Fix guest session cwd preflight scripts

Guest session cwd and command preflight helpers were emitting literal
`\\n` separators, so the guest shell saw malformed one-line scripts and
could fail `preflight_cwd` even when `/root/repo` already existed.

Replace those builders with real newlines, and fix the nearby attach
helper commands that were making the same mistake.

Add a small daemon guest-SSH seam so workspace preparation and session
start can share a fake backend in tests, then cover the regression with
an end-to-end daemon test for `PrepareVMWorkspace` followed by
`StartGuestSession` on `/root/repo`.

Validation: `GOCACHE=/tmp/banger-gocache go test ./internal/daemon` and
`GOCACHE=/tmp/banger-gocache go test ./...`.
This commit is contained in:
Thales Maciel 2026-04-13 18:26:19 -03:00
parent 37c4c091ec
commit 5e26fd7544
No known key found for this signature in database
GPG key ID: 33112E6833C34679
4 changed files with 296 additions and 49 deletions

View file

@ -54,6 +54,9 @@ type Daemon struct {
vmCaps []vmCapability
imageBuild func(context.Context, imageBuildSpec) error
requestHandler func(context.Context, rpc.Request) rpc.Response
guestWaitForSSH func(context.Context, string, string, time.Duration) error
guestDial func(context.Context, string, string) (guestSSHClient, error)
waitForGuestSessionReady func(context.Context, model.VMRecord, model.GuestSession) (model.GuestSession, error)
}
func Open(ctx context.Context) (d *Daemon, err error) {

