Golang label.Relabel函數代碼示例

func (m *Mount) bindMount(rootfs, mountLabel string) error {
	var (
		flags = syscall.MS_BIND | syscall.MS_REC
		dest  = filepath.Join(rootfs, m.Destination)
	)

	if !m.Writable {
		flags = flags | syscall.MS_RDONLY
	}

	if m.Slave {
		flags = flags | syscall.MS_SLAVE
	}

	stat, err := os.Stat(m.Source)
	if err != nil {
		return err
	}

	// FIXME: (crosbymichael) This does not belong here and should be done a layer above
	dest, err = symlink.FollowSymlinkInScope(dest, rootfs)
	if err != nil {
		return err
	}

	if err := createIfNotExists(dest, stat.IsDir()); err != nil {
		return fmt.Errorf("creating new bind mount target %s", err)
	}

	if err := syscall.Mount(m.Source, dest, "bind", uintptr(flags), ""); err != nil {
		return fmt.Errorf("mounting %s into %s %s", m.Source, dest, err)
	}

	if !m.Writable {
		if err := syscall.Mount(m.Source, dest, "bind", uintptr(flags|syscall.MS_REMOUNT), ""); err != nil {
			return fmt.Errorf("remounting %s into %s %s", m.Source, dest, err)
		}
	}

	if m.Relabel != "" {
		if err := label.Relabel(m.Source, mountLabel, m.Relabel); err != nil {
			return fmt.Errorf("relabeling %s to %s %s", m.Source, mountLabel, err)
		}
	}

	if m.Private {
		if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
			return fmt.Errorf("mounting %s private %s", dest, err)
		}
	}

	return nil
}

func setupBindmounts(rootfs string, mountConfig *MountConfig) error {
	bindMounts := mountConfig.Mounts
	for _, m := range bindMounts.OfType("bind") {
		var (
			flags = syscall.MS_BIND | syscall.MS_REC
			dest  = filepath.Join(rootfs, m.Destination)
		)
		if !m.Writable {
			flags = flags | syscall.MS_RDONLY
		}

		stat, err := os.Stat(m.Source)
		if err != nil {
			return err
		}

		dest, err = symlink.FollowSymlinkInScope(dest, rootfs)
		if err != nil {
			return err
		}

		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return fmt.Errorf("Creating new bind-mount target, %s", err)
		}

		if err := syscall.Mount(m.Source, dest, "bind", uintptr(flags), ""); err != nil {
			return fmt.Errorf("mounting %s into %s %s", m.Source, dest, err)
		}
		if !m.Writable {
			if err := syscall.Mount(m.Source, dest, "bind", uintptr(flags|syscall.MS_REMOUNT), ""); err != nil {
				return fmt.Errorf("remounting %s into %s %s", m.Source, dest, err)
			}
		}
		if m.Relabel != "" {
			if err := label.Relabel(m.Source, mountConfig.MountLabel, m.Relabel); err != nil {
				return fmt.Errorf("relabeling %s to %s %s", m.Source, mountConfig.MountLabel, err)
			}
		}
		if m.Private {
			if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return fmt.Errorf("mounting %s private %s", dest, err)
			}
		}
	}
	return nil
}

func (d *Driver) Create(id, parent string) error {
	dir := d.dir(id)
	if err := os.MkdirAll(path.Dir(dir), 0700); err != nil {
		return err
	}
	if err := os.Mkdir(dir, 0755); err != nil {
		return err
	}
	opts := []string{"level:s0"}
	if _, mountLabel, err := label.InitLabels(opts); err == nil {
		label.Relabel(dir, mountLabel, "")
	}
	if parent == "" {
		return nil
	}
	parentDir, err := d.Get(parent, "")
	if err != nil {
		return fmt.Errorf("%s: %s", parent, err)
	}
	if err := chrootarchive.CopyWithTar(parentDir, dir); err != nil {
		return err
	}
	return nil
}

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
		data = label.FormatMountLabel(m.Data, mountLabel)
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
	case "mqueue":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), ""); err != nil {
			return err
		}
		return label.SetFileLabel(dest, mountLabel)
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
				return err
			}
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags|syscall.MS_REMOUNT), ""); err != nil {
				return err
			}
		}
		if m.Relabel != "" {
			if err := label.Relabel(m.Source, mountLabel, m.Relabel); err != nil {
				return err
			}
		}
		if m.Flags&syscall.MS_PRIVATE != 0 {
			if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return err
			}
		}
	case "cgroup":
		mounts, err := cgroups.GetCgroupMounts()
		if err != nil {
			return err
		}
		var binds []*configs.Mount
		for _, mm := range mounts {
			dir, err := mm.GetThisCgroupDir()
			if err != nil {
				return err
			}
			binds = append(binds, &configs.Mount{
				Device:      "bind",
				Source:      filepath.Join(mm.Mountpoint, dir),
				Destination: filepath.Join(m.Destination, strings.Join(mm.Subsystems, ",")),
				Flags:       syscall.MS_BIND | syscall.MS_REC | syscall.MS_RDONLY,
			})
		}
//.........這裏部分代碼省略.........

