imagetools inspect: add --format flag

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/moby/buildkit/util/contentutil/buffer.go

@@ -0,0 +1,156 @@
+package contentutil
+
+import (
+	"bytes"
+	"context"
+	"io/ioutil"
+	"sync"
+	"time"
+
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/errdefs"
+	digest "github.com/opencontainers/go-digest"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+// Buffer is a content provider and ingester that keeps data in memory
+type Buffer interface {
+	content.Provider
+	content.Ingester
+}
+
+// NewBuffer returns a new buffer
+func NewBuffer() Buffer {
+	return &buffer{
+		buffers: map[digest.Digest][]byte{},
+		refs:    map[string]struct{}{},
+	}
+}
+
+type buffer struct {
+	mu      sync.Mutex
+	buffers map[digest.Digest][]byte
+	refs    map[string]struct{}
+}
+
+func (b *buffer) Writer(ctx context.Context, opts ...content.WriterOpt) (content.Writer, error) {
+	var wOpts content.WriterOpts
+	for _, opt := range opts {
+		if err := opt(&wOpts); err != nil {
+			return nil, err
+		}
+	}
+	b.mu.Lock()
+	if _, ok := b.refs[wOpts.Ref]; ok {
+		return nil, errors.Wrapf(errdefs.ErrUnavailable, "ref %s locked", wOpts.Ref)
+	}
+	b.mu.Unlock()
+	return &bufferedWriter{
+		main:     b,
+		digester: digest.Canonical.Digester(),
+		buffer:   bytes.NewBuffer(nil),
+		expected: wOpts.Desc.Digest,
+		releaseRef: func() {
+			b.mu.Lock()
+			delete(b.refs, wOpts.Ref)
+			b.mu.Unlock()
+		},
+	}, nil
+}
+
+func (b *buffer) ReaderAt(ctx context.Context, desc ocispecs.Descriptor) (content.ReaderAt, error) {
+	r, err := b.getBytesReader(ctx, desc.Digest)
+	if err != nil {
+		return nil, err
+	}
+	return &readerAt{Reader: r, Closer: ioutil.NopCloser(r), size: int64(r.Len())}, nil
+}
+
+func (b *buffer) getBytesReader(ctx context.Context, dgst digest.Digest) (*bytes.Reader, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if dt, ok := b.buffers[dgst]; ok {
+		return bytes.NewReader(dt), nil
+	}
+
+	return nil, errors.Wrapf(errdefs.ErrNotFound, "content %v", dgst)
+}
+
+func (b *buffer) addValue(k digest.Digest, dt []byte) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.buffers[k] = dt
+}
+
+type bufferedWriter struct {
+	main       *buffer
+	ref        string
+	offset     int64
+	total      int64
+	startedAt  time.Time
+	updatedAt  time.Time
+	buffer     *bytes.Buffer
+	expected   digest.Digest
+	digester   digest.Digester
+	releaseRef func()
+}
+
+func (w *bufferedWriter) Write(p []byte) (n int, err error) {
+	n, err = w.buffer.Write(p)
+	w.digester.Hash().Write(p[:n])
+	w.offset += int64(len(p))
+	w.updatedAt = time.Now()
+	return n, err
+}
+
+func (w *bufferedWriter) Close() error {
+	if w.buffer != nil {
+		w.releaseRef()
+		w.buffer = nil
+	}
+	return nil
+}
+
+func (w *bufferedWriter) Status() (content.Status, error) {
+	return content.Status{
+		Ref:       w.ref,
+		Offset:    w.offset,
+		Total:     w.total,
+		StartedAt: w.startedAt,
+		UpdatedAt: w.updatedAt,
+	}, nil
+}
+
+func (w *bufferedWriter) Digest() digest.Digest {
+	return w.digester.Digest()
+}
+
+func (w *bufferedWriter) Commit(ctx context.Context, size int64, expected digest.Digest, opt ...content.Opt) error {
+	if w.buffer == nil {
+		return errors.Errorf("can't commit already committed or closed")
+	}
+	if s := int64(w.buffer.Len()); size > 0 && size != s {
+		return errors.Errorf("unexpected commit size %d, expected %d", s, size)
+	}
+	dgst := w.digester.Digest()
+	if expected != "" && expected != dgst {
+		return errors.Errorf("unexpected digest: %v != %v", dgst, expected)
+	}
+	if w.expected != "" && w.expected != dgst {
+		return errors.Errorf("unexpected digest: %v != %v", dgst, w.expected)
+	}
+	w.main.addValue(dgst, w.buffer.Bytes())
+	return w.Close()
+}
+
+func (w *bufferedWriter) Truncate(size int64) error {
+	if size != 0 {
+		return errors.New("Truncate: unsupported size")
+	}
+	w.offset = 0
+	w.digester.Hash().Reset()
+	w.buffer.Reset()
+	return nil
+}

