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Merge pull request #14885 from jlhawn/fix_cp_symlink

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Fix copying of symlinks in containers
This commit is contained in:
David Calavera 2015-07-30 13:42:40 -07:00
commit 877d55447f
4 changed files with 171 additions and 94 deletions
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26
archive/archive.go
View file

@ -37,11 +37,13 @@ type (
Compression Compression
NoLchown bool
ChownOpts *TarChownOptions
Name string
IncludeSourceDir bool
// When unpacking, specifies whether overwriting a directory with a
// non-directory is allowed and vice versa.
NoOverwriteDirNonDir bool
// For each include when creating an archive, the included name will be
// replaced with the matching name from this map.
RebaseNames map[string]string
}
// Archiver allows the reuse of most utility functions of this package
@ -454,8 +456,9 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
seen := make(map[string]bool)
var renamedRelFilePath string // For when tar.Options.Name is set
for _, include := range options.IncludeFiles {
rebaseName := options.RebaseNames[include]
// We can't use filepath.Join(srcPath, include) because this will
// clean away a trailing "." or "/" which may be important.
walkRoot := strings.Join([]string{srcPath, include}, string(filepath.Separator))
@ -503,14 +506,17 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
}
seen[relFilePath] = true
// TODO Windows: Verify if this needs to be os.Pathseparator
// Rename the base resource
if options.Name != "" && filePath == srcPath+"/"+filepath.Base(relFilePath) {
renamedRelFilePath = relFilePath
}
// Set this to make sure the items underneath also get renamed
if options.Name != "" {
relFilePath = strings.Replace(relFilePath, renamedRelFilePath, options.Name, 1)
// Rename the base resource.
if rebaseName != "" {
var replacement string
if rebaseName != string(filepath.Separator) {
// Special case the root directory to replace with an
// empty string instead so that we don't end up with
// double slashes in the paths.
replacement = rebaseName
}
relFilePath = strings.Replace(relFilePath, include, replacement, 1)
}
if err := ta.addTarFile(filePath, relFilePath); err != nil {

2
archive/archive_test.go
View file

@ -695,7 +695,7 @@ func TestTarWithOptions(t *testing.T) {
{&TarOptions{ExcludePatterns: []string{"2"}}, 1},
{&TarOptions{ExcludePatterns: []string{"1", "folder*"}}, 2},
{&TarOptions{IncludeFiles: []string{"1", "1"}}, 2},
{&TarOptions{Name: "test", IncludeFiles: []string{"1"}}, 4},
{&TarOptions{IncludeFiles: []string{"1"}, RebaseNames: map[string]string{"1": "test"}}, 4},
}
for _, testCase := range cases {
changes, err := tarUntar(t, origin, testCase.opts)

