Current File : //lib/python3/dist-packages/cloudinit/filters/launch_index.py
# 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 file is part of cloud-init. See LICENSE file for license information.
import copy
import logging
from cloudinit import user_data as ud
from cloudinit import util
LOG = logging.getLogger(__name__)
class Filter:
def __init__(self, wanted_idx, allow_none=True):
self.wanted_idx = wanted_idx
self.allow_none = allow_none
def _select(self, message):
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 _do_filter(self, message):
# Don't use walk() here since we want to do the reforming of the
# messages ourselves and not flatten the message listings...
if not self._select(message):
return None
if message.is_multipart():
# Recreate it and its child messages
prev_msgs = message.get_payload(decode=False)
new_msgs = []
discarded = 0
for m in prev_msgs:
m = self._do_filter(m)
if m is not None:
new_msgs.append(m)
else:
discarded += 1
LOG.debug(
"Discarding %s multipart messages "
"which do not match launch index %s",
discarded,
self.wanted_idx,
)
new_message = copy.copy(message)
new_message.set_payload(new_msgs)
new_message[ud.ATTACHMENT_FIELD] = str(len(new_msgs))
return new_message
else:
return copy.copy(message)
def apply(self, root_message):
if self.wanted_idx is None:
return root_message
return self._do_filter(root_message)
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