distribution/docs/handlers/layerupload.go
Stephen J Day f1ea982e82 Check error returned from io.Copy
Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-04-22 12:35:08 -07:00

300 lines
9.6 KiB
Go

package handlers
import (
"fmt"
"io"
"net/http"
"net/url"
"os"
"github.com/docker/distribution"
ctxu "github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/registry/api/v2"
"github.com/gorilla/handlers"
)
// layerUploadDispatcher constructs and returns the layer upload handler for
// the given request context.
func layerUploadDispatcher(ctx *Context, r *http.Request) http.Handler {
luh := &layerUploadHandler{
Context: ctx,
UUID: getUploadUUID(ctx),
}
handler := http.Handler(handlers.MethodHandler{
"POST": http.HandlerFunc(luh.StartLayerUpload),
"GET": http.HandlerFunc(luh.GetUploadStatus),
"HEAD": http.HandlerFunc(luh.GetUploadStatus),
// TODO(stevvooe): Must implement patch support.
// "PATCH": http.HandlerFunc(luh.PutLayerChunk),
"PUT": http.HandlerFunc(luh.PutLayerUploadComplete),
"DELETE": http.HandlerFunc(luh.CancelLayerUpload),
})
if luh.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)
w.WriteHeader(http.StatusBadRequest)
luh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
})
}
luh.State = state
if state.Name != ctx.Repository.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, luh.Repository.Name())
w.WriteHeader(http.StatusBadRequest)
luh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
})
}
if state.UUID != luh.UUID {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(ctx).Infof("mismatched uuid in upload state: %q != %q", state.UUID, luh.UUID)
w.WriteHeader(http.StatusBadRequest)
luh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
})
}
layers := ctx.Repository.Layers()
upload, err := layers.Resume(luh.UUID)
if err != nil {
ctxu.GetLogger(ctx).Errorf("error resolving upload: %v", err)
if err == distribution.ErrLayerUploadUnknown {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusNotFound)
luh.Errors.Push(v2.ErrorCodeBlobUploadUnknown, err)
})
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusInternalServerError)
luh.Errors.Push(v2.ErrorCodeUnknown, err)
})
}
luh.Upload = upload
if state.Offset > 0 {
// Seek the layer 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(luh.State.Offset, os.SEEK_SET); err != nil {
defer upload.Close()
ctxu.GetLogger(ctx).Infof("error seeking layer upload: %v", err)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusBadRequest)
luh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
upload.Cancel()
})
} else if nn != luh.State.Offset {
defer upload.Close()
ctxu.GetLogger(ctx).Infof("seek to wrong offest: %d != %d", nn, luh.State.Offset)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusBadRequest)
luh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
upload.Cancel()
})
}
}
handler = closeResources(handler, luh.Upload)
}
return handler
}
// layerUploadHandler handles the http layer upload process.
type layerUploadHandler struct {
*Context
// UUID identifies the upload instance for the current request.
UUID string
Upload distribution.LayerUpload
State layerUploadState
}
// StartLayerUpload begins the layer upload process and allocates a server-
// side upload session.
func (luh *layerUploadHandler) StartLayerUpload(w http.ResponseWriter, r *http.Request) {
layers := luh.Repository.Layers()
upload, err := layers.Upload()
if err != nil {
w.WriteHeader(http.StatusInternalServerError) // Error conditions here?
luh.Errors.Push(v2.ErrorCodeUnknown, err)
return
}
luh.Upload = upload
defer luh.Upload.Close()
if err := luh.layerUploadResponse(w, r); err != nil {
w.WriteHeader(http.StatusInternalServerError) // Error conditions here?
luh.Errors.Push(v2.ErrorCodeUnknown, err)
return
}
w.Header().Set("Docker-Upload-UUID", luh.Upload.UUID())
w.WriteHeader(http.StatusAccepted)
}
// GetUploadStatus returns the status of a given upload, identified by uuid.
func (luh *layerUploadHandler) GetUploadStatus(w http.ResponseWriter, r *http.Request) {
if luh.Upload == nil {
w.WriteHeader(http.StatusNotFound)
luh.Errors.Push(v2.ErrorCodeBlobUploadUnknown)
return
}
if err := luh.layerUploadResponse(w, r); err != nil {
w.WriteHeader(http.StatusInternalServerError) // Error conditions here?
luh.Errors.Push(v2.ErrorCodeUnknown, err)
return
}
w.Header().Set("Docker-Upload-UUID", luh.UUID)
w.WriteHeader(http.StatusNoContent)
}
// PutLayerUploadComplete takes the final request of a layer upload. The final
// chunk may include all the layer data, the final chunk of layer data or no
// layer data. Any data provided is received and verified. If successful, the
// layer is linked into the blob store and 201 Created is returned with the
// canonical url of the layer.
