kaniko/vendor/github.com/google/go-containerregistry/v1/tarball/layer.go

145 lines
2.9 KiB
Go

// Copyright 2018 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tarball
import (
"compress/gzip"
"io"
"io/ioutil"
"os"
"github.com/google/go-containerregistry/v1"
"github.com/google/go-containerregistry/v1/v1util"
)
type layer struct {
digest v1.Hash
diffID v1.Hash
size int64
opener Opener
compressed bool
}
func (l *layer) Digest() (v1.Hash, error) {
return l.digest, nil
}
func (l *layer) DiffID() (v1.Hash, error) {
return l.diffID, nil
}
func (l *layer) Compressed() (io.ReadCloser, error) {
rc, err := l.opener()
if err == nil && !l.compressed {
return v1util.GzipReadCloser(rc)
}
return rc, err
}
func (l *layer) Uncompressed() (io.ReadCloser, error) {
rc, err := l.opener()
if err == nil && l.compressed {
return v1util.GunzipReadCloser(rc)
}
return rc, err
}
func (l *layer) Size() (int64, error) {
return l.size, nil
}
// LayerFromFile returns a v1.Layer given a tarball
func LayerFromFile(path string) (v1.Layer, error) {
opener := func() (io.ReadCloser, error) {
return os.Open(path)
}
return LayerFromOpener(opener)
}
// LayerFromOpener returns a v1.Layer given an Opener function
func LayerFromOpener(opener Opener) (v1.Layer, error) {
rc, err := opener()
if err != nil {
return nil, err
}
defer rc.Close()
compressed, err := v1util.IsGzipped(rc)
if err != nil {
return nil, err
}
var digest v1.Hash
var size int64
if digest, size, err = computeDigest(opener, compressed); err != nil {
return nil, err
}
diffID, err := computeDiffID(opener, compressed)
if err != nil {
return nil, err
}
return &layer{
digest: digest,
diffID: diffID,
size: size,
compressed: compressed,
opener: opener,
}, nil
}
func computeDigest(opener Opener, compressed bool) (v1.Hash, int64, error) {
rc, err := opener()
if err != nil {
return v1.Hash{}, 0, err
}
defer rc.Close()
if compressed {
return v1.SHA256(rc)
}
reader, err := v1util.GzipReadCloser(ioutil.NopCloser(rc))
if err != nil {
return v1.Hash{}, 0, err
}
return v1.SHA256(reader)
}
func computeDiffID(opener Opener, compressed bool) (v1.Hash, error) {
rc, err := opener()
if err != nil {
return v1.Hash{}, err
}
defer rc.Close()
if !compressed {
digest, _, err := v1.SHA256(rc)
return digest, err
}
reader, err := gzip.NewReader(rc)
if err != nil {
return v1.Hash{}, err
}
diffID, _, err := v1.SHA256(reader)
return diffID, err
}