daemon/archive_windows.go
package daemon // import "github.com/docker/docker/daemon"
import (
"errors"
"io"
"os"
"path/filepath"
"strings"
containertypes "github.com/docker/docker/api/types/container"
"github.com/docker/docker/api/types/events"
"github.com/docker/docker/container"
"github.com/docker/docker/errdefs"
"github.com/docker/docker/pkg/archive"
"github.com/docker/docker/pkg/chrootarchive"
"github.com/docker/docker/pkg/ioutils"
)
// containerStatPath stats the filesystem resource at the specified path in this
// container. Returns stat info about the resource.
func (daemon *Daemon) containerStatPath(container *container.Container, path string) (stat *containertypes.PathStat, err error) {
container.Lock()
defer container.Unlock()
// Make sure an online file-system operation is permitted.
if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
return nil, err
}
if err = daemon.Mount(container); err != nil {
return nil, err
}
defer daemon.Unmount(container)
err = daemon.mountVolumes(container)
defer container.DetachAndUnmount(daemon.LogVolumeEvent)
if err != nil {
return nil, err
}
// Normalize path before sending to rootfs
path = filepath.FromSlash(path)
resolvedPath, absPath, err := container.ResolvePath(path)
if err != nil {
return nil, err
}
return container.StatPath(resolvedPath, absPath)
}
// containerArchivePath creates an archive of the filesystem resource at the specified
// path in this container. Returns a tar archive of the resource and stat info
// about the resource.
func (daemon *Daemon) containerArchivePath(container *container.Container, path string) (content io.ReadCloser, stat *containertypes.PathStat, err error) {
container.Lock()
defer func() {
if err != nil {
// Wait to unlock the container until the archive is fully read
// (see the ReadCloseWrapper func below) or if there is an error
// before that occurs.
container.Unlock()
}
}()
// Make sure an online file-system operation is permitted.
if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
return nil, nil, err
}
if err = daemon.Mount(container); err != nil {
return nil, nil, err
}
defer func() {
if err != nil {
// unmount any volumes
container.DetachAndUnmount(daemon.LogVolumeEvent)
// unmount the container's rootfs
daemon.Unmount(container)
}
}()
if err = daemon.mountVolumes(container); err != nil {
return nil, nil, err
}
// Normalize path before sending to rootfs
path = filepath.FromSlash(path)
resolvedPath, absPath, err := container.ResolvePath(path)
if err != nil {
return nil, nil, err
}
stat, err = container.StatPath(resolvedPath, absPath)
if err != nil {
return nil, nil, err
}
// We need to rebase the archive entries if the last element of the
// resolved path was a symlink that was evaluated and is now different
// than the requested path. For example, if the given path was "/foo/bar/",
// but it resolved to "/var/lib/docker/containers/{id}/foo/baz/", we want
// to ensure that the archive entries start with "bar" and not "baz". This
// also catches the case when the root directory of the container is
// requested: we want the archive entries to start with "/" and not the
// container ID.
// Get the source and the base paths of the container resolved path in order
// to get the proper tar options for the rebase tar.
resolvedPath = filepath.Clean(resolvedPath)
if filepath.Base(resolvedPath) == "." {
resolvedPath += string(filepath.Separator) + "."
}
sourceDir := resolvedPath
sourceBase := "."
if stat.Mode&os.ModeDir == 0 { // not dir
sourceDir, sourceBase = filepath.Split(resolvedPath)
}
opts := archive.TarResourceRebaseOpts(sourceBase, filepath.Base(absPath))
data, err := chrootarchive.Tar(sourceDir, opts, container.BaseFS)
if err != nil {
return nil, nil, err
}
content = ioutils.NewReadCloserWrapper(data, func() error {
err := data.Close()
container.DetachAndUnmount(daemon.LogVolumeEvent)
daemon.Unmount(container)
container.Unlock()
return err
})
daemon.LogContainerEvent(container, events.ActionArchivePath)
return content, stat, nil
}
// containerExtractToDir extracts the given tar archive to the specified location in the
// filesystem of this container. The given path must be of a directory in the
// container. If it is not, the error will be an errdefs.InvalidParameter. If
// noOverwriteDirNonDir is true then it will be an error if unpacking the
// given content would cause an existing directory to be replaced with a non-
// directory and vice versa.
func (daemon *Daemon) containerExtractToDir(container *container.Container, path string, copyUIDGID, noOverwriteDirNonDir bool, content io.Reader) (err error) {
container.Lock()
defer container.Unlock()
// Make sure an online file-system operation is permitted.
if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
return err
}
if err = daemon.Mount(container); err != nil {
return err
}
defer daemon.Unmount(container)
err = daemon.mountVolumes(container)
defer container.DetachAndUnmount(daemon.LogVolumeEvent)
if err != nil {
return err
}
// Normalize path before sending to rootfs'
path = filepath.FromSlash(path)
// Check if a drive letter supplied, it must be the system drive. No-op except on Windows
path, err = archive.CheckSystemDriveAndRemoveDriveLetter(path)
if err != nil {
return err
}
// The destination path needs to be resolved to a host path, with all
// symbolic links followed in the scope of the container's rootfs. Note
// that we do not use `container.ResolvePath(path)` here because we need
// to also evaluate the last path element if it is a symlink. This is so
// that you can extract an archive to a symlink that points to a directory.
