Update vendor

vendor/github.com/google/go-containerregistry/pkg/v1/stream/README.md

@@ -0,0 +1,68 @@
+# `stream`
+
+[![GoDoc](https://godoc.org/github.com/google/go-containerregistry/pkg/v1/stream?status.svg)](https://godoc.org/github.com/google/go-containerregistry/pkg/v1/stream)
+
+The `stream` package contains an implementation of
+[`v1.Layer`](https://godoc.org/github.com/google/go-containerregistry/pkg/v1#Layer)
+that supports _streaming_ access, i.e. the layer contents are read once and not
+buffered.
+
+## Usage
+
+```go
+package main
+
+import (
+	"os"
+
+	"github.com/google/go-containerregistry/pkg/name"
+	"github.com/google/go-containerregistry/pkg/v1/remote"
+	"github.com/google/go-containerregistry/pkg/v1/stream"
+)
+
+// upload the contents of stdin as a layer to a local registry
+func main() {
+	repo, err := name.NewRepository("localhost:5000/stream")
+	if err != nil {
+		panic(err)
+	}
+
+	layer := stream.NewLayer(os.Stdin)
+
+	if err := remote.WriteLayer(repo, layer); err != nil {
+		panic(err)
+	}
+}
+```
+
+## Structure
+
+This implements the layer portion of an [image
+upload](/pkg/v1/remote#anatomy-of-an-image-upload). We launch a goroutine that
+is responsible for hashing the uncompressed contents to compute the `DiffID`,
+gzipping them to produce the `Compressed` contents, and hashing/counting the
+bytes to produce the `Digest`/`Size`. This goroutine writes to an
+`io.PipeWriter`, which blocks until `Compressed` reads the gzipped contents from
+the corresponding `io.PipeReader`.
+
+<p align="center">
+  <img src="/images/stream.dot.svg" />
+</p>
+
+## Caveats
+
+This assumes that you have an uncompressed layer (i.e. a tarball) and would like
+to compress it. Calling `Uncompressed` is always an error. Likewise, other
+methods are invalid until the contents of `Compressed` have been completely
+consumed and `Close`d.
+
+Using a `stream.Layer` will likely not work without careful consideration. For
+example, in the `mutate` package, we defer computing the manifest and config
+file until they are actually called. This allows you to `mutate.Append` a
+streaming layer to an image without accidentally consuming it. Similarly, in
+`remote.Write`, if calling `Digest` on a layer fails, we attempt to upload the
+layer anyway, understanding that we may be dealing with a `stream.Layer` whose
+contents need to be uploaded before we can upload the config file.
+
+Given the [structure](#structure) of how this is implemented, forgetting to
+`Close` a `stream.Layer` will leak a goroutine.

