cri-o/vendor/github.com/containers/image/docker/docker_image_dest.go
Dan Walsh d76645680f Bump image, storage, and image-spec
Bump containers/image (pulling in its new dependency on ostree-go),
containers/storage, and updated image-spec.

This pulls in the OCI v1.0 specifications and code that allows us to
support 1.0 images.

Signed-off-by: Dan Walsh <dwalsh@redhat.com>
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
2017-07-24 13:01:54 -04:00

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package docker
import (
"bytes"
"crypto/rand"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"os"
"path/filepath"
"github.com/Sirupsen/logrus"
"github.com/containers/image/docker/reference"
"github.com/containers/image/manifest"
"github.com/containers/image/types"
"github.com/docker/distribution/registry/api/errcode"
"github.com/docker/distribution/registry/api/v2"
"github.com/docker/distribution/registry/client"
"github.com/opencontainers/go-digest"
"github.com/pkg/errors"
)
var manifestMIMETypes = []string{
// TODO(runcom): we'll add OCI as part of another PR here
manifest.DockerV2Schema2MediaType,
manifest.DockerV2Schema1SignedMediaType,
manifest.DockerV2Schema1MediaType,
}
func supportedManifestMIMETypesMap() map[string]bool {
m := make(map[string]bool, len(manifestMIMETypes))
for _, mt := range manifestMIMETypes {
m[mt] = true
}
return m
}
type dockerImageDestination struct {
ref dockerReference
c *dockerClient
// State
manifestDigest digest.Digest // or "" if not yet known.
}
// newImageDestination creates a new ImageDestination for the specified image reference.
func newImageDestination(ctx *types.SystemContext, ref dockerReference) (types.ImageDestination, error) {
c, err := newDockerClient(ctx, ref, true, "pull,push")
if err != nil {
return nil, err
}
return &dockerImageDestination{
ref: ref,
c: c,
}, nil
}
// Reference returns the reference used to set up this destination. Note that this should directly correspond to user's intent,
// e.g. it should use the public hostname instead of the result of resolving CNAMEs or following redirects.
func (d *dockerImageDestination) Reference() types.ImageReference {
return d.ref
}
// Close removes resources associated with an initialized ImageDestination, if any.
func (d *dockerImageDestination) Close() error {
return nil
}
func (d *dockerImageDestination) SupportedManifestMIMETypes() []string {
return manifestMIMETypes
}
// SupportsSignatures returns an error (to be displayed to the user) if the destination certainly can't store signatures.
// Note: It is still possible for PutSignatures to fail if SupportsSignatures returns nil.
func (d *dockerImageDestination) SupportsSignatures() error {
if err := d.c.detectProperties(); err != nil {
return err
}
switch {
case d.c.signatureBase != nil:
return nil
case d.c.supportsSignatures:
return nil
default:
return errors.Errorf("X-Registry-Supports-Signatures extension not supported, and lookaside is not configured")
}
}
// ShouldCompressLayers returns true iff it is desirable to compress layer blobs written to this destination.
func (d *dockerImageDestination) ShouldCompressLayers() bool {
return true
}
// AcceptsForeignLayerURLs returns false iff foreign layers in manifest should be actually
// uploaded to the image destination, true otherwise.
func (d *dockerImageDestination) AcceptsForeignLayerURLs() bool {
return true
}
// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
func (d *dockerImageDestination) MustMatchRuntimeOS() bool {
return false
}
// sizeCounter is an io.Writer which only counts the total size of its input.
type sizeCounter struct{ size int64 }
func (c *sizeCounter) Write(p []byte) (n int, err error) {
c.size += int64(len(p))
return len(p), nil
}
// PutBlob writes contents of stream and returns data representing the result (with all data filled in).
// inputInfo.Digest can be optionally provided if known; it is not mandatory for the implementation to verify it.
// inputInfo.Size is the expected length of stream, if known.
// WARNING: The contents of stream are being verified on the fly. Until stream.Read() returns io.EOF, the contents of the data SHOULD NOT be available
// to any other readers for download using the supplied digest.
