72 lines
3.1 KiB
Python
72 lines
3.1 KiB
Python
# Copyright 2015-2016 Canonical Ltd.
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#
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# This file is part of the Coordinator Layer for Juju.
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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, but
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# WITHOUT ANY WARRANTY; without even the implied warranties of
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# MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
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# PURPOSE. See the 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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from charmhelpers.core import hookenv
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from charms.coordinator import coordinator, log
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import charms.reactive
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def initialize_coordinator_state():
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'''
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The coordinator.granted.{lockname} state will be set and the
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coordinator.requested.{lockname} state removed for every lock
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granted to the currently running hook.
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The coordinator.requested.{lockname} state will remain set for locks
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not yet granted
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'''
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log('Initializing coordinator layer')
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requested = set(coordinator.requests.get(hookenv.local_unit(), {}).keys())
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previously_requested = set(state.split('.', 2)[2]
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for state in charms.reactive.bus.get_states()
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if state.startswith('coordinator.requested.'))
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granted = set(coordinator.grants.get(hookenv.local_unit(), {}).keys())
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previously_granted = set(state.split('.', 2)[2]
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for state in charms.reactive.bus.get_states()
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if state.startswith('coordinator.granted.'))
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# Set reactive state for requested locks.
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for lock in requested:
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log('Requested {} lock'.format(lock), hookenv.DEBUG)
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charms.reactive.set_state('coordinator.requested.{}'.format(lock))
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# Set reactive state for locks that have been granted.
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for lock in granted:
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log('Granted {} lock'.format(lock), hookenv.DEBUG)
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charms.reactive.set_state('coordinator.granted.{}'.format(lock))
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# Remove reactive state for locks that have been released.
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for lock in (previously_granted - granted):
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log('Dropped {} lock'.format(lock), hookenv.DEBUG)
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charms.reactive.remove_state('coordinator.granted.{}'.format(lock))
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# Remove requested state for locks no longer requested and not granted.
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for lock in (previously_requested - requested - granted):
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log('Request for {} lock was dropped'.format(lock), hookenv.DEBUG)
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charms.reactive.remove_state('coordinator.requested.{}'.format(lock))
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# Per https://github.com/juju-solutions/charms.reactive/issues/33,
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# this module may be imported multiple times so ensure the
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# initialization hook is only registered once. I have to piggy back
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# onto the namespace of a module imported before reactive discovery
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# to do this.
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if not hasattr(charms.reactive, '_coordinator_registered'):
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hookenv.atstart(initialize_coordinator_state)
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charms.reactive._coordinator_registered = True
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