distribution/registry/handlers/manifests.go
Milos Gajdos 40c56bf1b6
Keep returning image for default arch to old clients fetching lists
This puts back the original flow where old clients are fetching manifest
lists schema1 images where we want to try returning some image for the
default architecture. This was incorrectly removed by one of the
previous commits.

Signed-off-by: Milos Gajdos <milosthegajdos@gmail.com>
2023-08-17 20:57:02 +01:00

487 lines
15 KiB
Go

package handlers
import (
"bytes"
"fmt"
"mime"
"net/http"
"strings"
"github.com/distribution/distribution/v3"
dcontext "github.com/distribution/distribution/v3/context"
"github.com/distribution/distribution/v3/manifest/manifestlist"
"github.com/distribution/distribution/v3/manifest/ocischema"
"github.com/distribution/distribution/v3/manifest/schema2"
"github.com/distribution/distribution/v3/reference"
"github.com/distribution/distribution/v3/registry/api/errcode"
v2 "github.com/distribution/distribution/v3/registry/api/v2"
"github.com/distribution/distribution/v3/registry/auth"
"github.com/distribution/distribution/v3/registry/storage/driver"
"github.com/gorilla/handlers"
"github.com/opencontainers/go-digest"
v1 "github.com/opencontainers/image-spec/specs-go/v1"
)
const (
defaultArch = "amd64"
defaultOS = "linux"
maxManifestBodySize = 4 << 20
imageClass = "image"
)
type storageType int
const (
manifestSchema2 storageType = iota // 0
manifestlistSchema // 1
ociSchema // 2
ociImageIndexSchema // 3
numStorageTypes // 4
)
// manifestDispatcher takes the request context and builds the
// appropriate handler for handling manifest requests.
func manifestDispatcher(ctx *Context, r *http.Request) http.Handler {
manifestHandler := &manifestHandler{
Context: ctx,
}
ref := getReference(ctx)
dgst, err := digest.Parse(ref)
if err != nil {
// We just have a tag
manifestHandler.Tag = ref
} else {
manifestHandler.Digest = dgst
}
mhandler := handlers.MethodHandler{
http.MethodGet: http.HandlerFunc(manifestHandler.GetManifest),
http.MethodHead: http.HandlerFunc(manifestHandler.GetManifest),
}
if !ctx.readOnly {
mhandler[http.MethodPut] = http.HandlerFunc(manifestHandler.PutManifest)
mhandler[http.MethodDelete] = http.HandlerFunc(manifestHandler.DeleteManifest)
}
return mhandler
}
// manifestHandler handles http operations on image manifests.
type manifestHandler struct {
*Context
// One of tag or digest gets set, depending on what is present in context.
Tag string
Digest digest.Digest
}
// GetManifest fetches the image manifest from the storage backend, if it exists.
func (imh *manifestHandler) GetManifest(w http.ResponseWriter, r *http.Request) {
dcontext.GetLogger(imh).Debug("GetImageManifest")
manifests, err := imh.Repository.Manifests(imh)
if err != nil {
imh.Errors = append(imh.Errors, err)
return
}
var supports [numStorageTypes]bool
// this parsing of Accept headers is not quite as full-featured as godoc.org's parser, but we don't care about "q=" values
// https://github.com/golang/gddo/blob/e91d4165076d7474d20abda83f92d15c7ebc3e81/httputil/header/header.go#L165-L202
for _, acceptHeader := range r.Header["Accept"] {
// r.Header[...] is a slice in case the request contains the same header more than once
// if the header isn't set, we'll get the zero value, which "range" will handle gracefully
// we need to split each header value on "," to get the full list of "Accept" values (per RFC 2616)
// https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
for _, mediaType := range strings.Split(acceptHeader, ",") {
if mediaType, _, err = mime.ParseMediaType(mediaType); err != nil {
continue
}
if mediaType == schema2.MediaTypeManifest {
supports[manifestSchema2] = true
}
if mediaType == manifestlist.MediaTypeManifestList {
supports[manifestlistSchema] = true
}
if mediaType == v1.MediaTypeImageManifest {
supports[ociSchema] = true
}
if mediaType == v1.MediaTypeImageIndex {
supports[ociImageIndexSchema] = true
}
}
}
if imh.Tag != "" {
tags := imh.Repository.Tags(imh)
desc, err := tags.Get(imh, imh.Tag)
if err != nil {
if _, ok := err.(distribution.ErrTagUnknown); ok {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err))
} else {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
return
}
imh.Digest = desc.Digest
}
if etagMatch(r, imh.Digest.String()) {
w.WriteHeader(http.StatusNotModified)
return
}
var options []distribution.ManifestServiceOption
if imh.Tag != "" {
options = append(options, distribution.WithTag(imh.Tag))
}
manifest, err := manifests.Get(imh, imh.Digest, options...)
if err != nil {
if _, ok := err.(distribution.ErrManifestUnknownRevision); ok {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err))
} else {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
return
}
// determine the type of the returned manifest
manifestType := manifestSchema2
manifestList, isManifestList := manifest.(*manifestlist.DeserializedManifestList)
if _, isOCImanifest := manifest.(*ocischema.DeserializedManifest); isOCImanifest {
manifestType = ociSchema
} else if isManifestList {
if manifestList.MediaType == manifestlist.MediaTypeManifestList {
manifestType = manifestlistSchema
} else if manifestList.MediaType == v1.MediaTypeImageIndex {
manifestType = ociImageIndexSchema
}
}
