMStateRunning
vm.Runtime.State = model.VMStateRunning
vm.Runtime.PID = fake.Process.Pid
vm.Runtime.APISockPath = apiSock
vm.Runtime.VSockPath = vsockSock
vm.Runtime.VSockCID = 10042
upsertDaemonVM(t, ctx, db, vm)
runner := &scriptedRunner{
t: t,
steps: []runnerStep{
sudoStep("", nil, "chown", fmt.Sprintf("%d:%d", os.Getuid(), os.Getgid()), vsockSock),
sudoStep("", nil, "chmod", "600", vsockSock),
},
}
d := &Daemon{store: db, runner: runner}
result, err := d.PingVM(ctx, vm.Name)
if err != nil {
t.Fatalf("PingVM: %v", err)
}
if !result.Alive {
t.Fatalf("PingVM result = %+v, want alive", result)
}
}
func TestHealthVMReturnsFalseForStoppedVM(t *testing.T) {
t.Parallel()
ctx := context.Background()
@ -348,12 +418,12 @@ func TestPingVMReturnsFalseForStoppedVM(t *testing.T) {
upsertDaemonVM(t, ctx, db, vm)
d := &Daemon{store: db}
result, err := d.PingVM(ctx, vm.Name)
result, err := d.HealthVM(ctx, vm.Name)
if err != nil {
t.Fatalf("PingVM: %v", err)
t.Fatalf("HealthVM: %v", err)
}
if result.Alive {
t.Fatalf("PingVM result = %+v, want not alive", result)
if result.Healthy {
t.Fatalf("HealthVM result = %+v, want not healthy", result)
}
}
@ -406,6 +476,64 @@ func TestFlattenNestedWorkHomeCopiesEntriesIndividually(t *testing.T) {
runner.assertExhausted()
}
func TestEnsureAuthorizedKeyOnWorkDiskRepairsNestedRootLayout(t *testing.T) {
t.Parallel()
workDiskDir := t.TempDir()
nestedHome := filepath.Join(workDiskDir, "root")
if err := os.MkdirAll(filepath.Join(nestedHome, ".ssh"), 0o700); err != nil {
t.Fatalf("MkdirAll(.ssh): %v", err)
}
if err := os.WriteFile(filepath.Join(nestedHome, ".bashrc"), []byte("export TEST_PROMPT=1\n"), 0o644); err != nil {
t.Fatalf("WriteFile(.bashrc): %v", err)
}
legacyKey := "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILEgacykey legacy@test\n"
if err := os.WriteFile(filepath.Join(nestedHome, ".ssh", "authorized_keys"), []byte(legacyKey), 0o600); err != nil {
t.Fatalf("WriteFile(authorized_keys): %v", err)
}
privateKey, err := rsa.GenerateKey(rand.Reader, 1024)
if err != nil {
t.Fatalf("GenerateKey: %v", err)
}
privateKeyPEM := pem.EncodeToMemory(&pem.Block{
Type: "RSA PRIVATE KEY",
Bytes: x509.MarshalPKCS1PrivateKey(privateKey),
})
sshKeyPath := filepath.Join(t.TempDir(), "id_rsa")
if err := os.WriteFile(sshKeyPath, privateKeyPEM, 0o600); err != nil {
t.Fatalf("WriteFile(private key): %v", err)
}
d := &Daemon{
runner: &filesystemRunner{t: t},
config: model.DaemonConfig{SSHKeyPath: sshKeyPath},
}
vm := testVM("seed-repair", "image-seed-repair", "172.16.0.61")
vm.Runtime.WorkDiskPath = workDiskDir
if err := d.ensureAuthorizedKeyOnWorkDisk(context.Background(), &vm); err != nil {
t.Fatalf("ensureAuthorizedKeyOnWorkDisk: %v", err)
}
if _, err := os.Stat(filepath.Join(workDiskDir, "root")); !os.IsNotExist(err) {
t.Fatalf("nested root still exists: %v", err)
}
if _, err := os.Stat(filepath.Join(workDiskDir, ".bashrc")); err != nil {
t.Fatalf(".bashrc missing at top level: %v", err)
}
data, err := os.ReadFile(filepath.Join(workDiskDir, ".ssh", "authorized_keys"))
if err != nil {
t.Fatalf("ReadFile(authorized_keys): %v", err)
}
content := string(data)
if !strings.Contains(content, strings.TrimSpace(legacyKey)) {
t.Fatalf("authorized_keys missing legacy key: %q", content)
}
if !strings.Contains(content, "ssh-rsa ") {
t.Fatalf("authorized_keys missing managed key: %q", content)
}
}
func TestCreateVMRejectsNonPositiveCPUAndMemory(t *testing.T) {
d := &Daemon{}
if _, err := d.CreateVM(context.Background(), api.VMCreateParams{VCPUCount: ptr(0)}); err == nil || !strings.Contains(err.Error(), "vcpu must be a positive integer") {
@ -824,6 +952,29 @@ func testImage(name string) model.Image {
}
}
func TestMergeAuthorizedKey(t *testing.T) {
t.Parallel()
managed := []byte("ssh-ed25519 AAAATESTKEY banger\n")
