distribution/docs/layer.go
Stephen J Day 3e84069959 Integrate contextual logging with regsitry app
This changeset integrates contextual logging into the registry web application.
Idiomatic context use is attempted within the current webapp layout. The
functionality is centered around making lifecycle objects (application and
request context) into contexts themselves. Relevant data has been moved into
the context where appropriate.  We still have some work to do to factor out the
registry.Context object and the dispatching functionality to remove some
awkward portions.

The api tests were slightly refactored to use a test environment to eliminate
common code.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-02-06 16:51:53 -08:00

76 lines
1.8 KiB
Go

package registry
import (
"net/http"
"github.com/docker/distribution/api/v2"
ctxu "github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/storage"
"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 storage.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)
}