Exemple #1
0
class TestDataSource(CiTestCase):

    with_logs = True
    maxDiff = None

    def setUp(self):
        super(TestDataSource, self).setUp()
        self.sys_cfg = {'datasource': {'_undef': {'key1': False}}}
        self.distro = 'distrotest'  # generally should be a Distro object
        self.paths = Paths({})
        self.datasource = DataSource(self.sys_cfg, self.distro, self.paths)

    def test_datasource_init(self):
        """DataSource initializes metadata attributes, ds_cfg and ud_proc."""
        self.assertEqual(self.paths, self.datasource.paths)
        self.assertEqual(self.sys_cfg, self.datasource.sys_cfg)
        self.assertEqual(self.distro, self.datasource.distro)
        self.assertIsNone(self.datasource.userdata)
        self.assertEqual({}, self.datasource.metadata)
        self.assertIsNone(self.datasource.userdata_raw)
        self.assertIsNone(self.datasource.vendordata)
        self.assertIsNone(self.datasource.vendordata_raw)
        self.assertEqual({'key1': False}, self.datasource.ds_cfg)
        self.assertIsInstance(self.datasource.ud_proc, UserDataProcessor)

    def test_datasource_init_gets_ds_cfg_using_dsname(self):
        """Init uses DataSource.dsname for sourcing ds_cfg."""
        sys_cfg = {'datasource': {'MyTestSubclass': {'key2': False}}}
        distro = 'distrotest'  # generally should be a Distro object
        datasource = DataSourceTestSubclassNet(sys_cfg, distro, self.paths)
        self.assertEqual({'key2': False}, datasource.ds_cfg)

    def test_str_is_classname(self):
        """The string representation of the datasource is the classname."""
        self.assertEqual('DataSource', str(self.datasource))
        self.assertEqual(
            'DataSourceTestSubclassNet',
            str(DataSourceTestSubclassNet('', '', self.paths)))

    def test_datasource_get_url_params_defaults(self):
        """get_url_params default url config settings for the datasource."""
        params = self.datasource.get_url_params()
        self.assertEqual(params.max_wait_seconds, self.datasource.url_max_wait)
        self.assertEqual(params.timeout_seconds, self.datasource.url_timeout)
        self.assertEqual(params.num_retries, self.datasource.url_retries)
        self.assertEqual(params.sec_between_retries,
                         self.datasource.url_sec_between_retries)

    def test_datasource_get_url_params_subclassed(self):
        """Subclasses can override get_url_params defaults."""
        sys_cfg = {'datasource': {'MyTestSubclass': {'key2': False}}}
        distro = 'distrotest'  # generally should be a Distro object
        datasource = DataSourceTestSubclassNet(sys_cfg, distro, self.paths)
        expected = (datasource.url_max_wait, datasource.url_timeout,
                    datasource.url_retries, datasource.url_sec_between_retries)
        url_params = datasource.get_url_params()
        self.assertNotEqual(self.datasource.get_url_params(), url_params)
        self.assertEqual(expected, url_params)

    def test_datasource_get_url_params_ds_config_override(self):
        """Datasource configuration options can override url param defaults."""
        sys_cfg = {
            'datasource': {
                'MyTestSubclass': {
                    'max_wait': '1', 'timeout': '2',
                    'retries': '3', 'sec_between_retries': 4
                }}}
        datasource = DataSourceTestSubclassNet(
            sys_cfg, self.distro, self.paths)
        expected = (1, 2, 3, 4)
        url_params = datasource.get_url_params()
        self.assertNotEqual(
            (datasource.url_max_wait, datasource.url_timeout,
             datasource.url_retries, datasource.url_sec_between_retries),
            url_params)
        self.assertEqual(expected, url_params)

    def test_datasource_get_url_params_is_zero_or_greater(self):
        """get_url_params ignores timeouts with a value below 0."""
        # Set an override that is below 0 which gets ignored.
        sys_cfg = {'datasource': {'_undef': {'timeout': '-1'}}}
        datasource = DataSource(sys_cfg, self.distro, self.paths)
        (_max_wait, timeout, _retries,
         _sec_between_retries) = datasource.get_url_params()
        self.assertEqual(0, timeout)

    def test_datasource_get_url_uses_defaults_on_errors(self):
        """On invalid system config values for url_params defaults are used."""
        # All invalid values should be logged
        sys_cfg = {'datasource': {
            '_undef': {
                'max_wait': 'nope', 'timeout': 'bug', 'retries': 'nonint'}}}
        datasource = DataSource(sys_cfg, self.distro, self.paths)
        url_params = datasource.get_url_params()
        expected = (datasource.url_max_wait, datasource.url_timeout,
                    datasource.url_retries, datasource.url_sec_between_retries)
        self.assertEqual(expected, url_params)
        logs = self.logs.getvalue()
        expected_logs = [
            "Config max_wait 'nope' is not an int, using default '-1'",
            "Config timeout 'bug' is not an int, using default '10'",
            "Config retries 'nonint' is not an int, using default '5'",
        ]
        for log in expected_logs:
            self.assertIn(log, logs)

    @mock.patch('cloudinit.sources.net.find_fallback_nic')
    def test_fallback_interface_is_discovered(self, m_get_fallback_nic):
        """The fallback_interface is discovered via find_fallback_nic."""
        m_get_fallback_nic.return_value = 'nic9'
        self.assertEqual('nic9', self.datasource.fallback_interface)

    @mock.patch('cloudinit.sources.net.find_fallback_nic')
    def test_fallback_interface_logs_undiscovered(self, m_get_fallback_nic):
        """Log a warning when fallback_interface can not discover the nic."""
        self.datasource._cloud_name = 'MySupahCloud'
        m_get_fallback_nic.return_value = None  # Couldn't discover nic
        self.assertIsNone(self.datasource.fallback_interface)
        self.assertEqual(
            'WARNING: Did not find a fallback interface on MySupahCloud.\n',
            self.logs.getvalue())

