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)

tests/unit/plugins/modules/test_docker_image.py

@@ -0,0 +1,117 @@
+# 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
+
+from ansible_collections.community.docker.plugins.modules.docker_image import ImageManager
+
+from ansible_collections.community.docker.plugins.module_utils.image_archive import (
+    api_image_id,
+    ImageArchiveInvalidException
+)
+
+from ..test_support.docker_image_archive_stubbing import (
+    write_imitation_archive,
+    write_irrelevant_tar,
+)
+
+
+def assert_no_logging(msg):
+    raise AssertionError('Should not have logged anything but logged %s' % msg)
+
+
+def capture_logging(messages):
+    def capture(msg):
+        messages.append(msg)
+
+    return capture
+
+
+@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'))
+
+
+def test_archived_image_action_when_missing(tar_file_name):
+    fake_name = 'a:latest'
+    fake_id = 'a1'
+
+    expected = 'Archived image %s to %s, since none present' % (fake_name, tar_file_name)
+
+    actual = ImageManager.archived_image_action(assert_no_logging, tar_file_name, fake_name, api_image_id(fake_id))
+
+    assert actual == expected
+
+
+def test_archived_image_action_when_current(tar_file_name):
+    fake_name = 'b:latest'
+    fake_id = 'b2'
+
+    write_imitation_archive(tar_file_name, fake_id, [fake_name])
+
+    actual = ImageManager.archived_image_action(assert_no_logging, tar_file_name, fake_name, api_image_id(fake_id))
+
+    assert actual is None
+
+
+def test_archived_image_action_when_invalid(tar_file_name):
+    fake_name = 'c:1.2.3'
+    fake_id = 'c3'
+
+    write_irrelevant_tar(tar_file_name)
+
+    expected = 'Archived image %s to %s, overwriting an unreadable archive file' % (fake_name, tar_file_name)
+
+    actual_log = []
+    actual = ImageManager.archived_image_action(
+        capture_logging(actual_log),
+        tar_file_name,
+        fake_name,
+        api_image_id(fake_id)
+    )
+
+    assert actual == expected
+
+    assert len(actual_log) == 1
+    assert actual_log[0].startswith('Unable to extract manifest summary from archive')
+
+
+def test_archived_image_action_when_obsolete_by_id(tar_file_name):
+    fake_name = 'd:0.0.1'
+    old_id = 'e5'
+    new_id = 'd4'
+
+    write_imitation_archive(tar_file_name, old_id, [fake_name])
+
+    expected = 'Archived image %s to %s, overwriting archive with image %s named %s' % (
+        fake_name, tar_file_name, old_id, fake_name
+    )
+    actual = ImageManager.archived_image_action(assert_no_logging, tar_file_name, fake_name, api_image_id(new_id))
+
+    assert actual == expected
+
+
+def test_archived_image_action_when_obsolete_by_name(tar_file_name):
+    old_name = 'hi'
+    new_name = 'd:0.0.1'
+    fake_id = 'd4'
+
+    write_imitation_archive(tar_file_name, fake_id, [old_name])
+
+    expected = 'Archived image %s to %s, overwriting archive with image %s named %s' % (
+        new_name, tar_file_name, fake_id, old_name
+    )
+    actual = ImageManager.archived_image_action(assert_no_logging, tar_file_name, new_name, api_image_id(fake_id))
+
+    print('actual   : %s', actual)
+    print('expected : %s', expected)
+    assert actual == expected

tests/unit/plugins/test_support/docker_image_archive_stubbing.py

@@ -0,0 +1,76 @@
+# 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 json
+import tarfile
+from tempfile import TemporaryFile
+
+
+def write_imitation_archive(file_name, image_id, repo_tags):
+    '''
+    Write a tar file meeting these requirements:
+
+    * Has a file manifest.json
+    * manifest.json contains a one-element array
+    * The element has a Config property with "[image_id].json" as the value name
+
+    :param file_name: Name of file to create
+    :type file_name: str
+    :param image_id: Fake sha256 hash (without the sha256: prefix)
+    :type image_id: str
+    :param repo_tags: list of fake image:tag's
+    :type repo_tags: list
+    '''
+
+    manifest = [
+        {
+            'Config': '%s.json' % image_id,
+            'RepoTags': repo_tags
+        }
+    ]
+
+    write_imitation_archive_with_manifest(file_name, manifest)
+
+
+def write_imitation_archive_with_manifest(file_name, manifest):
+    tf = tarfile.open(file_name, 'w')
+    try:
+        with TemporaryFile() as f:
+            f.write(json.dumps(manifest).encode('utf-8'))
+
+            ti = tarfile.TarInfo('manifest.json')
+            ti.size = f.tell()
+
+            f.seek(0)
+            tf.addfile(ti, f)
+
+    finally:
+        # In Python 2.6, this does not have __exit__
+        tf.close()
+
+
+def write_irrelevant_tar(file_name):
+    '''
+    Create a tar file that does not match the spec for "docker image save" / "docker image load" commands.
+
+    :param file_name: Name of tar file to create
+    :type file_name: str
+    '''
+
+    tf = tarfile.open(file_name, 'w')
+    try:
+        with TemporaryFile() as f:
+            f.write('Hello, world.'.encode('utf-8'))
+
+            ti = tarfile.TarInfo('hi.txt')
+            ti.size = f.tell()
+
+            f.seek(0)
+            tf.addfile(ti, f)
+
+    finally:
+        tf.close()