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https://github.com/vbatts/tar-split.git
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99c8914877
This allows reading the metadata contained in tar-split without expensively recreating the whole tar stream including full contents. We have two use cases for this: - In a situation where tar-split is distributed along with a separate metadata stream, ensuring that the two are exactly consistent - Reading the tar headers allows making a ~cheap check of consistency of on-disk layers, just checking that the files exist in expected sizes, without reading the full contents. This can be implemented outside of this repo, but it's not ideal: - The function necessarily hard-codes some assumptions about how tar-split determines the boundaries of SegmentType/FileType entries (or, indeed, whether it uses FileType entries at all). That's best maintained directly beside the code that creates this. - The ExpectedPadding() value is not currently exported, so the consumer would have to heuristically guess where the padding ends. Signed-off-by: Miloslav Trmač <mitr@redhat.com>
119 lines
3.6 KiB
Go
119 lines
3.6 KiB
Go
package asm
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import (
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"bytes"
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"fmt"
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"io"
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"testing"
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"time"
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"github.com/stretchr/testify/assert"
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"github.com/stretchr/testify/require"
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"github.com/vbatts/tar-split/archive/tar"
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"github.com/vbatts/tar-split/tar/storage"
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)
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func createTestTarheader(index int, typeFlag byte, size int64) tar.Header {
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n := (index + 1) * 100 // Use predictable, but distinct, values for all headers
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res := tar.Header{
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Typeflag: typeFlag,
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Name: fmt.Sprintf("name%d", n),
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Size: size,
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Mode: int64(n + 1),
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Uid: n + 2,
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Gid: n + 3,
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Uname: fmt.Sprintf("user%d", n),
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Gname: fmt.Sprintf("group%d", n),
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ModTime: time.Unix(int64(n+4), 0),
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AccessTime: time.Unix(int64(n+5), 0),
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ChangeTime: time.Unix(int64(n+6), 0),
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PAXRecords: map[string]string{fmt.Sprintf("key%d", n): fmt.Sprintf("value%d", n)},
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Format: tar.FormatPAX, // We must set a format, in the default one AccessTime and ChangeTime are discarded.
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}
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switch res.Typeflag {
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case tar.TypeLink, tar.TypeSymlink:
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res.Linkname = fmt.Sprintf("link%d", n)
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case tar.TypeChar, tar.TypeBlock:
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res.Devmajor = int64(n + 7)
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res.Devminor = int64(n + 8)
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}
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return res
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}
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func TestIterateHeaders(t *testing.T) {
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entries := []struct {
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typeFlag byte
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size int64
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}{
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{tar.TypeReg, 0},
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{tar.TypeReg, 1},
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{tar.TypeReg, 511},
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{tar.TypeReg, 512},
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{tar.TypeReg, 513},
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{tar.TypeLink, 0},
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{tar.TypeSymlink, 0},
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{tar.TypeChar, 0},
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{tar.TypeBlock, 0},
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{tar.TypeDir, 0},
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{tar.TypeFifo, 0},
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}
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var tarball bytes.Buffer
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var expected []tar.Header
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w := tar.NewWriter(&tarball)
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for i, e := range entries {
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hdr := createTestTarheader(i, e.typeFlag, e.size)
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err := w.WriteHeader(&hdr)
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require.NoError(t, err)
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data := make([]byte, e.size)
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_, err = w.Write(data)
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require.NoError(t, err)
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expected = append(expected, hdr)
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}
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err := w.Close()
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require.NoError(t, err)
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var tarSplit bytes.Buffer
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tsReader, err := NewInputTarStream(&tarball, storage.NewJSONPacker(&tarSplit), storage.NewDiscardFilePutter())
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require.NoError(t, err)
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_, err = io.Copy(io.Discard, tsReader)
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require.NoError(t, err)
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unpacker := storage.NewJSONUnpacker(&tarSplit)
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var actual []tar.Header
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err = IterateHeaders(unpacker, func(hdr *tar.Header) error {
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actual = append(actual, *hdr)
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return nil
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})
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require.NoError(t, err)
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assert.Equal(t, len(expected), len(actual))
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for i := range expected {
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expected := &expected[i]
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actual := &actual[i]
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assert.Equal(t, expected.Typeflag, actual.Typeflag)
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assert.Equal(t, expected.Name, actual.Name)
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assert.Equal(t, expected.Linkname, actual.Linkname)
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assert.Equal(t, expected.Size, actual.Size)
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assert.Equal(t, expected.Mode, actual.Mode)
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assert.Equal(t, expected.Uid, actual.Uid)
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assert.Equal(t, expected.Gid, actual.Gid)
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assert.Equal(t, expected.Uname, actual.Uname)
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assert.Equal(t, expected.Gname, actual.Gname)
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assert.True(t, actual.ModTime.Equal(expected.ModTime))
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assert.True(t, actual.AccessTime.Equal(expected.AccessTime))
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assert.True(t, actual.ChangeTime.Equal(expected.ChangeTime))
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assert.Equal(t, expected.Devmajor, actual.Devmajor)
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assert.Equal(t, expected.Devminor, actual.Devminor)
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assert.Equal(t, expected.Xattrs, actual.Xattrs) //nolint:staticcheck // We do want a comprehensive coverage in this test.
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// We can’t compare PAXRecords for complete equality, because tar.Writer adds atime and ctime entries. So ensure all expected records are present.
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for k, v := range expected.PAXRecords {
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v2, ok := actual.PAXRecords[k]
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assert.True(t, ok, k)
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assert.Equal(t, v, v2)
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}
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assert.Equal(t, expected.Format, actual.Format)
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}
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}
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