heat/heat/engine/resources/openstack/heat/value.py

113 lines
3.8 KiB
Python

#
# 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.common.i18n import _
from heat.engine import attributes
from heat.engine import constraints
from heat.engine.hot import parameters
from heat.engine import properties
from heat.engine import resource
from heat.engine import support
class Value(resource.Resource):
"""A resource which exposes its value property as an attribute.
This is useful for exposing a value that is a simple manipulation
of other template parameters and/or other resources.
"""
support_status = support.SupportStatus(version='7.0.0')
PROPERTIES = (
VALUE, TYPE,
) = (
'value', constraints.Schema.TYPE,
)
ATTRIBUTES = (
VALUE_ATTR,
) = (
'value',
)
properties_schema = {
VALUE: properties.Schema(
properties.Schema.ANY,
_('The expression to generate the "value" attribute.'),
required=True,
update_allowed=True,
),
TYPE: properties.Schema(
properties.Schema.STRING,
_('The type of the "value" property.'),
constraints=[constraints.AllowedValues(
parameters.HOTParamSchema.TYPES)],
update_allowed=True,
),
}
attributes_schema = {
VALUE_ATTR: attributes.Schema(
_('The value generated by this resource\'s properties "value" '
'expression, with type determined from the properties "type".'),
),
}
def _resolve_attribute(self, name):
props = self.frozen_definition().properties(self.properties_schema,
self.context)
if name == self.VALUE_ATTR:
return props[self.VALUE]
def handle_create(self):
self.resource_id_set(self.physical_resource_name())
def handle_update(self, json_snippet, tmpl_diff, prop_diff):
# allow update, no replace necessary (do not throw UpdateReplace).
# the resource properties are updated appropriately in parent class.
pass
def reparse(self, *args, **kwargs):
super(Value, self).reparse(*args, **kwargs)
value_type = self.properties[self.TYPE]
if value_type is None:
# We don't know what type the value is, anything goes
return
param_type_map = {
parameters.HOTParamSchema.STRING: constraints.Schema.STRING,
parameters.HOTParamSchema.NUMBER: constraints.Schema.NUMBER,
parameters.HOTParamSchema.LIST: constraints.Schema.LIST,
parameters.HOTParamSchema.MAP: constraints.Schema.MAP,
parameters.HOTParamSchema.BOOLEAN: constraints.Schema.BOOLEAN,
}
if value_type not in param_type_map:
# the self.TYPE value is not valid, the error will become
# apparent appropriately when its constraints are checked.
return
# We know the value's type, update value's property schema accordingly
self.properties.props[self.VALUE] = properties.Property(
properties.Schema(
param_type_map[value_type],
_('The expression to generate the "value" attribute.'),
required=True,
update_allowed=True,
))
def resource_mapping():
return {
'OS::Heat::Value': Value,
}