vendor/github.com/moby/buildkit/util/contentutil/copy.go

@@ -0,0 +1,94 @@
+package contentutil
+
+import (
+	"context"
+	"io"
+	"sync"
+
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/images"
+	"github.com/moby/buildkit/util/resolver/limited"
+	"github.com/moby/buildkit/util/resolver/retryhandler"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+func Copy(ctx context.Context, ingester content.Ingester, provider content.Provider, desc ocispecs.Descriptor, ref string, logger func([]byte)) error {
+	if _, err := retryhandler.New(limited.FetchHandler(ingester, &localFetcher{provider}, ref), logger)(ctx, desc); err != nil {
+		return err
+	}
+	return nil
+}
+
+type localFetcher struct {
+	content.Provider
+}
+
+func (f *localFetcher) Fetch(ctx context.Context, desc ocispecs.Descriptor) (io.ReadCloser, error) {
+	r, err := f.Provider.ReaderAt(ctx, desc)
+	if err != nil {
+		return nil, err
+	}
+	return &rc{ReaderAt: r}, nil
+}
+
+type rc struct {
+	content.ReaderAt
+	offset int64
+}
+
+func (r *rc) Read(b []byte) (int, error) {
+	n, err := r.ReadAt(b, r.offset)
+	r.offset += int64(n)
+	if n > 0 && err == io.EOF {
+		err = nil
+	}
+	return n, err
+}
+
+func (r *rc) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	case io.SeekStart:
+		r.offset = offset
+	case io.SeekCurrent:
+		r.offset += offset
+	case io.SeekEnd:
+		r.offset = r.Size() - offset
+	}
+	return r.offset, nil
+}
+
+func CopyChain(ctx context.Context, ingester content.Ingester, provider content.Provider, desc ocispecs.Descriptor) error {
+	var m sync.Mutex
+	manifestStack := []ocispecs.Descriptor{}
+
+	filterHandler := images.HandlerFunc(func(ctx context.Context, desc ocispecs.Descriptor) ([]ocispecs.Descriptor, error) {
+		switch desc.MediaType {
+		case images.MediaTypeDockerSchema2Manifest, ocispecs.MediaTypeImageManifest,
+			images.MediaTypeDockerSchema2ManifestList, ocispecs.MediaTypeImageIndex:
+			m.Lock()
+			manifestStack = append(manifestStack, desc)
+			m.Unlock()
+			return nil, images.ErrStopHandler
+		default:
+			return nil, nil
+		}
+	})
+	handlers := []images.Handler{
+		images.ChildrenHandler(provider),
+		filterHandler,
+		retryhandler.New(limited.FetchHandler(ingester, &localFetcher{provider}, ""), func(_ []byte) {}),
+	}
+
+	if err := images.Dispatch(ctx, images.Handlers(handlers...), nil, desc); err != nil {
+		return errors.WithStack(err)
+	}
+
+	for i := len(manifestStack) - 1; i >= 0; i-- {
+		if err := Copy(ctx, ingester, provider, manifestStack[i], "", nil); err != nil {
+			return errors.WithStack(err)
+		}
+	}
+
+	return nil
+}

