Add the "None" datasource

The None datasource is the last resort fallback datasource.  It is
identifiable by a property 'is_disconnected' that indicates that the
datasource used is "not connected to a datasource".

This will allow any thing that needs to run to still run in the absense
of a DataSource.

Also, we add a logging of the datasource found in final_message, and
a warning if the None datasource is found.

LP: #906669

1 files changed, 63 insertions, 0 deletions

diff --git a/cloudinit/sources/DataSourceNone.py b/cloudinit/sources/DataSourceNone.py
new file mode 100644
index 00000000..b186113c
--- /dev/null
+++ b/cloudinit/sources/DataSourceNone.py
@@ -0,0 +1,63 @@
+# vi: ts=4 expandtab
+#
+#    Copyright (C) 2012 Yahoo! Inc.
+#
+#    Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 3, as
+#    published by the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from cloudinit import log as logging
+from cloudinit import sources
+from cloudinit import util
+
+LOG = logging.getLogger(__name__)
+
+
+class DataSourceNone(sources.DataSource):
+    def __init__(self, sys_cfg, distro, paths, ud_proc=None):
+        sources.DataSource.__init__(self, sys_cfg, distro, paths, ud_proc)
+        self.userdata = {}
+        self.metadata = {}
+        self.userdata_raw = ''
+
+    def get_data(self):
+        # If the datasource config has any provided 'fallback'
+        # userdata or metadata, use it...
+        if 'userdata' in self.ds_cfg:
+            self.userdata = self.ds_cfg['userdata']
+            self.userdata_raw = util.yaml_dumps(self.userdata)
+        if 'metadata' in self.ds_cfg:
+            self.metadata = self.ds_cfg['metadata']
+        return True
+
+    def get_instance_id(self):
+        return 'iid-datasource-none'
+
+    def __str__(self):
+        return util.obj_name(self)
+
+    @property
+    def is_disconnected(self):
+        return True
+
+
+# Used to match classes to dependencies
+datasources = [
+  (DataSourceNone, (sources.DEP_FILESYSTEM, sources.DEP_NETWORK)),
+  (DataSourceNone, []),
+]
+
+
+# Return a list of data sources that match this set of dependencies
+def get_datasource_list(depends):
+    return sources.list_from_depends(depends, datasources)