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pkg/archive: new utilities for copying resources

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Adds TarResource and CopyTo functions to be used for creating
archives for use with the new `docker cp` behavior.

Adds multiple test cases for the CopyFrom and CopyTo
functions in the pkg/archive package.

Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
This commit is contained in:
Josh Hawn 2015-01-19 12:15:36 -08:00
parent 9511b53907
commit 33cd39caf0
5 changed files with 1031 additions and 32 deletions
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112
archive/archive.go
View file

@ -25,15 +25,23 @@ import (
)
type (
Archive io.ReadCloser
ArchiveReader io.Reader
Compression int
TarOptions struct {
IncludeFiles []string
ExcludePatterns []string
Compression Compression
NoLchown bool
Name string
Archive io.ReadCloser
ArchiveReader io.Reader
Compression int
TarChownOptions struct {
UID, GID int
}
TarOptions struct {
IncludeFiles []string
ExcludePatterns []string
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
}
// Archiver allows the reuse of most utility functions of this package
@ -262,7 +270,7 @@ func (ta *tarAppender) addTarFile(path, name string) error {
return nil
}
func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, Lchown bool) error {
func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, Lchown bool, chownOpts *TarChownOptions) error {
// hdr.Mode is in linux format, which we can use for sycalls,
// but for os.Foo() calls we need the mode converted to os.FileMode,
// so use hdrInfo.Mode() (they differ for e.g. setuid bits)
@ -328,9 +336,12 @@ func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, L
return fmt.Errorf("Unhandled tar header type %d\n", hdr.Typeflag)
}
// Lchown is not supported on Windows
if runtime.GOOS != "windows" {
if err := os.Lchown(path, hdr.Uid, hdr.Gid); err != nil && Lchown {
// Lchown is not supported on Windows.
if Lchown && runtime.GOOS != "windows" {
if chownOpts == nil {
chownOpts = &TarChownOptions{UID: hdr.Uid, GID: hdr.Gid}
}
if err := os.Lchown(path, chownOpts.UID, chownOpts.GID); err != nil {
return err
}
}
@ -396,6 +407,20 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
Buffer: pools.BufioWriter32KPool.Get(nil),
SeenFiles: make(map[uint64]string),
}
defer func() {
// Make sure to check the error on Close.
if err := ta.TarWriter.Close(); err != nil {
logrus.Debugf("Can't close tar writer: %s", err)
}
if err := compressWriter.Close(); err != nil {
logrus.Debugf("Can't close compress writer: %s", err)
}
if err := pipeWriter.Close(); err != nil {
logrus.Debugf("Can't close pipe writer: %s", err)
}
}()
// this buffer is needed for the duration of this piped stream
defer pools.BufioWriter32KPool.Put(ta.Buffer)
@ -404,7 +429,26 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
// mutating the filesystem and we can see transient errors
// from this
if options.IncludeFiles == nil {
stat, err := os.Lstat(srcPath)
if err != nil {
return
}
if !stat.IsDir() {
// We can't later join a non-dir with any includes because the
// 'walk' will error if "file/." is stat-ed and "file" is not a
// directory. So, we must split the source path and use the
// basename as the include.
if len(options.IncludeFiles) > 0 {
logrus.Warn("Tar: Can't archive a file with includes")
}
dir, base := SplitPathDirEntry(srcPath)
srcPath = dir
options.IncludeFiles = []string{base}
}
if len(options.IncludeFiles) == 0 {
options.IncludeFiles = []string{"."}
}
@ -412,19 +456,26 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
var renamedRelFilePath string // For when tar.Options.Name is set
for _, include := range options.IncludeFiles {
filepath.Walk(filepath.Join(srcPath, include), func(filePath string, f os.FileInfo, err error) error {
// 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))
filepath.Walk(walkRoot, func(filePath string, f os.FileInfo, err error) error {
if err != nil {
logrus.Debugf("Tar: Can't stat file %s to tar: %s", srcPath, err)
return nil
}
relFilePath, err := filepath.Rel(srcPath, filePath)
if err != nil || (relFilePath == "." && f.IsDir()) {
if err != nil || (!options.IncludeSourceDir && relFilePath == "." && f.IsDir()) {
// Error getting relative path OR we are looking
// at the root path. Skip in both situations.
// at the source directory path. Skip in both situations.
return nil
}
if options.IncludeSourceDir && include == "." && relFilePath != "." {
relFilePath = strings.Join([]string{".", relFilePath}, string(filepath.Separator))
}
skip := false
// If "include" is an exact match for the current file
@ -468,17 +519,6 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
return nil
})
}
// Make sure to check the error on Close.
if err := ta.TarWriter.Close(); err != nil {
logrus.Debugf("Can't close tar writer: %s", err)
}
if err := compressWriter.Close(); err != nil {
logrus.Debugf("Can't close compress writer: %s", err)
}
if err := pipeWriter.Close(); err != nil {
logrus.Debugf("Can't close pipe writer: %s", err)
}
}()
return pipeReader, nil
@ -543,9 +583,22 @@ loop:
// the layer is also a directory. Then we want to merge them (i.e.
// just apply the metadata from the layer).
if fi, err := os.Lstat(path); err == nil {
if options.NoOverwriteDirNonDir && fi.IsDir() && hdr.Typeflag != tar.TypeDir {
// If NoOverwriteDirNonDir is true then we cannot replace
// an existing directory with a non-directory from the archive.
return fmt.Errorf("cannot overwrite directory %q with non-directory %q", path, dest)
}
if options.NoOverwriteDirNonDir && !fi.IsDir() && hdr.Typeflag == tar.TypeDir {
// If NoOverwriteDirNonDir is true then we cannot replace
// an existing non-directory with a directory from the archive.
return fmt.Errorf("cannot overwrite non-directory %q with directory %q", path, dest)
}
if fi.IsDir() && hdr.Name == "." {
continue
}
if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) {
if err := os.RemoveAll(path); err != nil {
return err
@ -553,7 +606,8 @@ loop:
}
}
trBuf.Reset(tr)
if err := createTarFile(path, dest, hdr, trBuf, !options.NoLchown); err != nil {
if err := createTarFile(path, dest, hdr, trBuf, !options.NoLchown, options.ChownOpts); err != nil {
return err
}