vendor/github.com/moby/buildkit/util/contentutil/fetcher.go

@@ -0,0 +1,73 @@
+package contentutil
+
+import (
+	"context"
+	"io"
+
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/remotes"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+func FromFetcher(f remotes.Fetcher) content.Provider {
+	return &fetchedProvider{
+		f: f,
+	}
+}
+
+type fetchedProvider struct {
+	f remotes.Fetcher
+}
+
+func (p *fetchedProvider) ReaderAt(ctx context.Context, desc ocispecs.Descriptor) (content.ReaderAt, error) {
+	rc, err := p.f.Fetch(ctx, desc)
+	if err != nil {
+		return nil, err
+	}
+
+	return &readerAt{Reader: rc, Closer: rc, size: desc.Size}, nil
+}
+
+type readerAt struct {
+	io.Reader
+	io.Closer
+	size   int64
+	offset int64
+}
+
+func (r *readerAt) ReadAt(b []byte, off int64) (int, error) {
+	if ra, ok := r.Reader.(io.ReaderAt); ok {
+		return ra.ReadAt(b, off)
+	}
+
+	if r.offset != off {
+		if seeker, ok := r.Reader.(io.Seeker); ok {
+			if _, err := seeker.Seek(off, io.SeekStart); err != nil {
+				return 0, err
+			}
+			r.offset = off
+		} else {
+			return 0, errors.Errorf("unsupported offset")
+		}
+	}
+
+	var totalN int
+	for len(b) > 0 {
+		n, err := r.Reader.Read(b)
+		if err == io.EOF && n == len(b) {
+			err = nil
+		}
+		r.offset += int64(n)
+		totalN += n
+		b = b[n:]
+		if err != nil {
+			return totalN, err
+		}
+	}
+	return totalN, nil
+}
+
+func (r *readerAt) Size() int64 {
+	return r.size
+}

vendor/github.com/moby/buildkit/util/contentutil/multiprovider.go

@@ -0,0 +1,92 @@
+package contentutil
+
+import (
+	"context"
+	"sync"
+
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/errdefs"
+	digest "github.com/opencontainers/go-digest"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+// NewMultiProvider creates a new mutable provider with a base provider
+func NewMultiProvider(base content.Provider) *MultiProvider {
+	return &MultiProvider{
+		base: base,
+		sub:  map[digest.Digest]content.Provider{},
+	}
+}
+
+// MultiProvider is a provider backed by a mutable map of providers
+type MultiProvider struct {
+	mu   sync.RWMutex
+	base content.Provider
+	sub  map[digest.Digest]content.Provider
+}
+
+func (mp *MultiProvider) SnapshotLabels(descs []ocispecs.Descriptor, index int) map[string]string {
+	if len(descs) < index {
+		return nil
+	}
+	desc := descs[index]
+	type snapshotLabels interface {
+		SnapshotLabels([]ocispecs.Descriptor, int) map[string]string
+	}
+
+	mp.mu.RLock()
+	if p, ok := mp.sub[desc.Digest]; ok {
+		mp.mu.RUnlock()
+		if cd, ok := p.(snapshotLabels); ok {
+			return cd.SnapshotLabels(descs, index)
+		}
+	} else {
+		mp.mu.RUnlock()
+	}
+	if cd, ok := mp.base.(snapshotLabels); ok {
+		return cd.SnapshotLabels(descs, index)
+	}
+	return nil
+}
+
+func (mp *MultiProvider) CheckDescriptor(ctx context.Context, desc ocispecs.Descriptor) error {
+	type checkDescriptor interface {
+		CheckDescriptor(context.Context, ocispecs.Descriptor) error
+	}
+
+	mp.mu.RLock()
+	if p, ok := mp.sub[desc.Digest]; ok {
+		mp.mu.RUnlock()
+		if cd, ok := p.(checkDescriptor); ok {
+			return cd.CheckDescriptor(ctx, desc)
+		}
+	} else {
+		mp.mu.RUnlock()
+	}
+	if cd, ok := mp.base.(checkDescriptor); ok {
+		return cd.CheckDescriptor(ctx, desc)
+	}
+	return nil
+}
+
+// ReaderAt returns a content.ReaderAt
+func (mp *MultiProvider) ReaderAt(ctx context.Context, desc ocispecs.Descriptor) (content.ReaderAt, error) {
+	mp.mu.RLock()
+	if p, ok := mp.sub[desc.Digest]; ok {
+		mp.mu.RUnlock()
+		return p.ReaderAt(ctx, desc)
+	}
+	mp.mu.RUnlock()
+	if mp.base == nil {
+		return nil, errors.Wrapf(errdefs.ErrNotFound, "content %v", desc.Digest)
+	}
+	return mp.base.ReaderAt(ctx, desc)
+}
+
+// Add adds a new child provider for a specific digest
+func (mp *MultiProvider) Add(dgst digest.Digest, p content.Provider) {
+	mp.mu.Lock()
+	defer mp.mu.Unlock()
+	mp.sub[dgst] = p
+}

