func createTarStream(srcPath, dockerfilePath string) (io.ReadCloser, error) {
excludes, err := parseDockerignore(srcPath)
if err != nil {
return nil, err
}
includes := []string{"."}
// If .dockerignore mentions .dockerignore or the Dockerfile
// then make sure we send both files over to the daemon
// because Dockerfile is, obviously, needed no matter what, and
// .dockerignore is needed to know if either one needs to be
// removed. The deamon will remove them for us, if needed, after it
// parses the Dockerfile.
//
// https://github.com/docker/docker/issues/8330
//
forceIncludeFiles := []string{".dockerignore", dockerfilePath}
for _, includeFile := range forceIncludeFiles {
if includeFile == "" {
continue
}
keepThem, err := fileutils.Matches(includeFile, excludes)
if err != nil {
return nil, fmt.Errorf("cannot match .dockerfile: '%s', error: %s", includeFile, err)
}
if keepThem {
includes = append(includes, includeFile)
}
}
if err := validateContextDirectory(srcPath, excludes); err != nil {
return nil, err
}
tarOpts := &archive.TarOptions{
ExcludePatterns: excludes,
IncludeFiles: includes,
Compression: archive.Uncompressed,
NoLchown: true,
}
return archive.TarWithOptions(srcPath, tarOpts)
}
// validateContextDirectory checks if all the contents of the directory
// can be read and returns an error if some files can't be read.
// Symlinks which point to non-existing files don't trigger an error
func validateContextDirectory(srcPath string, excludes []string) error {
return filepath.Walk(filepath.Join(srcPath, "."), func(filePath string, f os.FileInfo, err error) error {
// skip this directory/file if it's not in the path, it won't get added to the context
if relFilePath, err := filepath.Rel(srcPath, filePath); err != nil {
return err
} else if skip, err := fileutils.Matches(relFilePath, excludes); err != nil {
return err
} else if skip {
if f.IsDir() {
return filepath.SkipDir
}
return nil
}
if err != nil {
if os.IsPermission(err) {
return fmt.Errorf("can't stat '%s'", filePath)
}
if os.IsNotExist(err) {
return nil
}
return err
}
// skip checking if symlinks point to non-existing files, such symlinks can be useful
// also skip named pipes, because they hanging on open
if f.Mode()&(os.ModeSymlink|os.ModeNamedPipe) != 0 {
return nil
}
if !f.IsDir() {
currentFile, err := os.Open(filePath)
if err != nil && os.IsPermission(err) {
return fmt.Errorf("no permission to read from '%s'", filePath)
}
currentFile.Close()
}
return nil
})
}