213
archive/copy.go
View file

@ -6,7 +6,6 @@ import (
"io"
"io/ioutil"
"os"
"path"
"path/filepath"
"strings"
@ -64,34 +63,33 @@ func SpecifiesCurrentDir(path string) bool {
return filepath.Base(path) == "."
}
// SplitPathDirEntry splits the given path between its
// parent directory and its basename in that directory.
func SplitPathDirEntry(localizedPath string) (dir, base string) {
normalizedPath := filepath.ToSlash(localizedPath)
vol := filepath.VolumeName(normalizedPath)
normalizedPath = normalizedPath[len(vol):]
// SplitPathDirEntry splits the given path between its directory name and its
// basename by first cleaning the path but preserves a trailing "." if the
// original path specified the current directory.
func SplitPathDirEntry(path string) (dir, base string) {
cleanedPath := filepath.Clean(path)
if normalizedPath == "/" {
// Specifies the root path.
return filepath.FromSlash(vol + normalizedPath), "."
if SpecifiesCurrentDir(path) {
cleanedPath += string(filepath.Separator) + "."
}
trimmedPath := vol + strings.TrimRight(normalizedPath, "/")
dir = filepath.FromSlash(path.Dir(trimmedPath))
base = filepath.FromSlash(path.Base(trimmedPath))
return dir, base
return filepath.Dir(cleanedPath), filepath.Base(cleanedPath)
}
// TarResource archives the resource at the given sourcePath into a Tar
// TarResource archives the resource described by the given CopyInfo to a Tar
// archive. A non-nil error is returned if sourcePath does not exist or is
// asserted to be a directory but exists as another type of file.
//
// This function acts as a convenient wrapper around TarWithOptions, which
// requires a directory as the source path. TarResource accepts either a
// directory or a file path and correctly sets the Tar options.
func TarResource(sourcePath string) (content Archive, err error) {
func TarResource(sourceInfo CopyInfo) (content Archive, err error) {
return TarResourceRebase(sourceInfo.Path, sourceInfo.RebaseName)
}
// TarResourceRebase is like TarResource but renames the first path element of
// items in the resulting tar archive to match the given rebaseName if not "".
func TarResourceRebase(sourcePath, rebaseName string) (content Archive, err error) {
if _, err = os.Lstat(sourcePath); err != nil {
// Catches the case where the source does not exist or is not a
// directory if asserted to be a directory, as this also causes an
@ -99,22 +97,6 @@ func TarResource(sourcePath string) (content Archive, err error) {
return
}
if len(sourcePath) > 1 && HasTrailingPathSeparator(sourcePath) {
// In the case where the source path is a symbolic link AND it ends
// with a path separator, we will want to evaluate the symbolic link.
trimmedPath := sourcePath[:len(sourcePath)-1]
stat, err := os.Lstat(trimmedPath)
if err != nil {
return nil, err
}
if stat.Mode()&os.ModeSymlink != 0 {
if sourcePath, err = filepath.EvalSymlinks(trimmedPath); err != nil {
return nil, err
}
}
}
// Separate the source path between it's directory and
// the entry in that directory which we are archiving.
sourceDir, sourceBase := SplitPathDirEntry(sourcePath)
@ -127,32 +109,137 @@ func TarResource(sourcePath string) (content Archive, err error) {
Compression: Uncompressed,
IncludeFiles: filter,
IncludeSourceDir: true,
RebaseNames: map[string]string{
sourceBase: rebaseName,
},
})
}
// CopyInfo holds basic info about the source
// or destination path of a copy operation.
type CopyInfo struct {
Path string
Exists bool
IsDir bool
Path string
Exists bool
IsDir bool
RebaseName string
}
// CopyInfoStatPath stats the given path to create a CopyInfo
// struct representing that resource. If mustExist is true, then
// it is an error if there is no file or directory at the given path.
func CopyInfoStatPath(path string, mustExist bool) (CopyInfo, error) {
pathInfo := CopyInfo{Path: path}
// CopyInfoSourcePath stats the given path to create a CopyInfo
// struct representing that resource for the source of an archive copy
// operation. The given path should be an absolute local path. A source path
// has all symlinks evaluated that appear before the last path separator ("/"
// on Unix). As it is to be a copy source, the path must exist.
func CopyInfoSourcePath(path string) (CopyInfo, error) {
// Split the given path into its Directory and Base components. We will
// evaluate symlinks in the directory component then append the base.
dirPath, basePath := filepath.Split(path)
fileInfo, err := os.Lstat(path)
if err == nil {
pathInfo.Exists, pathInfo.IsDir = true, fileInfo.IsDir()
} else if os.IsNotExist(err) && !mustExist {
err = nil
resolvedDirPath, err := filepath.EvalSymlinks(dirPath)
if err != nil {
return CopyInfo{}, err
}
return pathInfo, err
// resolvedDirPath will have been cleaned (no trailing path separators) so
