Golang os.Symlink函数代码示例

// TestRunDeviceSymlink checks run with device that follows symlink (#13840)
func (s *DockerSuite) TestRunDeviceSymlink(c *check.C) {
	testRequires(c, DaemonIsLinux, NotUserNamespace, NotArm, SameHostDaemon)
	if _, err := os.Stat("/dev/zero"); err != nil {
		c.Skip("Host does not have /dev/zero")
	}

	// Create a temporary directory to create symlink
	tmpDir, err := ioutil.TempDir("", "docker_device_follow_symlink_tests")
	c.Assert(err, checker.IsNil)

	defer os.RemoveAll(tmpDir)

	// Create a symbolic link to /dev/zero
	symZero := filepath.Join(tmpDir, "zero")
	err = os.Symlink("/dev/zero", symZero)
	c.Assert(err, checker.IsNil)

	// Create a temporary file "temp" inside tmpDir, write some data to "tmpDir/temp",
	// then create a symlink "tmpDir/file" to the temporary file "tmpDir/temp".
	tmpFile := filepath.Join(tmpDir, "temp")
	err = ioutil.WriteFile(tmpFile, []byte("temp"), 0666)
	c.Assert(err, checker.IsNil)
	symFile := filepath.Join(tmpDir, "file")
	err = os.Symlink(tmpFile, symFile)
	c.Assert(err, checker.IsNil)

	// md5sum of 'dd if=/dev/zero bs=4K count=8' is bb7df04e1b0a2570657527a7e108ae23
	out, _ := dockerCmd(c, "run", "--device", symZero+":/dev/symzero", "busybox", "sh", "-c", "dd if=/dev/symzero bs=4K count=8 | md5sum")
	c.Assert(strings.Trim(out, "\r\n"), checker.Contains, "bb7df04e1b0a2570657527a7e108ae23", check.Commentf("expected output bb7df04e1b0a2570657527a7e108ae23"))

	// symlink "tmpDir/file" to a file "tmpDir/temp" will result in an error as it is not a device.
	out, _, err = dockerCmdWithError("run", "--device", symFile+":/dev/symzero", "busybox", "sh", "-c", "dd if=/dev/symzero bs=4K count=8 | md5sum")
	c.Assert(err, check.NotNil)
	c.Assert(strings.Trim(out, "\r\n"), checker.Contains, "not a device node", check.Commentf("expected output 'not a device node'"))
}

func main() {

	flag.Parse()
	if randomDelay != nil && *randomDelay != "" {
		if dur, err := time.ParseDuration(*randomDelay); err != nil {
			log.Fatalf("Cannot parse duration '%s': %v", randomDelay, err)
		} else {
			rdur := time.Duration(randInt64(dur.Nanoseconds()))
			log.Printf("Waiting for %s of %s", rdur.String(), dur.String())
			time.Sleep(rdur)
		}
	}

	log.Printf("Updating geoip database at %s from %s via %s", *directory, *sourceHost, *protocol)
	if err := getClientIp(); err != nil {
		log.Fatalf("Can't get client IP: %v", err)
	}
	for _, p := range strings.Split(*productIds, ",") {
		getProduct(p)
	}
	if *dolinks {
		log.Printf("Making legacy links in %s", *directory)
		os.Symlink(path.Join(*directory, "GeoLiteCity.dat"), path.Join(*directory, "GeoIPCity.dat"))
		os.Symlink(path.Join(*directory, "GeoLiteCountry.dat"), path.Join(*directory, "GeoIP.dat"))
	}
	log.Printf("Done\n")
}

func TestCreationChecks(t *testing.T) {
	wd, clean := setup(t)
	defer clean()

	err := os.Mkdir(wd+"/store/foo", 0755)
	CheckSuccess(err)
	os.Symlink(wd+"/ro", wd+"/store/foo/READONLY")
	CheckSuccess(err)

	err = os.Mkdir(wd+"/store/ws2", 0755)
	CheckSuccess(err)
	os.Symlink(wd+"/ro", wd+"/store/ws2/READONLY")
	CheckSuccess(err)

	err = os.Symlink(wd+"/store/foo", wd+"/mnt/config/bar")
	CheckSuccess(err)

	err = os.Symlink(wd+"/store/foo", wd+"/mnt/config/foo")
	code := fuse.ToStatus(err)
	if code != fuse.EBUSY {
		t.Error("Should return EBUSY", err)
	}

	err = os.Symlink(wd+"/store/ws2", wd+"/mnt/config/config")
	code = fuse.ToStatus(err)
	if code != fuse.EINVAL {
		t.Error("Should return EINVAL", err)
	}
}

func (s *BundleSuite) TestExpandToWithBadLink(c *gc.C) {
	charmDir := charmtesting.Charms.ClonedDirPath(c.MkDir(), "dummy")
	badLink := filepath.Join(charmDir, "hooks", "badlink")