    @mock.patch('cloudinit.sources.net.find_fallback_nic')
    def test_wb_fallback_interface_is_cached(self, m_get_fallback_nic):
        """The fallback_interface is cached and won't be rediscovered."""
        self.datasource._fallback_interface = 'nic10'
        self.assertEqual('nic10', self.datasource.fallback_interface)
        m_get_fallback_nic.assert_not_called()

    def test__get_data_unimplemented(self):
        """Raise an error when _get_data is not implemented."""
        with self.assertRaises(NotImplementedError) as context_manager:
            self.datasource.get_data()
        self.assertIn(
            'Subclasses of DataSource must implement _get_data',
            str(context_manager.exception))
        datasource2 = InvalidDataSourceTestSubclassNet(
            self.sys_cfg, self.distro, self.paths)
        with self.assertRaises(NotImplementedError) as context_manager:
            datasource2.get_data()
        self.assertIn(
            'Subclasses of DataSource must implement _get_data',
            str(context_manager.exception))

    def test_get_data_calls_subclass__get_data(self):
        """Datasource.get_data uses the subclass' version of _get_data."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        self.assertTrue(datasource.get_data())
        self.assertEqual(
            {'availability_zone': 'myaz',
             'local-hostname': 'test-subclass-hostname',
             'region': 'myregion'},
            datasource.metadata)
        self.assertEqual('userdata_raw', datasource.userdata_raw)
        self.assertEqual('vendordata_raw', datasource.vendordata_raw)

    def test_get_hostname_strips_local_hostname_without_domain(self):
        """Datasource.get_hostname strips metadata local-hostname of domain."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        self.assertTrue(datasource.get_data())
        self.assertEqual(
            'test-subclass-hostname', datasource.metadata['local-hostname'])
        self.assertEqual('test-subclass-hostname', datasource.get_hostname())
        datasource.metadata['local-hostname'] = 'hostname.my.domain.com'
        self.assertEqual('hostname', datasource.get_hostname())

    def test_get_hostname_with_fqdn_returns_local_hostname_with_domain(self):
        """Datasource.get_hostname with fqdn set gets qualified hostname."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        self.assertTrue(datasource.get_data())
        datasource.metadata['local-hostname'] = 'hostname.my.domain.com'
        self.assertEqual(
            'hostname.my.domain.com', datasource.get_hostname(fqdn=True))

    def test_get_hostname_without_metadata_uses_system_hostname(self):
        """Datasource.gethostname runs util.get_hostname when no metadata."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        self.assertEqual({}, datasource.metadata)
        mock_fqdn = 'cloudinit.sources.util.get_fqdn_from_hosts'
        with mock.patch('cloudinit.sources.util.get_hostname') as m_gethost:
            with mock.patch(mock_fqdn) as m_fqdn:
                m_gethost.return_value = 'systemhostname.domain.com'
                m_fqdn.return_value = None  # No maching fqdn in /etc/hosts
                self.assertEqual('systemhostname', datasource.get_hostname())
                self.assertEqual(
                    'systemhostname.domain.com',
                    datasource.get_hostname(fqdn=True))

    def test_get_hostname_without_metadata_returns_none(self):
        """Datasource.gethostname returns None when metadata_only and no MD."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        self.assertEqual({}, datasource.metadata)
        mock_fqdn = 'cloudinit.sources.util.get_fqdn_from_hosts'
        with mock.patch('cloudinit.sources.util.get_hostname') as m_gethost:
            with mock.patch(mock_fqdn) as m_fqdn:
                self.assertIsNone(datasource.get_hostname(metadata_only=True))
                self.assertIsNone(
                    datasource.get_hostname(fqdn=True, metadata_only=True))
        self.assertEqual([], m_gethost.call_args_list)
        self.assertEqual([], m_fqdn.call_args_list)

    def test_get_hostname_without_metadata_prefers_etc_hosts(self):
        """Datasource.gethostname prefers /etc/hosts to util.get_hostname."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        self.assertEqual({}, datasource.metadata)
        mock_fqdn = 'cloudinit.sources.util.get_fqdn_from_hosts'
        with mock.patch('cloudinit.sources.util.get_hostname') as m_gethost:
            with mock.patch(mock_fqdn) as m_fqdn:
                m_gethost.return_value = 'systemhostname.domain.com'
                m_fqdn.return_value = 'fqdnhostname.domain.com'
                self.assertEqual('fqdnhostname', datasource.get_hostname())
                self.assertEqual('fqdnhostname.domain.com',
                                 datasource.get_hostname(fqdn=True))

    def test_get_data_does_not_write_instance_data_on_failure(self):
        """get_data does not write INSTANCE_JSON_FILE on get_data False."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}),
            get_data_retval=False)
        self.assertFalse(datasource.get_data())
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        self.assertFalse(
            os.path.exists(json_file), 'Found unexpected file %s' % json_file)

    def test_get_data_writes_json_instance_data_on_success(self):
        """get_data writes INSTANCE_JSON_FILE to run_dir as world readable."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        sys_info = {
            "python": "3.7",
            "platform":
                "Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal",
            "uname": ["Linux", "myhost", "5.4.0-24-generic", "SMP blah",
                      "x86_64"],
            "variant": "ubuntu", "dist": ["ubuntu", "20.04", "focal"]}
        with mock.patch("cloudinit.util.system_info", return_value=sys_info):
            datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        content = util.load_file(json_file)
        expected = {
            'base64_encoded_keys': [],
            'merged_cfg': REDACT_SENSITIVE_VALUE,
            'sensitive_keys': ['merged_cfg'],
            'sys_info': sys_info,
            'v1': {
                '_beta_keys': ['subplatform'],
                'availability-zone': 'myaz',
                'availability_zone': 'myaz',
                'cloud-name': 'subclasscloudname',
                'cloud_name': 'subclasscloudname',
                'distro': 'ubuntu',
                'distro_release': 'focal',
                'distro_version': '20.04',
                'instance-id': 'iid-datasource',
                'instance_id': 'iid-datasource',
                'local-hostname': 'test-subclass-hostname',
                'local_hostname': 'test-subclass-hostname',
                'kernel_release': '5.4.0-24-generic',
                'machine': 'x86_64',
                'platform': 'mytestsubclass',
                'public_ssh_keys': [],
                'python_version': '3.7',
                'region': 'myregion',
                'system_platform':
                    'Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal',
                'subplatform': 'unknown',
                'variant': 'ubuntu'},
            'ds': {

                '_doc': EXPERIMENTAL_TEXT,
                'meta_data': {'availability_zone': 'myaz',
                              'local-hostname': 'test-subclass-hostname',
                              'region': 'myregion'}}}
        self.assertEqual(expected, util.load_json(content))
        file_stat = os.stat(json_file)
        self.assertEqual(0o644, stat.S_IMODE(file_stat.st_mode))
        self.assertEqual(expected, util.load_json(content))

