76 lines
2.6 KiB
Python
76 lines
2.6 KiB
Python
# vi: ts=4 expandtab
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#
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# Copyright (C) 2012 Canonical Ltd.
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# Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
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# Copyright (C) 2012 Yahoo! Inc.
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#
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# Author: Scott Moser <scott.moser@canonical.com>
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# Author: Juerg Haefliger <juerg.haefliger@hp.com>
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# Author: Joshua Harlow <harlowja@yahoo-inc.com>
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License version 3, as
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# published by the Free Software Foundation.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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import copy
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from cloudinit import log as logging
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from cloudinit import user_data as ud
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from cloudinit import util
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LOG = logging.getLogger(__name__)
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class Filter(object):
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def __init__(self, wanted_idx, allow_none=True):
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self.wanted_idx = wanted_idx
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self.allow_none = allow_none
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def _select(self, message):
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msg_idx = message.get('Launch-Index', None)
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if self.allow_none and msg_idx is None:
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return True
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msg_idx = util.safe_int(msg_idx)
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if msg_idx != self.wanted_idx:
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return False
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return True
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def _do_filter(self, message):
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# Don't use walk() here since we want to do the reforming of the
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# messages ourselves and not flatten the message listings...
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if not self._select(message):
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return None
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if message.is_multipart():
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# Recreate it and its child messages
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prev_msgs = message.get_payload(decode=False)
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new_msgs = []
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discarded = 0
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for m in prev_msgs:
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m = self._do_filter(m)
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if m is not None:
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new_msgs.append(m)
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else:
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discarded += 1
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LOG.debug(("Discarding %s multipart messages "
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"which do not match launch index %s"),
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discarded, self.wanted_idx)
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new_message = copy.copy(message)
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new_message.set_payload(new_msgs)
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new_message[ud.ATTACHMENT_FIELD] = str(len(new_msgs))
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return new_message
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else:
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return copy.copy(message)
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def apply(self, root_message):
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if self.wanted_idx is None:
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return root_message
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return self._do_filter(root_message)
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