distribution/registry/handlers/blobupload.go
Michal Minar 4d15bf071c Defined ErrAccessDenied error
Middleware code may perform additional checks on blobs written. Allow it
to return access denied errors that will result in 403 Forbidden.

Signed-off-by: Michal Minar <miminar@redhat.com>
2016-02-22 21:12:59 +01:00

391 lines
13 KiB
Go

package handlers
import (
"fmt"
"net/http"
"net/url"
"os"
"github.com/docker/distribution"
ctxu "github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/reference"
"github.com/docker/distribution/registry/api/errcode"
"github.com/docker/distribution/registry/api/v2"
"github.com/docker/distribution/registry/storage"
"github.com/gorilla/handlers"
)
// blobUploadDispatcher constructs and returns the blob upload handler for the
// given request context.
func blobUploadDispatcher(ctx *Context, r *http.Request) http.Handler {
buh := &blobUploadHandler{
Context: ctx,
UUID: getUploadUUID(ctx),
}
handler := handlers.MethodHandler{
"GET": http.HandlerFunc(buh.GetUploadStatus),
"HEAD": http.HandlerFunc(buh.GetUploadStatus),
}
if !ctx.readOnly {
handler["POST"] = http.HandlerFunc(buh.StartBlobUpload)
handler["PATCH"] = http.HandlerFunc(buh.PatchBlobData)
handler["PUT"] = http.HandlerFunc(buh.PutBlobUploadComplete)
handler["DELETE"] = http.HandlerFunc(buh.CancelBlobUpload)
}
if buh.UUID != "" {
state, err := hmacKey(ctx.Config.HTTP.Secret).unpackUploadState(r.FormValue("_state"))
if err != nil {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(ctx).Infof("error resolving upload: %v", err)
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
})
}
buh.State = state
if state.Name != ctx.Repository.Named().Name() {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(ctx).Infof("mismatched repository name in upload state: %q != %q", state.Name, buh.Repository.Named().Name())
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
})
}
if state.UUID != buh.UUID {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(ctx).Infof("mismatched uuid in upload state: %q != %q", state.UUID, buh.UUID)
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
})
}
blobs := ctx.Repository.Blobs(buh)
upload, err := blobs.Resume(buh, buh.UUID)
if err != nil {
ctxu.GetLogger(ctx).Errorf("error resolving upload: %v", err)
if err == distribution.ErrBlobUploadUnknown {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadUnknown.WithDetail(err))
})
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
})
}
buh.Upload = upload
if state.Offset > 0 {
// Seek the blob upload to the correct spot if it's non-zero.
// These error conditions should be rare and demonstrate really
// problems. We basically cancel the upload and tell the client to
// start over.
if nn, err := upload.Seek(buh.State.Offset, os.SEEK_SET); err != nil {
defer upload.Close()
ctxu.GetLogger(ctx).Infof("error seeking blob upload: %v", err)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
upload.Cancel(buh)
})
} else if nn != buh.State.Offset {
defer upload.Close()
ctxu.GetLogger(ctx).Infof("seek to wrong offest: %d != %d", nn, buh.State.Offset)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
upload.Cancel(buh)
})
}
}
return closeResources(handler, buh.Upload)
}
return handler
}
// blobUploadHandler handles the http blob upload process.
type blobUploadHandler struct {
*Context
// UUID identifies the upload instance for the current request. Using UUID
// to key blob writers since this implementation uses UUIDs.