existing := []byte("ssh-ed25519 AAAAOTHER other\n")
merged := mergeAuthorizedKey(existing, managed)
got := string(merged)
if !strings.Contains(got, "ssh-ed25519 AAAAOTHER other") {
t.Fatalf("merged keys dropped existing entry: %q", got)
}
if !strings.Contains(got, "ssh-ed25519 AAAATESTKEY banger") {
t.Fatalf("merged keys missing managed entry: %q", got)
}
if strings.Count(got, "ssh-ed25519 AAAATESTKEY banger") != 1 {
t.Fatalf("managed key duplicated in %q", got)
}
merged = mergeAuthorizedKey(merged, managed)
if strings.Count(string(merged), "ssh-ed25519 AAAATESTKEY banger") != 1 {
t.Fatalf("managed key duplicated after second merge: %q", string(merged))
}
}
func startFakeFirecrackerProcess(t *testing.T, apiSock string) *exec.Cmd {
t.Helper()
@ -878,6 +1029,117 @@ type processKillingRunner struct {
proc *exec.Cmd
}
type filesystemRunner struct {
t *testing.T
}
func (r *filesystemRunner) Run(ctx context.Context, name string, args ...string) ([]byte, error) {
r.t.Helper()
return nil, fmt.Errorf("unexpected Run call: %s %v", name, args)
}
func (r *filesystemRunner) RunSudo(ctx context.Context, args ...string) ([]byte, error) {
r.t.Helper()
if len(args) == 0 {
return nil, errors.New("missing sudo command")
}
switch args[0] {
case "mount":
if len(args) != 3 {
return nil, fmt.Errorf("unexpected mount args: %v", args)
}
source, mountDir := args[1], args[2]
if err := os.Remove(mountDir); err != nil {
return nil, err
}
if err := os.Symlink(source, mountDir); err != nil {
return nil, err
}
return nil, nil
case "umount":
return nil, nil
case "chmod":
if len(args) != 3 {
return nil, fmt.Errorf("unexpected chmod args: %v", args)
}
mode, err := strconv.ParseUint(args[1], 8, 32)
if err != nil {
return nil, err
}
return nil, os.Chmod(args[2], os.FileMode(mode))
case "cp":
if len(args) != 4 || args[1] != "-a" {
return nil, fmt.Errorf("unexpected cp args: %v", args)
}
return nil, copyIntoDir(args[2], args[3])
case "rm":
if len(args) != 3 || args[1] != "-rf" {
return nil, fmt.Errorf("unexpected rm args: %v", args)
}
return nil, os.RemoveAll(args[2])
case "mkdir":
if len(args) != 3 || args[1] != "-p" {
return nil, fmt.Errorf("unexpected mkdir args: %v", args)
}
return nil, os.MkdirAll(args[2], 0o755)
case "cat":
if len(args) != 2 {
return nil, fmt.Errorf("unexpected cat args: %v", args)
}
return os.ReadFile(args[1])
case "install":
if len(args) != 5 || args[1] != "-m" {
return nil, fmt.Errorf("unexpected install args: %v", args)
}
mode, err := strconv.ParseUint(args[2], 8, 32)
if err != nil {
return nil, err
}
data, err := os.ReadFile(args[3])
if err != nil {
return nil, err
}
if err := os.MkdirAll(filepath.Dir(args[4]), 0o755); err != nil {
return nil, err
}
return nil, os.WriteFile(args[4], data, os.FileMode(mode))
default:
return nil, fmt.Errorf("unexpected sudo command: %v", args)
}
}
func copyIntoDir(sourcePath, targetDir string) error {
targetDir = strings.TrimSuffix(targetDir, "/")
info, err := os.Stat(sourcePath)
if err != nil {
return err
}
destPath := filepath.Join(targetDir, filepath.Base(sourcePath))
if info.IsDir() {
if err := os.MkdirAll(destPath, info.Mode().Perm()); err != nil {
return err
}
entries, err := os.ReadDir(sourcePath)
if err != nil {
return err
}
for _, entry := range entries {
if err := copyIntoDir(filepath.Join(sourcePath, entry.Name()), destPath); err != nil {
return err
}
}
return os.Chmod(destPath, info.Mode().Perm())
}
data, err := os.ReadFile(sourcePath)
if err != nil {
return err
}
if err := os.MkdirAll(filepath.Dir(destPath), 0o755); err != nil {
return err
}
return os.WriteFile(destPath, data, info.Mode().Perm())
}
func (r *processKillingRunner) Run(ctx context.Context, name string, args ...string) ([]byte, error) {
return r.scriptedRunner.Run(ctx, name, args...)
}