distribution/registry/handlers/images.go
Derek McGowan d7eb5d118a Fix schema1 manifest etag and docker content digest header
When schema2 manifests are rewritten as schema1 currently the etag and docker content digest header keep the value for the schema2 manifest.

Fixes #1444

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
2016-02-23 14:36:36 -08:00

356 lines
11 KiB
Go

package handlers
import (
"bytes"
"fmt"
"net/http"
"github.com/docker/distribution"
ctxu "github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/manifest/manifestlist"
"github.com/docker/distribution/manifest/schema1"
"github.com/docker/distribution/manifest/schema2"
"github.com/docker/distribution/reference"
"github.com/docker/distribution/registry/api/errcode"
"github.com/docker/distribution/registry/api/v2"
"github.com/gorilla/handlers"
)
// These constants determine which architecture and OS to choose from a
// manifest list when downconverting it to a schema1 manifest.
const (
defaultArch = "amd64"
defaultOS = "linux"
)
// imageManifestDispatcher takes the request context and builds the
// appropriate handler for handling image manifest requests.
func imageManifestDispatcher(ctx *Context, r *http.Request) http.Handler {
imageManifestHandler := &imageManifestHandler{
Context: ctx,
}
reference := getReference(ctx)
dgst, err := digest.ParseDigest(reference)
if err != nil {
// We just have a tag
imageManifestHandler.Tag = reference
} else {
imageManifestHandler.Digest = dgst
}
mhandler := handlers.MethodHandler{
"GET": http.HandlerFunc(imageManifestHandler.GetImageManifest),
"HEAD": http.HandlerFunc(imageManifestHandler.GetImageManifest),
}
if !ctx.readOnly {
mhandler["PUT"] = http.HandlerFunc(imageManifestHandler.PutImageManifest)
mhandler["DELETE"] = http.HandlerFunc(imageManifestHandler.DeleteImageManifest)
}
return mhandler
}
// imageManifestHandler handles http operations on image manifests.
type imageManifestHandler struct {
*Context
// One of tag or digest gets set, depending on what is present in context.
Tag string
Digest digest.Digest
}
// GetImageManifest fetches the image manifest from the storage backend, if it exists.
func (imh *imageManifestHandler) GetImageManifest(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(imh).Debug("GetImageManifest")
manifests, err := imh.Repository.Manifests(imh)
if err != nil {
imh.Errors = append(imh.Errors, err)
return
}
var manifest distribution.Manifest
if imh.Tag != "" {
tags := imh.Repository.Tags(imh)
desc, err := tags.Get(imh, imh.Tag)
if err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err))
return
}
imh.Digest = desc.Digest
}
if etagMatch(r, imh.Digest.String()) {
w.WriteHeader(http.StatusNotModified)
return
}
manifest, err = manifests.Get(imh, imh.Digest)
if err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err))
return
}
supportsSchema2 := false
supportsManifestList := false
if acceptHeaders, ok := r.Header["Accept"]; ok {
for _, mediaType := range acceptHeaders {
if mediaType == schema2.MediaTypeManifest {
supportsSchema2 = true
}
if mediaType == manifestlist.MediaTypeManifestList {
supportsManifestList = true
}
}
}
schema2Manifest, isSchema2 := manifest.(*schema2.DeserializedManifest)
manifestList, isManifestList := manifest.(*manifestlist.DeserializedManifestList)
// Only rewrite schema2 manifests when they are being fetched by tag.
// If they are being fetched by digest, we can't return something not
// matching the digest.
if imh.Tag != "" && isSchema2 && !supportsSchema2 {
// Rewrite manifest in schema1 format
ctxu.GetLogger(imh).Infof("rewriting manifest %s in schema1 format to support old client", imh.Digest.String())
manifest, err = imh.convertSchema2Manifest(schema2Manifest)
if err != nil {
return
}
} else if imh.Tag != "" && isManifestList && !supportsManifestList {
// Rewrite manifest in schema1 format
ctxu.GetLogger(imh).Infof("rewriting manifest list %s in schema1 format to support old client", imh.Digest.String())
// Find the image manifest corresponding to the default
// platform
var manifestDigest digest.Digest
for _, manifestDescriptor := range manifestList.Manifests {
if manifestDescriptor.Platform.Architecture == defaultArch && manifestDescriptor.Platform.OS == defaultOS {
manifestDigest = manifestDescriptor.Digest
break
}
}
if manifestDigest == "" {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown)
return
}
manifest, err = manifests.Get(imh, manifestDigest)
if err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err))
return
}
// If necessary, convert the image manifest
if schema2Manifest, isSchema2 := manifest.(*schema2.DeserializedManifest); isSchema2 && !supportsSchema2 {
manifest, err = imh.convertSchema2Manifest(schema2Manifest)
if err != nil {
return
}
}
}
ct, p, err := manifest.Payload()
if err != nil {
return
}
w.Header().Set("Content-Type", ct)
w.Header().Set("Content-Length", fmt.Sprint(len(p)))
w.Header().Set("Docker-Content-Digest", imh.Digest.String())
w.Header().Set("Etag", fmt.Sprintf(`"%s"`, imh.Digest))
w.Write(p)
}
func (imh *imageManifestHandler) convertSchema2Manifest(schema2Manifest *schema2.DeserializedManifest) (distribution.Manifest, error) {
targetDescriptor := schema2Manifest.Target()
blobs := imh.Repository.Blobs(imh)
