deb-heat/heat/engine/properties.py
Angus Salkeld b4013fd7f6 Fix some sphinx warnings/errors
- don't have link name clashes
- fix broken links
- pydoc fixes

Change-Id: I60e5bc1dda2eb66f5cb4d98cf048c73872278092
2014-10-01 10:22:31 +10:00

505 lines
18 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.
import collections
import six
from heat.common import exception
from heat.engine import constraints as constr
from heat.engine import function
from heat.engine import parameters
from heat.engine import support
SCHEMA_KEYS = (
REQUIRED, IMPLEMENTED, DEFAULT, TYPE, SCHEMA,
ALLOWED_PATTERN, MIN_VALUE, MAX_VALUE, ALLOWED_VALUES,
MIN_LENGTH, MAX_LENGTH, DESCRIPTION, UPDATE_ALLOWED,
IMMUTABLE,
) = (
'Required', 'Implemented', 'Default', 'Type', 'Schema',
'AllowedPattern', 'MinValue', 'MaxValue', 'AllowedValues',
'MinLength', 'MaxLength', 'Description', 'UpdateAllowed',
'Immutable',
)
class Schema(constr.Schema):
"""
Schema class for validating resource properties.
This class is used for defining schema constraints for resource properties.
It inherits generic validation features from the base Schema class and add
processing that is specific to resource properties.
"""
KEYS = (
TYPE, DESCRIPTION, DEFAULT, SCHEMA, REQUIRED, CONSTRAINTS,
UPDATE_ALLOWED, IMMUTABLE,
) = (
'type', 'description', 'default', 'schema', 'required', 'constraints',
'update_allowed', 'immutable',
)
def __init__(self, data_type, description=None,
default=None, schema=None,
required=False, constraints=None,
implemented=True,
update_allowed=False,
immutable=False,
support_status=support.SupportStatus()):
super(Schema, self).__init__(data_type, description, default,
schema, required, constraints)
self.implemented = implemented
self.update_allowed = update_allowed
self.immutable = immutable
self.support_status = support_status
# validate structural correctness of schema itself
self.validate()
@classmethod
def from_legacy(cls, schema_dict):
"""
Return a Property Schema object from a legacy schema dictionary.
"""
# Check for fully-fledged Schema objects
if isinstance(schema_dict, cls):
return schema_dict
unknown = [k for k in schema_dict if k not in SCHEMA_KEYS]
if unknown:
raise exception.InvalidSchemaError(
message=_('Unknown key(s) %s') % unknown)
def constraints():
def get_num(key):
val = schema_dict.get(key)
if val is not None:
val = Schema.str_to_num(val)
return val
if MIN_VALUE in schema_dict or MAX_VALUE in schema_dict:
yield constr.Range(get_num(MIN_VALUE), get_num(MAX_VALUE))
if MIN_LENGTH in schema_dict or MAX_LENGTH in schema_dict:
yield constr.Length(get_num(MIN_LENGTH), get_num(MAX_LENGTH))
if ALLOWED_VALUES in schema_dict:
yield constr.AllowedValues(schema_dict[ALLOWED_VALUES])
if ALLOWED_PATTERN in schema_dict:
yield constr.AllowedPattern(schema_dict[ALLOWED_PATTERN])
try:
data_type = schema_dict[TYPE]
except KeyError:
raise exception.InvalidSchemaError(
message=_('No %s specified') % TYPE)
if SCHEMA in schema_dict:
if data_type == Schema.LIST:
ss = cls.from_legacy(schema_dict[SCHEMA])
elif data_type == Schema.MAP:
schema_dicts = schema_dict[SCHEMA].items()
ss = dict((n, cls.from_legacy(sd)) for n, sd in schema_dicts)
else:
raise exception.InvalidSchemaError(
message=_('%(schema)s supplied for %(type)s %(data)s') %
dict(schema=SCHEMA, type=TYPE, data=data_type))
else:
ss = None
return cls(data_type,
description=schema_dict.get(DESCRIPTION),
default=schema_dict.get(DEFAULT),
schema=ss,
required=schema_dict.get(REQUIRED, False),
constraints=list(constraints()),
implemented=schema_dict.get(IMPLEMENTED, True),
update_allowed=schema_dict.get(UPDATE_ALLOWED, False),
immutable=schema_dict.get(IMMUTABLE, False))
@classmethod
def from_parameter(cls, param):
"""
Return a Property Schema corresponding to a Parameter Schema.
