sshcode/sshcode.go at master · Merith-TK/sshcode · GitHub

Repository navigation

History

689 lines (590 loc) · 18.1 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

package main

import (

"context"

"encoding/json"

"fmt"

"math/rand"

"net"

"net/http"

"os"

"os/exec"

"os/signal"

"path/filepath"

"runtime"

"strconv"

"strings"

"syscall"

"time"

"github.com/pkg/browser"

"go.coder.com/flog"

"golang.org/x/xerrors"

)

const codeServerDir = "~/.sshcode-server"

const (

sshDirectory = "~/.ssh"

sshDirectoryUnsafeModeMask = 0022

sshControlPath = sshDirectory + "/control-%h-%p-%r"

)

type options struct {

skipSync bool

syncBack bool

noOpen bool

reuseConnection bool

bindAddr string

remotePort string

sshFlags string

uploadCodeServer string

}

func sshCode(host, dir string, o options) error {

host, extraSSHFlags, err := parseHost(host)

if err != nil {

return xerrors.Errorf("failed to parse host IP: %w", err)

}

if extraSSHFlags != "" {

o.sshFlags = strings.Join([]string{extraSSHFlags, o.sshFlags}, " ")

}

o.bindAddr, err = parseBindAddr(o.bindAddr)

if err != nil {

return xerrors.Errorf("failed to parse bind address: %w", err)

}

if o.remotePort == "" {

o.remotePort, err = randomPort()

}

if err != nil {

return xerrors.Errorf("failed to find available remote port: %w", err)

}

// Check the SSH directory's permissions and warn the user if it is not safe.

o.reuseConnection = checkSSHDirectory(sshDirectory, o.reuseConnection)

// Start SSH master connection socket. This prevents multiple password prompts from appearing as authentication

// only happens on the initial connection.

if o.reuseConnection {

flog.Info("starting SSH master connection...")

newSSHFlags, cancel, err := startSSHMaster(o.sshFlags, sshControlPath, host)

defer cancel()

if err != nil {

flog.Error("failed to start SSH master connection: %v", err)

o.reuseConnection = false

} else {

o.sshFlags = newSSHFlags

}

// Upload local code-server or download code-server from CI server.

if o.uploadCodeServer != "" {

flog.Info("uploading local code-server binary...")

err = copyCodeServerBinary(o.sshFlags, host, o.uploadCodeServer, codeServerDir)

if err != nil {

return xerrors.Errorf("failed to upload local code-server binary to remote server: %w", err)

}

sshCmdStr :=

fmt.Sprintf("ssh %v %v 'chmod +x %v'",

o.sshFlags, host, codeServerDir,

)

sshCmd := exec.Command("sh", "-l", "-c", sshCmdStr)

sshCmd.Stdout = os.Stdout

sshCmd.Stderr = os.Stderr

err = sshCmd.Run()

if err != nil {

return xerrors.Errorf("failed to make code-server binary executable:\n---ssh cmd---\n%s: %w",

sshCmdStr,

err,

)

}

} else {

flog.Info("ensuring code-server is updated...")

dlScript, err := downloadScript(codeServerDir)

if err != nil {

return xerrors.New("failed to download latest code-server")

}

// Downloads the latest code-server and allows it to be executed.

sshCmdStr := fmt.Sprintf("ssh %v %v '/usr/bin/env bash -l'", o.sshFlags, host)

sshCmd := exec.Command("sh", "-l", "-c", sshCmdStr)

sshCmd.Stdout = os.Stdout

sshCmd.Stderr = os.Stderr

sshCmd.Stdin = strings.NewReader(dlScript)

err = sshCmd.Run()

if err != nil {

return xerrors.Errorf("failed to update code-server:\n---ssh cmd---\n%s"+

"\n---download script---\n%s: %w",

sshCmdStr,

dlScript,

err,

)

}

if !o.skipSync {

start := time.Now()

flog.Info("syncing settings")

err = syncUserSettings(o.sshFlags, host, false)

if err != nil {

return xerrors.Errorf("failed to sync settings: %w", err)