configJSON, err := blobs.Get(imh, targetDescriptor.Digest)
if err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err))
return nil, err
}
ref := imh.Repository.Name()
if imh.Tag != "" {
ref, err = reference.WithTag(imh.Repository.Name(), imh.Tag)
if err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeTagInvalid.WithDetail(err))
return nil, err
}
}
builder := schema1.NewConfigManifestBuilder(imh.Repository.Blobs(imh), imh.Context.App.trustKey, ref, configJSON)
for _, d := range schema2Manifest.References() {
if err := builder.AppendReference(d); err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err))
return nil, err
}
}
manifest, err := builder.Build(imh)
if err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err))
return nil, err
}
imh.Digest = digest.FromBytes(manifest.(*schema1.SignedManifest).Canonical)
return manifest, nil
}
func etagMatch(r *http.Request, etag string) bool {
for _, headerVal := range r.Header["If-None-Match"] {
if headerVal == etag || headerVal == fmt.Sprintf(`"%s"`, etag) { // allow quoted or unquoted
return true
}
}
return false
}
// PutImageManifest validates and stores an image in the registry.
func (imh *imageManifestHandler) PutImageManifest(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(imh).Debug("PutImageManifest")
manifests, err := imh.Repository.Manifests(imh)
if err != nil {
imh.Errors = append(imh.Errors, err)
return
}
var jsonBuf bytes.Buffer
if err := copyFullPayload(w, r, &jsonBuf, imh, "image manifest PUT", &imh.Errors); err != nil {
// copyFullPayload reports the error if necessary
return
}
mediaType := r.Header.Get("Content-Type")
manifest, desc, err := distribution.UnmarshalManifest(mediaType, jsonBuf.Bytes())
if err != nil {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err))
return
}
if imh.Digest != "" {
if desc.Digest != imh.Digest {
ctxu.GetLogger(imh).Errorf("payload digest does match: %q != %q", desc.Digest, imh.Digest)
imh.Errors = append(imh.Errors, v2.ErrorCodeDigestInvalid)
return
}
} else if imh.Tag != "" {
imh.Digest = desc.Digest
} else {
imh.Errors = append(imh.Errors, v2.ErrorCodeTagInvalid.WithDetail("no tag or digest specified"))
return
}
_, err = manifests.Put(imh, manifest)
if err != nil {
// TODO(stevvooe): These error handling switches really need to be
// handled by an app global mapper.
if err == distribution.ErrUnsupported {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnsupported)
return
}
switch err := err.(type) {
case distribution.ErrManifestVerification:
for _, verificationError := range err {
switch verificationError := verificationError.(type) {
case distribution.ErrManifestBlobUnknown:
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestBlobUnknown.WithDetail(verificationError.Digest))
case distribution.ErrManifestNameInvalid:
imh.Errors = append(imh.Errors, v2.ErrorCodeNameInvalid.WithDetail(err))
case distribution.ErrManifestUnverified:
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnverified)
default:
if verificationError == digest.ErrDigestInvalidFormat {
imh.Errors = append(imh.Errors, v2.ErrorCodeDigestInvalid)
} else {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown, verificationError)
}
}
}
default:
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
return
}
// Tag this manifest
if imh.Tag != "" {
tags := imh.Repository.Tags(imh)
err = tags.Tag(imh, imh.Tag, desc)
if err != nil {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
}
// Construct a canonical url for the uploaded manifest.
ref, err := reference.WithDigest(imh.Repository.Name(), imh.Digest)
if err != nil {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
location, err := imh.urlBuilder.BuildManifestURL(ref)
if err != nil {
// NOTE(stevvooe): Given the behavior above, this absurdly unlikely to
// happen. We'll log the error here but proceed as if it worked. Worst
// case, we set an empty location header.
ctxu.GetLogger(imh).Errorf("error building manifest url from digest: %v", err)
}
w.Header().Set("Location", location)
w.Header().Set("Docker-Content-Digest", imh.Digest.String())
w.WriteHeader(http.StatusCreated)
}
// DeleteImageManifest removes the manifest with the given digest from the registry.
func (imh *imageManifestHandler) DeleteImageManifest(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(imh).Debug("DeleteImageManifest")
manifests, err := imh.Repository.Manifests(imh)
if err != nil {
imh.Errors = append(imh.Errors, err)
return
}
err = manifests.Delete(imh, imh.Digest)
if err != nil {
switch err {
case digest.ErrDigestUnsupported:
case digest.ErrDigestInvalidFormat:
imh.Errors = append(imh.Errors, v2.ErrorCodeDigestInvalid)
return
case distribution.ErrBlobUnknown:
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown)
return
case distribution.ErrUnsupported:
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnsupported)
return
default:
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown)
return
}
}
tagService := imh.Repository.Tags(imh)
referencedTags, err := tagService.Lookup(imh, distribution.Descriptor{Digest: imh.Digest})
if err != nil {
imh.Errors = append(imh.Errors, err)
return
}
for _, tag := range referencedTags {
if err := tagService.Untag(imh, tag); err != nil {
imh.Errors = append(imh.Errors, err)
return
}
}
w.WriteHeader(http.StatusAccepted)
}