    def test_get_data_writes_redacted_public_json_instance_data(self):
        """get_data writes redacted content to public INSTANCE_JSON_FILE."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}),
            custom_metadata={
                'availability_zone': 'myaz',
                'local-hostname': 'test-subclass-hostname',
                'region': 'myregion',
                'some': {'security-credentials': {
                    'cred1': 'sekret', 'cred2': 'othersekret'}}})
        self.assertCountEqual(
            ('merged_cfg', 'security-credentials',),
            datasource.sensitive_metadata_keys)
        sys_info = {
            "python": "3.7",
            "platform":
                "Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal",
            "uname": ["Linux", "myhost", "5.4.0-24-generic", "SMP blah",
                      "x86_64"],
            "variant": "ubuntu", "dist": ["ubuntu", "20.04", "focal"]}
        with mock.patch("cloudinit.util.system_info", return_value=sys_info):
            datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        redacted = util.load_json(util.load_file(json_file))
        expected = {
            'base64_encoded_keys': [],
            'merged_cfg': REDACT_SENSITIVE_VALUE,
            'sensitive_keys': [
                'ds/meta_data/some/security-credentials', 'merged_cfg'],
            'sys_info': sys_info,
            'v1': {
                '_beta_keys': ['subplatform'],
                'availability-zone': 'myaz',
                'availability_zone': 'myaz',
                'cloud-name': 'subclasscloudname',
                'cloud_name': 'subclasscloudname',
                'distro': 'ubuntu',
                'distro_release': 'focal',
                'distro_version': '20.04',
                'instance-id': 'iid-datasource',
                'instance_id': 'iid-datasource',
                'local-hostname': 'test-subclass-hostname',
                'local_hostname': 'test-subclass-hostname',
                'kernel_release': '5.4.0-24-generic',
                'machine': 'x86_64',
                'platform': 'mytestsubclass',
                'public_ssh_keys': [],
                'python_version': '3.7',
                'region': 'myregion',
                'system_platform':
                    'Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal',
                'subplatform': 'unknown',
                'variant': 'ubuntu'},
            'ds': {
                '_doc': EXPERIMENTAL_TEXT,
                'meta_data': {
                    'availability_zone': 'myaz',
                    'local-hostname': 'test-subclass-hostname',
                    'region': 'myregion',
                    'some': {'security-credentials': REDACT_SENSITIVE_VALUE}}}
        }
        self.assertCountEqual(expected, redacted)
        file_stat = os.stat(json_file)
        self.assertEqual(0o644, stat.S_IMODE(file_stat.st_mode))

    def test_get_data_writes_json_instance_data_sensitive(self):
        """
        get_data writes unmodified data to sensitive file as root-readonly.
        """
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}),
            custom_metadata={
                'availability_zone': 'myaz',
                'local-hostname': 'test-subclass-hostname',
                'region': 'myregion',
                'some': {'security-credentials': {
                    'cred1': 'sekret', 'cred2': 'othersekret'}}})
        sys_info = {
            "python": "3.7",
            "platform":
                "Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal",
            "uname": ["Linux", "myhost", "5.4.0-24-generic", "SMP blah",
                      "x86_64"],
            "variant": "ubuntu", "dist": ["ubuntu", "20.04", "focal"]}

        self.assertCountEqual(
            ('merged_cfg', 'security-credentials',),
            datasource.sensitive_metadata_keys)
        with mock.patch("cloudinit.util.system_info", return_value=sys_info):
            datasource.get_data()
        sensitive_json_file = self.tmp_path(INSTANCE_JSON_SENSITIVE_FILE, tmp)
        content = util.load_file(sensitive_json_file)
        expected = {
            'base64_encoded_keys': [],
            'merged_cfg': {
                '_doc': (
                    'Merged cloud-init system config from '
                    '/etc/cloud/cloud.cfg and /etc/cloud/cloud.cfg.d/'
                ),
                'datasource': {'_undef': {'key1': False}}},
            'sensitive_keys': [
                'ds/meta_data/some/security-credentials', 'merged_cfg'],
            'sys_info': sys_info,
            'v1': {
                '_beta_keys': ['subplatform'],
                'availability-zone': 'myaz',
                'availability_zone': 'myaz',
                'cloud-name': 'subclasscloudname',
                'cloud_name': 'subclasscloudname',
                'distro': 'ubuntu',
                'distro_release': 'focal',
                'distro_version': '20.04',
                'instance-id': 'iid-datasource',
                'instance_id': 'iid-datasource',
                'kernel_release': '5.4.0-24-generic',
                'local-hostname': 'test-subclass-hostname',
                'local_hostname': 'test-subclass-hostname',
                'machine': 'x86_64',
                'platform': 'mytestsubclass',
                'public_ssh_keys': [],
                'python_version': '3.7',
                'region': 'myregion',
                'subplatform': 'unknown',
                'system_platform':
                    'Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal',
                'variant': 'ubuntu'},
            'ds': {
                '_doc': EXPERIMENTAL_TEXT,
                'meta_data': {
                    'availability_zone': 'myaz',
                    'local-hostname': 'test-subclass-hostname',
                    'region': 'myregion',
                    'some': {
                        'security-credentials':
                            {'cred1': 'sekret', 'cred2': 'othersekret'}}}}
        }
        self.assertCountEqual(expected, util.load_json(content))
        file_stat = os.stat(sensitive_json_file)
        self.assertEqual(0o600, stat.S_IMODE(file_stat.st_mode))
        self.assertEqual(expected, util.load_json(content))

    def test_get_data_handles_redacted_unserializable_content(self):
        """get_data warns unserializable content in INSTANCE_JSON_FILE."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}),
            custom_metadata={'key1': 'val1', 'key2': {'key2.1': self.paths}})
        datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        content = util.load_file(json_file)
        expected_metadata = {
            'key1': 'val1',
            'key2': {
                'key2.1': "Warning: redacted unserializable type <class"
                          " 'cloudinit.helpers.Paths'>"}}
        instance_json = util.load_json(content)
        self.assertEqual(
            expected_metadata, instance_json['ds']['meta_data'])

    def test_persist_instance_data_writes_ec2_metadata_when_set(self):
        """When ec2_metadata class attribute is set, persist to json."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        datasource.ec2_metadata = UNSET
        datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        instance_data = util.load_json(util.load_file(json_file))
        self.assertNotIn('ec2_metadata', instance_data['ds'])
        datasource.ec2_metadata = {'ec2stuff': 'is good'}
        datasource.persist_instance_data()
        instance_data = util.load_json(util.load_file(json_file))
        self.assertEqual(
            {'ec2stuff': 'is good'},
            instance_data['ds']['ec2_metadata'])

    def test_persist_instance_data_writes_network_json_when_set(self):
        """When network_data.json class attribute is set, persist to json."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}))
        datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        instance_data = util.load_json(util.load_file(json_file))
        self.assertNotIn('network_json', instance_data['ds'])
        datasource.network_json = {'network_json': 'is good'}
        datasource.persist_instance_data()
        instance_data = util.load_json(util.load_file(json_file))
        self.assertEqual(
            {'network_json': 'is good'},
            instance_data['ds']['network_json'])

