55 lines
1.7 KiB
Go
55 lines
1.7 KiB
Go
package chrootarchive
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import (
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"fmt"
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"io/ioutil"
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"os"
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"path/filepath"
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"github.com/docker/docker/pkg/archive"
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)
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// ApplyLayer parses a diff in the standard layer format from `layer`,
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// and applies it to the directory `dest`. The stream `layer` can only be
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// uncompressed.
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// Returns the size in bytes of the contents of the layer.
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func ApplyLayer(dest string, layer archive.ArchiveReader) (size int64, err error) {
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return applyLayerHandler(dest, layer, true)
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}
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// ApplyUncompressedLayer parses a diff in the standard layer format from
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// `layer`, and applies it to the directory `dest`. The stream `layer`
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// can only be uncompressed.
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// Returns the size in bytes of the contents of the layer.
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func ApplyUncompressedLayer(dest string, layer archive.ArchiveReader) (int64, error) {
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return applyLayerHandler(dest, layer, false)
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}
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// ApplyLayer parses a diff in the standard layer format from `layer`, and
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// applies it to the directory `dest`. Returns the size in bytes of the
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// contents of the layer.
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func applyLayerHandler(dest string, layer archive.ArchiveReader, decompress bool) (size int64, err error) {
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dest = filepath.Clean(dest)
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if decompress {
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decompressed, err := archive.DecompressStream(layer)
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if err != nil {
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return 0, err
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}
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defer decompressed.Close()
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layer = decompressed
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}
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tmpDir, err := ioutil.TempDir(os.Getenv("temp"), "temp-docker-extract")
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if err != nil {
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return 0, fmt.Errorf("ApplyLayer failed to create temp-docker-extract under %s. %s", dest, err)
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}
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s, err := archive.UnpackLayer(dest, layer)
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os.RemoveAll(tmpDir)
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if err != nil {
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return 0, fmt.Errorf("ApplyLayer %s failed UnpackLayer to %s", err, dest)
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}
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return s, nil
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}
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