	// Symlink targeting a path outside of the charm.
	err := os.Symlink("../../target", badLink)
	c.Assert(err, gc.IsNil)

	bundle := extBundleDir(c, charmDir)
	c.Assert(err, gc.IsNil)

	path := filepath.Join(c.MkDir(), "charm")
	err = bundle.ExpandTo(path)
	c.Assert(err, gc.ErrorMatches, `cannot extract "hooks/badlink": symlink "../../target" leads out of scope`)

	// Symlink targeting an absolute path.
	os.Remove(badLink)
	err = os.Symlink("/target", badLink)
	c.Assert(err, gc.IsNil)

	bundle = extBundleDir(c, charmDir)
	c.Assert(err, gc.IsNil)

	path = filepath.Join(c.MkDir(), "charm")
	err = bundle.ExpandTo(path)
	c.Assert(err, gc.ErrorMatches, `cannot extract "hooks/badlink": symlink "/target" is absolute`)
}

func TestCanonicalCircular(t *testing.T) {
	tmp1, err := tmpfile("circular")
	if err != nil {
		t.Fatal(err)
	}
	tmp2, err := tmpfile("circular")
	if err != nil {
		t.Fatal(nonil(err, os.Remove(tmp1)))
	}
	defer removeall(tmp1, tmp2)
	// Symlink tmp1 -> tmp2.
	if err = nonil(os.Remove(tmp1), os.Symlink(tmp2, tmp1)); err != nil {
		t.Fatal(err)
	}
	// Symlnik tmp2 -> tmp1.
	if err = nonil(os.Remove(tmp2), os.Symlink(tmp1, tmp2)); err != nil {
		t.Fatal(err)
	}
	if _, err = canonical(tmp1); err == nil {
		t.Fatalf("want canonical(%q)!=nil", tmp1)
	}
	if _, ok := err.(*os.PathError); !ok {
		t.Fatalf("want canonical(%q)=os.PathError; got %T", tmp1, err)
	}
}

func TestDetectSymlinkedDirectories(t *testing.T) {
	wd, clean := setup(t)
	defer clean()

	err := os.Mkdir(wd+"/backing1", 0755)
	if err != nil {
		t.Fatalf("Mkdir failed: %v", err)
	}

	err = os.Symlink(wd+"/ro", wd+"/backing1/READONLY")
	if err != nil {
		t.Fatalf("Symlink failed: %v", err)
	}

	err = os.Symlink(wd+"/backing1", wd+"/store/backing1")
	if err != nil {
		t.Fatalf("Symlink failed: %v", err)
	}

	scan := wd + "/mnt/config/" + _SCAN_CONFIG
	err = ioutil.WriteFile(scan, []byte("something"), 0644)
	if err != nil {
		t.Error("error writing:", err)
	}

	_, err = os.Lstat(wd + "/mnt/backing1")
	if err != nil {
		t.Fatalf("Lstat failed: %v", err)
	}
}

func (fs *FS) Symlink(target string, linkName string, context *fuse.Context) (code fuse.Status) {
	cryptfs.Debug.Printf("Symlink(\"%s\", \"%s\")", target, linkName)
	if fs.isFiltered(linkName) {
		return fuse.EPERM
	}
	cPath, err := fs.getBackingPath(linkName)
	if err != nil {
		return fuse.ToStatus(err)
	}
	// Old filesystem: symlinks are encrypted like paths (CBC)
	if !fs.args.DirIV {
		cTarget, err := fs.encryptPath(target)
		if err != nil {
			cryptfs.Warn.Printf("Symlink: BUG: we should not get an error here: %v", err)
			return fuse.ToStatus(err)
		}
		err = os.Symlink(cTarget, cPath)
		return fuse.ToStatus(err)
	}
	// Since gocryptfs v0.5 symlinks are encrypted like file contents (GCM)
	cBinTarget := fs.CryptFS.EncryptBlock([]byte(target), 0, nil)
	cTarget := base64.URLEncoding.EncodeToString(cBinTarget)

	err = os.Symlink(cTarget, cPath)
	cryptfs.Debug.Printf("Symlink: os.Symlink(%s, %s) = %v", cTarget, cPath, err)
	return fuse.ToStatus(err)
}

