update vendor

vendor/github.com/google/go-containerregistry/pkg/v1/daemon/image.go

@@ -0,0 +1,89 @@
+// 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 daemon
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"io/ioutil"
+	"sync"
+
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/tarball"
+)
+
+type imageOpener struct {
+	ref name.Reference
+	ctx context.Context
+
+	buffered bool
+	client   Client
+
+	once  sync.Once
+	bytes []byte
+	err   error
+}
+
+func (i *imageOpener) saveImage() (io.ReadCloser, error) {
+	return i.client.ImageSave(i.ctx, []string{i.ref.Name()})
+}
+
+func (i *imageOpener) bufferedOpener() (io.ReadCloser, error) {
+	// Store the tarball in memory and return a new reader into the bytes each time we need to access something.
+	i.once.Do(func() {
+		i.bytes, i.err = func() ([]byte, error) {
+			rc, err := i.saveImage()
+			if err != nil {
+				return nil, err
+			}
+			defer rc.Close()
+
+			return ioutil.ReadAll(rc)
+		}()
+	})
+
+	// Wrap the bytes in a ReadCloser so it looks like an opened file.
+	return ioutil.NopCloser(bytes.NewReader(i.bytes)), i.err
+}
+
+func (i *imageOpener) opener() tarball.Opener {
+	if i.buffered {
+		return i.bufferedOpener
+	}
+
+	// To avoid storing the tarball in memory, do a save every time we need to access something.
+	return i.saveImage
+}
+
+// Image provides access to an image reference from the Docker daemon,
+// applying functional options to the underlying imageOpener before
+// resolving the reference into a v1.Image.
+func Image(ref name.Reference, options ...Option) (v1.Image, error) {
+	o, err := makeOptions(options...)
+	if err != nil {
+		return nil, err
+	}
+
+	i := &imageOpener{
+		ref:      ref,
+		buffered: o.buffered,
+		client:   o.client,
+		ctx:      o.ctx,
+	}
+
+	return tarball.Image(i.opener(), nil)
+}