For the userdata 'post-filtering' add in a new folder that

can contain filters that serve this purpose only and add in
the initial launch-index filter and replace the code in 
the datasource class that previously did this.

2 files changed, 84 insertions, 0 deletions

diff --git a/cloudinit/filters/__init__.py b/cloudinit/filters/__init__.py
new file mode 100644
index 00000000..da124641
--- /dev/null
+++ b/cloudinit/filters/__init__.py
@@ -0,0 +1,21 @@
+# vi: ts=4 expandtab
+#
+#    Copyright (C) 2012 Canonical Ltd.
+#    Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
+#    Copyright (C) 2012 Yahoo! Inc.
+#
+#    Author: Scott Moser <scott.moser@canonical.com>
+#    Author: Juerg Haefliger <juerg.haefliger@hp.com>
+#    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/>.
diff --git a/cloudinit/filters/launch_index.py b/cloudinit/filters/launch_index.py
new file mode 100644
index 00000000..b9e108c4
--- /dev/null
+++ b/cloudinit/filters/launch_index.py
@@ -0,0 +1,63 @@
+# vi: ts=4 expandtab
+#
+#    Copyright (C) 2012 Canonical Ltd.
+#    Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
+#    Copyright (C) 2012 Yahoo! Inc.
+#
+#    Author: Scott Moser <scott.moser@canonical.com>
+#    Author: Juerg Haefliger <juerg.haefliger@hp.com>
+#    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/>.
+
+import copy
+
+from cloudinit import log as logging
+from cloudinit import user_data as ud
+from cloudinit import util
+
+LOG = logging.getLogger(__name__)
+
+
+class Filter(object):
+    def __init__(self, wanted_idx, allow_none=True):
+        self.wanted_idx = wanted_idx
+        self.allow_none = allow_none
+
+    def _select(self, message):
+        if ud.is_skippable(message):
+            return False
+        msg_idx = message.get('Launch-Index', None)
+        if self.allow_none and msg_idx is None:
+            return True
+        msg_idx = util.safe_int(msg_idx)
+        if msg_idx != self.wanted_idx:
+            return False
+        return True
+
+    def apply(self, base_message):
+        if not base_message.is_multipart() or self.wanted_idx is None:
+            return base_message
+        prev_msgs = base_message.get_payload(decode=False)
+        to_attach = []
+        for sub_msg in base_message.walk():
+            if self._select(sub_msg):
+                to_attach.append(sub_msg)
+        if len(prev_msgs) != len(to_attach):
+            LOG.debug(("Discarding %s multipart messages "
+                       "which do not match launch index %s"),
+                      (len(prev_msgs) - len(to_attach)), self.wanted_idx)
+        filtered_msg = copy.deepcopy(base_message)
+        filtered_msg.set_payload(to_attach)
+        filtered_msg[ud.ATTACHMENT_FIELD] = str(len(to_attach))
+        return filtered_msg