// we can manually join it with the base path element.
resolvedPath := resolvedDirPath + string(filepath.Separator) + basePath
var rebaseName string
if HasTrailingPathSeparator(path) && filepath.Base(path) != filepath.Base(resolvedPath) {
// In the case where the path had a trailing separator and a symlink
// evaluation has changed the last path component, we will need to
// rebase the name in the archive that is being copied to match the
// originally requested name.
rebaseName = filepath.Base(path)
}
stat, err := os.Lstat(resolvedPath)
if err != nil {
return CopyInfo{}, err
}
return CopyInfo{
Path: resolvedPath,
Exists: true,
IsDir: stat.IsDir(),
RebaseName: rebaseName,
}, nil
}
// CopyInfoDestinationPath stats the given path to create a CopyInfo
// struct representing that resource for the destination of an archive copy
// operation. The given path should be an absolute local path.
func CopyInfoDestinationPath(path string) (info CopyInfo, err error) {
maxSymlinkIter := 10 // filepath.EvalSymlinks uses 255, but 10 already seems like a lot.
originalPath := path
stat, err := os.Lstat(path)
if err == nil && stat.Mode()&os.ModeSymlink == 0 {
// The path exists and is not a symlink.
return CopyInfo{
Path: path,
Exists: true,
IsDir: stat.IsDir(),
}, nil
}
// While the path is a symlink.
for n := 0; err == nil && stat.Mode()&os.ModeSymlink != 0; n++ {
if n > maxSymlinkIter {
// Don't follow symlinks more than this arbitrary number of times.
return CopyInfo{}, errors.New("too many symlinks in " + originalPath)
}
// The path is a symbolic link. We need to evaluate it so that the
// destination of the copy operation is the link target and not the
// link itself. This is notably different than CopyInfoSourcePath which
// only evaluates symlinks before the last appearing path separator.
// Also note that it is okay if the last path element is a broken
// symlink as the copy operation should create the target.
var linkTarget string
linkTarget, err = os.Readlink(path)
if err != nil {
return CopyInfo{}, err
}
if !filepath.IsAbs(linkTarget) {
// Join with the parent directory.
dstParent, _ := SplitPathDirEntry(path)
linkTarget = filepath.Join(dstParent, linkTarget)
}
path = linkTarget
stat, err = os.Lstat(path)
}
if err != nil {
// It's okay if the destination path doesn't exist. We can still
// continue the copy operation if the parent directory exists.
if !os.IsNotExist(err) {
return CopyInfo{}, err
}
// Ensure destination parent dir exists.
dstParent, _ := SplitPathDirEntry(path)
parentDirStat, err := os.Lstat(dstParent)
if err != nil {
return CopyInfo{}, err
}
if !parentDirStat.IsDir() {
return CopyInfo{}, ErrNotDirectory
}
return CopyInfo{Path: path}, nil
}
// The path exists after resolving symlinks.
return CopyInfo{
Path: path,
Exists: true,
IsDir: stat.IsDir(),
}, nil
}
// PrepareArchiveCopy prepares the given srcContent archive, which should
@ -210,6 +297,13 @@ func PrepareArchiveCopy(srcContent ArchiveReader, srcInfo, dstInfo CopyInfo) (ds
// rebaseArchiveEntries rewrites the given srcContent archive replacing
// an occurance of oldBase with newBase at the beginning of entry names.
func rebaseArchiveEntries(srcContent ArchiveReader, oldBase, newBase string) Archive {
if oldBase == "/" {
// If oldBase specifies the root directory, use an empty string as
// oldBase instead so that newBase doesn't replace the path separator
// that all paths will start with.
oldBase = ""
}
rebased, w := io.Pipe()
go func() {
@ -259,11 +353,11 @@ func CopyResource(srcPath, dstPath string) error {
srcPath = PreserveTrailingDotOrSeparator(filepath.Clean(srcPath), srcPath)
dstPath = PreserveTrailingDotOrSeparator(filepath.Clean(dstPath), dstPath)
if srcInfo, err = CopyInfoStatPath(srcPath, true); err != nil {
if srcInfo, err = CopyInfoSourcePath(srcPath); err != nil {
return err
}
content, err := TarResource(srcPath)
content, err := TarResource(srcInfo)
if err != nil {
return err
}
@ -275,24 +369,13 @@ func CopyResource(srcPath, dstPath string) error {
// CopyTo handles extracting the given content whose
// entries should be sourced from srcInfo to dstPath.
func CopyTo(content ArchiveReader, srcInfo CopyInfo, dstPath string) error {
dstInfo, err := CopyInfoStatPath(dstPath, false)
// The destination path need not exist, but CopyInfoDestinationPath will
// ensure that at least the parent directory exists.
dstInfo, err := CopyInfoDestinationPath(dstPath)
if err != nil {
return err
}
if !dstInfo.Exists {
// Ensure destination parent dir exists.
dstParent, _ := SplitPathDirEntry(dstPath)
dstStat, err := os.Lstat(dstParent)
if err != nil {
return err
}
if !dstStat.IsDir() {
return ErrNotDirectory
}
}
dstDir, copyArchive, err := PrepareArchiveCopy(content, srcInfo, dstInfo)
if err != nil {
return err