    def test_get_data_base64encodes_unserializable_bytes(self):
        """On py3, get_data base64encodes any unserializable content."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg, self.distro, Paths({'run_dir': tmp}),
            custom_metadata={'key1': 'val1', 'key2': {'key2.1': b'\x123'}})
        self.assertTrue(datasource.get_data())
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        content = util.load_file(json_file)
        instance_json = util.load_json(content)
        self.assertCountEqual(
            ['ds/meta_data/key2/key2.1'],
            instance_json['base64_encoded_keys'])
        self.assertEqual(
            {'key1': 'val1', 'key2': {'key2.1': 'EjM='}},
            instance_json['ds']['meta_data'])

    def test_get_hostname_subclass_support(self):
        """Validate get_hostname signature on all subclasses of DataSource."""
        base_args = inspect.getfullargspec(DataSource.get_hostname)
        # Import all DataSource subclasses so we can inspect them.
        modules = util.find_modules(os.path.dirname(os.path.dirname(__file__)))
        for _loc, name in modules.items():
            mod_locs, _ = importer.find_module(name, ['cloudinit.sources'], [])
            if mod_locs:
                importer.import_module(mod_locs[0])
        for child in DataSource.__subclasses__():
            if 'Test' in child.dsname:
                continue
            self.assertEqual(
                base_args,
                inspect.getfullargspec(child.get_hostname),
                '%s does not implement DataSource.get_hostname params'
                % child)
            for grandchild in child.__subclasses__():
                self.assertEqual(
                    base_args,
                    inspect.getfullargspec(grandchild.get_hostname),
                    '%s does not implement DataSource.get_hostname params'
                    % grandchild)

    def test_clear_cached_attrs_resets_cached_attr_class_attributes(self):
        """Class attributes listed in cached_attr_defaults are reset."""
        count = 0
        # Setup values for all cached class attributes
        for attr, value in self.datasource.cached_attr_defaults:
            setattr(self.datasource, attr, count)
            count += 1
        self.datasource._dirty_cache = True
        self.datasource.clear_cached_attrs()
        for attr, value in self.datasource.cached_attr_defaults:
            self.assertEqual(value, getattr(self.datasource, attr))

    def test_clear_cached_attrs_noops_on_clean_cache(self):
        """Class attributes listed in cached_attr_defaults are reset."""
        count = 0
        # Setup values for all cached class attributes
        for attr, _ in self.datasource.cached_attr_defaults:
            setattr(self.datasource, attr, count)
            count += 1
        self.datasource._dirty_cache = False   # Fake clean cache
        self.datasource.clear_cached_attrs()
        count = 0
        for attr, _ in self.datasource.cached_attr_defaults:
            self.assertEqual(count, getattr(self.datasource, attr))
            count += 1

    def test_clear_cached_attrs_skips_non_attr_class_attributes(self):
        """Skip any cached_attr_defaults which aren't class attributes."""
        self.datasource._dirty_cache = True
        self.datasource.clear_cached_attrs()
        for attr in ('ec2_metadata', 'network_json'):
            self.assertFalse(hasattr(self.datasource, attr))

    def test_clear_cached_attrs_of_custom_attrs(self):
        """Custom attr_values can be passed to clear_cached_attrs."""
        self.datasource._dirty_cache = True
        cached_attr_name = self.datasource.cached_attr_defaults[0][0]
        setattr(self.datasource, cached_attr_name, 'himom')
        self.datasource.myattr = 'orig'
        self.datasource.clear_cached_attrs(
            attr_defaults=(('myattr', 'updated'),))
        self.assertEqual('himom', getattr(self.datasource, cached_attr_name))
        self.assertEqual('updated', self.datasource.myattr)

    @mock.patch.dict(DataSource.default_update_events, {
        EventScope.NETWORK: {EventType.BOOT_NEW_INSTANCE}})
    @mock.patch.dict(DataSource.supported_update_events, {
        EventScope.NETWORK: {EventType.BOOT_NEW_INSTANCE}})
    def test_update_metadata_only_acts_on_supported_update_events(self):
        """update_metadata_if_supported wont get_data on unsupported events."""
        self.assertEqual(
            {EventScope.NETWORK: set([EventType.BOOT_NEW_INSTANCE])},
            self.datasource.default_update_events
        )

        def fake_get_data():
            raise Exception('get_data should not be called')

        self.datasource.get_data = fake_get_data
        self.assertFalse(
            self.datasource.update_metadata_if_supported(
                source_event_types=[EventType.BOOT]))

    @mock.patch.dict(DataSource.supported_update_events, {
        EventScope.NETWORK: {EventType.BOOT_NEW_INSTANCE}})
    def test_update_metadata_returns_true_on_supported_update_event(self):
        """update_metadata_if_supported returns get_data on supported events"""
        def fake_get_data():
            return True

        self.datasource.get_data = fake_get_data
        self.datasource._network_config = 'something'
        self.datasource._dirty_cache = True
        self.assertTrue(
            self.datasource.update_metadata_if_supported(
                source_event_types=[
                    EventType.BOOT, EventType.BOOT_NEW_INSTANCE]))
        self.assertEqual(UNSET, self.datasource._network_config)

        self.assertIn(
            "DEBUG: Update datasource metadata and network config due to"
            " events: boot-new-instance",
            self.logs.getvalue()
        )
class TestDataSource(CiTestCase):

    with_logs = True
    maxDiff = None

    def setUp(self):
        super(TestDataSource, self).setUp()
        self.sys_cfg = {"datasource": {"_undef": {"key1": False}}}
        self.distro = "distrotest"  # generally should be a Distro object
        self.paths = Paths({})
        self.datasource = DataSource(self.sys_cfg, self.distro, self.paths)

    def test_datasource_init(self):
        """DataSource initializes metadata attributes, ds_cfg and ud_proc."""
        self.assertEqual(self.paths, self.datasource.paths)
        self.assertEqual(self.sys_cfg, self.datasource.sys_cfg)
        self.assertEqual(self.distro, self.datasource.distro)
        self.assertIsNone(self.datasource.userdata)
        self.assertEqual({}, self.datasource.metadata)
        self.assertIsNone(self.datasource.userdata_raw)
        self.assertIsNone(self.datasource.vendordata)
        self.assertIsNone(self.datasource.vendordata_raw)
        self.assertEqual({"key1": False}, self.datasource.ds_cfg)
        self.assertIsInstance(self.datasource.ud_proc, UserDataProcessor)

    def test_datasource_init_gets_ds_cfg_using_dsname(self):
        """Init uses DataSource.dsname for sourcing ds_cfg."""
        sys_cfg = {"datasource": {"MyTestSubclass": {"key2": False}}}
        distro = "distrotest"  # generally should be a Distro object
        datasource = DataSourceTestSubclassNet(sys_cfg, distro, self.paths)
        self.assertEqual({"key2": False}, datasource.ds_cfg)