// Consider the given path as an absolute path in the container.
absPath := archive.PreserveTrailingDotOrSeparator(filepath.Join(string(filepath.Separator), path), path)
// This will evaluate the last path element if it is a symlink.
resolvedPath, err := container.GetResourcePath(absPath)
if err != nil {
return err
}
stat, err := os.Lstat(resolvedPath)
if err != nil {
return err
}
if !stat.IsDir() {
return errdefs.InvalidParameter(errors.New("extraction point is not a directory"))
}
// Need to check if the path is in a volume. If it is, it cannot be in a
// read-only volume. If it is not in a volume, the container cannot be
// configured with a read-only rootfs.
// Use the resolved path relative to the container rootfs as the new
// absPath. This way we fully follow any symlinks in a volume that may
// lead back outside the volume.
//
// The Windows implementation of filepath.Rel in golang 1.4 does not
// support volume style file path semantics. On Windows when using the
// filter driver, we are guaranteed that the path will always be
// a volume file path.
var baseRel string
if strings.HasPrefix(resolvedPath, `\\?\Volume{`) {
if strings.HasPrefix(resolvedPath, container.BaseFS) {
baseRel = resolvedPath[len(container.BaseFS):]
if baseRel[:1] == `\` {
baseRel = baseRel[1:]
}
}
} else {
baseRel, err = filepath.Rel(container.BaseFS, resolvedPath)
}
if err != nil {
return err
}
// Make it an absolute path.
absPath = filepath.Join(string(filepath.Separator), baseRel)
toVolume, err := checkIfPathIsInAVolume(container, absPath)
if err != nil {
return err
}
if !toVolume && container.HostConfig.ReadonlyRootfs {
return errdefs.InvalidParameter(errors.New("container rootfs is marked read-only"))
}
options := daemon.defaultTarCopyOptions(noOverwriteDirNonDir)
if copyUIDGID {
var err error
// tarCopyOptions will appropriately pull in the right uid/gid for the
// user/group and will set the options.
options, err = daemon.tarCopyOptions(container, noOverwriteDirNonDir)
if err != nil {
return err
}
}
if err := chrootarchive.UntarWithRoot(content, resolvedPath, options, container.BaseFS); err != nil {
return err
}
daemon.LogContainerEvent(container, events.ActionExtractToDir)
return nil
}
func (daemon *Daemon) containerCopy(container *container.Container, resource string) (rc io.ReadCloser, err error) {
if resource[0] == '/' || resource[0] == '\\' {
resource = resource[1:]
}
container.Lock()
defer func() {
if err != nil {
// Wait to unlock the container until the archive is fully read
// (see the ReadCloseWrapper func below) or if there is an error
// before that occurs.
container.Unlock()
}
}()
// Make sure an online file-system operation is permitted.
if err := daemon.isOnlineFSOperationPermitted(container); err != nil {
return nil, err
}
if err := daemon.Mount(container); err != nil {
return nil, err
}
defer func() {
if err != nil {
// unmount any volumes
container.DetachAndUnmount(daemon.LogVolumeEvent)
// unmount the container's rootfs
daemon.Unmount(container)
}
}()
if err := daemon.mountVolumes(container); err != nil {
return nil, err
}
// Normalize path before sending to rootfs
resource = filepath.FromSlash(resource)
basePath, err := container.GetResourcePath(resource)
if err != nil {
return nil, err
}
stat, err := os.Stat(basePath)
if err != nil {
return nil, err
}
var filter []string
if !stat.IsDir() {
d, f := filepath.Split(basePath)
basePath = d
filter = []string{f}
}
archv, err := chrootarchive.Tar(basePath, &archive.TarOptions{
Compression: archive.Uncompressed,
IncludeFiles: filter,
}, container.BaseFS)
if err != nil {
return nil, err
}
reader := ioutils.NewReadCloserWrapper(archv, func() error {
err := archv.Close()
container.DetachAndUnmount(daemon.LogVolumeEvent)
daemon.Unmount(container)
container.Unlock()
return err
})
daemon.LogContainerEvent(container, events.ActionCopy)
return reader, nil
}
// checkIfPathIsInAVolume checks if the path is in a volume. If it is, it
// cannot be in a read-only volume. If it is not in a volume, the container
// cannot be configured with a read-only rootfs.
//
// This is a no-op on Windows which does not support read-only volumes, or
// extracting to a mount point inside a volume. TODO Windows: FIXME Post-TP5
func checkIfPathIsInAVolume(container *container.Container, absPath string) (bool, error) {
return false, nil
}
// isOnlineFSOperationPermitted returns an error if an online filesystem operation
// is not permitted (such as stat or for copying). Running Hyper-V containers
// cannot have their file-system interrogated from the host as the filter is
// loaded inside the utility VM, not the host.
// IMPORTANT: The container lock MUST be held when calling this function.
func (daemon *Daemon) isOnlineFSOperationPermitted(container *container.Container) error {
if !container.Running {
return nil
}
// Determine isolation. If not specified in the hostconfig, use daemon default.
actualIsolation := container.HostConfig.Isolation
if containertypes.Isolation.IsDefault(containertypes.Isolation(actualIsolation)) {
actualIsolation = daemon.defaultIsolation
}
if containertypes.Isolation.IsHyperV(actualIsolation) {
return errors.New("filesystem operations against a running Hyper-V container are not supported")
}
return nil
}