distribution/docs/handlers/layer.go
David Lawrence 952f39edff Refactoring cloudfactory layer handler into a more generic storage
middleware concept.

This also breaks the dependency the storage package had on goamz
Signed-off-by: David Lawrence <david.lawrence@docker.com> (github: endophage)
2015-03-11 08:56:28 -07:00

67 lines
1.6 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")
layerStore := lh.Repository.Layers()
layerReader, err := layerStore.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
}
layerReader.ServeHTTP(w, r)
}