    def test_str_is_classname(self):
        """The string representation of the datasource is the classname."""
        self.assertEqual("DataSource", str(self.datasource))
        self.assertEqual(
            "DataSourceTestSubclassNet",
            str(DataSourceTestSubclassNet("", "", self.paths)),
        )

    def test_datasource_get_url_params_defaults(self):
        """get_url_params default url config settings for the datasource."""
        params = self.datasource.get_url_params()
        self.assertEqual(params.max_wait_seconds, self.datasource.url_max_wait)
        self.assertEqual(params.timeout_seconds, self.datasource.url_timeout)
        self.assertEqual(params.num_retries, self.datasource.url_retries)
        self.assertEqual(params.sec_between_retries,
                         self.datasource.url_sec_between_retries)

    def test_datasource_get_url_params_subclassed(self):
        """Subclasses can override get_url_params defaults."""
        sys_cfg = {"datasource": {"MyTestSubclass": {"key2": False}}}
        distro = "distrotest"  # generally should be a Distro object
        datasource = DataSourceTestSubclassNet(sys_cfg, distro, self.paths)
        expected = (
            datasource.url_max_wait,
            datasource.url_timeout,
            datasource.url_retries,
            datasource.url_sec_between_retries,
        )
        url_params = datasource.get_url_params()
        self.assertNotEqual(self.datasource.get_url_params(), url_params)
        self.assertEqual(expected, url_params)

    def test_datasource_get_url_params_ds_config_override(self):
        """Datasource configuration options can override url param defaults."""
        sys_cfg = {
            "datasource": {
                "MyTestSubclass": {
                    "max_wait": "1",
                    "timeout": "2",
                    "retries": "3",
                    "sec_between_retries": 4,
                }
            }
        }
        datasource = DataSourceTestSubclassNet(sys_cfg, self.distro,
                                               self.paths)
        expected = (1, 2, 3, 4)
        url_params = datasource.get_url_params()
        self.assertNotEqual(
            (
                datasource.url_max_wait,
                datasource.url_timeout,
                datasource.url_retries,
                datasource.url_sec_between_retries,
            ),
            url_params,
        )
        self.assertEqual(expected, url_params)

    def test_datasource_get_url_params_is_zero_or_greater(self):
        """get_url_params ignores timeouts with a value below 0."""
        # Set an override that is below 0 which gets ignored.
        sys_cfg = {"datasource": {"_undef": {"timeout": "-1"}}}
        datasource = DataSource(sys_cfg, self.distro, self.paths)
        (
            _max_wait,
            timeout,
            _retries,
            _sec_between_retries,
        ) = datasource.get_url_params()
        self.assertEqual(0, timeout)

    def test_datasource_get_url_uses_defaults_on_errors(self):
        """On invalid system config values for url_params defaults are used."""
        # All invalid values should be logged
        sys_cfg = {
            "datasource": {
                "_undef": {
                    "max_wait": "nope",
                    "timeout": "bug",
                    "retries": "nonint",
                }
            }
        }
        datasource = DataSource(sys_cfg, self.distro, self.paths)
        url_params = datasource.get_url_params()
        expected = (
            datasource.url_max_wait,
            datasource.url_timeout,
            datasource.url_retries,
            datasource.url_sec_between_retries,
        )
        self.assertEqual(expected, url_params)
        logs = self.logs.getvalue()
        expected_logs = [
            "Config max_wait 'nope' is not an int, using default '-1'",
            "Config timeout 'bug' is not an int, using default '10'",
            "Config retries 'nonint' is not an int, using default '5'",
        ]
        for log in expected_logs:
            self.assertIn(log, logs)

    @mock.patch("cloudinit.sources.net.find_fallback_nic")
    def test_fallback_interface_is_discovered(self, m_get_fallback_nic):
        """The fallback_interface is discovered via find_fallback_nic."""
        m_get_fallback_nic.return_value = "nic9"
        self.assertEqual("nic9", self.datasource.fallback_interface)

    @mock.patch("cloudinit.sources.net.find_fallback_nic")
    def test_fallback_interface_logs_undiscovered(self, m_get_fallback_nic):
        """Log a warning when fallback_interface can not discover the nic."""
        self.datasource._cloud_name = "MySupahCloud"
        m_get_fallback_nic.return_value = None  # Couldn't discover nic
        self.assertIsNone(self.datasource.fallback_interface)
        self.assertEqual(
            "WARNING: Did not find a fallback interface on MySupahCloud.\n",
            self.logs.getvalue(),
        )

    @mock.patch("cloudinit.sources.net.find_fallback_nic")
    def test_wb_fallback_interface_is_cached(self, m_get_fallback_nic):
        """The fallback_interface is cached and won't be rediscovered."""
        self.datasource._fallback_interface = "nic10"
        self.assertEqual("nic10", self.datasource.fallback_interface)
        m_get_fallback_nic.assert_not_called()

    def test__get_data_unimplemented(self):
        """Raise an error when _get_data is not implemented."""
        with self.assertRaises(NotImplementedError) as context_manager:
            self.datasource.get_data()
        self.assertIn(
            "Subclasses of DataSource must implement _get_data",
            str(context_manager.exception),
        )
        datasource2 = InvalidDataSourceTestSubclassNet(self.sys_cfg,
                                                       self.distro, self.paths)
        with self.assertRaises(NotImplementedError) as context_manager:
            datasource2.get_data()
        self.assertIn(
            "Subclasses of DataSource must implement _get_data",
            str(context_manager.exception),
        )

    def test_get_data_calls_subclass__get_data(self):
        """Datasource.get_data uses the subclass' version of _get_data."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        self.assertTrue(datasource.get_data())
        self.assertEqual(
            {
                "availability_zone": "myaz",
                "local-hostname": "test-subclass-hostname",
                "region": "myregion",
            },
            datasource.metadata,
        )
        self.assertEqual("userdata_raw", datasource.userdata_raw)
        self.assertEqual("vendordata_raw", datasource.vendordata_raw)

    def test_get_hostname_strips_local_hostname_without_domain(self):
        """Datasource.get_hostname strips metadata local-hostname of domain."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        self.assertTrue(datasource.get_data())
        self.assertEqual("test-subclass-hostname",
                         datasource.metadata["local-hostname"])
        self.assertEqual("test-subclass-hostname",
                         datasource.get_hostname().hostname)
        datasource.metadata["local-hostname"] = "hostname.my.domain.com"
        self.assertEqual("hostname", datasource.get_hostname().hostname)

    def test_get_hostname_with_fqdn_returns_local_hostname_with_domain(self):
        """Datasource.get_hostname with fqdn set gets qualified hostname."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        self.assertTrue(datasource.get_data())
        datasource.metadata["local-hostname"] = "hostname.my.domain.com"
        self.assertEqual(
            "hostname.my.domain.com",
            datasource.get_hostname(fqdn=True).hostname,
        )