vendor/github.com/google/go-containerregistry/pkg/v1/stream/layer.go

@@ -0,0 +1,224 @@
+// 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 stream
+
+import (
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"hash"
+	"io"
+	"sync"
+
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/types"
+)
+
+var (
+	// ErrNotComputed is returned when the requested value is not yet
+	// computed because the stream has not been consumed yet.
+	ErrNotComputed = errors.New("value not computed until stream is consumed")
+
+	// ErrConsumed is returned by Compressed when the underlying stream has
+	// already been consumed and closed.
+	ErrConsumed = errors.New("stream was already consumed")
+)
+
+// Layer is a streaming implementation of v1.Layer.
+type Layer struct {
+	blob        io.ReadCloser
+	consumed    bool
+	compression int
+
+	mu             sync.Mutex
+	digest, diffID *v1.Hash
+	size           int64
+}
+
+var _ v1.Layer = (*Layer)(nil)
+
+// LayerOption applies options to layer
+type LayerOption func(*Layer)
+
+// WithCompressionLevel sets the gzip compression. See `gzip.NewWriterLevel` for possible values.
+func WithCompressionLevel(level int) LayerOption {
+	return func(l *Layer) {
+		l.compression = level
+	}
+}
+
+// NewLayer creates a Layer from an io.ReadCloser.
+func NewLayer(rc io.ReadCloser, opts ...LayerOption) *Layer {
+	layer := &Layer{
+		blob:        rc,
+		compression: gzip.BestSpeed,
+	}
+
+	for _, opt := range opts {
+		opt(layer)
+	}
+
+	return layer
+}
+
+// Digest implements v1.Layer.
+func (l *Layer) Digest() (v1.Hash, error) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.digest == nil {
+		return v1.Hash{}, ErrNotComputed
+	}
+	return *l.digest, nil
+}
+
+// DiffID implements v1.Layer.
+func (l *Layer) DiffID() (v1.Hash, error) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.diffID == nil {
+		return v1.Hash{}, ErrNotComputed
+	}
+	return *l.diffID, nil
+}
+
+// Size implements v1.Layer.
+func (l *Layer) Size() (int64, error) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	if l.size == 0 {
+		return 0, ErrNotComputed
+	}
+	return l.size, nil
+}
+
+// MediaType implements v1.Layer
+func (l *Layer) MediaType() (types.MediaType, error) {
+	// We return DockerLayer for now as uncompressed layers
+	// are unimplemented
+	return types.DockerLayer, nil
+}
+
+// Uncompressed implements v1.Layer.
+func (l *Layer) Uncompressed() (io.ReadCloser, error) {
+	return nil, errors.New("NYI: stream.Layer.Uncompressed is not implemented")
+}
+
+// Compressed implements v1.Layer.
+func (l *Layer) Compressed() (io.ReadCloser, error) {
+	if l.consumed {
+		return nil, ErrConsumed
+	}
+	return newCompressedReader(l)
+}
+
+type compressedReader struct {
+	closer io.Closer // original blob's Closer.
+
+	h, zh hash.Hash // collects digests of compressed and uncompressed stream.
+	pr    io.Reader
+	count *countWriter
+
+	l *Layer // stream.Layer to update upon Close.
+}
+
+func newCompressedReader(l *Layer) (*compressedReader, error) {
+	h := sha256.New()
+	zh := sha256.New()
+	count := &countWriter{}
+
+	// gzip.Writer writes to the output stream via pipe, a hasher to
+	// capture compressed digest, and a countWriter to capture compressed
+	// size.
+	pr, pw := io.Pipe()
+	zw, err := gzip.NewWriterLevel(io.MultiWriter(pw, zh, count), l.compression)
+	if err != nil {
+		return nil, err
+	}
+
+	cr := &compressedReader{
+		closer: newMultiCloser(zw, l.blob),
+		pr:     pr,
+		h:      h,
+		zh:     zh,
+		count:  count,
+		l:      l,
+	}
+	go func() {
+		if _, err := io.Copy(io.MultiWriter(h, zw), l.blob); err != nil {
+			pw.CloseWithError(err)
+			return
+		}
+		// Now close the compressed reader, to flush the gzip stream
+		// and calculate digest/diffID/size. This will cause pr to
+		// return EOF which will cause readers of the Compressed stream
+		// to finish reading.
+		pw.CloseWithError(cr.Close())
+	}()
+
+	return cr, nil
+}
+
+func (cr *compressedReader) Read(b []byte) (int, error) { return cr.pr.Read(b) }
+
+func (cr *compressedReader) Close() error {
+	cr.l.mu.Lock()
+	defer cr.l.mu.Unlock()
+
+	// Close the inner ReadCloser.
+	if err := cr.closer.Close(); err != nil {
+		return err
+	}
+
+	diffID, err := v1.NewHash("sha256:" + hex.EncodeToString(cr.h.Sum(nil)))
+	if err != nil {
+		return err
+	}
+	cr.l.diffID = &diffID
+
+	digest, err := v1.NewHash("sha256:" + hex.EncodeToString(cr.zh.Sum(nil)))
+	if err != nil {
+		return err
+	}
+	cr.l.digest = &digest
+
+	cr.l.size = cr.count.n
+	cr.l.consumed = true
+	return nil
+}
+
+// countWriter counts bytes written to it.
+type countWriter struct{ n int64 }
+
+func (c *countWriter) Write(p []byte) (int, error) {
+	c.n += int64(len(p))
+	return len(p), nil
+}
+
+// multiCloser is a Closer that collects multiple Closers and Closes them in order.
+type multiCloser []io.Closer
+
+var _ io.Closer = (multiCloser)(nil)
+
+func newMultiCloser(c ...io.Closer) multiCloser { return multiCloser(c) }
+
+func (m multiCloser) Close() error {
+	for _, c := range m {
+		if err := c.Close(); err != nil {
+			return err
+		}
+	}
+	return nil
+}