View file

@ -50,6 +50,35 @@ var guestSessionHostCommandOutputFunc = func(ctx context.Context, name string, a
return output, fmt.Errorf("%s: %w: %s", command, err, detail)
}
type guestSSHClient interface {
Close() error
RunScript(context.Context, string, io.Writer) error
UploadFile(context.Context, string, os.FileMode, []byte, io.Writer) error
StreamTar(context.Context, string, string, io.Writer) error
StreamTarEntries(context.Context, string, []string, string, io.Writer) error
}
func (d *Daemon) waitForGuestSSH(ctx context.Context, address string, interval time.Duration) error {
if d != nil && d.guestWaitForSSH != nil {
return d.guestWaitForSSH(ctx, address, d.config.SSHKeyPath, interval)
}
return guest.WaitForSSH(ctx, address, d.config.SSHKeyPath, interval)
}
func (d *Daemon) dialGuest(ctx context.Context, address string) (guestSSHClient, error) {
if d != nil && d.guestDial != nil {
return d.guestDial(ctx, address, d.config.SSHKeyPath)
}
return guest.Dial(ctx, address, d.config.SSHKeyPath)
}
func (d *Daemon) waitForGuestSessionReadyHook(ctx context.Context, vm model.VMRecord, session model.GuestSession) (model.GuestSession, error) {
if d != nil && d.waitForGuestSessionReady != nil {
return d.waitForGuestSessionReady(ctx, vm, session)
}
return d.waitForGuestSessionReadyDefault(ctx, vm, session)
}
type guestSessionController struct {
stream *guest.StreamSession
streams []*guest.StreamSession
@ -215,10 +244,10 @@ func (d *Daemon) startGuestSessionLocked(ctx context.Context, vm model.VMRecord,
return session, nil
}
address := net.JoinHostPort(vm.Runtime.GuestIP, "22")
if err := guest.WaitForSSH(ctx, address, d.config.SSHKeyPath, 250*time.Millisecond); err != nil {
if err := d.waitForGuestSSH(ctx, address, 250*time.Millisecond); err != nil {
return fail("ssh_unavailable", fmt.Sprintf("guest ssh unavailable: %v", err), "")
}
client, err := guest.Dial(ctx, address, d.config.SSHKeyPath)
client, err := d.dialGuest(ctx, address)
if err != nil {
return fail("dial_guest", fmt.Sprintf("dial guest ssh: %v", err), "")
}
@ -243,7 +272,7 @@ func (d *Daemon) startGuestSessionLocked(ctx context.Context, vm model.VMRecord,
}
readyCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
defer cancel()
updated, err := d.waitForGuestSessionReady(readyCtx, vm, session)
updated, err := d.waitForGuestSessionReadyHook(readyCtx, vm, session)
if err != nil {
return fail("ready_wait", "guest session did not report ready state", err.Error())
}
@ -628,7 +657,7 @@ func (d *Daemon) watchGuestSessionAttach(id string, controller *guestSessionCont
}
}
func (d *Daemon) waitForGuestSessionReady(ctx context.Context, vm model.VMRecord, session model.GuestSession) (model.GuestSession, error) {
func (d *Daemon) waitForGuestSessionReadyDefault(ctx context.Context, vm model.VMRecord, session model.GuestSession) (model.GuestSession, error) {
for {
updated, err := d.refreshGuestSession(ctx, vm, session)
if err == nil {
@ -1037,35 +1066,35 @@ func normalizeGuestSessionRequiredCommands(command string, extras []string) []st
func guestSessionCWDPreflightScript(cwd string) string {
var script strings.Builder
script.WriteString("set -euo pipefail\\n")
fmt.Fprintf(&script, "DIR=%s\\n", guestShellQuote(defaultGuestSessionCWD(cwd)))
script.WriteString("if [ ! -d \"$DIR\" ]; then echo \"missing cwd: $DIR\"; exit 1; fi\\n")
script.WriteString("set -euo pipefail\n")
fmt.Fprintf(&script, "DIR=%s\n", guestShellQuote(defaultGuestSessionCWD(cwd)))
script.WriteString("if [ ! -d \"$DIR\" ]; then echo \"missing cwd: $DIR\"; exit 1; fi\n")
return script.String()
}
func guestSessionCommandPreflightScript(commands []string) string {
var script strings.Builder
script.WriteString("set -euo pipefail\\n")
script.WriteString("check_command() {\\n")
script.WriteString(" cmd=\\\"$1\\\"\\n")
script.WriteString(" case \\\"$cmd\\\" in\\n")
script.WriteString(" */*) [ -x \\\"$cmd\\\" ] || { echo \\\"missing command: $cmd\\\"; exit 1; } ;;\\n")
script.WriteString(" *) command -v \\\"$cmd\\\" >/dev/null 2>&1 || { echo \\\"missing command: $cmd\\\"; exit 1; } ;;\\n")
script.WriteString(" esac\\n")
script.WriteString("}\\n")
script.WriteString("set -euo pipefail\n")
script.WriteString("check_command() {\n")
script.WriteString(" cmd=\"$1\"\n")
script.WriteString(" case \"$cmd\" in\n")
script.WriteString(" */*) [ -x \"$cmd\" ] || { echo \"missing command: $cmd\"; exit 1; } ;;\n")
script.WriteString(" *) command -v \"$cmd\" >/dev/null 2>&1 || { echo \"missing command: $cmd\"; exit 1; } ;;\n")
script.WriteString(" esac\n")
script.WriteString("}\n")
for _, command := range commands {
fmt.Fprintf(&script, "check_command %s\\n", guestShellQuote(command))
fmt.Fprintf(&script, "check_command %s\n", guestShellQuote(command))
}
return script.String()
}
func guestSessionAttachInputCommand(sessionID string) string {
path := guestSessionStdinPipePath(sessionID)
return "bash -lc " + guestShellQuote(fmt.Sprintf("set -euo pipefail\\n[ -p %s ] || mkfifo -m 600 %s\\nexec cat > %s\\n", guestShellQuote(path), guestShellQuote(path), guestShellQuote(path)))
return "bash -lc " + guestShellQuote(fmt.Sprintf("set -euo pipefail\n[ -p %s ] || mkfifo -m 600 %s\nexec cat > %s\n", guestShellQuote(path), guestShellQuote(path), guestShellQuote(path)))
}
func guestSessionAttachTailCommand(path string) string {
return "bash -lc " + guestShellQuote(fmt.Sprintf("set -euo pipefail\\ntouch %s\\nexec tail -n 0 -F %s 2>/dev/null\\n", guestShellQuote(path), guestShellQuote(path)))
return "bash -lc " + guestShellQuote(fmt.Sprintf("set -euo pipefail\ntouch %s\nexec tail -n 0 -F %s 2>/dev/null\n", guestShellQuote(path), guestShellQuote(path)))
}
func guestSessionEnvLines(values map[string]string) []string {

