github.com/c12o16h1/go/src@v0.0.0-20200114212001-5a151c0f00ed/syscall/exec_linux_test.go (about) 1 // Copyright 2015 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build linux 6 7 package syscall_test 8 9 import ( 10 "flag" 11 "fmt" 12 "github.com/c12o16h1/go/src/internal/testenv" 13 "io" 14 "io/ioutil" 15 "os" 16 "os/exec" 17 "os/user" 18 "path/filepath" 19 "runtime" 20 "strconv" 21 "strings" 22 "syscall" 23 "testing" 24 "unsafe" 25 ) 26 27 func isDocker() bool { 28 _, err := os.Stat("/.dockerenv") 29 return err == nil 30 } 31 32 func isLXC() bool { 33 return os.Getenv("container") == "lxc" 34 } 35 36 func skipInContainer(t *testing.T) { 37 // TODO: the callers of this func are using this func to skip 38 // tests when running as some sort of "fake root" that's uid 0 39 // but lacks certain Linux capabilities. Most of the Go builds 40 // run in privileged containers, though, where root is much 41 // closer (if not identical) to the real root. We should test 42 // for what we need exactly (which capabilities are active?), 43 // instead of just assuming "docker == bad". Then we'd get more test 44 // coverage on a bunch of builders too. 45 if isDocker() { 46 t.Skip("skip this test in Docker container") 47 } 48 if isLXC() { 49 t.Skip("skip this test in LXC container") 50 } 51 } 52 53 func skipNoUserNamespaces(t *testing.T) { 54 if _, err := os.Stat("/proc/self/ns/user"); err != nil { 55 if os.IsNotExist(err) { 56 t.Skip("kernel doesn't support user namespaces") 57 } 58 if os.IsPermission(err) { 59 t.Skip("unable to test user namespaces due to permissions") 60 } 61 t.Fatalf("Failed to stat /proc/self/ns/user: %v", err) 62 } 63 } 64 65 func skipUnprivilegedUserClone(t *testing.T) { 66 // Skip the test if the sysctl that prevents unprivileged user 67 // from creating user namespaces is enabled. 68 data, errRead := ioutil.ReadFile("/proc/sys/kernel/unprivileged_userns_clone") 69 if errRead != nil || len(data) < 1 || data[0] == '0' { 70 t.Skip("kernel prohibits user namespace in unprivileged process") 71 } 72 } 73 74 // Check if we are in a chroot by checking if the inode of / is 75 // different from 2 (there is no better test available to non-root on 76 // linux). 77 func isChrooted(t *testing.T) bool { 78 root, err := os.Stat("/") 79 if err != nil { 80 t.Fatalf("cannot stat /: %v", err) 81 } 82 return root.Sys().(*syscall.Stat_t).Ino != 2 83 } 84 85 func checkUserNS(t *testing.T) { 86 skipInContainer(t) 87 skipNoUserNamespaces(t) 88 if isChrooted(t) { 89 // create_user_ns in the kernel (see 90 // https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/kernel/user_namespace.c) 91 // forbids the creation of user namespaces when chrooted. 92 t.Skip("cannot create user namespaces when chrooted") 93 } 94 // On some systems, there is a sysctl setting. 95 if os.Getuid() != 0 { 96 skipUnprivilegedUserClone(t) 97 } 98 // On Centos 7 make sure they set the kernel parameter user_namespace=1 99 // See issue 16283 and 20796. 100 if _, err := os.Stat("/sys/module/user_namespace/parameters/enable"); err == nil { 101 buf, _ := ioutil.ReadFile("/sys/module/user_namespace/parameters/enabled") 102 if !strings.HasPrefix(string(buf), "Y") { 103 t.Skip("kernel doesn't support user namespaces") 104 } 105 } 106 107 // On Centos 7.5+, user namespaces are disabled if user.max_user_namespaces = 0 108 if _, err := os.Stat("/proc/sys/user/max_user_namespaces"); err == nil { 109 buf, errRead := ioutil.ReadFile("/proc/sys/user/max_user_namespaces") 110 if errRead == nil && buf[0] == '0' { 111 t.Skip("kernel doesn't support user namespaces") 112 } 113 } 114 115 // When running under the Go continuous build, skip tests for 116 // now when under Kubernetes. (where things are root but not quite) 117 // Both of these are our own environment variables. 