Datasources: Formalize DataSource get_data and related properties.

Each DataSource subclass must define its own get_data method. This branch
formalizes our DataSource class to require that subclasses define an
explicit dsname for sourcing cloud-config datasource configuration.
Subclasses must also override the _get_data method or a
NotImplementedError is raised.

The branch also writes /run/cloud-init/instance-data.json. This file
contains all meta-data, user-data and vendor-data and a standardized set
of metadata keys in a json blob which other utilities with root-access
could make use of. Because some meta-data or user-data is potentially
sensitive the file is only readable by root.

Generally most metadata content types should be json serializable. If
specific keys or values are not serializable, those specific values will
be base64encoded and the key path will be listed under the top-level key
'base64-encoded-keys' in instance-data.json. If json writing fails due to
other TypeErrors or UnicodeDecodeErrors, a warning log will be emitted to
/var/log/cloud-init.log and no instance-data.json will be created.

1 files changed, 13 insertions, 9 deletions

diff --git a/tests/unittests/test_datasource/test_altcloud.py b/tests/unittests/test_datasource/test_altcloud.py
index a4dfb540..3253f3ad 100644
--- a/tests/unittests/test_datasource/test_altcloud.py
+++ b/tests/unittests/test_datasource/test_altcloud.py
@@ -18,7 +18,7 @@ import tempfile
 from cloudinit import helpers
 from cloudinit import util
 
-from cloudinit.tests.helpers import TestCase
+from cloudinit.tests.helpers import CiTestCase
 
 import cloudinit.sources.DataSourceAltCloud as dsac
 
@@ -97,7 +97,7 @@ def _dmi_data(expected):
     return _data
 
 
-class TestGetCloudType(TestCase):
+class TestGetCloudType(CiTestCase):
     '''
     Test to exercise method: DataSourceAltCloud.get_cloud_type()
     '''
@@ -143,14 +143,16 @@ class TestGetCloudType(TestCase):
         self.assertEqual('UNKNOWN', dsrc.get_cloud_type())
 
 
-class TestGetDataCloudInfoFile(TestCase):
+class TestGetDataCloudInfoFile(CiTestCase):
     '''
     Test to exercise method: DataSourceAltCloud.get_data()
     With a contrived CLOUD_INFO_FILE
     '''
     def setUp(self):
         '''Set up.'''
-        self.paths = helpers.Paths({'cloud_dir': '/tmp'})
+        self.tmp = self.tmp_dir()
+        self.paths = helpers.Paths(
+            {'cloud_dir': self.tmp, 'run_dir': self.tmp})
         self.cloud_info_file = tempfile.mkstemp()[1]
         self.dmi_data = util.read_dmi_data
         dsac.CLOUD_INFO_FILE = self.cloud_info_file
@@ -207,14 +209,16 @@ class TestGetDataCloudInfoFile(TestCase):
         self.assertEqual(False, dsrc.get_data())
 
 
-class TestGetDataNoCloudInfoFile(TestCase):
+class TestGetDataNoCloudInfoFile(CiTestCase):
     '''
     Test to exercise method: DataSourceAltCloud.get_data()
     Without a CLOUD_INFO_FILE
     '''
     def setUp(self):
         '''Set up.'''
-        self.paths = helpers.Paths({'cloud_dir': '/tmp'})
+        self.tmp = self.tmp_dir()
+        self.paths = helpers.Paths(
+            {'cloud_dir': self.tmp, 'run_dir': self.tmp})
         self.dmi_data = util.read_dmi_data
         dsac.CLOUD_INFO_FILE = \
             'no such file'
@@ -254,7 +258,7 @@ class TestGetDataNoCloudInfoFile(TestCase):
         self.assertEqual(False, dsrc.get_data())
 
 
-class TestUserDataRhevm(TestCase):
+class TestUserDataRhevm(CiTestCase):
     '''
     Test to exercise method: DataSourceAltCloud.user_data_rhevm()
     '''
@@ -320,7 +324,7 @@ class TestUserDataRhevm(TestCase):
         self.assertEqual(False, dsrc.user_data_rhevm())
 
 
-class TestUserDataVsphere(TestCase):
+class TestUserDataVsphere(CiTestCase):
     '''
     Test to exercise method: DataSourceAltCloud.user_data_vsphere()
     '''
@@ -368,7 +372,7 @@ class TestUserDataVsphere(TestCase):
         self.assertEqual(1, m_mount_cb.call_count)
 
 
-class TestReadUserDataCallback(TestCase):
+class TestReadUserDataCallback(CiTestCase):
     '''
     Test to exercise method: DataSourceAltCloud.read_user_data_callback()
     '''