func makeTestDir(t *testing.T) string {
	cwd, err := os.Getwd()
	TestExpectSuccess(t, err)
	AddTestFinalizer(func() {
		TestExpectSuccess(t, os.Chdir(cwd))
	})
	dir := TempDir(t)
	TestExpectSuccess(t, os.Chdir(dir))
	mode := os.FileMode(0755)
	os.Mkdir(cwd, mode) //Don't care about return value.  For some reason CWD is not created by go test on all systems.
	TestExpectSuccess(t, os.Mkdir("a", mode))
	TestExpectSuccess(t, os.Mkdir("a/b", mode))
	TestExpectSuccess(t, os.Mkdir("a/b/c", mode))
	TestExpectSuccess(t, os.Mkdir("a/b/c/d", mode))
	TestExpectSuccess(t, os.Mkdir("a/b/i", mode))
	TestExpectSuccess(t, os.Mkdir("a/b/i/j", mode))
	TestExpectSuccess(t, ioutil.WriteFile("a/b/c/d/e", []byte{}, mode))
	TestExpectSuccess(t, ioutil.WriteFile("a/b/c/f", []byte{}, mode))
	TestExpectSuccess(t, ioutil.WriteFile("a/b/g", []byte{}, mode))
	TestExpectSuccess(t, ioutil.WriteFile("a/b/i/j/k", []byte{}, mode))
	TestExpectSuccess(t, os.Symlink("/bin/bash", "a/b/bash"))
	TestExpectSuccess(t, os.Symlink("../i", "a/b/c/l"))
	TestExpectSuccess(t, os.Symlink("g", "a/b/h"))
	TestExpectSuccess(t, os.Symlink("k", "a/b/i/j/l"))
	TestExpectSuccess(t, os.Symlink("../../g", "a/b/i/j/m"))
	return dir
}

func Symlink(oldname, newname string, overwrite bool) error {
	err := os.Symlink(oldname, newname)
	if err == nil {
		return nil // Success
	}
	if !os.IsExist(err) {
		return err // Failure
	}
	// Failure, file exists
	symbolic := false
	{
		stat, err := os.Lstat(newname)
		if err != nil {
			return err
		}
		symbolic = stat.Mode()&os.ModeSymlink != 0
	}
	if !symbolic {
		return err
	}
	if !overwrite {
		return nil
	}
	err = os.Remove(newname)
	if err != nil {
		return err
	}
	return os.Symlink(oldname, newname)
}

func symlinkDirs() (err error) {
	err = os.RemoveAll(SITE_DIR + "/_posts")
	if err != nil {
		return err
	}
	err = os.RemoveAll(SITE_DIR + "/uploads")
	if err != nil {
		return err
	}

	postsAbs, err := filepath.Abs(POSTS_REPO_DIR + "/posts")
	if err != nil {
		return errors.New("Unable to get absolute path of posts directory")
	}

	uploadsAbs, err := filepath.Abs(POSTS_REPO_DIR + "/uploads")
	if err != nil {
		return errors.New("Unable to get absolute path of uploads directory")
	}
	err = os.Symlink(postsAbs, SITE_DIR+"/_posts")
	if err != nil {
		return err
	}
	err = os.Symlink(uploadsAbs, SITE_DIR+"/uploads")
	if err != nil {
		return err
	}
	return nil
}

func TestGeneralCase(t *testing.T) {
	fn := new(WalkFn)
	root := makeEmptyRoot(t)
	defer os.RemoveAll(root)

	ensure.Nil(t, os.MkdirAll(filepath.Join(root, "a", "a1"), 0755))
	createFile(t, filepath.Join(root, "a", "a1", "1"))

	ensure.Nil(t, os.Mkdir(filepath.Join(root, "b"), 0755))
	createFile(t, filepath.Join(root, "b", "2"))

	ensure.Nil(t, os.Symlink(filepath.Join(root, "b"), filepath.Join(root, "a", "a1", "a2")))

	ensure.Nil(t, os.Symlink(filepath.Join(root, "a", "a1", "1"), filepath.Join(root, "top")))

	ensure.Nil(t, Walk(root, fn.walkFn))

	ensure.DeepEqual(t,
		fn.List,
		[]string{
			root,
			filepath.Join(root, "a"),
			filepath.Join(root, "a", "a1"),
			filepath.Join(root, "a", "a1", "1"),
			filepath.Join(root, "a", "a1", "a2"),
			filepath.Join(root, "a", "a1", "a2", "2"),
			filepath.Join(root, "b"),
			filepath.Join(root, "b", "2"),
			filepath.Join(root, "top"),
		},
	)
}

func (s *BundleSuite) TestExpandToWithBadLink(c *C) {
	charmDir := testing.Charms.ClonedDirPath(c.MkDir(), "dummy")
	badLink := filepath.Join(charmDir, "hooks", "badlink")

	// Symlink targeting a path outside of the charm.
	err := os.Symlink("../../target", badLink)
	c.Assert(err, IsNil)

	bundle, err := charm.ReadBundle(extBundleDir(c, charmDir))
	c.Assert(err, IsNil)

	path := filepath.Join(c.MkDir(), "charm")
	err = bundle.ExpandTo(path)
	c.Assert(err, ErrorMatches, `symlink "hooks/badlink" links out of charm: "../../target"`)

