package daemon // import "github.com/docker/docker/daemon" import ( "io" "os" "path/filepath" "strings" "github.com/docker/docker/api/types" "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" "github.com/docker/docker/pkg/system" "github.com/pkg/errors" ) // ErrExtractPointNotDirectory is used to convey that the operation to extract // a tar archive to a directory in a container has failed because the specified // path does not refer to a directory. var ErrExtractPointNotDirectory = errors.New("extraction point is not a directory") // The daemon will use the following interfaces if the container fs implements // these for optimized copies to and from the container. type extractor interface { ExtractArchive(src io.Reader, dst string, opts *archive.TarOptions) error } type archiver interface { ArchivePath(src string, opts *archive.TarOptions) (io.ReadCloser, error) } // helper functions to extract or archive func extractArchive(i interface{}, src io.Reader, dst string, opts *archive.TarOptions, root string) error { if ea, ok := i.(extractor); ok { return ea.ExtractArchive(src, dst, opts) } return chrootarchive.UntarWithRoot(src, dst, opts, root) } func archivePath(i interface{}, src string, opts *archive.TarOptions, root string) (io.ReadCloser, error) { if ap, ok := i.(archiver); ok { return ap.ArchivePath(src, opts) } return chrootarchive.Tar(src, opts, root) } // ContainerCopy performs a deprecated operation of archiving the resource at // the specified path in the container identified by the given name. func (daemon *Daemon) ContainerCopy(name string, res string) (io.ReadCloser, error) { ctr, err := daemon.GetContainer(name) if err != nil { return nil, err } // Make sure an online file-system operation is permitted. if err := daemon.isOnlineFSOperationPermitted(ctr); err != nil { return nil, errdefs.System(err) } data, err := daemon.containerCopy(ctr, res) if err == nil { return data, nil } if os.IsNotExist(err) { return nil, containerFileNotFound{res, name} } return nil, errdefs.System(err) } // ContainerStatPath stats the filesystem resource at the specified path in the // container identified by the given name. func (daemon *Daemon) ContainerStatPath(name string, path string) (stat *types.ContainerPathStat, err error) { ctr, err := daemon.GetContainer(name) if err != nil { return nil, err } // Make sure an online file-system operation is permitted. if err := daemon.isOnlineFSOperationPermitted(ctr); err != nil { return nil, errdefs.System(err) } stat, err = daemon.containerStatPath(ctr, path) if err == nil { return stat, nil } if os.IsNotExist(err) { return nil, containerFileNotFound{path, name} } return nil, errdefs.System(err) } // ContainerArchivePath creates an archive of the filesystem resource at the // specified path in the container identified by the given name. Returns a // tar archive of the resource and whether it was a directory or a single file. func (daemon *Daemon) ContainerArchivePath(name string, path string) (content io.ReadCloser, stat *types.ContainerPathStat, err error) { ctr, err := daemon.GetContainer(name) if err != nil { return nil, nil, err } // Make sure an online file-system operation is permitted. if err := daemon.isOnlineFSOperationPermitted(ctr); err != nil { return nil, nil, errdefs.System(err) } content, stat, err = daemon.containerArchivePath(ctr, path) if err == nil { return content, stat, nil } if os.IsNotExist(err) { return nil, nil, containerFileNotFound{path, name} } return nil, nil, errdefs.System(err) } // ContainerExtractToDir extracts the given archive to the specified location // in the filesystem of the container identified by the given name. The given // path must be of a directory in the container. If it is not, the error will // be ErrExtractPointNotDirectory. 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(name, path string, copyUIDGID, noOverwriteDirNonDir bool, content io.Reader) error { ctr, err := daemon.GetContainer(name) if err != nil { return err } // Make sure an online file-system operation is permitted. if err := daemon.isOnlineFSOperationPermitted(ctr); err != nil { return errdefs.System(err) } err = daemon.containerExtractToDir(ctr, path, copyUIDGID, noOverwriteDirNonDir, content) if err == nil { return nil } if os.IsNotExist(err) { return containerFileNotFound{path, name} } return errdefs.System(err) } // 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 *types.ContainerPathStat, err error) { container.Lock() defer container.Unlock() 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 *types.ContainerPathStat, 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() } }() 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. driver := container.BaseFS // 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 := archivePath(driver, sourceDir, opts, string(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, "archive-path") 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 ErrExtractPointNotDirectory. 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() 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) driver := container.BaseFS // Check if a drive letter supplied, it must be the system drive. No-op except on Windows path, err = system.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 ErrExtractPointNotDirectory } // 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, string(driver)) { baseRel = resolvedPath[len(string(driver)):] if baseRel[:1] == `\` { baseRel = baseRel[1:] } } } else { baseRel, err = filepath.Rel(string(driver), resolvedPath) } if err != nil { return err } // Make it an absolute path. absPath = filepath.Join(string(filepath.Separator), baseRel) // @ TODO: gupta-ak: Technically, this works since it no-ops // on Windows and the file system is local anyway on linux. // But eventually, it should be made driver aware. toVolume, err := checkIfPathIsInAVolume(container, absPath) if err != nil { return err } if !toVolume && container.HostConfig.ReadonlyRootfs { return ErrRootFSReadOnly } 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 := extractArchive(driver, content, resolvedPath, options, string(container.BaseFS)); err != nil { return err } daemon.LogContainerEvent(container, "extract-to-dir") 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() } }() 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) driver := container.BaseFS 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 := archivePath(driver, basePath, &archive.TarOptions{ Compression: archive.Uncompressed, IncludeFiles: filter, }, string(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, "copy") return reader, nil }