// registerMountPoints initializes the container mount points with the configured volumes and bind mounts.
// It follows the next sequence to decide what to mount in each final destination:
//
// 1. Select the previously configured mount points for the containers, if any.
// 2. Select the volumes mounted from another containers. Overrides previously configured mount point destination.
// 3. Select the bind mounts set by the client. Overrides previously configured mount point destinations.
func (daemon *Daemon) registerMountPoints(container *Container, hostConfig *runconfig.HostConfig) error {
	binds := map[string]bool{}
	mountPoints := map[string]*mountPoint{}

	// 1. Read already configured mount points.
	for name, point := range container.MountPoints {
		mountPoints[name] = point
	}

	// 2. Read volumes from other containers.
	for _, v := range hostConfig.VolumesFrom {
		containerID, mode, err := parseVolumesFrom(v)
		if err != nil {
			return err
		}

		c, err := daemon.Get(containerID)
		if err != nil {
			return err
		}

		for _, m := range c.MountPoints {
			cp := m
			cp.RW = m.RW && mode != "ro"

			if len(m.Source) == 0 {
				v, err := createVolume(m.Name, m.Driver)
				if err != nil {
					return err
				}
				cp.Volume = v
			}

			mountPoints[cp.Destination] = cp
		}
	}

	// 3. Read bind mounts
	for _, b := range hostConfig.Binds {
		// #10618
		bind, err := parseBindMount(b, container.MountLabel, container.Config)
		if err != nil {
			return err
		}

		if binds[bind.Destination] {
			return fmt.Errorf("Duplicate bind mount %s", bind.Destination)
		}

		if len(bind.Name) > 0 && len(bind.Driver) > 0 {
			// create the volume
			v, err := createVolume(bind.Name, bind.Driver)
			if err != nil {
				return err
			}
			bind.Volume = v
			bind.Source = v.Path()
			// Since this is just a named volume and not a typical bind, set to shared mode `z`
			if bind.Relabel == "" {
				bind.Relabel = "z"
			}
		}

		if err := label.Relabel(bind.Source, container.MountLabel, bind.Relabel); err != nil {
			return err
		}
		binds[bind.Destination] = true
		mountPoints[bind.Destination] = bind
	}

	// Keep backwards compatible structures
	bcVolumes := map[string]string{}
	bcVolumesRW := map[string]bool{}
	for _, m := range mountPoints {
		if m.BackwardsCompatible() {
			bcVolumes[m.Destination] = m.Path()
			bcVolumesRW[m.Destination] = m.RW
		}
	}

	container.Lock()
	container.MountPoints = mountPoints
	container.Volumes = bcVolumes
	container.VolumesRW = bcVolumesRW
	container.Unlock()

	return nil
}

// Create creates a new container from the given configuration with a given name.
func (daemon *Daemon) Create(config *runconfig.Config, hostConfig *runconfig.HostConfig, name string) (*Container, []string, error) {
	var (
		container *Container
		warnings  []string
		img       *image.Image
		imgID     string
		err       error
	)

	if config.Image != "" {
		img, err = daemon.repositories.LookupImage(config.Image)
		if err != nil {
			return nil, nil, err
		}
		if err = img.CheckDepth(); err != nil {
			return nil, nil, err
		}
		imgID = img.ID
	}

	if err := daemon.mergeAndVerifyConfig(config, img); err != nil {
		return nil, nil, err
	}
	if !config.NetworkDisabled && daemon.SystemConfig().IPv4ForwardingDisabled {
		warnings = append(warnings, "IPv4 forwarding is disabled.")
	}
	if hostConfig == nil {
		hostConfig = &runconfig.HostConfig{}
	}
	if hostConfig.SecurityOpt == nil {
		hostConfig.SecurityOpt, err = daemon.GenerateSecurityOpt(hostConfig.IpcMode, hostConfig.PidMode)
		if err != nil {
			return nil, nil, err
		}
	}
	if container, err = daemon.newContainer(name, config, imgID); err != nil {
		return nil, nil, err
	}
	if err := daemon.Register(container); err != nil {
		return nil, nil, err
	}
	if err := daemon.createRootfs(container); err != nil {
		return nil, nil, err
	}
	if err := daemon.setHostConfig(container, hostConfig); err != nil {
		return nil, nil, err
	}
	if err := container.Mount(); err != nil {
		return nil, nil, err
	}
	defer container.Unmount()