vendor/github.com/moby/buildkit/util/contentutil/pusher.go

@@ -0,0 +1,122 @@
+package contentutil
+
+import (
+	"context"
+	"runtime"
+	"sync"
+	"time"
+
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/remotes"
+	digest "github.com/opencontainers/go-digest"
+	"github.com/pkg/errors"
+)
+
+func FromPusher(p remotes.Pusher) content.Ingester {
+	var mu sync.Mutex
+	c := sync.NewCond(&mu)
+	return &pushingIngester{
+		mu:     &mu,
+		c:      c,
+		p:      p,
+		active: map[digest.Digest]struct{}{},
+	}
+}
+
+type pushingIngester struct {
+	p remotes.Pusher
+
+	mu     *sync.Mutex
+	c      *sync.Cond
+	active map[digest.Digest]struct{}
+}
+
+// Writer implements content.Ingester. desc.MediaType must be set for manifest blobs.
+func (i *pushingIngester) Writer(ctx context.Context, opts ...content.WriterOpt) (content.Writer, error) {
+	var wOpts content.WriterOpts
+	for _, opt := range opts {
+		if err := opt(&wOpts); err != nil {
+			return nil, err
+		}
+	}
+	if wOpts.Ref == "" {
+		return nil, errors.Wrap(errdefs.ErrInvalidArgument, "ref must not be empty")
+	}
+
+	st := time.Now()
+
+	i.mu.Lock()
+	for {
+		if time.Since(st) > time.Hour {
+			i.mu.Unlock()
+			return nil, errors.Wrapf(errdefs.ErrUnavailable, "ref %v locked", wOpts.Desc.Digest)
+		}
+		if _, ok := i.active[wOpts.Desc.Digest]; ok {
+			i.c.Wait()
+		} else {
+			break
+		}
+	}
+
+	i.active[wOpts.Desc.Digest] = struct{}{}
+	i.mu.Unlock()
+
+	var once sync.Once
+	release := func() {
+		once.Do(func() {
+			i.mu.Lock()
+			delete(i.active, wOpts.Desc.Digest)
+			i.c.Broadcast()
+			i.mu.Unlock()
+		})
+	}
+
+	// pusher requires desc.MediaType to determine the PUT URL, especially for manifest blobs.
+	contentWriter, err := i.p.Push(ctx, wOpts.Desc)
+	if err != nil {
+		release()
+		return nil, err
+	}
+	runtime.SetFinalizer(contentWriter, func(_ content.Writer) {
+		release()
+	})
+	return &writer{
+		Writer:           contentWriter,
+		contentWriterRef: wOpts.Ref,
+		release:          release,
+	}, nil
+}
+
+type writer struct {
+	content.Writer          // returned from pusher.Push
+	contentWriterRef string // ref passed for Writer()
+	release          func()
+}
+
+func (w *writer) Status() (content.Status, error) {
+	st, err := w.Writer.Status()
+	if err != nil {
+		return st, err
+	}
+	if w.contentWriterRef != "" {
+		st.Ref = w.contentWriterRef
+	}
+	return st, nil
+}
+
+func (w *writer) Commit(ctx context.Context, size int64, expected digest.Digest, opts ...content.Opt) error {
+	err := w.Writer.Commit(ctx, size, expected, opts...)
+	if w.release != nil {
+		w.release()
+	}
+	return err
+}
+
+func (w *writer) Close() error {
+	err := w.Writer.Close()
+	if w.release != nil {
+		w.release()
+	}
+	return err
+}