118 // See Issue 12815. 119 if os.Getenv("GO_BUILDER_NAME") != "" && os.Getenv("IN_KUBERNETES") == "1" { 120 t.Skip("skipping test on Kubernetes-based builders; see Issue 12815") 121 } 122 } 123 124 func whoamiCmd(t *testing.T, uid, gid int, setgroups bool) *exec.Cmd { 125 checkUserNS(t) 126 cmd := exec.Command("whoami") 127 cmd.SysProcAttr = &syscall.SysProcAttr{ 128 Cloneflags: syscall.CLONE_NEWUSER, 129 UidMappings: []syscall.SysProcIDMap{ 130 {ContainerID: 0, HostID: uid, Size: 1}, 131 }, 132 GidMappings: []syscall.SysProcIDMap{ 133 {ContainerID: 0, HostID: gid, Size: 1}, 134 }, 135 GidMappingsEnableSetgroups: setgroups, 136 } 137 return cmd 138 } 139 140 func testNEWUSERRemap(t *testing.T, uid, gid int, setgroups bool) { 141 cmd := whoamiCmd(t, uid, gid, setgroups) 142 out, err := cmd.CombinedOutput() 143 if err != nil { 144 t.Fatalf("Cmd failed with err %v, output: %s", err, out) 145 } 146 sout := strings.TrimSpace(string(out)) 147 want := "root" 148 if sout != want { 149 t.Fatalf("whoami = %q; want %q", out, want) 150 } 151 } 152 153 func TestCloneNEWUSERAndRemapRootDisableSetgroups(t *testing.T) { 154 if os.Getuid() != 0 { 155 t.Skip("skipping root only test") 156 } 157 testNEWUSERRemap(t, 0, 0, false) 158 } 159 160 func TestCloneNEWUSERAndRemapRootEnableSetgroups(t *testing.T) { 161 if os.Getuid() != 0 { 162 t.Skip("skipping root only test") 163 } 164 testNEWUSERRemap(t, 0, 0, true) 165 } 166 167 func TestCloneNEWUSERAndRemapNoRootDisableSetgroups(t *testing.T) { 168 if os.Getuid() == 0 { 169 t.Skip("skipping unprivileged user only test") 170 } 171 testNEWUSERRemap(t, os.Getuid(), os.Getgid(), false) 172 } 173 174 func TestCloneNEWUSERAndRemapNoRootSetgroupsEnableSetgroups(t *testing.T) { 175 if os.Getuid() == 0 { 176 t.Skip("skipping unprivileged user only test") 177 } 178 cmd := whoamiCmd(t, os.Getuid(), os.Getgid(), true) 179 err := cmd.Run() 180 if err == nil { 181 t.Skip("probably old kernel without security fix") 182 } 183 if !os.IsPermission(err) { 184 t.Fatalf("Unprivileged gid_map rewriting with GidMappingsEnableSetgroups must fail") 185 } 186 } 187 188 func TestEmptyCredGroupsDisableSetgroups(t *testing.T) { 189 cmd := whoamiCmd(t, os.Getuid(), os.Getgid(), false) 190 cmd.SysProcAttr.Credential = &syscall.Credential{} 191 if err := cmd.Run(); err != nil { 192 t.Fatal(err) 193 } 194 } 195 196 func TestUnshare(t *testing.T) { 197 skipInContainer(t) 198 // Make sure we are running as root so we have permissions to use unshare 199 // and create a network namespace. 200 if os.Getuid() != 0 { 201 t.Skip("kernel prohibits unshare in unprivileged process, unless using user namespace") 202 } 203 204 // When running under the Go continuous build, skip tests for 205 // now when under Kubernetes. (where things are root but not quite) 206 // Both of these are our own environment variables. 207 // See Issue 12815. 