Remove registry v2 code path

As this feature requires more testing it is much safter to get the
underlying changes into the codebase first then enable the feature in
another release after proper testing and verification can be done.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

graph/pull.go

@@ -75,6 +75,7 @@ func (s *TagStore) CmdPull(job *engine.Job) engine.Status {
 	if n := len(job.Args); n != 1 && n != 2 {
 		return job.Errorf("Usage: %s IMAGE [TAG]", job.Name)
 	}
+
 	var (
 		localName   = job.Args[0]
 		tag         string
@@ -83,6 +84,7 @@ func (s *TagStore) CmdPull(job *engine.Job) engine.Status {
 		metaHeaders map[string][]string
 		mirrors     []string
 	)
+
 	if len(job.Args) > 1 {
 		tag = job.Args[1]
 	}
@@ -132,18 +134,6 @@ func (s *TagStore) CmdPull(job *engine.Job) engine.Status {
 		mirrors = s.mirrors
 	}
 
-	if isOfficial || endpoint.Version == registry.APIVersion2 {
-		j := job.Eng.Job("trust_update_base")
-		if err = j.Run(); err != nil {
-			return job.Errorf("error updating trust base graph: %s", err)
-		}
-
-		if err := s.pullV2Repository(job.Eng, r, job.Stdout, localName, remoteName, tag, sf, job.GetenvBool("parallel")); err == nil {
-			return engine.StatusOK
-		} else if err != registry.ErrDoesNotExist {
-			log.Errorf("Error from V2 registry: %s", err)
-		}
-	}
 	if err = s.pullRepository(r, job.Stdout, localName, remoteName, tag, sf, job.GetenvBool("parallel"), mirrors); err != nil {
 		return job.Error(err)
 	}