    def test_get_hostname_without_metadata_uses_system_hostname(self):
        """Datasource.gethostname runs util.get_hostname when no metadata."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        self.assertEqual({}, datasource.metadata)
        mock_fqdn = "cloudinit.sources.util.get_fqdn_from_hosts"
        with mock.patch("cloudinit.sources.util.get_hostname") as m_gethost:
            with mock.patch(mock_fqdn) as m_fqdn:
                m_gethost.return_value = "systemhostname.domain.com"
                m_fqdn.return_value = None  # No maching fqdn in /etc/hosts
                self.assertEqual("systemhostname",
                                 datasource.get_hostname().hostname)
                self.assertEqual(
                    "systemhostname.domain.com",
                    datasource.get_hostname(fqdn=True).hostname,
                )

    def test_get_hostname_without_metadata_returns_none(self):
        """Datasource.gethostname returns None when metadata_only and no MD."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        self.assertEqual({}, datasource.metadata)
        mock_fqdn = "cloudinit.sources.util.get_fqdn_from_hosts"
        with mock.patch("cloudinit.sources.util.get_hostname") as m_gethost:
            with mock.patch(mock_fqdn) as m_fqdn:
                self.assertIsNone(
                    datasource.get_hostname(metadata_only=True).hostname)
                self.assertIsNone(
                    datasource.get_hostname(fqdn=True,
                                            metadata_only=True).hostname)
        self.assertEqual([], m_gethost.call_args_list)
        self.assertEqual([], m_fqdn.call_args_list)

    def test_get_hostname_without_metadata_prefers_etc_hosts(self):
        """Datasource.gethostname prefers /etc/hosts to util.get_hostname."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        self.assertEqual({}, datasource.metadata)
        mock_fqdn = "cloudinit.sources.util.get_fqdn_from_hosts"
        with mock.patch("cloudinit.sources.util.get_hostname") as m_gethost:
            with mock.patch(mock_fqdn) as m_fqdn:
                m_gethost.return_value = "systemhostname.domain.com"
                m_fqdn.return_value = "fqdnhostname.domain.com"
                self.assertEqual("fqdnhostname",
                                 datasource.get_hostname().hostname)
                self.assertEqual(
                    "fqdnhostname.domain.com",
                    datasource.get_hostname(fqdn=True).hostname,
                )

    def test_get_data_does_not_write_instance_data_on_failure(self):
        """get_data does not write INSTANCE_JSON_FILE on get_data False."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg,
            self.distro,
            Paths({"run_dir": tmp}),
            get_data_retval=False,
        )
        self.assertFalse(datasource.get_data())
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        self.assertFalse(os.path.exists(json_file),
                         "Found unexpected file %s" % json_file)

    def test_get_data_writes_json_instance_data_on_success(self):
        """get_data writes INSTANCE_JSON_FILE to run_dir as world readable."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        sys_info = {
            "python": "3.7",
            "platform":
            ("Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal"),
            "uname": [
                "Linux",
                "myhost",
                "5.4.0-24-generic",
                "SMP blah",
                "x86_64",
            ],
            "variant": "ubuntu",
            "dist": ["ubuntu", "20.04", "focal"],
        }
        with mock.patch("cloudinit.util.system_info", return_value=sys_info):
            with mock.patch(
                    "cloudinit.sources.canonical_cloud_id",
                    return_value="canonical_cloud_id",
            ):
                datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        content = util.load_file(json_file)
        expected = {
            "base64_encoded_keys": [],
            "merged_cfg": REDACT_SENSITIVE_VALUE,
            "sensitive_keys": ["merged_cfg"],
            "sys_info": sys_info,
            "v1": {
                "_beta_keys": ["subplatform"],
                "availability-zone":
                "myaz",
                "availability_zone":
                "myaz",
                "cloud_id":
                "canonical_cloud_id",
                "cloud-name":
                "subclasscloudname",
                "cloud_name":
                "subclasscloudname",
                "distro":
                "ubuntu",
                "distro_release":
                "focal",
                "distro_version":
                "20.04",
                "instance-id":
                "iid-datasource",
                "instance_id":
                "iid-datasource",
                "local-hostname":
                "test-subclass-hostname",
                "local_hostname":
                "test-subclass-hostname",
                "kernel_release":
                "5.4.0-24-generic",
                "machine":
                "x86_64",
                "platform":
                "mytestsubclass",
                "public_ssh_keys": [],
                "python_version":
                "3.7",
                "region":
                "myregion",
                "system_platform":
                ("Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal"),
                "subplatform":
                "unknown",
                "variant":
                "ubuntu",
            },
            "ds": {
                "_doc": EXPERIMENTAL_TEXT,
                "meta_data": {
                    "availability_zone": "myaz",
                    "local-hostname": "test-subclass-hostname",
                    "region": "myregion",
                },
            },
        }
        self.assertEqual(expected, util.load_json(content))
        file_stat = os.stat(json_file)
        self.assertEqual(0o644, stat.S_IMODE(file_stat.st_mode))
        self.assertEqual(expected, util.load_json(content))

    def test_get_data_writes_redacted_public_json_instance_data(self):
        """get_data writes redacted content to public INSTANCE_JSON_FILE."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg,
            self.distro,
            Paths({"run_dir": tmp}),
            custom_metadata={
                "availability_zone": "myaz",
                "local-hostname": "test-subclass-hostname",
                "region": "myregion",
                "some": {
                    "security-credentials": {
                        "cred1": "sekret",
                        "cred2": "othersekret",
                    }
                },
            },
        )
        self.assertCountEqual(
            (
                "merged_cfg",
                "security-credentials",
            ),
            datasource.sensitive_metadata_keys,
        )
        sys_info = {
            "python": "3.7",
            "platform":
            ("Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal"),
            "uname": [
                "Linux",
                "myhost",
                "5.4.0-24-generic",
                "SMP blah",
                "x86_64",
            ],
            "variant": "ubuntu",
            "dist": ["ubuntu", "20.04", "focal"],
        }
        with mock.patch("cloudinit.util.system_info", return_value=sys_info):
            datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        redacted = util.load_json(util.load_file(json_file))
        expected = {
            "base64_encoded_keys": [],
            "merged_cfg":
            REDACT_SENSITIVE_VALUE,
            "sensitive_keys": [
                "ds/meta_data/some/security-credentials",
                "merged_cfg",
            ],
            "sys_info":
            sys_info,
            "v1": {
                "_beta_keys": ["subplatform"],
                "availability-zone":
                "myaz",
                "availability_zone":
                "myaz",
                "cloud-name":
                "subclasscloudname",
                "cloud_name":
                "subclasscloudname",
                "distro":
                "ubuntu",
                "distro_release":
                "focal",
                "distro_version":
                "20.04",
                "instance-id":
                "iid-datasource",
                "instance_id":
                "iid-datasource",
                "local-hostname":
                "test-subclass-hostname",
                "local_hostname":
                "test-subclass-hostname",
                "kernel_release":
                "5.4.0-24-generic",
                "machine":
                "x86_64",
                "platform":
                "mytestsubclass",
                "public_ssh_keys": [],
                "python_version":
                "3.7",
                "region":
                "myregion",
                "system_platform":
                ("Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal"),
                "subplatform":
                "unknown",
                "variant":
                "ubuntu",
            },
            "ds": {
                "_doc": EXPERIMENTAL_TEXT,
                "meta_data": {
                    "availability_zone": "myaz",
                    "local-hostname": "test-subclass-hostname",
                    "region": "myregion",
                    "some": {
                        "security-credentials": REDACT_SENSITIVE_VALUE
                    },
                },
            },
        }
        self.assertCountEqual(expected, redacted)
        file_stat = os.stat(json_file)
        self.assertEqual(0o644, stat.S_IMODE(file_stat.st_mode))