24
archive/copy_test.go
View file

@ -138,13 +138,7 @@ func TestCopyErrSrcNotExists(t *testing.T) {
tmpDirA, tmpDirB := getTestTempDirs(t)
defer removeAllPaths(tmpDirA, tmpDirB)
content, err := TarResource(filepath.Join(tmpDirA, "file1"))
if err == nil {
content.Close()
t.Fatal("expected IsNotExist error, but got nil instead")
}
if !os.IsNotExist(err) {
if _, err := CopyInfoSourcePath(filepath.Join(tmpDirA, "file1")); !os.IsNotExist(err) {
t.Fatalf("expected IsNotExist error, but got %T: %s", err, err)
}
}
@ -158,13 +152,7 @@ func TestCopyErrSrcNotDir(t *testing.T) {
// Load A with some sample files and directories.
createSampleDir(t, tmpDirA)
content, err := TarResource(joinTrailingSep(tmpDirA, "file1"))
if err == nil {
content.Close()
t.Fatal("expected IsNotDir error, but got nil instead")
}
if !isNotDir(err) {
if _, err := CopyInfoSourcePath(joinTrailingSep(tmpDirA, "file1")); !isNotDir(err) {
t.Fatalf("expected IsNotDir error, but got %T: %s", err, err)
}
}
@ -181,7 +169,7 @@ func TestCopyErrDstParentNotExists(t *testing.T) {
srcInfo := CopyInfo{Path: filepath.Join(tmpDirA, "file1"), Exists: true, IsDir: false}
// Try with a file source.
content, err := TarResource(srcInfo.Path)
content, err := TarResource(srcInfo)
if err != nil {
t.Fatalf("unexpected error %T: %s", err, err)
}
@ -199,7 +187,7 @@ func TestCopyErrDstParentNotExists(t *testing.T) {
// Try with a directory source.
srcInfo = CopyInfo{Path: filepath.Join(tmpDirA, "dir1"), Exists: true, IsDir: true}
content, err = TarResource(srcInfo.Path)
content, err = TarResource(srcInfo)
if err != nil {
t.Fatalf("unexpected error %T: %s", err, err)
}
@ -228,7 +216,7 @@ func TestCopyErrDstNotDir(t *testing.T) {
// Try with a file source.
srcInfo := CopyInfo{Path: filepath.Join(tmpDirA, "file1"), Exists: true, IsDir: false}
content, err := TarResource(srcInfo.Path)
content, err := TarResource(srcInfo)
if err != nil {
t.Fatalf("unexpected error %T: %s", err, err)
}
@ -245,7 +233,7 @@ func TestCopyErrDstNotDir(t *testing.T) {
// Try with a directory source.
srcInfo = CopyInfo{Path: filepath.Join(tmpDirA, "dir1"), Exists: true, IsDir: true}
content, err = TarResource(srcInfo.Path)
content, err = TarResource(srcInfo)
if err != nil {
t.Fatalf("unexpected error %T: %s", err, err)
}