Fixes#13740
Update ManifestExist to return Descriptor instead of digest
For docker 20.10 or containerd, it HEAD the manifest before pull, then
it GET the manifest with digest, add logic to handle this scenario and
correlate the tag between the digest in proxy cache
Signed-off-by: stonezdj <stonezdj@gmail.com>
This reverts commit e6f80259
This reverts commit 918fe125
Signed-off-by: stonezdj <stonezdj@gmail.com>
Revert "Add content type and length in header"
This reverts commit ca379111
Signed-off-by: stonezdj <stonezdj@gmail.com>