208 if os.Getenv("GO_BUILDER_NAME") != "" && os.Getenv("IN_KUBERNETES") == "1" { 209 t.Skip("skipping test on Kubernetes-based builders; see Issue 12815") 210 } 211 212 path := "/proc/net/dev" 213 if _, err := os.Stat(path); err != nil { 214 if os.IsNotExist(err) { 215 t.Skip("kernel doesn't support proc filesystem") 216 } 217 if os.IsPermission(err) { 218 t.Skip("unable to test proc filesystem due to permissions") 219 } 220 t.Fatal(err) 221 } 222 if _, err := os.Stat("/proc/self/ns/net"); err != nil { 223 if os.IsNotExist(err) { 224 t.Skip("kernel doesn't support net namespace") 225 } 226 t.Fatal(err) 227 } 228 229 orig, err := ioutil.ReadFile(path) 230 if err != nil { 231 t.Fatal(err) 232 } 233 origLines := strings.Split(strings.TrimSpace(string(orig)), "\n") 234 235 cmd := exec.Command("cat", path) 236 cmd.SysProcAttr = &syscall.SysProcAttr{ 237 Unshareflags: syscall.CLONE_NEWNET, 238 } 239 out, err := cmd.CombinedOutput() 240 if err != nil { 241 if strings.Contains(err.Error(), "operation not permitted") { 242 // Issue 17206: despite all the checks above, 243 // this still reportedly fails for some users. 244 // (older kernels?). Just skip. 245 t.Skip("skipping due to permission error") 246 } 247 t.Fatalf("Cmd failed with err %v, output: %s", err, out) 248 } 249 250 // Check there is only the local network interface 251 sout := strings.TrimSpace(string(out)) 252 if !strings.Contains(sout, "lo:") { 253 t.Fatalf("Expected lo network interface to exist, got %s", sout) 254 } 255 256 lines := strings.Split(sout, "\n") 257 if len(lines) >= len(origLines) { 258 t.Fatalf("Got %d lines of output, want <%d", len(lines), len(origLines)) 259 } 260 } 261 262 func TestGroupCleanup(t *testing.T) { 263 if os.Getuid() != 0 { 264 t.Skip("we need root for credential") 265 } 266 cmd := exec.Command("id") 267 cmd.SysProcAttr = &syscall.SysProcAttr{ 268 Credential: &syscall.Credential{ 269 Uid: 0, 270 Gid: 0, 271 }, 272 } 273 out, err := cmd.CombinedOutput() 274 if err != nil { 275 t.Fatalf("Cmd failed with err %v, output: %s", err, out) 276 } 277 strOut := strings.TrimSpace(string(out)) 278 expected := "uid=0(root) gid=0(root)" 279 // Just check prefix because some distros reportedly output a 280 // context parameter; see https://golang.org/issue/16224. 281 // Alpine does not output groups; see https://golang.org/issue/19938. 282 if !strings.HasPrefix(strOut, expected) { 283 t.Errorf("id command output: %q, expected prefix: %q", strOut, expected) 284 } 285 } 286 287 func TestGroupCleanupUserNamespace(t *testing.T) { 288 if os.Getuid() != 0 { 289 t.Skip("we need root for credential") 290 } 291 checkUserNS(t) 292 cmd := exec.Command("id") 293 uid, gid := os.Getuid(), os.Getgid() 294 cmd.SysProcAttr = &syscall.SysProcAttr{ 295 Cloneflags: syscall.CLONE_NEWUSER, 296 Credential: &syscall.Credential{ 297 Uid: uint32(uid), 298 Gid: uint32(gid), 299 }, 300 UidMappings: []syscall.SysProcIDMap{ 301 {ContainerID: 0, HostID: uid, Size: 1}, 302 }, 303 GidMappings: []syscall.SysProcIDMap{ 304 {ContainerID: 0, HostID: gid, Size: 1}, 305 }, 306 } 307 out, err := cmd.CombinedOutput() 308 if err != nil { 309 t.Fatalf("Cmd failed with err %v, output: %s", err, out) 310 } 311 strOut := strings.TrimSpace(string(out)) 312 313 // Strings we've seen in the wild. 314 expected := []string{ 315 "uid=0(root) gid=0(root) groups=0(root)", 316 "uid=0(root) gid=0(root) groups=0(root),65534(nobody)", 317 "uid=0(root) gid=0(root) groups=0(root),65534(nogroup)", 318 "uid=0(root) gid=0(root) groups=0(root),65534", 319 "uid=0(root) gid=0(root) groups=0(root),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody),65534(nobody)", // Alpine; see https://golang.org/issue/19938 320 "uid=0(root) gid=0(root) groups=0(root) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023", // CentOS with SELinux context, see https://golang.org/issue/34547 321 } 322 for _, e := range expected { 323 if strOut == e { 324 return 325 } 326 } 327 t.Errorf("id command output: %q, expected one of %q", strOut, expected) 328 } 329 330 // TestUnshareHelperProcess isn't a real test. It's used as a helper process 331 // for TestUnshareMountNameSpace. 