Define a formal manifest interface and implement in the schema1 and schema2 manifests

This will allow us to pass arbitrary manifests to the model

image/docker/schema2/manifest.py

@@ -7,6 +7,7 @@ from jsonschema import validate as validate_schema, ValidationError
 
 from digest import digest_tools
 from image.docker import ManifestException
+from image.docker.interfaces import ManifestInterface
 from image.docker.schema2 import (DOCKER_SCHEMA2_MANIFEST_CONTENT_TYPE,
                                   DOCKER_SCHEMA2_CONFIG_CONTENT_TYPE,
                                   DOCKER_SCHEMA2_LAYER_CONTENT_TYPE,
@@ -39,7 +40,7 @@ class MalformedSchema2Manifest(ManifestException):
   pass
 
 
-class DockerSchema2Manifest(object):
+class DockerSchema2Manifest(ManifestInterface):
   METASCHEMA = {
     'type': 'object',
     'properties': {
@@ -121,6 +122,7 @@ class DockerSchema2Manifest(object):
 
   def __init__(self, manifest_bytes):
     self._layers = None
+    self._payload = manifest_bytes
 
     try:
       self._parsed = json.loads(manifest_bytes)
@@ -136,6 +138,18 @@ class DockerSchema2Manifest(object):
   def schema_version(self):
     return 2
 
+  @property
+  def manifest_dict(self):
+    return self._parsed
+
+  @property
+  def media_type(self):
+    return self._parsed[DOCKER_SCHEMA2_MANIFEST_MEDIATYPE_KEY]
+
+  @property
+  def digest(self):
+    return digest_tools.sha256_digest(self._payload)
+
   @property
   def config(self):
     config = self._parsed[DOCKER_SCHEMA2_MANIFEST_CONFIG_KEY]
@@ -153,6 +167,18 @@ class DockerSchema2Manifest(object):
   def leaf_layer(self):
     return self.layers[-1]
 
+  @property
+  def leaf_layer_v1_image_id(self):
+    return list(self.layers_with_v1_ids)[-1].v1_id
+
+  @property
+  def blob_digests(self):
+    return [str(layer.digest) for layer in self.layers]
+
+  @property
+  def bytes(self):
+    return self._payload
+
   def _generate_layers(self):
     for index, layer in enumerate(self._parsed[DOCKER_SCHEMA2_MANIFEST_LAYERS_KEY]):
       content_type = layer[DOCKER_SCHEMA2_MANIFEST_MEDIATYPE_KEY]