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Diffstat (limited to 'pkg/v1/layout/image.go')
-rw-r--r-- | pkg/v1/layout/image.go | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/pkg/v1/layout/image.go b/pkg/v1/layout/image.go new file mode 100644 index 0000000..c9ae966 --- /dev/null +++ b/pkg/v1/layout/image.go @@ -0,0 +1,139 @@ +// 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 layout + +import ( + "fmt" + "io" + "os" + "sync" + + v1 "github.com/google/go-containerregistry/pkg/v1" + "github.com/google/go-containerregistry/pkg/v1/partial" + "github.com/google/go-containerregistry/pkg/v1/types" +) + +type layoutImage struct { + path Path + desc v1.Descriptor + manifestLock sync.Mutex // Protects rawManifest + rawManifest []byte +} + +var _ partial.CompressedImageCore = (*layoutImage)(nil) + +// Image reads a v1.Image with digest h from the Path. +func (l Path) Image(h v1.Hash) (v1.Image, error) { + ii, err := l.ImageIndex() + if err != nil { + return nil, err + } + + return ii.Image(h) +} + +func (li *layoutImage) MediaType() (types.MediaType, error) { + return li.desc.MediaType, nil +} + +// Implements WithManifest for partial.Blobset. +func (li *layoutImage) Manifest() (*v1.Manifest, error) { + return partial.Manifest(li) +} + +func (li *layoutImage) RawManifest() ([]byte, error) { + li.manifestLock.Lock() + defer li.manifestLock.Unlock() + if li.rawManifest != nil { + return li.rawManifest, nil + } + + b, err := li.path.Bytes(li.desc.Digest) + if err != nil { + return nil, err + } + + li.rawManifest = b + return li.rawManifest, nil +} + +func (li *layoutImage) RawConfigFile() ([]byte, error) { + manifest, err := li.Manifest() + if err != nil { + return nil, err + } + + return li.path.Bytes(manifest.Config.Digest) +} + +func (li *layoutImage) LayerByDigest(h v1.Hash) (partial.CompressedLayer, error) { + manifest, err := li.Manifest() + if err != nil { + return nil, err + } + + if h == manifest.Config.Digest { + return &compressedBlob{ + path: li.path, + desc: manifest.Config, + }, nil + } + + for _, desc := range manifest.Layers { + if h == desc.Digest { + return &compressedBlob{ + path: li.path, + desc: desc, + }, nil + } + } + + return nil, fmt.Errorf("could not find layer in image: %s", h) +} + +type compressedBlob struct { + path Path + desc v1.Descriptor +} + +func (b *compressedBlob) Digest() (v1.Hash, error) { + return b.desc.Digest, nil +} + +func (b *compressedBlob) Compressed() (io.ReadCloser, error) { + return b.path.Blob(b.desc.Digest) +} + +func (b *compressedBlob) Size() (int64, error) { + return b.desc.Size, nil +} + +func (b *compressedBlob) MediaType() (types.MediaType, error) { + return b.desc.MediaType, nil +} + +// Descriptor implements partial.withDescriptor. +func (b *compressedBlob) Descriptor() (*v1.Descriptor, error) { + return &b.desc, nil +} + +// See partial.Exists. +func (b *compressedBlob) Exists() (bool, error) { + _, err := os.Stat(b.path.blobPath(b.desc.Digest)) + if os.IsNotExist(err) { + return false, nil + } + return err == nil, err +} |