distribution/testutil/tarfile.go
Cory Snider d0f5aa670b Move context package internal
Our context package predates the establishment of current best practices
regarding context usage and it shows. It encourages bad practices such
as using contexts to propagate non-request-scoped values like the
application version and using string-typed keys for context values. Move
the package internal to remove it from the API surface of
distribution/v3@v3.0.0 so we are free to iterate on it without being
constrained by compatibility.

Signed-off-by: Cory Snider <csnider@mirantis.com>
2023-10-27 10:58:37 -04:00

115 lines
2.9 KiB
Go

package testutil
import (
"archive/tar"
"bytes"
crand "crypto/rand"
"fmt"
"io"
mrand "math/rand"
"time"
"github.com/distribution/distribution/v3"
"github.com/distribution/distribution/v3/internal/dcontext"
"github.com/opencontainers/go-digest"
)
// CreateRandomTarFile creates a random tarfile, returning it as an
// io.ReadSeeker along with its digest. An error is returned if there is a
// problem generating valid content.
func CreateRandomTarFile() (rs io.ReadSeeker, dgst digest.Digest, err error) {
nFiles := mrand.Intn(10) + 10
target := &bytes.Buffer{}
wr := tar.NewWriter(target)
// Perturb this on each iteration of the loop below.
header := &tar.Header{
Mode: 0o644,
ModTime: time.Now(),
Typeflag: tar.TypeReg,
Uname: "randocalrissian",
Gname: "cloudcity",
AccessTime: time.Now(),
ChangeTime: time.Now(),
}
for fileNumber := 0; fileNumber < nFiles; fileNumber++ {
fileSize := mrand.Int63n(1<<20) + 1<<20
header.Name = fmt.Sprint(fileNumber)
header.Size = fileSize
if err := wr.WriteHeader(header); err != nil {
return nil, "", err
}
randomData := make([]byte, fileSize)
// Fill up the buffer with some random data.
n, err := crand.Read(randomData)
if n != len(randomData) {
return nil, "", fmt.Errorf("short read creating random reader: %v bytes != %v bytes", n, len(randomData))
}
if err != nil {
return nil, "", err
}
nn, err := io.Copy(wr, bytes.NewReader(randomData))
if nn != fileSize {
return nil, "", fmt.Errorf("short copy writing random file to tar")
}
if err != nil {
return nil, "", err
}
if err := wr.Flush(); err != nil {
return nil, "", err
}
}
if err := wr.Close(); err != nil {
return nil, "", err
}
dgst = digest.FromBytes(target.Bytes())
return bytes.NewReader(target.Bytes()), dgst, nil
}
// CreateRandomLayers returns a map of n digests. We don't particularly care
// about the order of said digests (since they're all random anyway).
func CreateRandomLayers(n int) (map[digest.Digest]io.ReadSeeker, error) {
digestMap := map[digest.Digest]io.ReadSeeker{}
for i := 0; i < n; i++ {
rs, ds, err := CreateRandomTarFile()
if err != nil {
return nil, fmt.Errorf("unexpected error generating test layer file: %v", err)
}
digestMap[ds] = rs
}
return digestMap, nil
}
// UploadBlobs lets you upload blobs to a repository
func UploadBlobs(repository distribution.Repository, layers map[digest.Digest]io.ReadSeeker) error {
ctx := dcontext.Background()
for dgst, rs := range layers {
wr, err := repository.Blobs(ctx).Create(ctx)
if err != nil {
return fmt.Errorf("unexpected error creating upload: %v", err)
}
if _, err := io.Copy(wr, rs); err != nil {
return fmt.Errorf("unexpected error copying to upload: %v", err)
}
if _, err := wr.Commit(ctx, distribution.Descriptor{Digest: dgst}); err != nil {
return fmt.Errorf("unexpected error committinng upload: %v", err)
}
}
return nil
}