UUID string
Upload distribution.BlobWriter
State blobUploadState
}
// StartBlobUpload begins the blob upload process and allocates a server-side
// blob writer session, optionally mounting the blob from a separate repository.
func (buh *blobUploadHandler) StartBlobUpload(w http.ResponseWriter, r *http.Request) {
var options []distribution.BlobCreateOption
fromRepo := r.FormValue("from")
mountDigest := r.FormValue("mount")
if mountDigest != "" && fromRepo != "" {
opt, err := buh.createBlobMountOption(fromRepo, mountDigest)
if opt != nil && err == nil {
options = append(options, opt)
}
}
blobs := buh.Repository.Blobs(buh)
upload, err := blobs.Create(buh, options...)
if err != nil {
if ebm, ok := err.(distribution.ErrBlobMounted); ok {
if err := buh.writeBlobCreatedHeaders(w, ebm.Descriptor); err != nil {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
} else if err == distribution.ErrUnsupported {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnsupported)
} else {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
return
}
buh.Upload = upload
defer buh.Upload.Close()
if err := buh.blobUploadResponse(w, r, true); err != nil {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
w.Header().Set("Docker-Upload-UUID", buh.Upload.ID())
w.WriteHeader(http.StatusAccepted)
}
// GetUploadStatus returns the status of a given upload, identified by id.
func (buh *blobUploadHandler) GetUploadStatus(w http.ResponseWriter, r *http.Request) {
if buh.Upload == nil {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadUnknown)
return
}
// TODO(dmcgowan): Set last argument to false in blobUploadResponse when
// resumable upload is supported. This will enable returning a non-zero
// range for clients to begin uploading at an offset.
if err := buh.blobUploadResponse(w, r, true); err != nil {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
w.Header().Set("Docker-Upload-UUID", buh.UUID)
w.WriteHeader(http.StatusNoContent)
}
// PatchBlobData writes data to an upload.
func (buh *blobUploadHandler) PatchBlobData(w http.ResponseWriter, r *http.Request) {
if buh.Upload == nil {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadUnknown)
return
}
ct := r.Header.Get("Content-Type")
if ct != "" && ct != "application/octet-stream" {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(fmt.Errorf("Bad Content-Type")))
// TODO(dmcgowan): encode error
return
}
// TODO(dmcgowan): support Content-Range header to seek and write range
if err := copyFullPayload(w, r, buh.Upload, buh, "blob PATCH", &buh.Errors); err != nil {
// copyFullPayload reports the error if necessary
return
}
if err := buh.blobUploadResponse(w, r, false); err != nil {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
w.WriteHeader(http.StatusAccepted)
}
// PutBlobUploadComplete takes the final request of a blob upload. The
// request may include all the blob data or no blob data. Any data
// provided is received and verified. If successful, the blob is linked
// into the blob store and 201 Created is returned with the canonical
// url of the blob.
func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *http.Request) {
if buh.Upload == nil {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadUnknown)
return
}
dgstStr := r.FormValue("digest") // TODO(stevvooe): Support multiple digest parameters!
if dgstStr == "" {
// no digest? return error, but allow retry.
buh.Errors = append(buh.Errors, v2.ErrorCodeDigestInvalid.WithDetail("digest missing"))
return
}
dgst, err := digest.ParseDigest(dgstStr)
if err != nil {
// no digest? return error, but allow retry.
buh.Errors = append(buh.Errors, v2.ErrorCodeDigestInvalid.WithDetail("digest parsing failed"))
return
}
if err := copyFullPayload(w, r, buh.Upload, buh, "blob PUT", &buh.Errors); err != nil {
// copyFullPayload reports the error if necessary
return
}
desc, err := buh.Upload.Commit(buh, distribution.Descriptor{
Digest: dgst,
// TODO(stevvooe): This isn't wildly important yet, but we should
// really set the length and mediatype. For now, we can let the
// backend take care of this.
})
if err != nil {
switch err := err.(type) {
case distribution.ErrBlobInvalidDigest:
buh.Errors = append(buh.Errors, v2.ErrorCodeDigestInvalid.WithDetail(err))
default:
switch err {
case distribution.ErrAccessDenied:
buh.Errors = append(buh.Errors, errcode.ErrorCodeDenied)
case distribution.ErrUnsupported:
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnsupported)
case distribution.ErrBlobInvalidLength, distribution.ErrBlobDigestUnsupported:
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadInvalid.WithDetail(err))
default:
ctxu.GetLogger(buh).Errorf("unknown error completing upload: %#v", err)
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
}
// Clean up the backend blob data if there was an error.
