Implement support for schema 2 manifests

data/registry_model/__init__.py

@@ -6,5 +6,17 @@ from data.registry_model.registry_oci_model import oci_model
 
 logger = logging.getLogger(__name__)
 
-registry_model = oci_model if os.getenv('OCI_DATA_MODEL') == 'true' else pre_oci_model
-logger.debug('Using registry model `%s`', registry_model)
+
+class RegistryModelProxy(object):
+  def __init__(self):
+    self._model = oci_model if os.getenv('OCI_DATA_MODEL') == 'true' else pre_oci_model
+
+  def set_for_testing(self, use_oci_model):
+    self._model = oci_model if use_oci_model else pre_oci_model
+    logger.debug('Changed registry model to `%s` for testing', self._model)
+
+  def __getattr__(self, attr):
+    return getattr(self._model, attr)
+
+registry_model = RegistryModelProxy()
+logger.debug('Using registry model `%s`', registry_model._model)

data/registry_model/interface.py

@@ -7,6 +7,10 @@ class RegistryDataInterface(object):
       of all tables that store registry-specific information, such as Manifests, Blobs, Images,
       and Labels.
   """
+  @abstractmethod
+  def supports_schema2(self, namespace_name):
+    """ Returns whether the implementation of the data interface supports schema 2 format
+        manifests. """
 
   @abstractmethod
   def find_matching_tag(self, repository_ref, tag_names):

data/registry_model/registry_oci_model.py

@@ -21,6 +21,10 @@ class OCIModel(SharedModel, RegistryDataInterface):
   OCIModel implements the data model for the registry API using a database schema
   after it was changed to support the OCI specification.
   """
+  def supports_schema2(self, namespace_name):
+    """ Returns whether the implementation of the data interface supports schema 2 format
+        manifests. """
+    return True
 
   def find_matching_tag(self, repository_ref, tag_names):
     """ Finds an alive tag in the repository matching one of the given tag names and returns it

data/registry_model/registry_pre_oci_model.py

@@ -27,6 +27,10 @@ class PreOCIModel(SharedModel, RegistryDataInterface):
   PreOCIModel implements the data model for the registry API using a database schema
   before it was changed to support the OCI specification.
   """
+  def supports_schema2(self, namespace_name):
+    """ Returns whether the implementation of the data interface supports schema 2 format
+        manifests. """
+    return False
 
   def find_matching_tag(self, repository_ref, tag_names):
     """ Finds an alive tag in the repository matching one of the given tag names and returns it