// If stream.Read() at any time, ESPECIALLY at end of input, returns an error, PutBlob MUST 1) fail, and 2) delete any data stored so far.
func (d *dockerImageDestination) PutBlob(stream io.Reader, inputInfo types.BlobInfo) (types.BlobInfo, error) {
if inputInfo.Digest.String() != "" {
haveBlob, size, err := d.HasBlob(inputInfo)
if err != nil {
return types.BlobInfo{}, err
}
if haveBlob {
return types.BlobInfo{Digest: inputInfo.Digest, Size: size}, nil
}
}
// FIXME? Chunked upload, progress reporting, etc.
uploadPath := fmt.Sprintf(blobUploadPath, reference.Path(d.ref.ref))
logrus.Debugf("Uploading %s", uploadPath)
res, err := d.c.makeRequest("POST", uploadPath, nil, nil)
if err != nil {
return types.BlobInfo{}, err
}
defer res.Body.Close()
if res.StatusCode != http.StatusAccepted {
logrus.Debugf("Error initiating layer upload, response %#v", *res)
return types.BlobInfo{}, errors.Errorf("Error initiating layer upload to %s, status %d", uploadPath, res.StatusCode)
}
uploadLocation, err := res.Location()
if err != nil {
return types.BlobInfo{}, errors.Wrap(err, "Error determining upload URL")
}
digester := digest.Canonical.Digester()
sizeCounter := &sizeCounter{}
tee := io.TeeReader(stream, io.MultiWriter(digester.Hash(), sizeCounter))
res, err = d.c.makeRequestToResolvedURL("PATCH", uploadLocation.String(), map[string][]string{"Content-Type": {"application/octet-stream"}}, tee, inputInfo.Size, true)
if err != nil {
logrus.Debugf("Error uploading layer chunked, response %#v", res)
return types.BlobInfo{}, err
}
defer res.Body.Close()
computedDigest := digester.Digest()
uploadLocation, err = res.Location()
if err != nil {
return types.BlobInfo{}, errors.Wrap(err, "Error determining upload URL")
}
// FIXME: DELETE uploadLocation on failure
locationQuery := uploadLocation.Query()
// TODO: check inputInfo.Digest == computedDigest https://github.com/containers/image/pull/70#discussion_r77646717
locationQuery.Set("digest", computedDigest.String())
uploadLocation.RawQuery = locationQuery.Encode()
res, err = d.c.makeRequestToResolvedURL("PUT", uploadLocation.String(), map[string][]string{"Content-Type": {"application/octet-stream"}}, nil, -1, true)
if err != nil {
return types.BlobInfo{}, err
}
defer res.Body.Close()
if res.StatusCode != http.StatusCreated {
logrus.Debugf("Error uploading layer, response %#v", *res)
return types.BlobInfo{}, errors.Errorf("Error uploading layer to %s, status %d", uploadLocation, res.StatusCode)
}
logrus.Debugf("Upload of layer %s complete", computedDigest)
return types.BlobInfo{Digest: computedDigest, Size: sizeCounter.size}, nil
}
// HasBlob returns true iff the image destination already contains a blob with the matching digest which can be reapplied using ReapplyBlob.
// Unlike PutBlob, the digest can not be empty. If HasBlob returns true, the size of the blob must also be returned.
// If the destination does not contain the blob, or it is unknown, HasBlob ordinarily returns (false, -1, nil);
// it returns a non-nil error only on an unexpected failure.
func (d *dockerImageDestination) HasBlob(info types.BlobInfo) (bool, int64, error) {
if info.Digest == "" {
return false, -1, errors.Errorf(`"Can not check for a blob with unknown digest`)
}
checkPath := fmt.Sprintf(blobsPath, reference.Path(d.ref.ref), info.Digest.String())
logrus.Debugf("Checking %s", checkPath)
res, err := d.c.makeRequest("HEAD", checkPath, nil, nil)
if err != nil {
return false, -1, err
}
defer res.Body.Close()
switch res.StatusCode {
case http.StatusOK:
logrus.Debugf("... already exists")
return true, getBlobSize(res), nil
case http.StatusUnauthorized:
logrus.Debugf("... not authorized")
return false, -1, errors.Errorf("not authorized to read from destination repository %s", reference.Path(d.ref.ref))
case http.StatusNotFound:
logrus.Debugf("... not present")
return false, -1, nil
default:
return false, -1, errors.Errorf("failed to read from destination repository %s: %v", reference.Path(d.ref.ref), http.StatusText(res.StatusCode))
}
}
func (d *dockerImageDestination) ReapplyBlob(info types.BlobInfo) (types.BlobInfo, error) {
return info, nil
}
// PutManifest writes manifest to the destination.