	for spec := range config.Volumes {
		var (
			name, destination string
			parts             = strings.Split(spec, ":")
		)
		switch len(parts) {
		case 2:
			name, destination = parts[0], filepath.Clean(parts[1])
		default:
			name = stringid.GenerateRandomID()
			destination = filepath.Clean(parts[0])
		}
		// Skip volumes for which we already have something mounted on that
		// destination because of a --volume-from.
		if container.isDestinationMounted(destination) {
			continue
		}
		path, err := container.GetResourcePath(destination)
		if err != nil {
			return nil, nil, err
		}

		stat, err := os.Stat(path)
		if err == nil && !stat.IsDir() {
			return nil, nil, fmt.Errorf("cannot mount volume over existing file, file exists %s", path)
		}

		v, err := createVolume(name, config.VolumeDriver)
		if err != nil {
			return nil, nil, err
		}
		if err := label.Relabel(v.Path(), container.MountLabel, "z"); err != nil {
			return nil, nil, err
		}

		if err := container.copyImagePathContent(v, destination); err != nil {
			return nil, nil, err
		}

		container.addMountPointWithVolume(destination, v, true)
	}
	if err := container.ToDisk(); err != nil {
		return nil, nil, err
	}
	return container, warnings, nil
}

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
		data = label.FormatMountLabel(m.Data, mountLabel)
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "mqueue", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
				return err
			}
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags|syscall.MS_REMOUNT), ""); err != nil {
				return err
			}
		}
		if m.Relabel != "" {
			if err := label.Relabel(m.Source, mountLabel, m.Relabel); err != nil {
				return err
			}
		}
		if m.Flags&syscall.MS_PRIVATE != 0 {
			if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return err
			}
		}
	default:
		return fmt.Errorf("unknown mount device %q to %q", m.Device, m.Destination)
	}
	return nil
}

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
		data = label.FormatMountLabel(m.Data, mountLabel)
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "mqueue", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
				return err
			}
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags|syscall.MS_REMOUNT), ""); err != nil {
				return err
			}
		}
		if m.Relabel != "" {
			if err := label.Relabel(m.Source, mountLabel, m.Relabel); err != nil {
				return err
			}
		}
		if m.Flags&syscall.MS_PRIVATE != 0 {
			if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return err
			}
		}
	default:
		return fmt.Errorf("unknown mount device %q to %q", m.Device, m.Destination)
	}
	return nil
}

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
		data = label.FormatMountLabel(m.Data, mountLabel)
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
	case "mqueue":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), ""); err != nil {
			return err
		}
		return label.SetFileLabel(dest, mountLabel)
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
				return err
			}
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags|syscall.MS_REMOUNT), ""); err != nil {
				return err
			}
		}
		if m.Relabel != "" {
			if err := label.Relabel(m.Source, mountLabel, m.Relabel); err != nil {
				return err
			}
		}
		if m.Flags&syscall.MS_PRIVATE != 0 {
			if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return err
			}
		}
	case "cgroup":
		mounts, err := cgroups.GetCgroupMounts()
		if err != nil {
			return err
		}
		var binds []*configs.Mount
		for _, mm := range mounts {
			dir, err := mm.GetThisCgroupDir()
			if err != nil {
				return err
			}
			binds = append(binds, &configs.Mount{
				Device:      "bind",
				Source:      filepath.Join(mm.Mountpoint, dir),
				Destination: filepath.Join(m.Destination, strings.Join(mm.Subsystems, ",")),
				Flags:       syscall.MS_BIND | syscall.MS_REC | syscall.MS_RDONLY,
			})
		}
		tmpfs := &configs.Mount{
			Device:      "tmpfs",
			Destination: m.Destination,
			Flags:       syscall.MS_NOEXEC | syscall.MS_NOSUID | syscall.MS_NODEV,
		}
		if err := mountToRootfs(tmpfs, rootfs, mountLabel); err != nil {
			return err
		}
		for _, b := range binds {
			if err := mountToRootfs(b, rootfs, mountLabel); err != nil {
//.........這裏部分代碼省略.........