if manifestType == ociSchema && !supports[ociSchema] {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithMessage("OCI manifest found, but accept header does not support OCI manifests"))
return
}
if manifestType == ociImageIndexSchema && !supports[ociImageIndexSchema] {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithMessage("OCI index found, but accept header does not support OCI indexes"))
return
}
if imh.Tag != "" && manifestType == manifestlistSchema && !supports[manifestlistSchema] {
// Rewrite manifest in schema1 format
dcontext.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 {
if _, ok := err.(distribution.ErrManifestUnknownRevision); ok {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err))
} else {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
return
}
if _, isSchema2 := manifest.(*schema2.DeserializedManifest); isSchema2 && !supports[manifestSchema2] {
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithMessage("Schema 2 manifest not supported by client"))
return
} else {
imh.Digest = manifestDigest
}
}
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 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
}
// PutManifest validates and stores a manifest in the registry.
func (imh *manifestHandler) PutManifest(w http.ResponseWriter, r *http.Request) {
dcontext.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(imh, w, r, &jsonBuf, maxManifestBodySize, "image manifest PUT"); err != nil {
// copyFullPayload reports the error if necessary
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err.Error()))
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 {
dcontext.GetLogger(imh).Errorf("payload digest does not 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
}
isAnOCIManifest := mediaType == v1.MediaTypeImageManifest || mediaType == v1.MediaTypeImageIndex
if isAnOCIManifest {
dcontext.GetLogger(imh).Debug("Putting an OCI Manifest!")
} else {
dcontext.GetLogger(imh).Debug("Putting a Docker Manifest!")
}
var options []distribution.ManifestServiceOption
if imh.Tag != "" {
options = append(options, distribution.WithTag(imh.Tag))
}
if err := imh.applyResourcePolicy(manifest); err != nil {
imh.Errors = append(imh.Errors, err)
return
}
_, err = manifests.Put(imh, manifest, options...)
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
}
if err == distribution.ErrAccessDenied {
imh.Errors = append(imh.Errors, errcode.ErrorCodeDenied)
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)
}
}
}
case errcode.Error:
imh.Errors = append(imh.Errors, err)
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.Named(), 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.
dcontext.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)
dcontext.GetLogger(imh).Debug("Succeeded in putting manifest!")
}
// applyResourcePolicy checks whether the resource class matches what has
// been authorized and allowed by the policy configuration.
func (imh *manifestHandler) applyResourcePolicy(manifest distribution.Manifest) error {
allowedClasses := imh.App.Config.Policy.Repository.Classes
if len(allowedClasses) == 0 {
return nil
}
var class string
switch m := manifest.(type) {
case *schema2.DeserializedManifest:
switch m.Config.MediaType {
case schema2.MediaTypeImageConfig:
class = imageClass
case schema2.MediaTypePluginConfig:
class = "plugin"
default:
return errcode.ErrorCodeDenied.WithMessage("unknown manifest class for " + m.Config.MediaType)
}
case *ocischema.DeserializedManifest:
switch m.Config.MediaType {
case v1.MediaTypeImageConfig:
class = imageClass
default:
return errcode.ErrorCodeDenied.WithMessage("unknown manifest class for " + m.Config.MediaType)
}
}
if class == "" {
return nil
}
// Check to see if class is allowed in registry
var allowedClass bool
for _, c := range allowedClasses {
if class == c {
allowedClass = true
break
}
}
if !allowedClass {
return errcode.ErrorCodeDenied.WithMessage(fmt.Sprintf("registry does not allow %s manifest", class))
}
resources := auth.AuthorizedResources(imh)
n := imh.Repository.Named().Name()
var foundResource bool
for _, r := range resources {
if r.Name == n {
if r.Class == "" {
r.Class = imageClass
}
if r.Class == class {
return nil
}
foundResource = true
}
}
// resource was found but no matching class was found
if foundResource {
return errcode.ErrorCodeDenied.WithMessage(fmt.Sprintf("repository not authorized for %s manifest", class))
}
return nil
}
// DeleteManifest removes the manifest with the given digest or the tag with the given name from the registry.
func (imh *manifestHandler) DeleteManifest(w http.ResponseWriter, r *http.Request) {
dcontext.GetLogger(imh).Debug("DeleteImageManifest")
if imh.App.isCache {
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnsupported)
return
}
if imh.Tag != "" {
dcontext.GetLogger(imh).Debug("DeleteImageTag")
tagService := imh.Repository.Tags(imh.Context)
if err := tagService.Untag(imh.Context, imh.Tag); err != nil {
switch err.(type) {
case distribution.ErrTagUnknown, driver.PathNotFoundError:
imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err))
default:
imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
return
}
w.WriteHeader(http.StatusAccepted)
return
}
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)
}