}

flog.Info("synced settings in %s", time.Since(start))

flog.Info("syncing extensions")

err = syncExtensions(o.sshFlags, host, false)

if err != nil {

return xerrors.Errorf("failed to sync extensions: %w", err)

}

flog.Info("synced extensions in %s", time.Since(start))

}

codeServerFlags := []string{

fmt.Sprintf("--bind-addr 127.0.0.1:%v", o.remotePort),

"--auth none",

}

codeServerCmdStr := fmt.Sprintf("%v/code-server %v %v", codeServerDir, dir, strings.Join(codeServerFlags, " "))

flog.Info("starting code-server...")

flog.Info("Tunneling remote port %v to %v", o.remotePort, o.bindAddr)

sshCmdStr :=

fmt.Sprintf("ssh -tt -q -L %v:localhost:%v %v %v '%v'",

o.bindAddr, o.remotePort, o.sshFlags, host, codeServerCmdStr,

)

// Starts code-server and forwards the remote port.

sshCmd := exec.Command("sh", "-l", "-c", sshCmdStr)

sshCmd.Stdin = os.Stdin

sshCmd.Stdout = os.Stdout

sshCmd.Stderr = os.Stderr

err = sshCmd.Start()

if err != nil {

return xerrors.Errorf("failed to start code-server: %w", err)

}

url := fmt.Sprintf("http://%s", o.bindAddr)

ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)

defer cancel()

client := http.Client{

Timeout: time.Second * 3,

}

for {

if ctx.Err() != nil {

return xerrors.Errorf("code-server didn't start in time: %w", ctx.Err())

}

// Waits for code-server to be available before opening the browser.

resp, err := client.Get(url)

if err != nil {

continue

}

resp.Body.Close()

break

}

ctx, cancel = context.WithCancel(context.Background())

if !o.noOpen {

openBrowser(url)

}

go func() {

defer cancel()

sshCmd.Wait()

}()

c := make(chan os.Signal)

signal.Notify(c, os.Interrupt)

select {

case <-ctx.Done():

case <-c:

}

flog.Info("shutting down")

if !o.syncBack || o.skipSync {

return nil

}

flog.Info("synchronizing VS Code back to local")

err = syncExtensions(o.sshFlags, host, true)

if err != nil {

return xerrors.Errorf("failed to sync extensions back: %w", err)

}

err = syncUserSettings(o.sshFlags, host, true)

if err != nil {

return xerrors.Errorf("failed to sync user settings back: %w", err)

}

return nil

}

// expandPath returns an expanded version of path.

func expandPath(path string) string {

path = filepath.Clean(os.ExpandEnv(path))

// Replace tilde notation in path with the home directory. You can't replace the first instance of `~` in the

// string with the homedir as having a tilde in the middle of a filename is valid.

homedir := os.Getenv("HOME")

if homedir != "" {

if path == "~" {

path = homedir

} else if strings.HasPrefix(path, "~/") {

path = filepath.Join(homedir, path[2:])

}

return filepath.Clean(path)

}

func parseBindAddr(bindAddr string) (string, error) {

if !strings.Contains(bindAddr, ":") {

bindAddr += ":"

}

host, port, err := net.SplitHostPort(bindAddr)

if err != nil {

return "", err

}

if host == "" {

host = "127.0.0.1"

}

if port == "" {

port, err = randomPort()

}

if err != nil {

return "", err

}

return net.JoinHostPort(host, port), nil

}

func openBrowser(url string) {

var openCmd *exec.Cmd

const (

macPath = "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"

wslPath = "/mnt/c/Program Files (x86)/Google/Chrome/Application/chrome.exe"

winPath = "C:/Program Files (x86)/Google/Chrome/Application/chrome.exe"

)

switch {

case commandExists("chrome"):

openCmd = exec.Command("chrome", chromeOptions(url)...)

case commandExists("google-chrome"):

openCmd = exec.Command("google-chrome", chromeOptions(url)...)

case commandExists("google-chrome-stable"):

openCmd = exec.Command("google-chrome-stable", chromeOptions(url)...)

case commandExists("chromium"):

openCmd = exec.Command("chromium", chromeOptions(url)...)

