deb-heat/heat/engine/resources/wait_condition.py
huangtianhua 6e5dfcfa1d I18N support for log message and attributes schema
The log message and attributes schema should support i18n.

Change-Id: Iea8a73ba8aabd3c12efe43cdda9188f9216f50de
2014-02-28 14:35:09 +08:00

300 lines
11 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.
import json
from heat.common import exception
from heat.common import identifier
from heat.engine import constraints
from heat.engine import properties
from heat.engine import resource
from heat.engine import scheduler
from heat.engine import signal_responder
from heat.openstack.common import log as logging
logger = logging.getLogger(__name__)
class WaitConditionHandle(signal_responder.SignalResponder):
'''
the main point of this class is to :
have no dependancies (so the instance can reference it)
generate a unique url (to be returned in the reference)
then the cfn-signal will use this url to post to and
WaitCondition will poll it to see if has been written to.
'''
properties_schema = {}
def handle_create(self):
super(WaitConditionHandle, self).handle_create()
self.resource_id_set(self._get_user_id())
def FnGetRefId(self):
'''
Override the default resource FnGetRefId so we return the signed URL
'''
if self.resource_id:
wc = signal_responder.WAITCONDITION
return unicode(self._get_signed_url(signal_type=wc))
else:
return unicode(self.name)
def _metadata_format_ok(self, metadata):
"""
Check the format of the provided metadata is as expected.
metadata must use the following format:
{
"Status" : "Status (must be SUCCESS or FAILURE)"
"UniqueId" : "Some ID, should be unique for Count>1",
"Data" : "Arbitrary Data",
"Reason" : "Reason String"
}
"""
expected_keys = ['Data', 'Reason', 'Status', 'UniqueId']
if sorted(metadata.keys()) == expected_keys:
return metadata['Status'] in WAIT_STATUSES
def metadata_update(self, new_metadata=None):
'''
Validate and update the resource metadata
'''
if new_metadata is None:
return
if self._metadata_format_ok(new_metadata):
rsrc_metadata = self.metadata
if new_metadata['UniqueId'] in rsrc_metadata:
logger.warning(_("Overwriting Metadata item for UniqueId %s!")
% new_metadata['UniqueId'])
safe_metadata = {}
for k in ('Data', 'Reason', 'Status'):
safe_metadata[k] = new_metadata[k]
# Note we can't update self.metadata directly, as it
# is a Metadata descriptor object which only supports get/set
rsrc_metadata.update({new_metadata['UniqueId']: safe_metadata})
self.metadata = rsrc_metadata
else:
logger.error(_("Metadata failed validation for %s") % self.name)
raise ValueError(_("Metadata format invalid"))
def get_status(self):
'''
Return a list of the Status values for the handle signals
'''
return [self.metadata[s]['Status']
for s in self.metadata]
def get_status_reason(self, status):
'''
Return the reason associated with a particular status
If there is more than one handle signal matching the specified status
then return a semicolon delimited string containing all reasons
'''
return ';'.join([self.metadata[s]['Reason']
for s in self.metadata
if self.metadata[s]['Status'] == status])
WAIT_STATUSES = (
STATUS_FAILURE,
STATUS_SUCCESS,
) = (
'FAILURE',
'SUCCESS',
)
class UpdateWaitConditionHandle(WaitConditionHandle):
'''
This works identically to a regular WaitConditionHandle, except that
on update it clears all signals received and changes the handle. Using
this handle means that you must setup the signal senders to send their
signals again any time the update handle changes. This allows us to roll
out new configurations and be confident that they are rolled out once
UPDATE COMPLETE is reached.