332 func TestUnshareMountNameSpaceHelper(*testing.T) { 333 if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" { 334 return 335 } 336 defer os.Exit(0) 337 if err := syscall.Mount("none", flag.Args()[0], "proc", 0, ""); err != nil { 338 fmt.Fprintf(os.Stderr, "unshare: mount %v failed: %v", os.Args, err) 339 os.Exit(2) 340 } 341 } 342 343 // Test for Issue 38471: unshare fails because systemd has forced / to be shared 344 func TestUnshareMountNameSpace(t *testing.T) { 345 skipInContainer(t) 346 // Make sure we are running as root so we have permissions to use unshare 347 // and create a network namespace. 348 if os.Getuid() != 0 { 349 t.Skip("kernel prohibits unshare in unprivileged process, unless using user namespace") 350 } 351 352 d, err := ioutil.TempDir("", "unshare") 353 if err != nil { 354 t.Fatalf("tempdir: %v", err) 355 } 356 357 cmd := exec.Command(os.Args[0], "-test.run=TestUnshareMountNameSpaceHelper", d) 358 cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"} 359 cmd.SysProcAttr = &syscall.SysProcAttr{Unshareflags: syscall.CLONE_NEWNS} 360 361 o, err := cmd.CombinedOutput() 362 if err != nil { 363 if strings.Contains(err.Error(), ": permission denied") { 364 t.Skipf("Skipping test (golang.org/issue/19698); unshare failed due to permissions: %s, %v", o, err) 365 } 366 t.Fatalf("unshare failed: %s, %v", o, err) 367 } 368 369 // How do we tell if the namespace was really unshared? It turns out 370 // to be simple: just try to remove the directory. If it's still mounted 371 // on the rm will fail with EBUSY. Then we have some cleanup to do: 372 // we must unmount it, then try to remove it again. 373 374 if err := os.Remove(d); err != nil { 375 t.Errorf("rmdir failed on %v: %v", d, err) 376 if err := syscall.Unmount(d, syscall.MNT_FORCE); err != nil { 377 t.Errorf("Can't unmount %v: %v", d, err) 378 } 379 if err := os.Remove(d); err != nil { 380 t.Errorf("rmdir after unmount failed on %v: %v", d, err) 381 } 382 } 383 } 384 385 // Test for Issue 20103: unshare fails when chroot is used 386 func TestUnshareMountNameSpaceChroot(t *testing.T) { 387 skipInContainer(t) 388 // Make sure we are running as root so we have permissions to use unshare 389 // and create a network namespace. 390 if os.Getuid() != 0 { 391 t.Skip("kernel prohibits unshare in unprivileged process, unless using user namespace") 392 } 393 394 d, err := ioutil.TempDir("", "unshare") 395 if err != nil { 396 t.Fatalf("tempdir: %v", err) 397 } 398 399 // Since we are doing a chroot, we need the binary there, 400 // and it must be statically linked. 