if err := buh.Upload.Cancel(buh); err != nil {
// If the cleanup fails, all we can do is observe and report.
ctxu.GetLogger(buh).Errorf("error canceling upload after error: %v", err)
}
return
}
if err := buh.writeBlobCreatedHeaders(w, desc); err != nil {
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
return
}
}
// CancelBlobUpload cancels an in-progress upload of a blob.
func (buh *blobUploadHandler) CancelBlobUpload(w http.ResponseWriter, r *http.Request) {
if buh.Upload == nil {
buh.Errors = append(buh.Errors, v2.ErrorCodeBlobUploadUnknown)
return
}
w.Header().Set("Docker-Upload-UUID", buh.UUID)
if err := buh.Upload.Cancel(buh); err != nil {
ctxu.GetLogger(buh).Errorf("error encountered canceling upload: %v", err)
buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(err))
}
w.WriteHeader(http.StatusNoContent)
}
// blobUploadResponse provides a standard request for uploading blobs and
// chunk responses. This sets the correct headers but the response status is
// left to the caller. The fresh argument is used to ensure that new blob
// uploads always start at a 0 offset. This allows disabling resumable push by
// always returning a 0 offset on check status.
func (buh *blobUploadHandler) blobUploadResponse(w http.ResponseWriter, r *http.Request, fresh bool) error {
var offset int64
if !fresh {
var err error
offset, err = buh.Upload.Seek(0, os.SEEK_CUR)
if err != nil {
ctxu.GetLogger(buh).Errorf("unable get current offset of blob upload: %v", err)
return err
}
}
// TODO(stevvooe): Need a better way to manage the upload state automatically.
buh.State.Name = buh.Repository.Named().Name()
buh.State.UUID = buh.Upload.ID()
buh.State.Offset = offset
buh.State.StartedAt = buh.Upload.StartedAt()
token, err := hmacKey(buh.Config.HTTP.Secret).packUploadState(buh.State)
if err != nil {
ctxu.GetLogger(buh).Infof("error building upload state token: %s", err)
return err
}
uploadURL, err := buh.urlBuilder.BuildBlobUploadChunkURL(
buh.Repository.Named(), buh.Upload.ID(),
url.Values{
"_state": []string{token},
})
if err != nil {
ctxu.GetLogger(buh).Infof("error building upload url: %s", err)
return err
}
endRange := offset
if endRange > 0 {
endRange = endRange - 1
}
w.Header().Set("Docker-Upload-UUID", buh.UUID)
w.Header().Set("Location", uploadURL)
w.Header().Set("Content-Length", "0")
w.Header().Set("Range", fmt.Sprintf("0-%d", endRange))
return nil
}
// mountBlob attempts to mount a blob from another repository by its digest. If
// successful, the blob is linked into the blob store and 201 Created is
// returned with the canonical url of the blob.
func (buh *blobUploadHandler) createBlobMountOption(fromRepo, mountDigest string) (distribution.BlobCreateOption, error) {
dgst, err := digest.ParseDigest(mountDigest)
if err != nil {
return nil, err
}
ref, err := reference.ParseNamed(fromRepo)
if err != nil {
return nil, err
}
canonical, err := reference.WithDigest(ref, dgst)
if err != nil {
return nil, err
}
return storage.WithMountFrom(canonical), nil
}
// writeBlobCreatedHeaders writes the standard headers describing a newly
// created blob. A 201 Created is written as well as the canonical URL and
// blob digest.
func (buh *blobUploadHandler) writeBlobCreatedHeaders(w http.ResponseWriter, desc distribution.Descriptor) error {
ref, err := reference.WithDigest(buh.Repository.Named(), desc.Digest)
if err != nil {
return err
}
blobURL, err := buh.urlBuilder.BuildBlobURL(ref)
if err != nil {
return err
}
w.Header().Set("Location", blobURL)
w.Header().Set("Content-Length", "0")
w.Header().Set("Docker-Content-Digest", desc.Digest.String())
w.WriteHeader(http.StatusCreated)
return nil
}