vendor/github.com/moby/buildkit/util/contentutil/refs.go

@@ -0,0 +1,109 @@
+package contentutil
+
+import (
+	"context"
+	"net/http"
+	"sync"
+
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/remotes"
+	"github.com/containerd/containerd/remotes/docker"
+	"github.com/moby/buildkit/version"
+	"github.com/moby/locker"
+	digest "github.com/opencontainers/go-digest"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+func ProviderFromRef(ref string) (ocispecs.Descriptor, content.Provider, error) {
+	headers := http.Header{}
+	headers.Set("User-Agent", version.UserAgent())
+	remote := docker.NewResolver(docker.ResolverOptions{
+		Client:  http.DefaultClient,
+		Headers: headers,
+	})
+
+	name, desc, err := remote.Resolve(context.TODO(), ref)
+	if err != nil {
+		return ocispecs.Descriptor{}, nil, err
+	}
+
+	fetcher, err := remote.Fetcher(context.TODO(), name)
+	if err != nil {
+		return ocispecs.Descriptor{}, nil, err
+	}
+	return desc, FromFetcher(fetcher), nil
+}
+
+func IngesterFromRef(ref string) (content.Ingester, error) {
+	headers := http.Header{}
+	headers.Set("User-Agent", version.UserAgent())
+	remote := docker.NewResolver(docker.ResolverOptions{
+		Client:  http.DefaultClient,
+		Headers: headers,
+	})
+
+	p, err := remote.Pusher(context.TODO(), ref)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ingester{
+		locker: locker.New(),
+		pusher: &pusher{p},
+	}, nil
+}
+
+type pusher struct {
+	remotes.Pusher
+}
+
+type ingester struct {
+	locker *locker.Locker
+	pusher remotes.Pusher
+}
+
+func (w *ingester) Writer(ctx context.Context, opts ...content.WriterOpt) (content.Writer, error) {
+	var wo content.WriterOpts
+	for _, o := range opts {
+		if err := o(&wo); err != nil {
+			return nil, err
+		}
+	}
+	if wo.Ref == "" {
+		return nil, errors.Wrap(errdefs.ErrInvalidArgument, "ref must not be empty")
+	}
+	w.locker.Lock(wo.Ref)
+	var once sync.Once
+	unlock := func() {
+		once.Do(func() {
+			w.locker.Unlock(wo.Ref)
+		})
+	}
+	writer, err := w.pusher.Push(ctx, wo.Desc)
+	if err != nil {
+		unlock()
+		return nil, err
+	}
+	return &lockedWriter{unlock: unlock, Writer: writer}, nil
+}
+
+type lockedWriter struct {
+	unlock func()
+	content.Writer
+}
+
+func (w *lockedWriter) Commit(ctx context.Context, size int64, expected digest.Digest, opts ...content.Opt) error {
+	err := w.Writer.Commit(ctx, size, expected, opts...)
+	if err == nil {
+		w.unlock()
+	}
+	return err
+}
+
+func (w *lockedWriter) Close() error {
+	err := w.Writer.Close()
+	w.unlock()
+	return err
+}