401 x := filepath.Join(d, "syscall.test") 402 cmd := exec.Command(testenv.GoToolPath(t), "test", "-c", "-o", x, "syscall") 403 cmd.Env = append(os.Environ(), "CGO_ENABLED=0") 404 if o, err := cmd.CombinedOutput(); err != nil { 405 t.Fatalf("Build of syscall in chroot failed, output %v, err %v", o, err) 406 } 407 408 cmd = exec.Command("/syscall.test", "-test.run=TestUnshareMountNameSpaceHelper", "/") 409 cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"} 410 cmd.SysProcAttr = &syscall.SysProcAttr{Chroot: d, Unshareflags: syscall.CLONE_NEWNS} 411 412 o, err := cmd.CombinedOutput() 413 if err != nil { 414 if strings.Contains(err.Error(), ": permission denied") { 415 t.Skipf("Skipping test (golang.org/issue/19698); unshare failed due to permissions: %s, %v", o, err) 416 } 417 t.Fatalf("unshare failed: %s, %v", o, err) 418 } 419 420 // How do we tell if the namespace was really unshared? It turns out 421 // to be simple: just try to remove the executable. If it's still mounted 422 // on, the rm will fail. Then we have some cleanup to do: 423 // we must force unmount it, then try to remove it again. 424 425 if err := os.Remove(x); err != nil { 426 t.Errorf("rm failed on %v: %v", x, err) 427 if err := syscall.Unmount(d, syscall.MNT_FORCE); err != nil { 428 t.Fatalf("Can't unmount %v: %v", d, err) 429 } 430 if err := os.Remove(x); err != nil { 431 t.Fatalf("rm failed on %v: %v", x, err) 432 } 433 } 434 435 if err := os.Remove(d); err != nil { 436 t.Errorf("rmdir failed on %v: %v", d, err) 437 } 438 } 439 440 func TestUnshareUidGidMappingHelper(*testing.T) { 441 if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" { 442 return 443 } 444 defer os.Exit(0) 445 if err := syscall.Chroot(os.TempDir()); err != nil { 446 fmt.Fprintln(os.Stderr, err) 447 os.Exit(2) 448 } 449 } 450 451 // Test for Issue 29789: unshare fails when uid/gid mapping is specified 452 func TestUnshareUidGidMapping(t *testing.T) { 453 if os.Getuid() == 0 { 454 t.Skip("test exercises unprivileged user namespace, fails with privileges") 455 } 456 checkUserNS(t) 457 cmd := exec.Command(os.Args[0], "-test.run=TestUnshareUidGidMappingHelper") 458 cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1") 459 cmd.SysProcAttr = &syscall.SysProcAttr{ 460 Unshareflags: syscall.CLONE_NEWNS | syscall.CLONE_NEWUSER, 461 GidMappingsEnableSetgroups: false, 462 UidMappings: []syscall.SysProcIDMap{ 463 { 464 ContainerID: 0, 465 HostID: syscall.Getuid(), 466 Size: 1, 467 }, 468 }, 469 GidMappings: []syscall.SysProcIDMap{ 470 { 471 ContainerID: 0, 472 HostID: syscall.Getgid(), 473 Size: 1, 474 }, 475 }, 476 } 477 out, err := cmd.CombinedOutput() 478 if err != nil { 479 t.Fatalf("Cmd failed with err %v, output: %s", err, out) 480 } 481 } 482 483 type capHeader struct { 484 version uint32 485 pid int32 486 } 487 488 type capData struct { 489 effective uint32 490 permitted uint32 491 inheritable uint32 492 } 493 494 const CAP_SYS_TIME = 25 495 const CAP_SYSLOG = 34 496 497 type caps struct { 498 hdr capHeader 499 data [2]capData 500 } 501 502 func getCaps() (caps, error) { 503 var c caps 504 505 // Get capability version 506 if _, _, errno := syscall.Syscall(syscall.SYS_CAPGET, uintptr(unsafe.Pointer(&c.hdr)), uintptr(unsafe.Pointer(nil)), 0); errno != 0 { 507 return c, fmt.Errorf("SYS_CAPGET: %v", errno) 508 } 509 510 // Get current capabilities 511 if _, _, errno := syscall.Syscall(syscall.SYS_CAPGET, uintptr(unsafe.Pointer(&c.hdr)), uintptr(unsafe.Pointer(&c.data[0])), 0); errno != 0 { 512 return c, fmt.Errorf("SYS_CAPGET: %v", errno) 513 } 514 515 return c, nil 516 } 517 518 func mustSupportAmbientCaps(t *testing.T) { 519 var uname syscall.Utsname 520 if err := syscall.Uname(&uname); err != nil { 521 t.Fatalf("Uname: %v", err) 522 } 523 var buf [65]byte 524 for i, b := range uname.Release { 525 buf[i] = byte(b) 526 } 527 ver := string(buf[:]) 528 if i := strings.Index(ver, "\x00"); i != -1 { 529 ver = ver[:i] 530 } 531 if strings.HasPrefix(ver, "2.") || 532 strings.HasPrefix(ver, "3.") || 533 strings.HasPrefix(ver, "4.1.") || 534 strings.HasPrefix(ver, "4.2.") { 535 t.Skipf("kernel version %q predates required 4.3; skipping test", ver) 536 } 537 } 538 539 // TestAmbientCapsHelper isn't a real test. It's used as a helper process for 540 // TestAmbientCaps. 