distribution/docs/handlers/layer.go
Stephen J Day 553d48d618 Move layer interface definitions to distribution package
After consideration, it has been decided that the interfaces defined in the
storage package provide a good base for interacting with various registry
instances. Whether interacting with a remote API or a local, on-disk registry,
these types have proved flexible. By moving them here, they can become the
central components of interacting with distribution components.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-02-12 14:26:46 -08:00

76 lines
1.8 KiB
Go

package handlers
import (
"net/http"
"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"
)
// layerDispatcher uses the request context to build a layerHandler.
func layerDispatcher(ctx *Context, r *http.Request) http.Handler {
dgst, err := getDigest(ctx)
if err != nil {
if err == errDigestNotAvailable {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusNotFound)
ctx.Errors.Push(v2.ErrorCodeDigestInvalid, err)
})
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ctx.Errors.Push(v2.ErrorCodeDigestInvalid, err)
})
}
layerHandler := &layerHandler{
Context: ctx,
Digest: dgst,
}
return handlers.MethodHandler{
"GET": http.HandlerFunc(layerHandler.GetLayer),
"HEAD": http.HandlerFunc(layerHandler.GetLayer),
}
}
// layerHandler serves http layer requests.
type layerHandler struct {
*Context
Digest digest.Digest
}
// GetLayer fetches the binary data from backend storage returns it in the
// response.
func (lh *layerHandler) GetLayer(w http.ResponseWriter, r *http.Request) {
ctxu.GetLogger(lh).Debug("GetImageLayer")
layers := lh.Repository.Layers()
layer, err := layers.Fetch(lh.Digest)
if err != nil {
switch err := err.(type) {
case distribution.ErrUnknownLayer:
w.WriteHeader(http.StatusNotFound)
lh.Errors.Push(v2.ErrorCodeBlobUnknown, err.FSLayer)
default:
lh.Errors.Push(v2.ErrorCodeUnknown, err)
}
return
}
defer layer.Close()
if lh.layerHandler != nil {
handler, _ := lh.layerHandler.Resolve(layer)
if handler != nil {
handler.ServeHTTP(w, r)
return
}
}
http.ServeContent(w, r, layer.Digest().String(), layer.CreatedAt(), layer)
}