	// Symlink targeting an absolute path.
	os.Remove(badLink)
	err = os.Symlink("/target", badLink)
	c.Assert(err, IsNil)

	bundle, err = charm.ReadBundle(extBundleDir(c, charmDir))
	c.Assert(err, IsNil)

	path = filepath.Join(c.MkDir(), "charm")
	err = bundle.ExpandTo(path)
	c.Assert(err, ErrorMatches, `symlink "hooks/badlink" is absolute: "/target"`)
}

// CopySource copies the source into the HostPath
func (p *Runner) CopySource() error {
	timer := util.NewTimer()
	f := p.formatter

	err := os.MkdirAll(p.options.HostPath(), 0755)
	if err != nil {
		return err
	}

	// Link the path to BuildPath("latest") for easy access
	err = os.RemoveAll(p.options.BuildPath("latest"))
	if err != nil {
		return err
	}
	err = os.Symlink(p.options.HostPath(), p.options.BuildPath("latest"))
	if err != nil {
		return err
	}

	err = os.Symlink(p.ProjectDir(), p.options.HostPath("source"))
	if err != nil {
		return err
	}
	if p.options.Verbose {
		p.logger.Printf(f.Success("Source -> Staging Area", timer.String()))
	}
	return nil
}

// (Un)install symbolic runlevel links
func (s *sysv) manageSymlinks(confPath string, install bool) error {
	var cmd *exec.Cmd

	if _, err := exec.LookPath("chkconfig"); err == nil {
		if install {
			cmd = exec.Command("chkconfig", "--add", s.Name)
		} else {
			cmd = exec.Command("chkconfig", "--del", s.Name)
		}
	} else if _, err := exec.LookPath("update-rc.d"); err == nil {
		if install {
			cmd = exec.Command("update-rc.d", s.Name, "defaults")
		} else {
			cmd = exec.Command("update-rc.d", "-f", s.Name, "remove")
		}
	}

	if cmd != nil {
		if err := cmd.Run(); err != nil {
			return fmt.Errorf("Failed to run %q: %s", strings.Join(cmd.Args, " "), err)
		}
	} else {
		/* Manually install/remove symlinks */
		var base = "/etc"

		/* Debian/ubuntu use /etc/rc[0-6].d; RedHat uses /etc/rc.d/rc[0-6].d */
		if _, err := os.Stat("/etc/rc.d/"); err == nil {
			base = "/etc/rc.d"
		} else if _, err := os.Stat(base + "/rc0.d"); os.IsNotExist(err) {
			fmt.Fprintf(os.Stderr, "FIXME: no suitable rc.d directory found in /etc")
			os.Exit(1)
		}

		for _, i := range strings.Split(defaultStartLevels, "") {
			path := fmt.Sprintf("%s/rc%s.d/S%s%s", base, i, defaultStartPriority, s.Name)
			if install {
				if err := os.Symlink(confPath, path); err != nil {
					return fmt.Errorf("Failed to create startup link %s: %s", path, err)
				}
			} else {
				if err := os.Remove(path); err != nil {
					return fmt.Errorf("Failed to remove startup link %s: %s", path, err)
				}
			}
		}
		for _, i := range strings.Split(defaultStopLevels, "") {
			path := fmt.Sprintf("%s/rc%s.d/K%s%s", base, i, defaultStopPriority, s.Name)
			if install {
				if err := os.Symlink(confPath, path); err != nil {
					return fmt.Errorf("Failed to create shutdown link %s: %s", path, err)
				}
			} else {
				if err := os.Remove(path); err != nil {
					return fmt.Errorf("Failed to remove shutdown link %s: %s", path, err)
				}
			}
		}
	}
	return nil
}

// Add creates a symlink in the SRCLIBPATH so that the toolchain in dir is
// available at the toolchainPath.
func Add(dir, toolchainPath string, opt *AddOpt) error {
	if opt == nil {
		opt = &AddOpt{}
	}
	if !opt.Force {
		if _, err := Lookup(toolchainPath); !os.IsNotExist(err) {
			return fmt.Errorf("a toolchain already exists at toolchain path %q", toolchainPath)
		}
	}

	absDir, err := filepath.Abs(dir)
	if err != nil {
		return err
	}

	srclibpathEntry := strings.SplitN(srclib.Path, ":", 2)[0]
	targetDir := filepath.Join(srclibpathEntry, toolchainPath)

	if err := os.MkdirAll(filepath.Dir(targetDir), 0700); err != nil {
		return err
	}

	if !opt.Force {
		return os.Symlink(absDir, targetDir)
	}
	// Force install the toolchain by removing the directory if
	// the symlink fails, and then try the symlink again.
	if err := os.Symlink(absDir, targetDir); err != nil {
		if err := os.RemoveAll(targetDir); err != nil {
			return err
		}
		return os.Symlink(absDir, targetDir)
	}
	return nil
}