Move registry package out of repo root

Since the repo is no longer just the registry, we are moving the registry web
application package out of the repo root into a sub-package. We may break down
the registry package further to separate webapp components and bring the client
package under it. This change accomplishes the task of freeing up the repo root
for a distribution-oriented package. A stub doc.go file is left in place to
declare intent.

Signed-off-by: Stephen J Day <stephen.day@docker.com>

tags.go

@@ -1,60 +0,0 @@
-package registry
-
-import (
-	"encoding/json"
-	"net/http"
-
-	"github.com/docker/distribution/api/v2"
-	"github.com/docker/distribution/storage"
-	"github.com/gorilla/handlers"
-)
-
-// tagsDispatcher constructs the tags handler api endpoint.
-func tagsDispatcher(ctx *Context, r *http.Request) http.Handler {
-	tagsHandler := &tagsHandler{
-		Context: ctx,
-	}
-
-	return handlers.MethodHandler{
-		"GET": http.HandlerFunc(tagsHandler.GetTags),
-	}
-}
-
-// tagsHandler handles requests for lists of tags under a repository name.
-type tagsHandler struct {
-	*Context
-}
-
-type tagsAPIResponse struct {
-	Name string   `json:"name"`
-	Tags []string `json:"tags"`
-}
-
-// GetTags returns a json list of tags for a specific image name.
-func (th *tagsHandler) GetTags(w http.ResponseWriter, r *http.Request) {
-	defer r.Body.Close()
-	manifests := th.services.Manifests()
-
-	tags, err := manifests.Tags(th.Name)
-	if err != nil {
-		switch err := err.(type) {
-		case storage.ErrUnknownRepository:
-			w.WriteHeader(404)
-			th.Errors.Push(v2.ErrorCodeNameUnknown, map[string]string{"name": th.Name})
-		default:
-			th.Errors.PushErr(err)
-		}
-		return
-	}
-
-	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-
-	enc := json.NewEncoder(w)
-	if err := enc.Encode(tagsAPIResponse{
-		Name: th.Name,
-		Tags: tags,
-	}); err != nil {
-		th.Errors.PushErr(err)
-		return
-	}
-}