    def test_get_data_writes_json_instance_data_sensitive(self):
        """
        get_data writes unmodified data to sensitive file as root-readonly.
        """
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg,
            self.distro,
            Paths({"run_dir": tmp}),
            custom_metadata={
                "availability_zone": "myaz",
                "local-hostname": "test-subclass-hostname",
                "region": "myregion",
                "some": {
                    "security-credentials": {
                        "cred1": "sekret",
                        "cred2": "othersekret",
                    }
                },
            },
        )
        sys_info = {
            "python": "3.7",
            "platform":
            ("Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal"),
            "uname": [
                "Linux",
                "myhost",
                "5.4.0-24-generic",
                "SMP blah",
                "x86_64",
            ],
            "variant": "ubuntu",
            "dist": ["ubuntu", "20.04", "focal"],
        }

        self.assertCountEqual(
            (
                "merged_cfg",
                "security-credentials",
            ),
            datasource.sensitive_metadata_keys,
        )
        with mock.patch("cloudinit.util.system_info", return_value=sys_info):
            with mock.patch(
                    "cloudinit.sources.canonical_cloud_id",
                    return_value="canonical-cloud-id",
            ):
                datasource.get_data()
        sensitive_json_file = self.tmp_path(INSTANCE_JSON_SENSITIVE_FILE, tmp)
        content = util.load_file(sensitive_json_file)
        expected = {
            "base64_encoded_keys": [],
            "merged_cfg": {
                "_doc": ("Merged cloud-init system config from "
                         "/etc/cloud/cloud.cfg and /etc/cloud/cloud.cfg.d/"),
                "datasource": {
                    "_undef": {
                        "key1": False
                    }
                },
            },
            "sensitive_keys": [
                "ds/meta_data/some/security-credentials",
                "merged_cfg",
            ],
            "sys_info":
            sys_info,
            "v1": {
                "_beta_keys": ["subplatform"],
                "availability-zone":
                "myaz",
                "availability_zone":
                "myaz",
                "cloud_id":
                "canonical-cloud-id",
                "cloud-name":
                "subclasscloudname",
                "cloud_name":
                "subclasscloudname",
                "distro":
                "ubuntu",
                "distro_release":
                "focal",
                "distro_version":
                "20.04",
                "instance-id":
                "iid-datasource",
                "instance_id":
                "iid-datasource",
                "kernel_release":
                "5.4.0-24-generic",
                "local-hostname":
                "test-subclass-hostname",
                "local_hostname":
                "test-subclass-hostname",
                "machine":
                "x86_64",
                "platform":
                "mytestsubclass",
                "public_ssh_keys": [],
                "python_version":
                "3.7",
                "region":
                "myregion",
                "subplatform":
                "unknown",
                "system_platform":
                ("Linux-5.4.0-24-generic-x86_64-with-Ubuntu-20.04-focal"),
                "variant":
                "ubuntu",
            },
            "ds": {
                "_doc": EXPERIMENTAL_TEXT,
                "meta_data": {
                    "availability_zone": "myaz",
                    "local-hostname": "test-subclass-hostname",
                    "region": "myregion",
                    "some": {
                        "security-credentials": {
                            "cred1": "sekret",
                            "cred2": "othersekret",
                        }
                    },
                },
            },
        }
        self.assertCountEqual(expected, util.load_json(content))
        file_stat = os.stat(sensitive_json_file)
        self.assertEqual(0o600, stat.S_IMODE(file_stat.st_mode))
        self.assertEqual(expected, util.load_json(content))

    def test_get_data_handles_redacted_unserializable_content(self):
        """get_data warns unserializable content in INSTANCE_JSON_FILE."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg,
            self.distro,
            Paths({"run_dir": tmp}),
            custom_metadata={
                "key1": "val1",
                "key2": {
                    "key2.1": self.paths
                }
            },
        )
        datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        content = util.load_file(json_file)
        expected_metadata = {
            "key1": "val1",
            "key2": {
                "key2.1": ("Warning: redacted unserializable type <class"
                           " 'cloudinit.helpers.Paths'>")
            },
        }
        instance_json = util.load_json(content)
        self.assertEqual(expected_metadata, instance_json["ds"]["meta_data"])

    def test_persist_instance_data_writes_ec2_metadata_when_set(self):
        """When ec2_metadata class attribute is set, persist to json."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        datasource.ec2_metadata = UNSET
        datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        instance_data = util.load_json(util.load_file(json_file))
        self.assertNotIn("ec2_metadata", instance_data["ds"])
        datasource.ec2_metadata = {"ec2stuff": "is good"}
        datasource.persist_instance_data()
        instance_data = util.load_json(util.load_file(json_file))
        self.assertEqual({"ec2stuff": "is good"},
                         instance_data["ds"]["ec2_metadata"])

    def test_persist_instance_data_writes_canonical_cloud_id_and_symlink(self):
        """canonical-cloud-id class attribute is set, persist to json."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        cloud_id_link = os.path.join(tmp, "cloud-id")
        cloud_id_file = os.path.join(tmp, "cloud-id-my-cloud")
        cloud_id2_file = os.path.join(tmp, "cloud-id-my-cloud2")
        for filename in (cloud_id_file, cloud_id_link, cloud_id2_file):
            self.assertFalse(os.path.exists(filename),
                             "Unexpected link found {filename}")
        with mock.patch("cloudinit.sources.canonical_cloud_id",
                        return_value="my-cloud"):
            datasource.get_data()
        self.assertEqual("my-cloud\n", util.load_file(cloud_id_link))
        # A symlink with the generic /run/cloud-init/cloud-id link is present
        self.assertTrue(util.is_link(cloud_id_link))
        # When cloud-id changes, symlink and content change
        with mock.patch("cloudinit.sources.canonical_cloud_id",
                        return_value="my-cloud2"):
            datasource.persist_instance_data()
        self.assertEqual("my-cloud2\n", util.load_file(cloud_id2_file))
        # Previous cloud-id-<cloud-type> file removed
        self.assertFalse(os.path.exists(cloud_id_file))
        # Generic link persisted which contains canonical-cloud-id as content
        self.assertTrue(util.is_link(cloud_id_link))
        self.assertEqual("my-cloud2\n", util.load_file(cloud_id_link))