541 func TestAmbientCapsHelper(*testing.T) { 542 if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" { 543 return 544 } 545 defer os.Exit(0) 546 547 caps, err := getCaps() 548 if err != nil { 549 fmt.Fprintln(os.Stderr, err) 550 os.Exit(2) 551 } 552 if caps.data[0].effective&(1<<uint(CAP_SYS_TIME)) == 0 { 553 fmt.Fprintln(os.Stderr, "CAP_SYS_TIME unexpectedly not in the effective capability mask") 554 os.Exit(2) 555 } 556 if caps.data[1].effective&(1<<uint(CAP_SYSLOG&31)) == 0 { 557 fmt.Fprintln(os.Stderr, "CAP_SYSLOG unexpectedly not in the effective capability mask") 558 os.Exit(2) 559 } 560 } 561 562 func TestAmbientCaps(t *testing.T) { 563 // Make sure we are running as root so we have permissions to use unshare 564 // and create a network namespace. 565 if os.Getuid() != 0 { 566 t.Skip("kernel prohibits unshare in unprivileged process, unless using user namespace") 567 } 568 569 testAmbientCaps(t, false) 570 } 571 572 func TestAmbientCapsUserns(t *testing.T) { 573 checkUserNS(t) 574 testAmbientCaps(t, true) 575 } 576 577 func testAmbientCaps(t *testing.T, userns bool) { 578 skipInContainer(t) 579 mustSupportAmbientCaps(t) 580 581 skipUnprivilegedUserClone(t) 582 583 // skip on android, due to lack of lookup support 584 if runtime.GOOS == "android" { 585 t.Skip("skipping test on android; see Issue 27327") 586 } 587 588 u, err := user.Lookup("nobody") 589 if err != nil { 590 t.Fatal(err) 591 } 592 uid, err := strconv.ParseInt(u.Uid, 0, 32) 593 if err != nil { 594 t.Fatal(err) 595 } 596 gid, err := strconv.ParseInt(u.Gid, 0, 32) 597 if err != nil { 598 t.Fatal(err) 599 } 600 601 // Copy the test binary to a temporary location which is readable by nobody. 602 f, err := ioutil.TempFile("", "gotest") 603 if err != nil { 604 t.Fatal(err) 605 } 606 defer os.Remove(f.Name()) 607 defer f.Close() 608 e, err := os.Open(os.Args[0]) 609 if err != nil { 610 t.Fatal(err) 611 } 612 defer e.Close() 613 if _, err := io.Copy(f, e); err != nil { 614 t.Fatal(err) 615 } 616 if err := f.Chmod(0755); err != nil { 617 t.Fatal(err) 618 } 619 if err := f.Close(); err != nil { 620 t.Fatal(err) 621 } 622 623 cmd := exec.Command(f.Name(), "-test.run=TestAmbientCapsHelper") 624 cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"} 625 cmd.Stdout = os.Stdout 626 cmd.Stderr = os.Stderr 627 cmd.SysProcAttr = &syscall.SysProcAttr{ 628 Credential: &syscall.Credential{ 629 Uid: uint32(uid), 630 Gid: uint32(gid), 631 }, 632 AmbientCaps: []uintptr{CAP_SYS_TIME, CAP_SYSLOG}, 633 } 634 if userns { 635 cmd.SysProcAttr.Cloneflags = syscall.CLONE_NEWUSER 636 const nobody = 65534 637 uid := os.Getuid() 638 gid := os.Getgid() 639 cmd.SysProcAttr.UidMappings = []syscall.SysProcIDMap{{ 640 ContainerID: int(nobody), 641 HostID: int(uid), 642 Size: int(1), 643 }} 644 cmd.SysProcAttr.GidMappings = []syscall.SysProcIDMap{{ 645 ContainerID: int(nobody), 646 HostID: int(gid), 647 Size: int(1), 648 }} 649 650 // Set credentials to run as user and group nobody. 651 cmd.SysProcAttr.Credential = &syscall.Credential{ 652 Uid: nobody, 653 Gid: nobody, 654 } 655 } 656 if err := cmd.Run(); err != nil { 657 t.Fatal(err.Error()) 658 } 659 }