// FIXME? This should also receive a MIME type if known, to differentiate between schema versions.
// If the destination is in principle available, refuses this manifest type (e.g. it does not recognize the schema),
// but may accept a different manifest type, the returned error must be an ManifestTypeRejectedError.
func (d *dockerImageDestination) PutManifest(m []byte) error {
digest, err := manifest.Digest(m)
if err != nil {
return err
}
d.manifestDigest = digest
refTail, err := d.ref.tagOrDigest()
if err != nil {
return err
}
path := fmt.Sprintf(manifestPath, reference.Path(d.ref.ref), refTail)
headers := map[string][]string{}
mimeType := manifest.GuessMIMEType(m)
if mimeType != "" {
headers["Content-Type"] = []string{mimeType}
}
res, err := d.c.makeRequest("PUT", path, headers, bytes.NewReader(m))
if err != nil {
return err
}
defer res.Body.Close()
if res.StatusCode != http.StatusCreated {
err = errors.Wrapf(client.HandleErrorResponse(res), "Error uploading manifest to %s", path)
if isManifestInvalidError(errors.Cause(err)) {
err = types.ManifestTypeRejectedError{Err: err}
}
return err
}
return nil
}
// isManifestInvalidError returns true iff err from client.HandleErrorReponse is a “manifest invalid” error.
func isManifestInvalidError(err error) bool {
errors, ok := err.(errcode.Errors)
if !ok || len(errors) == 0 {
return false
}
ec, ok := errors[0].(errcode.ErrorCoder)
if !ok {
return false
}
// ErrorCodeManifestInvalid is returned by OpenShift with acceptschema2=false.
// ErrorCodeTagInvalid is returned by docker/distribution (at least as of commit ec87e9b6971d831f0eff752ddb54fb64693e51cd)
// when uploading to a tag (because it cant find a matching tag inside the manifest)
return ec.ErrorCode() == v2.ErrorCodeManifestInvalid || ec.ErrorCode() == v2.ErrorCodeTagInvalid
}
func (d *dockerImageDestination) PutSignatures(signatures [][]byte) error {
// Do not fail if we dont really need to support signatures.
if len(signatures) == 0 {
return nil
}
if err := d.c.detectProperties(); err != nil {
return err
}
switch {
case d.c.signatureBase != nil:
return d.putSignaturesToLookaside(signatures)
case d.c.supportsSignatures:
return d.putSignaturesToAPIExtension(signatures)
default:
return errors.Errorf("X-Registry-Supports-Signatures extension not supported, and lookaside is not configured")
}
}
// putSignaturesToLookaside implements PutSignatures() from the lookaside location configured in s.c.signatureBase,
// which is not nil.
func (d *dockerImageDestination) putSignaturesToLookaside(signatures [][]byte) error {
// FIXME? This overwrites files one at a time, definitely not atomic.
// A failure when updating signatures with a reordered copy could lose some of them.
// Skip dealing with the manifest digest if not necessary.
if len(signatures) == 0 {
return nil
}
if d.manifestDigest.String() == "" {
// This shouldnt happen, ImageDestination users are required to call PutManifest before PutSignatures
return errors.Errorf("Unknown manifest digest, can't add signatures")
}
// NOTE: Keep this in sync with docs/signature-protocols.md!
for i, signature := range signatures {
url := signatureStorageURL(d.c.signatureBase, d.manifestDigest, i)
if url == nil {
return errors.Errorf("Internal error: signatureStorageURL with non-nil base returned nil")
}
err := d.putOneSignature(url, signature)
if err != nil {
return err
}
}
// Remove any other signatures, if present.
// We stop at the first missing signature; if a previous deleting loop aborted
// prematurely, this may not clean up all of them, but one missing signature
// is enough for dockerImageSource to stop looking for other signatures, so that
// is sufficient.
for i := len(signatures); ; i++ {
url := signatureStorageURL(d.c.signatureBase, d.manifestDigest, i)
if url == nil {
return errors.Errorf("Internal error: signatureStorageURL with non-nil base returned nil")
}
missing, err := d.c.deleteOneSignature(url)
if err != nil {
return err
}
if missing {
break
}
}
return nil
}
// putOneSignature stores one signature to url.