'''
def update(self, after, before=None, prev_resource=None):
raise resource.UpdateReplace(self.name)
class WaitConditionFailure(Exception):
def __init__(self, wait_condition, handle):
reasons = handle.get_status_reason(STATUS_FAILURE)
super(WaitConditionFailure, self).__init__(reasons)
class WaitConditionTimeout(Exception):
def __init__(self, wait_condition, handle):
reasons = handle.get_status_reason(STATUS_SUCCESS)
vals = {'len': len(reasons),
'count': wait_condition.properties[wait_condition.COUNT]}
if reasons:
vals['reasons'] = reasons
message = (_('%(len)d of %(count)d received - %(reasons)s') % vals)
else:
message = (_('%(len)d of %(count)d received') % vals)
super(WaitConditionTimeout, self).__init__(message)
class WaitCondition(resource.Resource):
PROPERTIES = (
HANDLE, TIMEOUT, COUNT,
) = (
'Handle', 'Timeout', 'Count',
)
properties_schema = {
HANDLE: properties.Schema(
properties.Schema.STRING,
_('A reference to the wait condition handle used to signal this '
'wait condition.'),
required=True
),
TIMEOUT: properties.Schema(
properties.Schema.NUMBER,
_('The number of seconds to wait for the correct number of '
'signals to arrive.'),
required=True,
constraints=[
constraints.Range(1, 43200),
]
),
COUNT: properties.Schema(
properties.Schema.NUMBER,
_('The number of success signals that must be received before '
'the stack creation process continues.'),
constraints=[
constraints.Range(min=1),
],
default=1,
update_allowed=True
),
}
update_allowed_keys = ('Properties',)
def __init__(self, name, json_snippet, stack):
super(WaitCondition, self).__init__(name, json_snippet, stack)
def _validate_handle_url(self):
handle_url = self.properties[self.HANDLE]
handle_id = identifier.ResourceIdentifier.from_arn_url(handle_url)
if handle_id.tenant != self.stack.context.tenant_id:
raise ValueError(_("WaitCondition invalid Handle tenant %s") %
handle_id.tenant)
if handle_id.stack_name != self.stack.name:
raise ValueError(_("WaitCondition invalid Handle stack %s") %
handle_id.stack_name)
if handle_id.stack_id != self.stack.id:
raise ValueError(_("WaitCondition invalid Handle stack %s") %
handle_id.stack_id)
if handle_id.resource_name not in self.stack:
raise ValueError(_("WaitCondition invalid Handle %s") %
handle_id.resource_name)
if not isinstance(self.stack[handle_id.resource_name],
WaitConditionHandle):
raise ValueError(_("WaitCondition invalid Handle %s") %
handle_id.resource_name)
def _get_handle_resource_name(self):
handle_url = self.properties[self.HANDLE]
handle_id = identifier.ResourceIdentifier.from_arn_url(handle_url)
return handle_id.resource_name
def _wait(self, handle):
while True:
try:
yield
except scheduler.Timeout:
timeout = WaitConditionTimeout(self, handle)
logger.info(_('%(name)s Timed out (%(timeout)s)') % {
'name': str(self), 'timeout': str(timeout)})
raise timeout
handle_status = handle.get_status()
if any(s != STATUS_SUCCESS for s in handle_status):
failure = WaitConditionFailure(self, handle)
logger.info(_('%(name)s Failed (%(failure)s)') % {
'name': str(self), 'failure': str(failure)})
raise failure
if len(handle_status) >= self.properties[self.COUNT]:
logger.info(_("%s Succeeded") % str(self))
return
def handle_create(self):
self._validate_handle_url()
handle_res_name = self._get_handle_resource_name()
handle = self.stack[handle_res_name]
self.resource_id_set(handle_res_name)
runner = scheduler.TaskRunner(self._wait, handle)
runner.start(timeout=float(self.properties[self.TIMEOUT]))
return runner
def check_create_complete(self, runner):
return runner.step()
def handle_update(self, json_snippet, tmpl_diff, prop_diff):
if prop_diff:
self.properties = properties.Properties(
self.properties_schema, json_snippet.get('Properties', {}),
self.stack.resolve_runtime_data, self.name, self.context)
handle_res_name = self._get_handle_resource_name()
handle = self.stack[handle_res_name]
runner = scheduler.TaskRunner(self._wait, handle)
runner.start(timeout=float(self.properties[self.TIMEOUT]))
return runner
def check_update_complete(self, runner):
return runner.step()
def handle_delete(self):
if self.resource_id is None:
return
handle = self.stack[self.resource_id]
handle.metadata = {}
def FnGetAtt(self, key):
res = {}
handle_res_name = self._get_handle_resource_name()
handle = self.stack[handle_res_name]
if key == 'Data':
meta = handle.metadata
# Note, can't use a dict generator on python 2.6, hence:
res = dict([(k, meta[k]['Data']) for k in meta])
else:
raise exception.InvalidTemplateAttribute(resource=self.name,
key=key)
logger.debug(_('%(name)s.GetAtt(%(key)s) == %(res)s') %
{'name': self.name,
'key': key,
'res': res})
return unicode(json.dumps(res))
def resource_mapping():
return {
'AWS::CloudFormation::WaitCondition': WaitCondition,
'AWS::CloudFormation::WaitConditionHandle': WaitConditionHandle,
'OS::Heat::UpdateWaitConditionHandle': UpdateWaitConditionHandle,
}