Unify the get_layers calls across all implements of manifest schemas to ensure we have a common type returned

Also renames some methods to make it more clear what kind of information they return

image/docker/schema2/test/test_manifest.py

@@ -98,20 +98,81 @@ def test_valid_manifest():
   assert not manifest.has_remote_layer
   assert manifest.has_legacy_image
 
-  assert len(manifest.layers) == 4
-  assert manifest.layers[0].compressed_size == 1234
-  assert str(manifest.layers[0].digest) == 'sha256:ec4b8955958665577945c89419d1af06b5f7636b4ac3da7f12184802ad867736'
-  assert not manifest.layers[0].is_remote
+  retriever = ContentRetrieverForTesting.for_config({
+    "config": {
+      "Labels": {},
+    },
+    "rootfs": {"type": "layers", "diff_ids": []},
+    "history": [
+      {
+        "created": "2018-04-03T18:37:09.284840891Z",
+        "created_by": "foo"
+      },
+      {
+        "created": "2018-04-12T18:37:09.284840891Z",
+        "created_by": "bar"
+      },
+      {
+        "created": "2018-04-03T18:37:09.284840891Z",
+        "created_by": "foo"
+      },
+      {
+        "created": "2018-04-12T18:37:09.284840891Z",
+        "created_by": "bar"
+      },
+    ],
+  }, 'sha256:b5b2b2c507a0944348e0303114d8d93aaaa081732b86451d9bce1f432a537bc7', 1885)
 
-  assert manifest.leaf_layer == manifest.layers[3]
-  assert not manifest.leaf_layer.is_remote
-  assert manifest.leaf_layer.compressed_size == 73109
+  assert len(manifest.filesystem_layers) == 4
+  assert manifest.filesystem_layers[0].compressed_size == 1234
+  assert str(manifest.filesystem_layers[0].digest) == 'sha256:ec4b8955958665577945c89419d1af06b5f7636b4ac3da7f12184802ad867736'
+  assert not manifest.filesystem_layers[0].is_remote
+
+  assert manifest.leaf_filesystem_layer == manifest.filesystem_layers[3]
+  assert not manifest.leaf_filesystem_layer.is_remote
+  assert manifest.leaf_filesystem_layer.compressed_size == 73109
 
   blob_digests = list(manifest.blob_digests)
-  expected = [str(layer.digest) for layer in manifest.layers] + [manifest.config.digest]
+  expected = [str(layer.digest) for layer in manifest.filesystem_layers] + [manifest.config.digest]
   assert blob_digests == expected
   assert list(manifest.local_blob_digests) == expected
 
+  manifest_image_layers = list(manifest.get_layers(retriever))
+  assert len(manifest_image_layers) == len(list(manifest.filesystem_layers))
+  for index in range(0, 4):
+    assert manifest_image_layers[index].blob_digest == str(manifest.filesystem_layers[index].digest)
+
+
+def test_valid_remote_manifest():
+  manifest = DockerSchema2Manifest(REMOTE_MANIFEST_BYTES)
+  assert manifest.config.size == 1885
+  assert str(manifest.config.digest) == 'sha256:b5b2b2c507a0944348e0303114d8d93aaaa081732b86451d9bce1f432a537bc7'
+  assert manifest.media_type == "application/vnd.docker.distribution.manifest.v2+json"
+  assert manifest.has_remote_layer
+
+  assert len(manifest.filesystem_layers) == 4
+  assert manifest.filesystem_layers[0].compressed_size == 1234
+  assert str(manifest.filesystem_layers[0].digest) == 'sha256:ec4b8955958665577945c89419d1af06b5f7636b4ac3da7f12184802ad867736'
+  assert manifest.filesystem_layers[0].is_remote
+  assert manifest.filesystem_layers[0].urls == ['http://some/url']
+
+  assert manifest.leaf_filesystem_layer == manifest.filesystem_layers[3]
+  assert not manifest.leaf_filesystem_layer.is_remote
+  assert manifest.leaf_filesystem_layer.compressed_size == 73109
+
+  expected = set([str(layer.digest) for layer in manifest.filesystem_layers] + 
+                 [manifest.config.digest])
+
+  blob_digests = set(manifest.blob_digests)
+  local_digests = set(manifest.local_blob_digests)
+
+  assert blob_digests == expected
+  assert local_digests == (expected - {manifest.filesystem_layers[0].digest})
+
+  assert manifest.has_remote_layer
+  assert manifest.get_leaf_layer_v1_image_id(None) is None
+  assert manifest.get_legacy_image_ids(None) is None
+
   retriever = ContentRetrieverForTesting.for_config({
     "config": {
       "Labels": {},
@@ -137,40 +198,10 @@ def test_valid_manifest():
     ],
   }, 'sha256:b5b2b2c507a0944348e0303114d8d93aaaa081732b86451d9bce1f432a537bc7', 1885)
 
-  manifest_image_layers = list(manifest._manifest_image_layers(retriever))
-  assert len(manifest_image_layers) == len(list(manifest.layers))
+  manifest_image_layers = list(manifest.get_layers(retriever))
+  assert len(manifest_image_layers) == len(list(manifest.filesystem_layers))
   for index in range(0, 4):
-    assert manifest_image_layers[index].blob_digest == str(manifest.layers[index].digest)
-
-
-def test_valid_remote_manifest():
-  manifest = DockerSchema2Manifest(REMOTE_MANIFEST_BYTES)
-  assert manifest.config.size == 1885
-  assert str(manifest.config.digest) == 'sha256:b5b2b2c507a0944348e0303114d8d93aaaa081732b86451d9bce1f432a537bc7'
-  assert manifest.media_type == "application/vnd.docker.distribution.manifest.v2+json"
-  assert manifest.has_remote_layer
-
-  assert len(manifest.layers) == 4
-  assert manifest.layers[0].compressed_size == 1234
-  assert str(manifest.layers[0].digest) == 'sha256:ec4b8955958665577945c89419d1af06b5f7636b4ac3da7f12184802ad867736'
-  assert manifest.layers[0].is_remote
-  assert manifest.layers[0].urls == ['http://some/url']
-
-  assert manifest.leaf_layer == manifest.layers[3]
-  assert not manifest.leaf_layer.is_remote
-  assert manifest.leaf_layer.compressed_size == 73109
-
-  expected = set([str(layer.digest) for layer in manifest.layers] + [manifest.config.digest])
-
-  blob_digests = set(manifest.blob_digests)
-  local_digests = set(manifest.local_blob_digests)
-
-  assert blob_digests == expected
-  assert local_digests == (expected - {manifest.layers[0].digest})
-
-  assert manifest.has_remote_layer
-  assert manifest.get_leaf_layer_v1_image_id(None) is None
-  assert manifest.get_legacy_image_ids(None) is None
+    assert manifest_image_layers[index].blob_digest == str(manifest.filesystem_layers[index].digest)
 
 
 def test_schema2_builder():
@@ -179,11 +210,11 @@ def test_schema2_builder():
   builder = DockerSchema2ManifestBuilder()
   builder.set_config_digest(manifest.config.digest, manifest.config.size)
 
-  for layer in manifest.layers:
+  for layer in manifest.filesystem_layers:
     builder.add_layer(layer.digest, layer.compressed_size, urls=layer.urls)
 
   built = builder.build()
-  assert built.layers == manifest.layers
+  assert built.filesystem_layers == manifest.filesystem_layers
   assert built.config == manifest.config