    def test_persist_instance_data_writes_network_json_when_set(self):
        """When network_data.json class attribute is set, persist to json."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(self.sys_cfg, self.distro,
                                               Paths({"run_dir": tmp}))
        datasource.get_data()
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        instance_data = util.load_json(util.load_file(json_file))
        self.assertNotIn("network_json", instance_data["ds"])
        datasource.network_json = {"network_json": "is good"}
        datasource.persist_instance_data()
        instance_data = util.load_json(util.load_file(json_file))
        self.assertEqual({"network_json": "is good"},
                         instance_data["ds"]["network_json"])

    def test_get_data_base64encodes_unserializable_bytes(self):
        """On py3, get_data base64encodes any unserializable content."""
        tmp = self.tmp_dir()
        datasource = DataSourceTestSubclassNet(
            self.sys_cfg,
            self.distro,
            Paths({"run_dir": tmp}),
            custom_metadata={
                "key1": "val1",
                "key2": {
                    "key2.1": b"\x123"
                }
            },
        )
        self.assertTrue(datasource.get_data())
        json_file = self.tmp_path(INSTANCE_JSON_FILE, tmp)
        content = util.load_file(json_file)
        instance_json = util.load_json(content)
        self.assertCountEqual(["ds/meta_data/key2/key2.1"],
                              instance_json["base64_encoded_keys"])
        self.assertEqual(
            {
                "key1": "val1",
                "key2": {
                    "key2.1": "EjM="
                }
            },
            instance_json["ds"]["meta_data"],
        )

    def test_get_hostname_subclass_support(self):
        """Validate get_hostname signature on all subclasses of DataSource."""
        base_args = inspect.getfullargspec(DataSource.get_hostname)
        # Import all DataSource subclasses so we can inspect them.
        modules = util.find_modules(os.path.dirname(os.path.dirname(__file__)))
        for _loc, name in modules.items():
            mod_locs, _ = importer.find_module(name, ["cloudinit.sources"], [])
            if mod_locs:
                importer.import_module(mod_locs[0])
        for child in DataSource.__subclasses__():
            if "Test" in child.dsname:
                continue
            self.assertEqual(
                base_args,
                inspect.getfullargspec(child.get_hostname),
                "%s does not implement DataSource.get_hostname params" % child,
            )
            for grandchild in child.__subclasses__():
                self.assertEqual(
                    base_args,
                    inspect.getfullargspec(grandchild.get_hostname),
                    "%s does not implement DataSource.get_hostname params" %
                    grandchild,
                )

    def test_clear_cached_attrs_resets_cached_attr_class_attributes(self):
        """Class attributes listed in cached_attr_defaults are reset."""
        count = 0
        # Setup values for all cached class attributes
        for attr, value in self.datasource.cached_attr_defaults:
            setattr(self.datasource, attr, count)
            count += 1
        self.datasource._dirty_cache = True
        self.datasource.clear_cached_attrs()
        for attr, value in self.datasource.cached_attr_defaults:
            self.assertEqual(value, getattr(self.datasource, attr))

    def test_clear_cached_attrs_noops_on_clean_cache(self):
        """Class attributes listed in cached_attr_defaults are reset."""
        count = 0
        # Setup values for all cached class attributes
        for attr, _ in self.datasource.cached_attr_defaults:
            setattr(self.datasource, attr, count)
            count += 1
        self.datasource._dirty_cache = False  # Fake clean cache
        self.datasource.clear_cached_attrs()
        count = 0
        for attr, _ in self.datasource.cached_attr_defaults:
            self.assertEqual(count, getattr(self.datasource, attr))
            count += 1

    def test_clear_cached_attrs_skips_non_attr_class_attributes(self):
        """Skip any cached_attr_defaults which aren't class attributes."""
        self.datasource._dirty_cache = True
        self.datasource.clear_cached_attrs()
        for attr in ("ec2_metadata", "network_json"):
            self.assertFalse(hasattr(self.datasource, attr))

    def test_clear_cached_attrs_of_custom_attrs(self):
        """Custom attr_values can be passed to clear_cached_attrs."""
        self.datasource._dirty_cache = True
        cached_attr_name = self.datasource.cached_attr_defaults[0][0]
        setattr(self.datasource, cached_attr_name, "himom")
        self.datasource.myattr = "orig"
        self.datasource.clear_cached_attrs(attr_defaults=(("myattr",
                                                           "updated"), ))
        self.assertEqual("himom", getattr(self.datasource, cached_attr_name))
        self.assertEqual("updated", self.datasource.myattr)

    @mock.patch.dict(
        DataSource.default_update_events,
        {EventScope.NETWORK: {EventType.BOOT_NEW_INSTANCE}},
    )
    @mock.patch.dict(
        DataSource.supported_update_events,
        {EventScope.NETWORK: {EventType.BOOT_NEW_INSTANCE}},
    )
    def test_update_metadata_only_acts_on_supported_update_events(self):
        """update_metadata_if_supported wont get_data on unsupported events."""
        self.assertEqual(
            {EventScope.NETWORK: set([EventType.BOOT_NEW_INSTANCE])},
            self.datasource.default_update_events,
        )

        def fake_get_data():
            raise Exception("get_data should not be called")

        self.datasource.get_data = fake_get_data
        self.assertFalse(
            self.datasource.update_metadata_if_supported(
                source_event_types=[EventType.BOOT]))

    @mock.patch.dict(
        DataSource.supported_update_events,
        {EventScope.NETWORK: {EventType.BOOT_NEW_INSTANCE}},
    )
    def test_update_metadata_returns_true_on_supported_update_event(self):
        """update_metadata_if_supported returns get_data on supported events"""
        def fake_get_data():
            return True

        self.datasource.get_data = fake_get_data
        self.datasource._network_config = "something"
        self.datasource._dirty_cache = True
        self.assertTrue(
            self.datasource.update_metadata_if_supported(source_event_types=[
                EventType.BOOT,
                EventType.BOOT_NEW_INSTANCE,
            ]))
        self.assertEqual(UNSET, self.datasource._network_config)

        self.assertIn(
            "DEBUG: Update datasource metadata and network config due to"
            " events: boot-new-instance",
            self.logs.getvalue(),
        )