View file

@ -0,0 +1,216 @@
package daemon
import (
"context"
"fmt"
"io"
"log/slog"
"os"
"os/exec"
"path/filepath"
"strings"
"testing"
"time"
"banger/internal/api"
"banger/internal/model"
)
type fakeGuestSSHClient struct {
t *testing.T
existingDirs map[string]bool
closed bool
}
func (f *fakeGuestSSHClient) Close() error {
f.closed = true
return nil
}
func (f *fakeGuestSSHClient) RunScript(_ context.Context, script string, _ io.Writer) error {
f.t.Helper()
switch {
case strings.Contains(script, `\n`):
return fmt.Errorf("script still contains escaped newline literals: %q", script)
case strings.Contains(script, `echo "missing cwd: $DIR"`):
if strings.Contains(script, "DIR='/root/repo'\n") && f.existingDirs["/root/repo"] {
return nil
}
return fmt.Errorf("missing cwd")
case strings.Contains(script, "check_command() {"):
return nil
case strings.Contains(script, `git config --global --add safe.directory "$DIR"`):
if strings.Contains(script, "DIR='/root/repo'\n") {
f.existingDirs["/root/repo"] = true
return nil
}
return fmt.Errorf("workspace finalize used unexpected guest path")
case strings.Contains(script, "chmod -R a-w"):
if f.existingDirs["/root/repo"] {
return nil
}
return fmt.Errorf("workspace path missing during readonly chmod")
case strings.Contains(script, "nohup bash "):
return nil
default:
return nil
}
}
func (f *fakeGuestSSHClient) UploadFile(_ context.Context, _ string, _ os.FileMode, _ []byte, _ io.Writer) error {
return nil
}
func (f *fakeGuestSSHClient) StreamTar(_ context.Context, _ string, command string, _ io.Writer) error {
if strings.Contains(command, "/root/repo") {
f.existingDirs["/root/repo"] = true
return nil
}
return fmt.Errorf("unexpected StreamTar command: %s", command)
}
func (f *fakeGuestSSHClient) StreamTarEntries(_ context.Context, _ string, _ []string, command string, _ io.Writer) error {
if strings.Contains(command, "/root/repo") {
f.existingDirs["/root/repo"] = true
return nil
}
return fmt.Errorf("unexpected StreamTarEntries command: %s", command)
}
func TestGuestSessionPreflightScriptsUseRealNewlines(t *testing.T) {
t.Parallel()
cwdScript := guestSessionCWDPreflightScript("/root/repo")
if strings.Contains(cwdScript, `\n`) {
t.Fatalf("cwd preflight script still contains escaped newline literals: %q", cwdScript)
}
if !strings.Contains(cwdScript, "\n") {
t.Fatalf("cwd preflight script should contain real newlines: %q", cwdScript)
}
commandScript := guestSessionCommandPreflightScript([]string{"git", "pi"})
if strings.Contains(commandScript, `\n`) {
t.Fatalf("command preflight script still contains escaped newline literals: %q", commandScript)
}
if !strings.Contains(commandScript, "\n") {
t.Fatalf("command preflight script should contain real newlines: %q", commandScript)
}
attachInput := guestSessionAttachInputCommand("session-id")
if strings.Contains(attachInput, `\n`) {
t.Fatalf("attach input command still contains escaped newline literals: %q", attachInput)
}
attachTail := guestSessionAttachTailCommand("/tmp/stdout.log")
if strings.Contains(attachTail, `\n`) {
t.Fatalf("attach tail command still contains escaped newline literals: %q", attachTail)
}
}
func TestPrepareWorkspaceThenStartGuestSessionPassesCWDPreflight(t *testing.T) {
ctx := context.Background()
db := openDaemonStore(t)
repoRoot := filepath.Join(t.TempDir(), "repo")
if err := os.MkdirAll(repoRoot, 0o755); err != nil {
t.Fatalf("MkdirAll(repoRoot): %v", err)
}
if err := os.WriteFile(filepath.Join(repoRoot, "README.md"), []byte("hello\n"), 0o644); err != nil {
t.Fatalf("WriteFile(README.md): %v", err)
}
runGit := func(args ...string) {
t.Helper()
cmd := exec.Command("git", append([]string{"-C", repoRoot}, args...)...)
output, err := cmd.CombinedOutput()
if err != nil {
t.Fatalf("git %s: %v\n%s", strings.Join(args, " "), err, output)
}
}
runGit("init", "-b", "main")
runGit("config", "user.name", "Test User")
runGit("config", "user.email", "test@example.com")
runGit("add", ".")
runGit("commit", "-m", "initial")
apiSock := filepath.Join(t.TempDir(), "fc.sock")
firecracker := exec.Command("bash", "-lc", fmt.Sprintf("exec -a %q sleep 60", "firecracker --api-sock "+apiSock))
if err := firecracker.Start(); err != nil {
t.Fatalf("start fake firecracker: %v", err)
}
t.Cleanup(func() {
if firecracker.Process != nil {
_ = firecracker.Process.Kill()
_, _ = firecracker.Process.Wait()
}
})
vm := testVM("pi-devbox", "image-pi", "172.16.0.77")
vm.State = model.VMStateRunning
vm.Runtime.State = model.VMStateRunning
vm.Runtime.PID = firecracker.Process.Pid
vm.Runtime.APISockPath = apiSock
upsertDaemonVM(t, ctx, db, vm)
fakeClient := &fakeGuestSSHClient{t: t, existingDirs: map[string]bool{}}
d := &Daemon{
store: db,
config: model.DaemonConfig{SSHKeyPath: filepath.Join(t.TempDir(), "id_ed25519")},
logger: slog.New(slog.NewTextHandler(io.Discard, nil)),
}
d.guestWaitForSSH = func(context.Context, string, string, time.Duration) error { return nil }
d.guestDial = func(context.Context, string, string) (guestSSHClient, error) { return fakeClient, nil }
d.waitForGuestSessionReady = func(_ context.Context, _ model.VMRecord, session model.GuestSession) (model.GuestSession, error) {
now := model.Now()
session.Status = model.GuestSessionStatusRunning
session.GuestPID = 4242
session.StartedAt = now
session.UpdatedAt = now
session.Attachable = session.StdinMode == model.GuestSessionStdinPipe
session.Reattachable = session.StdinMode == model.GuestSessionStdinPipe
return session, nil
}
workspace, err := d.PrepareVMWorkspace(ctx, api.VMWorkspacePrepareParams{
IDOrName: vm.Name,
SourcePath: repoRoot,
GuestPath: "/root/repo",
ReadOnly: true,
})
if err != nil {
t.Fatalf("PrepareVMWorkspace: %v", err)
}
if workspace.GuestPath != "/root/repo" {
t.Fatalf("PrepareVMWorkspace guest path = %q, want /root/repo", workspace.GuestPath)
}
if !fakeClient.existingDirs["/root/repo"] {
t.Fatalf("workspace prepare did not mark /root/repo as present in fake guest")
}
session, err := d.StartGuestSession(ctx, api.GuestSessionStartParams{
VMIDOrName: vm.Name,
Name: "testpi",
Command: "pi",
Args: []string{"--mode", "rpc", "--no-session"},
CWD: "/root/repo",
StdinMode: string(model.GuestSessionStdinPipe),
RequiredCommands: []string{"git"},
})
if err != nil {
t.Fatalf("StartGuestSession: %v", err)
}
if session.Status != model.GuestSessionStatusRunning {
t.Fatalf("session status = %q, want %q", session.Status, model.GuestSessionStatusRunning)
}
if session.LaunchStage != "" {
t.Fatalf("session launch stage = %q, want empty", session.LaunchStage)
}
if session.LaunchMessage != "" {
t.Fatalf("session launch message = %q, want empty", session.LaunchMessage)
}
if session.GuestPID == 0 {
t.Fatalf("session guest pid = 0, want non-zero")
}
if !session.Attachable {
t.Fatalf("session should be attachable for pipe stdin mode")
}
}

