Add method for retrieving a V1-compatible manifest for any manifest or manifest list

This is used to serve older clients that don't support the V2 schema format

image/docker/schema2/test/test_list.py

@@ -50,6 +50,22 @@ MANIFESTLIST_BYTES = json.dumps({
   ]
 })
 
+NO_AMD_MANIFESTLIST_BYTES = json.dumps({
+  "schemaVersion": 2,
+  "mediaType": "application/vnd.docker.distribution.manifest.list.v2+json",
+  "manifests": [
+    {
+      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
+      "size": 983,
+      "digest": "sha256:e6",
+      "platform": {
+        "architecture": "ppc64le",
+        "os": "linux",
+      }
+    },
+  ]
+})
+
 def test_valid_manifestlist():
   def _get_manifest(digest):
     if digest == 'sha256:e6':
@@ -75,13 +91,33 @@ def test_valid_manifestlist():
       assert isinstance(manifest.manifest_obj, DockerSchema1Manifest)
       assert manifest.manifest_obj.schema_version == 1
 
-  assert manifestlist.get_v1_compatible_manifest(_get_manifest).manifest_obj.schema_version == 1
+  compatible_manifest = manifestlist.get_v1_compatible_manifest('foo', 'bar', 'baz', _get_manifest)
+  assert compatible_manifest.schema_version == 1
 
   assert manifestlist.layers is None
   assert manifestlist.leaf_layer_v1_image_id is None
   assert manifestlist.legacy_image_ids is None
 
 
+def test_get_v1_compatible_manifest_no_matching_list():
+  def _get_manifest(digest):
+    if digest == 'sha256:e6':
+      return v22_bytes
+    else:
+      return v21_bytes
+
+  manifestlist = DockerSchema2ManifestList(NO_AMD_MANIFESTLIST_BYTES)
+  assert len(manifestlist.manifests(_get_manifest)) == 1
+  assert (manifestlist.digest ==
+          'sha256:50150251101420a020ab4a3e77e9d167a18b09bd4eeb0cc65e0eafab95cf79cf')
+
+  assert manifestlist.media_type == 'application/vnd.docker.distribution.manifest.list.v2+json'
+  assert manifestlist.bytes == NO_AMD_MANIFESTLIST_BYTES
+
+  compatible_manifest = manifestlist.get_v1_compatible_manifest('foo', 'bar', 'baz', _get_manifest)
+  assert compatible_manifest is None
+
+
 def test_builder():
   def _get_manifest(digest):
     if digest == 'sha256:e6':

image/docker/schema2/test/test_manifest.py

@@ -3,7 +3,8 @@ import pytest
 
 from app import docker_v2_signing_key
 from image.docker.schema1 import (DockerSchema1ManifestBuilder,
-                                  DOCKER_SCHEMA1_SIGNED_MANIFEST_CONTENT_TYPE)
+                                  DOCKER_SCHEMA1_SIGNED_MANIFEST_CONTENT_TYPE,
+                                  DOCKER_SCHEMA1_MANIFEST_CONTENT_TYPE)
 from image.docker.schema2.manifest import (MalformedSchema2Manifest, DockerSchema2Manifest,
                                            DockerSchema2ManifestBuilder)
 from image.docker.schema2.test.test_config import CONFIG_BYTES
@@ -132,6 +133,44 @@ def test_build_schema1():
     assert digest == str(list(manifest.blob_digests)[index])
 
 
+def test_get_v1_compatible_manifest():
+  def _get_config(digest):
+    config_str = json.dumps({
+      "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"
+        },
+      ],
+    })
+    return config_str + ' ' * (1885 - len(config_str))
+
+  manifest = DockerSchema2Manifest(MANIFEST_BYTES)
+  schema1 = manifest.get_v1_compatible_manifest('somenamespace', 'somename', 'sometag', _get_config)
+  assert schema1 is not None
+  assert schema1.media_type == DOCKER_SCHEMA1_MANIFEST_CONTENT_TYPE
+  assert len(schema1.layers) == len(manifest.layers)
+  assert set(schema1.image_ids) == set([l.v1_id for l in manifest.layers_with_v1_ids])
+  assert set(schema1.parent_image_ids) == set([l.v1_parent_id for l in
+                                               manifest.layers_with_v1_ids if l.v1_parent_id])
+
+
 def test_generate_legacy_layers():
   builder = DockerSchema2ManifestBuilder()
   builder.add_layer('sha256:abc123', 123)