case commandExists("chromium-browser"):

openCmd = exec.Command("chromium-browser", chromeOptions(url)...)

case pathExists(macPath):

openCmd = exec.Command(macPath, chromeOptions(url)...)

case pathExists(wslPath):

openCmd = exec.Command(wslPath, chromeOptions(url)...)

case pathExists(winPath):

openCmd = exec.Command(winPath, chromeOptions(url)...)

default:

err := browser.OpenURL(url)

if err != nil {

flog.Error("failed to open browser: %v", err)

}

return

}

// We do not use CombinedOutput because if there is no chrome instance, this will block

// and become the parent process instead of using an existing chrome instance.

err := openCmd.Start()

if err != nil {

flog.Error("failed to open browser: %v", err)

}

func chromeOptions(url string) []string {

return []string{"--app=" + url, "--disable-extensions", "--disable-plugins", "--incognito"}

}

// Checks if a command exists locally.

func commandExists(name string) bool {

_, err := exec.LookPath(name)

return err == nil

}

func pathExists(name string) bool {

_, err := os.Stat(name)

return err == nil

}

// randomPort picks a random port to start code-server on.

func randomPort() (string, error) {

const (

minPort = 1024

maxPort = 65535

maxTries = 10

)

for i := 0; i < maxTries; i++ {

port := rand.Intn(maxPort-minPort+1) + minPort

l, err := net.Listen("tcp", fmt.Sprintf(":%d", port))

if err == nil {

_ = l.Close()

return strconv.Itoa(port), nil

}

flog.Info("port taken: %d", port)

}

return "", xerrors.Errorf("max number of tries exceeded: %d", maxTries)

}

// checkSSHDirectory performs sanity and safety checks on sshDirectory, and

// returns a new value for o.reuseConnection depending on the checks.

func checkSSHDirectory(sshDirectory string, reuseConnection bool) bool {

if runtime.GOOS == "windows" {

flog.Info("OS is windows, disabling connection reuse feature")

return false

}

sshDirectoryMode, err := os.Lstat(expandPath(sshDirectory))

if err != nil {

if reuseConnection {

flog.Info("failed to stat %v directory, disabling connection reuse feature: %v", sshDirectory, err)

}

reuseConnection = false

} else {

if !sshDirectoryMode.IsDir() {

if reuseConnection {

flog.Info("%v is not a directory, disabling connection reuse feature", sshDirectory)

} else {

flog.Info("warning: %v is not a directory", sshDirectory)

}

reuseConnection = false

}

if sshDirectoryMode.Mode().Perm()&sshDirectoryUnsafeModeMask != 0 {

flog.Info("warning: the %v directory has unsafe permissions, they should only be writable by "+

"the owner (and files inside should be set to 0600)", sshDirectory)

}

return reuseConnection

}

// startSSHMaster starts an SSH master connection and waits for it to be ready.

// It returns a new set of SSH flags for child SSH processes to use.

func startSSHMaster(sshFlags string, sshControlPath string, host string) (string, func(), error) {

ctx, cancel := context.WithCancel(context.Background())

newSSHFlags := fmt.Sprintf(`%v -o "ControlPath=%v"`, sshFlags, sshControlPath)

// -MN means "start a master socket and don't open a session, just connect".

sshCmdStr := fmt.Sprintf(`exec ssh %v -MNq %v`, newSSHFlags, host)

sshMasterCmd := exec.CommandContext(ctx, "sh", "-c", sshCmdStr)

sshMasterCmd.Stdin = os.Stdin

sshMasterCmd.Stderr = os.Stderr

// Gracefully stop the SSH master.

stopSSHMaster := func() {

if sshMasterCmd.Process != nil {

if sshMasterCmd.ProcessState != nil && sshMasterCmd.ProcessState.Exited() {

return

}

err := sshMasterCmd.Process.Signal(syscall.SIGTERM)

if err != nil {

flog.Error("failed to send SIGTERM to SSH master process: %v", err)

}

cancel()

}

// Start ssh master and wait. Waiting prevents the process from becoming a zombie process if it dies before

// sshcode does, and allows sshMasterCmd.ProcessState to be populated.

