Add NoCloudConfigDriveService metadata provider

Add support for NoCloud metadata provider, where the metadata
is provided on a config-drive (vfat or iso9660) with the label
cidata or CIDATA.

The folder structure for NoCloud is:

  * /user-data
  * /meta-data

The user-data and meta-data files respect the EC2 metadata
service format.

Supported features for the NoCloud metadata service:
  * instance id
  * hostname
  * plublic keys
  * static network configuration (Debian format)
  * user data

More information:
cloudinit.readthedocs.io/en/latest/topics/datasources/nocloud.html

Change-Id: Ib434cf2b2b21bf9faa58e05ba40eb0135385c9ea
Implements: blueprint nocloud-metadata-support

cloudbaseinit/metadata/services/nocloudservice.py

@@ -0,0 +1,70 @@
+# Copyright 2020 Cloudbase Solutions Srl
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from oslo_log import log as oslo_logging
+
+from cloudbaseinit import conf as cloudbaseinit_conf
+from cloudbaseinit.metadata.services import base
+from cloudbaseinit.metadata.services import baseconfigdrive
+from cloudbaseinit.utils import debiface
+from cloudbaseinit.utils import serialization
+
+
+CONF = cloudbaseinit_conf.CONF
+LOG = oslo_logging.getLogger(__name__)
+
+
+class NoCloudConfigDriveService(baseconfigdrive.BaseConfigDriveService):
+
+    def __init__(self):
+        super(NoCloudConfigDriveService, self).__init__(
+            'cidata', 'meta-data')
+        self._meta_data = {}
+
+    def get_user_data(self):
+        return self._get_cache_data("user-data")
+
+    def _get_meta_data(self):
+        if self._meta_data:
+            return self._meta_data
+
+        raw_meta_data = self._get_cache_data("meta-data", decode=True)
+        try:
+            self._meta_data = (
+                serialization.parse_json_yaml(raw_meta_data))
+        except base.YamlParserConfigError as ex:
+            LOG.error("Metadata could not be parsed")
+            LOG.exception(ex)
+
+        return self._meta_data
+
+    def get_host_name(self):
+        return self._get_meta_data().get('local-hostname')
+
+    def get_instance_id(self):
+        return self._get_meta_data().get('instance-id')
+
+    def get_public_keys(self):
+        raw_ssh_keys = self._get_meta_data().get('public-keys')
+        if not raw_ssh_keys:
+            return []
+
+        return [raw_ssh_keys[key].get('openssh-key') for key in raw_ssh_keys]
+
+    def get_network_details(self):
+        debian_net_config = self._get_meta_data().get('network-interfaces')
+        if not debian_net_config:
+            return None
+
+        return debiface.parse(debian_net_config)

cloudbaseinit/tests/metadata/services/test_nocloudservice.py

@@ -0,0 +1,90 @@
+# Copyright 2020 Cloudbase Solutions Srl
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+
+import importlib
+import os
+import unittest
+
+try:
+    import unittest.mock as mock
+except ImportError:
+    import mock
+
+from cloudbaseinit.tests import testutils
+
+MODULE_PATH = "cloudbaseinit.metadata.services.nocloudservice"
+
+
+class TestNoCloudConfigDriveService(unittest.TestCase):
+
+    def setUp(self):
+        self._win32com_mock = mock.MagicMock()
+        self._ctypes_mock = mock.MagicMock()
+        self._ctypes_util_mock = mock.MagicMock()
+        self._win32com_client_mock = mock.MagicMock()
+        self._pywintypes_mock = mock.MagicMock()
+
+        self._module_patcher = mock.patch.dict(
+            'sys.modules',
+            {'win32com': self._win32com_mock,
+             'ctypes': self._ctypes_mock,
+             'ctypes.util': self._ctypes_util_mock,
+             'win32com.client': self._win32com_client_mock,
+             'pywintypes': self._pywintypes_mock})
+        self._module_patcher.start()
+        self.addCleanup(self._module_patcher.stop)
+
+        self.configdrive_module = importlib.import_module(MODULE_PATH)
+        self._config_drive = (
+            self.configdrive_module.NoCloudConfigDriveService())
+        self.snatcher = testutils.LogSnatcher(MODULE_PATH)
+
+    @mock.patch('os.path.normpath')
+    @mock.patch('os.path.join')
+    def test_get_data(self, mock_join, mock_normpath):
+        fake_path = os.path.join('fake', 'path')
+        with mock.patch('six.moves.builtins.open',
+                        mock.mock_open(read_data='fake data'), create=True):
+            response = self._config_drive._get_data(fake_path)
+            self.assertEqual('fake data', response)
+            mock_join.assert_called_with(
+                self._config_drive._metadata_path, fake_path)
+            mock_normpath.assert_called_once_with(mock_join.return_value)
+
+    @mock.patch('shutil.rmtree')
+    def test_cleanup(self, mock_rmtree):
+        fake_path = os.path.join('fake', 'path')
+        self._config_drive._metadata_path = fake_path
+        mock_mgr = mock.Mock()
+        self._config_drive._mgr = mock_mgr
+        mock_mgr.target_path = fake_path
+        self._config_drive.cleanup()
+        mock_rmtree.assert_called_once_with(fake_path,
+                                            ignore_errors=True)
+        self.assertEqual(None, self._config_drive._metadata_path)
+
+    @mock.patch(MODULE_PATH + '.NoCloudConfigDriveService._get_meta_data')
+    def test_get_public_keys(self, mock_get_metadata):
+        fake_key = 'fake key'
+        expected_result = [fake_key]
+        mock_get_metadata.return_value = {
+            'public-keys': {
+                '0': {
+                    'openssh-key': fake_key
+                }
+            }
+        }
+        result = self._config_drive.get_public_keys()
+        self.assertEqual(result, expected_result)

doc/source/services.rst

@@ -113,6 +113,61 @@ Config options for `config_drive` section:
     * locations (list: ["cdrom", "hdd", "partition"])
 
 
+.. _nocloudconfigdrive:
+
+NoCloud configuration drive
+-------------------------------
+
+.. class:: cloudbaseinit.metadata.services.nocloudservice.NoCloudConfigDriveService
+
+NoCloudConfigDriveService is similar to OpenStack config drive metadata in terms of
+the medium on which the data is provided (as an attached ISO, partition or disk) and
+similar to the EC2 metadata in terms of how the metadata files are named and structured.
+
+The metadata is provided on a config-drive (vfat or iso9660) with the label cidata or CIDATA.
+
+The folder structure for NoCloud is:
+
+  * /user-data
+  * /meta-data
+
+The user-data and meta-data files respect the EC2 metadata service format.
+
+Capabilities:
+
+    * instance id
+    * hostname
+    * public keys
+    * static network configuration (Debian format)
+    * user data
+
+Config options for `config_drive` section:
+
+    * raw_hdd (bool: True)
+    * cdrom (bool: True)
+    * vfat (bool: True)
+    * types (list: ["vfat", "iso"])
+    * locations (list: ["cdrom", "hdd", "partition"])
+
+Example metadata:
+
+.. code-block:: yaml
+
+    instance-id: windows1
+    network-interfaces: |
+      iface Ethernet0 inet static
+      address 10.0.0.2
+      network 10.0.0.0
+      netmask 255.255.255.0
+      broadcast 10.0.0.255
+      gateway 10.0.0.1
+      hwaddress ether 00:11:22:33:44:55
+    hostname: windowshost1
+
+
+More information on the NoCloud metadata service specifications can be found
+`here <https://cloudinit.readthedocs.io/en/latest/topics/datasources/nocloud.html>`_.
+
 Amazon EC2
 ----------