194 lines
7.2 KiB
Python
194 lines
7.2 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
|
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
from heat.db import api as db_api
|
|
|
|
from heat.engine import dependencies
|
|
from heat.engine import resource
|
|
from heat.engine import scheduler
|
|
|
|
from heat.openstack.common import log as logging
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class StackUpdate(object):
|
|
"""
|
|
A Task to perform the update of an existing stack to a new template.
|
|
"""
|
|
|
|
def __init__(self, existing_stack, new_stack, previous_stack,
|
|
rollback=False):
|
|
"""Initialise with the existing stack and the new stack."""
|
|
self.existing_stack = existing_stack
|
|
self.new_stack = new_stack
|
|
self.previous_stack = previous_stack
|
|
|
|
self.rollback = rollback
|
|
|
|
self.existing_snippets = dict((r.name, r.parsed_template())
|
|
for r in self.existing_stack)
|
|
|
|
def __repr__(self):
|
|
if self.rollback:
|
|
return '%s Rollback' % str(self.existing_stack)
|
|
else:
|
|
return '%s Update' % str(self.existing_stack)
|
|
|
|
@scheduler.wrappertask
|
|
def __call__(self):
|
|
"""Return a co-routine that updates the stack."""
|
|
|
|
cleanup_prev = scheduler.DependencyTaskGroup(
|
|
self.previous_stack.dependencies,
|
|
self._remove_backup_resource,
|
|
reverse=True)
|
|
|
|
update = scheduler.DependencyTaskGroup(self.dependencies(),
|
|
self._resource_update)
|
|
|
|
if not self.rollback:
|
|
yield cleanup_prev()
|
|
|
|
try:
|
|
yield update()
|
|
finally:
|
|
self.previous_stack.reset_dependencies()
|
|
|
|
def _resource_update(self, res):
|
|
if res.name in self.new_stack and self.new_stack[res.name] is res:
|
|
return self._process_new_resource_update(res)
|
|
else:
|
|
return self._process_existing_resource_update(res)
|
|
|
|
@scheduler.wrappertask
|
|
def _remove_backup_resource(self, prev_res):
|
|
if prev_res.state not in ((prev_res.INIT, prev_res.COMPLETE),
|
|
(prev_res.DELETE, prev_res.COMPLETE)):
|
|
logger.debug("Deleting backup resource %s" % prev_res.name)
|
|
yield prev_res.destroy()
|
|
|
|
@staticmethod
|
|
def _exchange_stacks(existing_res, prev_res):
|
|
db_api.resource_exchange_stacks(existing_res.stack.context,
|
|
existing_res.id, prev_res.id)
|
|
existing_res.stack, prev_res.stack = prev_res.stack, existing_res.stack
|
|
existing_res.stack[existing_res.name] = existing_res
|
|
prev_res.stack[prev_res.name] = prev_res
|
|
|
|
@scheduler.wrappertask
|
|
def _create_resource(self, new_res):
|
|
res_name = new_res.name
|
|
|
|
# Clean up previous resource
|
|
if res_name in self.previous_stack:
|
|
prev_res = self.previous_stack[res_name]
|
|
|
|
if prev_res.state not in ((prev_res.INIT, prev_res.COMPLETE),
|
|
(prev_res.DELETE, prev_res.COMPLETE)):
|
|
# Swap in the backup resource if it is in a valid state,
|
|
# instead of creating a new resource
|
|
if prev_res.status == prev_res.COMPLETE:
|
|
logger.debug("Swapping in backup Resource %s" % res_name)
|
|
self._exchange_stacks(self.existing_stack[res_name],
|
|
prev_res)
|
|
return
|
|
|
|
logger.debug("Deleting backup Resource %s" % res_name)
|
|
yield prev_res.destroy()
|
|
|
|
# Back up existing resource
|
|
if res_name in self.existing_stack:
|
|
logger.debug("Backing up existing Resource %s" % res_name)
|
|
existing_res = self.existing_stack[res_name]
|
|
existing_res.stack = self.previous_stack
|
|
self.previous_stack[res_name] = existing_res
|
|
existing_res.state_set(existing_res.UPDATE, existing_res.COMPLETE)
|
|
|
|
new_res.stack = self.existing_stack
|
|
self.existing_stack[res_name] = new_res
|
|
yield new_res.create()
|
|
|
|
@scheduler.wrappertask
|
|
def _process_new_resource_update(self, new_res):
|
|
res_name = new_res.name
|
|
|
|
if res_name in self.existing_stack:
|
|
existing_res = self.existing_stack[res_name]
|
|
try:
|
|
yield self._update_in_place(existing_res,
|
|
new_res)
|
|
except resource.UpdateReplace:
|
|
pass
|
|
else:
|
|
logger.info("Resource %s for stack %s updated" %
|
|
(res_name, self.existing_stack.name))
|
|
return
|
|
|
|
yield self._create_resource(new_res)
|
|
|
|
@scheduler.wrappertask
|
|
def _update_in_place(self, existing_res, new_res):
|
|
# Compare resolved pre/post update resource snippets,
|
|
# note the new resource snippet is resolved in the context
|
|
# of the existing stack (which is the stack being updated)
|
|
existing_snippet = self.existing_snippets[existing_res.name]
|
|
new_snippet = self.existing_stack.resolve_runtime_data(new_res.t)
|
|
|
|
if new_snippet != existing_snippet:
|
|
yield existing_res.update(new_snippet, existing_snippet)
|
|
|
|
@scheduler.wrappertask
|
|
def _process_existing_resource_update(self, existing_res):
|
|
res_name = existing_res.name
|
|
|
|
if res_name in self.previous_stack:
|
|
yield self._remove_backup_resource(self.previous_stack[res_name])
|
|
|
|
if res_name in self.new_stack:
|
|
new_res = self.new_stack[res_name]
|
|
if new_res.state == (new_res.INIT, new_res.COMPLETE):
|
|
# Already updated in-place
|
|
return
|
|
|
|
if existing_res.stack is not self.previous_stack:
|
|
yield existing_res.destroy()
|
|
|
|
if res_name not in self.new_stack:
|
|
del self.existing_stack.resources[res_name]
|
|
|
|
def dependencies(self):
|
|
'''
|
|
Return a Dependencies object representing the dependencies between
|
|
update operations to move from an existing stack definition to a new
|
|
one.
|
|
'''
|
|
existing_deps = self.existing_stack.dependencies
|
|
new_deps = self.new_stack.dependencies
|
|
|
|
def edges():
|
|
# Create/update the new stack's resources in create order
|
|
for e in new_deps.graph().edges():
|
|
yield e
|
|
# Destroy/cleanup the old stack's resources in delete order
|
|
for e in existing_deps.graph(reverse=True).edges():
|
|
yield e
|
|
# Don't cleanup old resources until after they have been replaced
|
|
for res in self.existing_stack:
|
|
if res.name in self.new_stack:
|
|
yield (res, self.new_stack[res.name])
|
|
|
|
return dependencies.Dependencies(edges())
|