err := sshMasterCmd.Start()

go sshMasterCmd.Wait()

if err != nil {

return "", stopSSHMaster, err

}

err = checkSSHMaster(sshMasterCmd, newSSHFlags, host)

if err != nil {

stopSSHMaster()

return "", stopSSHMaster, xerrors.Errorf("SSH master wasn't ready on time: %w", err)

}

return newSSHFlags, stopSSHMaster, nil

}

// checkSSHMaster polls every second for 30 seconds to check if the SSH master

// is ready.

func checkSSHMaster(sshMasterCmd *exec.Cmd, sshFlags string, host string) error {

var (

maxTries = 30

sleepDur = time.Second

err error

)

for i := 0; i < maxTries; i++ {

// Check if the master is running.

if sshMasterCmd.Process == nil || (sshMasterCmd.ProcessState != nil && sshMasterCmd.ProcessState.Exited()) {

return xerrors.Errorf("SSH master process is not running")

}

// Check if it's ready.

sshCmdStr := fmt.Sprintf(`ssh %v -O check %v`, sshFlags, host)

sshCmd := exec.Command("sh", "-c", sshCmdStr)

err = sshCmd.Run()

if err == nil {

return nil

}

time.Sleep(sleepDur)

}

return xerrors.Errorf("max number of tries exceeded: %d", maxTries)

}

// copyCodeServerBinary copies a code-server binary from local to remote.

func copyCodeServerBinary(sshFlags string, host string, localPath string, remotePath string) error {

if err := validateIsFile(localPath); err != nil {

return err

}

var (

src = localPath

dest = host + ":" + remotePath

)

return rsync(src, dest, sshFlags)

}

func syncUserSettings(sshFlags string, host string, back bool) error {

localConfDir, err := configDir()

if err != nil {

return err

}

err = ensureDir(localConfDir)

if err != nil {

return err

}

var remoteSettingsDir = "~/.local/share/code-server/User/"

if runtime.GOOS == "windows" {

remoteSettingsDir = ".local/share/code-server/User/"

}

var (

src = localConfDir + "/"

dest = host + ":" + remoteSettingsDir

)

if back {

dest, src = src, dest

}

// Append "/" to have rsync copy the contents of the dir.

return rsync(src, dest, sshFlags, "workspaceStorage", "logs", "CachedData")

}

func syncExtensions(sshFlags string, host string, back bool) error {

localExtensionsDir, err := extensionsDir()

if err != nil {

return err

}

err = ensureDir(localExtensionsDir)

if err != nil {

return err

}

var remoteExtensionsDir = "~/.local/share/code-server/extensions/"

if runtime.GOOS == "windows" {

remoteExtensionsDir = ".local/share/code-server/extensions/"

}

var (

src = localExtensionsDir + "/"

dest = host + ":" + remoteExtensionsDir

)

if back {

dest, src = src, dest

}

return rsync(src, dest, sshFlags)

}

func rsync(src string, dest string, sshFlags string, excludePaths ...string) error {

excludeFlags := make([]string, len(excludePaths))

for i, path := range excludePaths {

excludeFlags[i] = "--exclude=" + path

}

cmd := exec.Command("rsync", append(excludeFlags, "-azvr",

"-e", "ssh "+sshFlags,

// Only update newer directories, and sync times

// to keep things simple.

"-u", "--times",

// This is more unsafe, but it's obnoxious having to enter VS Code

// locally in order to properly delete an extension.

"--delete",

"--copy-unsafe-links",

"-zz",

src, dest,

)...,

)

cmd.Stdout = os.Stdout

cmd.Stderr = os.Stderr

err := cmd.Run()

if err != nil {

return xerrors.Errorf("failed to rsync '%s' to '%s': %w", src, dest, err)

