diff options
Diffstat (limited to 'cloudinit/tests')
| -rw-r--r-- | cloudinit/tests/test_persistence.py | 118 | ||||
| -rw-r--r-- | cloudinit/tests/test_upgrade.py | 45 |
2 files changed, 163 insertions, 0 deletions
diff --git a/cloudinit/tests/test_persistence.py b/cloudinit/tests/test_persistence.py new file mode 100644 index 00000000..7b64ced9 --- /dev/null +++ b/cloudinit/tests/test_persistence.py @@ -0,0 +1,118 @@ +# Copyright (C) 2020 Canonical Ltd. +# +# Author: Daniel Watkins <oddbloke@ubuntu.com> +# +# This file is part of cloud-init. See LICENSE file for license information. +""" +Tests for cloudinit.persistence. + +Per https://docs.python.org/3/library/pickle.html, only "classes that are +defined at the top level of a module" can be pickled. This means that all of +our ``CloudInitPickleMixin`` subclasses for testing must be defined at +module-level (rather than being defined inline or dynamically in the body of +test methods, as we would do without this constraint). + +``TestPickleMixin.test_subclasses`` iterates over a list of all of these +classes, and tests that they round-trip through a pickle dump/load. As the +interface we're testing is that ``_unpickle`` is called appropriately on +subclasses, our subclasses define their assertions in their ``_unpickle`` +implementation. (This means that the assertions will not be executed if +``_unpickle`` is not called at all; we have +``TestPickleMixin.test_unpickle_called`` to ensure it is called.) + +To avoid manually maintaining a list of classes for parametrization we use a +simple metaclass, ``_Collector``, to gather them up. +""" + +import pickle +from unittest import mock + +import pytest + +from cloudinit.persistence import CloudInitPickleMixin + + +class _Collector(type): + """Any class using this as a metaclass will be stored in test_classes.""" + + test_classes = [] + + def __new__(cls, *args): + new_cls = super().__new__(cls, *args) + _Collector.test_classes.append(new_cls) + return new_cls + + +class InstanceVersionNotUsed(CloudInitPickleMixin, metaclass=_Collector): + """Test that the class version is used over one set in instance state.""" + + _ci_pkl_version = 1 + + def __init__(self): + self._ci_pkl_version = 2 + + def _unpickle(self, ci_pkl_version: int) -> None: + assert 1 == ci_pkl_version + + +class MissingVersionHandled(CloudInitPickleMixin, metaclass=_Collector): + """Test that pickles without ``_ci_pkl_version`` are handled gracefully. + + This is tested by overriding ``__getstate__`` so the dumped pickle of this + class will not have ``_ci_pkl_version`` included. + """ + + def __getstate__(self): + return self.__dict__ + + def _unpickle(self, ci_pkl_version: int) -> None: + assert 0 == ci_pkl_version + + +class OverridenVersionHonored(CloudInitPickleMixin, metaclass=_Collector): + """Test that the subclass's version is used.""" + + _ci_pkl_version = 1 + + def _unpickle(self, ci_pkl_version: int) -> None: + assert 1 == ci_pkl_version + + +class StateIsRestored(CloudInitPickleMixin, metaclass=_Collector): + """Instance state should be restored before ``_unpickle`` is called.""" + + def __init__(self): + self.some_state = "some state" + + def _unpickle(self, ci_pkl_version: int) -> None: + assert "some state" == self.some_state + + +class UnpickleCanBeUnoverriden(CloudInitPickleMixin, metaclass=_Collector): + """Subclasses should not need to override ``_unpickle``.""" + + +class VersionDefaultsToZero(CloudInitPickleMixin, metaclass=_Collector): + """Test that the default version is 0.""" + + def _unpickle(self, ci_pkl_version: int) -> None: + assert 0 == ci_pkl_version + + +class TestPickleMixin: + def test_unpickle_called(self): + """Test that self._unpickle is called on unpickle.""" + with mock.patch.object( + CloudInitPickleMixin, "_unpickle" + ) as m_unpickle: + pickle.loads(pickle.dumps(CloudInitPickleMixin())) + assert 1 == m_unpickle.call_count + + @pytest.mark.parametrize("cls", _Collector.test_classes) + def test_subclasses(self, cls): + """For each collected class, round-trip through pickle dump/load. + + Assertions are implemented in ``cls._unpickle``, and so are evoked as + part of the pickle load. + """ + pickle.loads(pickle.dumps(cls())) diff --git a/cloudinit/tests/test_upgrade.py b/cloudinit/tests/test_upgrade.py new file mode 100644 index 00000000..f79a2536 --- /dev/null +++ b/cloudinit/tests/test_upgrade.py @@ -0,0 +1,45 @@ +# Copyright (C) 2020 Canonical Ltd. +# +# Author: Daniel Watkins <oddbloke@ubuntu.com> +# +# This file is part of cloud-init. See LICENSE file for license information. + +"""Upgrade testing for cloud-init. + +This module tests cloud-init's behaviour across upgrades. Specifically, it +specifies a set of invariants that the current codebase expects to be true (as +tests in ``TestUpgrade``) and then checks that these hold true after unpickling +``obj.pkl``s from previous versions of cloud-init; those pickles are stored in +``tests/data/old_pickles/``. +""" + +import operator +import pathlib + +import pytest + +from cloudinit.stages import _pkl_load +from cloudinit.tests.helpers import resourceLocation + + +class TestUpgrade: + @pytest.fixture( + params=pathlib.Path(resourceLocation("old_pickles")).glob("*.pkl"), + scope="class", + ids=operator.attrgetter("name"), + ) + def previous_obj_pkl(self, request): + """Load each pickle to memory once, then run all tests against it. + + Test implementations _must not_ modify the ``previous_obj_pkl`` which + they are passed, as that will affect tests that run after them. + """ + return _pkl_load(str(request.param)) + + def test_networking_set_on_distro(self, previous_obj_pkl): + """We always expect to have ``.networking`` on ``Distro`` objects.""" + assert previous_obj_pkl.distro.networking is not None + + def test_blacklist_drivers_set_on_networking(self, previous_obj_pkl): + """We always expect Networking.blacklist_drivers to be initialised.""" + assert previous_obj_pkl.distro.networking.blacklist_drivers is None |