func (luh *layerUploadHandler) PutLayerUploadComplete(w http.ResponseWriter, r *http.Request) {
if luh.Upload == nil {
w.WriteHeader(http.StatusNotFound)
luh.Errors.Push(v2.ErrorCodeBlobUploadUnknown)
return
}
dgstStr := r.FormValue("digest") // TODO(stevvooe): Support multiple digest parameters!
if dgstStr == "" {
// no digest? return error, but allow retry.
w.WriteHeader(http.StatusBadRequest)
luh.Errors.Push(v2.ErrorCodeDigestInvalid, "digest missing")
return
}
dgst, err := digest.ParseDigest(dgstStr)
if err != nil {
// no digest? return error, but allow retry.
w.WriteHeader(http.StatusNotFound)
luh.Errors.Push(v2.ErrorCodeDigestInvalid, "digest parsing failed")
return
}
// TODO(stevvooe): Check the incoming range header here, per the
// specification. LayerUpload should be seeked (sought?) to that position.
// TODO(stevvooe): Consider checking the error on this copy.
// Theoretically, problems should be detected during verification but we
// may miss a root cause.
// Read in the final chunk, if any.
if _, err := io.Copy(luh.Upload, r.Body); err != nil {
ctxu.GetLogger(luh).Errorf("unknown error copying into upload: %v", err)
w.WriteHeader(http.StatusInternalServerError)
luh.Errors.Push(v2.ErrorCodeUnknown, err)
}
layer, err := luh.Upload.Finish(dgst)
if err != nil {
switch err := err.(type) {
case distribution.ErrLayerInvalidDigest:
w.WriteHeader(http.StatusBadRequest)
luh.Errors.Push(v2.ErrorCodeDigestInvalid, err)
default:
ctxu.GetLogger(luh).Errorf("unknown error completing upload: %#v", err)
w.WriteHeader(http.StatusInternalServerError)
luh.Errors.Push(v2.ErrorCodeUnknown, err)
}
// Clean up the backend layer data if there was an error.
if err := luh.Upload.Cancel(); err != nil {
// If the cleanup fails, all we can do is observe and report.
ctxu.GetLogger(luh).Errorf("error canceling upload after error: %v", err)
}
return
}
// Build our canonical layer url
layerURL, err := luh.urlBuilder.BuildBlobURL(luh.Repository.Name(), layer.Digest())
if err != nil {
luh.Errors.Push(v2.ErrorCodeUnknown, err)
w.WriteHeader(http.StatusInternalServerError)
return
}
w.Header().Set("Location", layerURL)
w.Header().Set("Content-Length", "0")
w.Header().Set("Docker-Content-Digest", layer.Digest().String())
w.WriteHeader(http.StatusCreated)
}
// CancelLayerUpload cancels an in-progress upload of a layer.
func (luh *layerUploadHandler) CancelLayerUpload(w http.ResponseWriter, r *http.Request) {
if luh.Upload == nil {
w.WriteHeader(http.StatusNotFound)
luh.Errors.Push(v2.ErrorCodeBlobUploadUnknown)
return
}
w.Header().Set("Docker-Upload-UUID", luh.UUID)
if err := luh.Upload.Cancel(); err != nil {
ctxu.GetLogger(luh).Errorf("error encountered canceling upload: %v", err)
w.WriteHeader(http.StatusInternalServerError)
luh.Errors.PushErr(err)
}
w.WriteHeader(http.StatusNoContent)
}
// layerUploadResponse provides a standard request for uploading layers and
// chunk responses. This sets the correct headers but the response status is
// left to the caller.
func (luh *layerUploadHandler) layerUploadResponse(w http.ResponseWriter, r *http.Request) error {
offset, err := luh.Upload.Seek(0, os.SEEK_CUR)
if err != nil {
ctxu.GetLogger(luh).Errorf("unable get current offset of layer upload: %v", err)
return err
}
// TODO(stevvooe): Need a better way to manage the upload state automatically.
luh.State.Name = luh.Repository.Name()
luh.State.UUID = luh.Upload.UUID()
luh.State.Offset = offset
luh.State.StartedAt = luh.Upload.StartedAt()
token, err := hmacKey(luh.Config.HTTP.Secret).packUploadState(luh.State)
if err != nil {
ctxu.GetLogger(luh).Infof("error building upload state token: %s", err)
return err
}
uploadURL, err := luh.urlBuilder.BuildBlobUploadChunkURL(
luh.Repository.Name(), luh.Upload.UUID(),
url.Values{
"_state": []string{token},
})
if err != nil {
ctxu.GetLogger(luh).Infof("error building upload url: %s", err)
return err
}
w.Header().Set("Docker-Upload-UUID", luh.UUID)
w.Header().Set("Location", uploadURL)
w.Header().Set("Content-Length", "0")
w.Header().Set("Range", fmt.Sprintf("0-%d", luh.State.Offset))
return nil
}