// NOTE: Keep this in sync with docs/signature-protocols.md!
func (d *dockerImageDestination) putOneSignature(url *url.URL, signature []byte) error {
switch url.Scheme {
case "file":
logrus.Debugf("Writing to %s", url.Path)
err := os.MkdirAll(filepath.Dir(url.Path), 0755)
if err != nil {
return err
}
err = ioutil.WriteFile(url.Path, signature, 0644)
if err != nil {
return err
}
return nil
case "http", "https":
return errors.Errorf("Writing directly to a %s sigstore %s is not supported. Configure a sigstore-staging: location", url.Scheme, url.String())
default:
return errors.Errorf("Unsupported scheme when writing signature to %s", url.String())
}
}
// deleteOneSignature deletes a signature from url, if it exists.
// If it successfully determines that the signature does not exist, returns (true, nil)
// NOTE: Keep this in sync with docs/signature-protocols.md!
func (c *dockerClient) deleteOneSignature(url *url.URL) (missing bool, err error) {
switch url.Scheme {
case "file":
logrus.Debugf("Deleting %s", url.Path)
err := os.Remove(url.Path)
if err != nil && os.IsNotExist(err) {
return true, nil
}
return false, err
case "http", "https":
return false, errors.Errorf("Writing directly to a %s sigstore %s is not supported. Configure a sigstore-staging: location", url.Scheme, url.String())
default:
return false, errors.Errorf("Unsupported scheme when deleting signature from %s", url.String())
}
}
// putSignaturesToAPIExtension implements PutSignatures() using the X-Registry-Supports-Signatures API extension.
func (d *dockerImageDestination) putSignaturesToAPIExtension(signatures [][]byte) error {
// Skip dealing with the manifest digest, or reading the old state, if not necessary.
if len(signatures) == 0 {
return nil
}
if d.manifestDigest.String() == "" {
// This shouldnt happen, ImageDestination users are required to call PutManifest before PutSignatures
return errors.Errorf("Unknown manifest digest, can't add signatures")
}
// Because image signatures are a shared resource in Atomic Registry, the default upload
// always adds signatures. Eventually we should also allow removing signatures,
// but the X-Registry-Supports-Signatures API extension does not support that yet.
existingSignatures, err := d.c.getExtensionsSignatures(d.ref, d.manifestDigest)
if err != nil {
return err
}
existingSigNames := map[string]struct{}{}
for _, sig := range existingSignatures.Signatures {
existingSigNames[sig.Name] = struct{}{}
}
sigExists:
for _, newSig := range signatures {
for _, existingSig := range existingSignatures.Signatures {
if existingSig.Version == extensionSignatureSchemaVersion && existingSig.Type == extensionSignatureTypeAtomic && bytes.Equal(existingSig.Content, newSig) {
continue sigExists
}
}
// The API expect us to invent a new unique name. This is racy, but hopefully good enough.
var signatureName string
for {
randBytes := make([]byte, 16)
n, err := rand.Read(randBytes)
if err != nil || n != 16 {
return errors.Wrapf(err, "Error generating random signature len %d", n)
}
signatureName = fmt.Sprintf("%s@%032x", d.manifestDigest.String(), randBytes)
if _, ok := existingSigNames[signatureName]; !ok {
break
}
}
sig := extensionSignature{
Version: extensionSignatureSchemaVersion,
Name: signatureName,
Type: extensionSignatureTypeAtomic,
Content: newSig,
}
body, err := json.Marshal(sig)
if err != nil {
return err
}
path := fmt.Sprintf(extensionsSignaturePath, reference.Path(d.ref.ref), d.manifestDigest.String())
res, err := d.c.makeRequest("PUT", path, nil, bytes.NewReader(body))
if err != nil {
return err
}
defer res.Body.Close()
if res.StatusCode != http.StatusCreated {
body, err := ioutil.ReadAll(res.Body)
if err == nil {
logrus.Debugf("Error body %s", string(body))
}
logrus.Debugf("Error uploading signature, status %d, %#v", res.StatusCode, res)
return errors.Errorf("Error uploading signature to %s, status %d", path, res.StatusCode)
}
}
return nil
}
// Commit marks the process of storing the image as successful and asks for the image to be persisted.
// WARNING: This does not have any transactional semantics:
// - Uploaded data MAY be visible to others before Commit() is called
// - Uploaded data MAY be removed or MAY remain around if Close() is called without Commit() (i.e. rollback is allowed but not guaranteed)
func (d *dockerImageDestination) Commit() error {
return nil
}