Make image archive/save idempotent, using image id and repo tags as keys (#500)

tests/unit/plugins/module_utils/test_image_archive.py

@@ -0,0 +1,94 @@
+# Copyright 2022 Red Hat | Ansible
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import pytest
+import tarfile
+
+from ansible_collections.community.docker.plugins.module_utils.image_archive import (
+    api_image_id,
+    archived_image_manifest,
+    ImageArchiveInvalidException
+)
+
+from ..test_support.docker_image_archive_stubbing import (
+    write_imitation_archive,
+    write_imitation_archive_with_manifest,
+    write_irrelevant_tar,
+)
+
+
+@pytest.fixture
+def tar_file_name(tmpdir):
+    '''
+    Return the name of a non-existing tar file in an existing temporary directory.
+    '''
+
+    # Cast to str required by Python 2.x
+    return str(tmpdir.join('foo.tar'))
+
+
+@pytest.mark.parametrize('expected, value', [
+    ('sha256:foo', 'foo'),
+    ('sha256:bar', 'bar')
+])
+def test_api_image_id_from_archive_id(expected, value):
+    assert api_image_id(value) == expected
+
+
+def test_archived_image_manifest_extracts(tar_file_name):
+    expected_id = "abcde12345"
+    expected_tags = ["foo:latest", "bar:v1"]
+
+    write_imitation_archive(tar_file_name, expected_id, expected_tags)
+
+    actual = archived_image_manifest(tar_file_name)
+
+    assert actual.image_id == expected_id
+    assert actual.repo_tags == expected_tags
+
+
+def test_archived_image_manifest_extracts_nothing_when_file_not_present(tar_file_name):
+    image_id = archived_image_manifest(tar_file_name)
+
+    assert image_id is None
+
+
+def test_archived_image_manifest_raises_when_file_not_a_tar():
+    try:
+        archived_image_manifest(__file__)
+        raise AssertionError()
+    except ImageArchiveInvalidException as e:
+        assert isinstance(e.cause, tarfile.ReadError)
+        assert str(__file__) in str(e)
+
+
+def test_archived_image_manifest_raises_when_tar_missing_manifest(tar_file_name):
+    write_irrelevant_tar(tar_file_name)
+
+    try:
+        archived_image_manifest(tar_file_name)
+        raise AssertionError()
+    except ImageArchiveInvalidException as e:
+        assert isinstance(e.cause, KeyError)
+        assert 'manifest.json' in str(e.cause)
+
+
+def test_archived_image_manifest_raises_when_manifest_missing_id(tar_file_name):
+    manifest = [
+        {
+            'foo': 'bar'
+        }
+    ]
+
+    write_imitation_archive_with_manifest(tar_file_name, manifest)
+
+    try:
+        archived_image_manifest(tar_file_name)
+        raise AssertionError()
+    except ImageArchiveInvalidException as e:
+        assert isinstance(e.cause, KeyError)
+        assert 'Config' in str(e.cause)