}

return nil

}

type release struct {

Assets []asset `json:"assets"`

}

type asset struct {

DownloadURL string `json:"browser_download_url"`

}

func downloadScript(codeServerDir string) (string, error) {

url := "https://api.github.com/repos/cdr/code-server/releases/latest"

req, err := http.Get(url)

if err != nil {

return "", err

}

defer req.Body.Close()

data := release{}

json.NewDecoder(req.Body).Decode(&data)

var downloadURL string

for _, asset := range data.Assets {

if strings.Contains(asset.DownloadURL, "linux-amd64") {

downloadURL = asset.DownloadURL

}

archiveName := downloadURL[strings.LastIndex(downloadURL, "/")+1:]

assetName := strings.TrimSuffix(archiveName, ".tar.gz")

return fmt.Sprintf(

`set -euxo pipefail || exit 1

[ "$(uname -m)" != "x86_64" ] && echo "Unsupported server architecture $(uname -m). code-server only has releases for x86_64 systems." && exit 1

pkill -f %v || true

mkdir -p %v

cd %v

if [ ! -d %v ]; then

curl -L %v > release.tar.gz

tar -xzf release.tar.gz

rm release.tar.gz

ln -sf ./%v/bin/code-server code-server`,

codeServerDir,

assetName,

downloadURL,

assetName,

), nil

}

// ensureDir creates a directory if it does not exist.

func ensureDir(path string) error {

_, err := os.Stat(path)

if os.IsNotExist(err) {

// This fixes a issue where Go reads `/c/` as `C:\c\` and creates

// empty directories on the client that don't need to exist.

if runtime.GOOS == "windows" && strings.HasPrefix(path, "/c/") {

path = "C:" + path[2:]

}

err = os.MkdirAll(path, 0750)

}

if err != nil {

return err

}

return nil

}

// validateIsFile tries to stat the specified path and ensure it's a file.

func validateIsFile(path string) error {

info, err := os.Stat(path)

if err != nil {

return err

}

if info.IsDir() {

return xerrors.New("path is a directory")

}

return nil

}

// parseHost parses the host argument. If 'gcp:' is prefixed to the

// host then a lookup is done using gcloud to determine the external IP and any

// additional SSH arguments that should be used for ssh commands. Otherwise, host

// is returned.

func parseHost(host string) (parsedHost string, additionalFlags string, err error) {

host = strings.TrimSpace(host)

switch {

case strings.HasPrefix(host, "gcp:"):

instance := strings.TrimPrefix(host, "gcp:")

return parseGCPSSHCmd(instance)

default:

return host, "", nil

}

// parseGCPSSHCmd parses the IP address and flags used by 'gcloud' when

// ssh'ing to an instance.

func parseGCPSSHCmd(instance string) (ip, sshFlags string, err error) {

dryRunCmd := fmt.Sprintf("gcloud compute ssh --dry-run %v", instance)

out, err := exec.Command("sh", "-l", "-c", dryRunCmd).CombinedOutput()

if err != nil {

return "", "", xerrors.Errorf("%s: %w", out, err)

}

toks := strings.Split(string(out), " ")

if len(toks) < 2 {

return "", "", xerrors.Errorf("unexpected output for '%v' command, %s", dryRunCmd, out)

}

// Slice off the '/usr/bin/ssh' prefix and the '<user>@<ip>' suffix.

sshFlags = strings.Join(toks[1:len(toks)-1], " ")

// E.g. foo@1.2.3.4.

userIP := toks[len(toks)-1]

return strings.TrimSpace(userIP), sshFlags, nil

}

// gitbashWindowsDir strips a the msys2 install directory from the beginning of

// the path. On msys2, if a user provides `/workspace` sshcode will receive

// `C:/msys64/workspace` which won't work on the remote host.

func gitbashWindowsDir(dir string) string {

// Don't bother figuring out path if it's relative to home dir.

if strings.HasPrefix(dir, "~/") {

if dir == "~" {

return "~/"

}

return dir

}

mingwPrefix, err := exec.Command("sh", "-c", "{ cd / && pwd -W; }").Output()

if err != nil {

// Default to a sane location.

mingwPrefix = []byte("C:/mingw64")

}

prefix := strings.TrimSuffix(string(mingwPrefix), "/\n")

return strings.TrimPrefix(dir, prefix)

}

sshcode/sshcode.go at master · Merith-TK/sshcode · GitHub

Repository navigation

Expand file tree

Breadcrumbs

sshcode.go

Latest commit

History

Breadcrumbs

sshcode.go

File metadata and controls