View file

@ -14,7 +14,6 @@ import (
"time"
"banger/internal/api"
"banger/internal/guest"
"banger/internal/model"
"banger/internal/system"
)
@ -77,10 +76,10 @@ func (d *Daemon) prepareVMWorkspaceLocked(ctx context.Context, vm model.VMRecord
return model.WorkspacePrepareResult{}, fmt.Errorf("workspace mode %q does not support git submodules in %s (%s); use --mode full_copy", mode, spec.RepoRoot, strings.Join(spec.Submodules, ", "))
}
address := net.JoinHostPort(vm.Runtime.GuestIP, "22")
if err := guest.WaitForSSH(ctx, address, d.config.SSHKeyPath, 250*time.Millisecond); err != nil {
if err := d.waitForGuestSSH(ctx, address, 250*time.Millisecond); err != nil {
return model.WorkspacePrepareResult{}, fmt.Errorf("guest ssh unavailable: %w", err)
}
client, err := guest.Dial(ctx, address, d.config.SSHKeyPath)
client, err := d.dialGuest(ctx, address)
if err != nil {
return model.WorkspacePrepareResult{}, fmt.Errorf("dial guest ssh: %w", err)
}
@ -179,7 +178,7 @@ func inspectWorkspaceRepo(ctx context.Context, rawPath, branchName, fromRef stri
}, nil
}
func importWorkspaceRepoToGuest(ctx context.Context, client *guest.Client, spec workspaceRepoSpec, guestPath string, mode model.WorkspacePrepareMode) error {
func importWorkspaceRepoToGuest(ctx context.Context, client guestSSHClient, spec workspaceRepoSpec, guestPath string, mode model.WorkspacePrepareMode) error {
switch mode {
case model.WorkspacePrepareModeFullCopy:
var copyLog bytes.Buffer