Fix conversion of schema 2 manifests to schema 1 manifests

Also adds a number of conversion tests and clarify the interfaces a bit more

image/docker/schema2/test/test_conversion.py

@@ -0,0 +1,65 @@
+import json
+
+from image.docker.schema1 import DockerSchema1Manifest
+from image.docker.schema2.manifest import DockerSchema2Manifest
+from image.docker.schema2.test.conversion_data import (SCHEMA1_BYTES, SCHEMA2_MANIFEST_BYTES,
+                                                       SCHEMA2_CONFIG_BYTES)
+from image.docker.schemautil import ContentRetrieverForTesting
+
+def test_legacy_layers():
+  retriever = ContentRetrieverForTesting({
+    'sha256:e7a06c2e5b7afb1bbfa9124812e87f1138c4c10d77e0a217f0b8c8c9694dc5cf': SCHEMA2_CONFIG_BYTES,
+  })
+
+  schema2 = DockerSchema2Manifest(SCHEMA2_MANIFEST_BYTES)
+  schema1 = DockerSchema1Manifest(SCHEMA1_BYTES, validate=False)
+
+  # Check legacy layers
+  schema2_legacy_layers = list(schema2.generate_legacy_layers({}, retriever))
+  schema1_legacy_layers = list(schema1.generate_legacy_layers({}, retriever))
+  assert len(schema1_legacy_layers) == len(schema2_legacy_layers)
+
+  for index in range(0, len(schema1_legacy_layers)):
+    schema1_legacy_layer = schema1_legacy_layers[index]
+    schema2_legacy_layer = schema2_legacy_layers[index]
+    assert schema1_legacy_layer.content_checksum == schema2_legacy_layer.content_checksum
+    assert schema1_legacy_layer.comment == schema2_legacy_layer.comment
+    assert schema1_legacy_layer.command == schema2_legacy_layer.command
+
+
+def test_conversion():
+  retriever = ContentRetrieverForTesting({
+    'sha256:e7a06c2e5b7afb1bbfa9124812e87f1138c4c10d77e0a217f0b8c8c9694dc5cf': SCHEMA2_CONFIG_BYTES,
+  })
+
+  schema2 = DockerSchema2Manifest(SCHEMA2_MANIFEST_BYTES)
+  schema1 = DockerSchema1Manifest(SCHEMA1_BYTES, validate=False)
+
+  converted = schema2.get_schema1_manifest('devtable', 'somerepo', 'latest', retriever)
+  assert len(converted.layers) == len(schema1.layers)
+
+  image_id_map = {}
+  for index in range(0, len(converted.layers)):
+    converted_layer = converted.layers[index]
+    schema1_layer = schema1.layers[index]
+
+    image_id_map[schema1_layer.v1_metadata.image_id] = converted_layer.v1_metadata.image_id
+
+    assert str(schema1_layer.digest) == str(converted_layer.digest)
+
+    schema1_parent_id = schema1_layer.v1_metadata.parent_image_id
+    converted_parent_id = converted_layer.v1_metadata.parent_image_id
+    assert (schema1_parent_id is None) == (converted_parent_id is None)
+
+    if schema1_parent_id is not None:
+      assert image_id_map[schema1_parent_id] == converted_parent_id
+
+    assert schema1_layer.v1_metadata.created == converted_layer.v1_metadata.created
+    assert schema1_layer.v1_metadata.comment == converted_layer.v1_metadata.comment
+    assert schema1_layer.v1_metadata.command == converted_layer.v1_metadata.command
+    assert schema1_layer.v1_metadata.labels == converted_layer.v1_metadata.labels
+
+    schema1_container_config = json.loads(schema1_layer.raw_v1_metadata)['container_config']
+    converted_container_config = json.loads(converted_layer.raw_v1_metadata)['container_config']
+
+    assert schema1_container_config == converted_container_config