Convert a parameter schema from a provider template to a property
Schema for the corresponding resource facade.
"""
# map param types to property types
param_type_map = {
param.STRING: cls.STRING,
param.NUMBER: cls.NUMBER,
param.LIST: cls.LIST,
param.MAP: cls.MAP,
param.BOOLEAN: cls.BOOLEAN
}
# make update_allowed true by default on TemplateResources
# as the template should deal with this.
return cls(data_type=param_type_map.get(param.type, cls.MAP),
description=param.description,
required=param.required,
constraints=param.constraints,
update_allowed=True,
immutable=False)
def allowed_param_prop_type(self):
"""
Return allowed type of Property Schema converted from parameter.
Especially, when generating Schema from parameter, Integer Property
Schema will be supplied by Number parameter.
"""
param_type_map = {
self.INTEGER: self.NUMBER,
self.STRING: self.STRING,
self.NUMBER: self.NUMBER,
self.BOOLEAN: self.BOOLEAN,
self.LIST: self.LIST,
self.MAP: self.MAP
}
return param_type_map[self.type]
def __getitem__(self, key):
if key == self.UPDATE_ALLOWED:
return self.update_allowed
elif key == self.IMMUTABLE:
return self.immutable
else:
return super(Schema, self).__getitem__(key)
raise KeyError(key)
def schemata(schema_dicts):
"""
Return dictionary of Schema objects for given dictionary of schemata.
The input schemata are converted from the legacy (dictionary-based)
format to Schema objects where necessary.
"""
return dict((n, Schema.from_legacy(s)) for n, s in schema_dicts.items())
class Property(object):
def __init__(self, schema, name=None, context=None):
self.schema = Schema.from_legacy(schema)
self.name = name
self.context = context
def required(self):
return self.schema.required
def implemented(self):
return self.schema.implemented
def update_allowed(self):
return self.schema.update_allowed
def immutable(self):
return self.schema.immutable
def has_default(self):
return self.schema.default is not None
def default(self):
return self.schema.default
def type(self):
return self.schema.type
def support_status(self):
return self.schema.support_status
def _get_integer(self, value):
if value is None:
value = self.has_default() and self.default() or 0
try:
value = int(value)
except ValueError:
raise TypeError(_("Value '%s' is not an integer") % value)
else:
return value
def _get_number(self, value):
if value is None:
value = self.has_default() and self.default() or 0
return Schema.str_to_num(value)
def _get_string(self, value):
if value is None:
value = self.has_default() and self.default() or ''
if not isinstance(value, basestring):
raise ValueError(_('Value must be a string'))
return value
def _get_children(self, child_values, keys=None, validate=False):
if self.schema.schema is not None:
if keys is None:
keys = list(self.schema.schema)
schemata = dict((k, self.schema.schema[k]) for k in keys)
properties = Properties(schemata, dict(child_values),
parent_name=self.name,
context=self.context)
if validate:
properties.validate()
return ((k, properties[k]) for k in keys)
else:
return child_values
def _get_map(self, value, validate=False):
if value is None:
value = self.has_default() and self.default() or {}
if not isinstance(value, collections.Mapping):
raise TypeError(_('"%s" is not a map') % value)
return dict(self._get_children(six.iteritems(value),
validate=validate))
def _get_list(self, value, validate=False):
if value is None:
value = self.has_default() and self.default() or []
if (not isinstance(value, collections.Sequence) or
isinstance(value, basestring)):
raise TypeError(_('"%s" is not a list') % repr(value))
return [v[1] for v in self._get_children(enumerate(value),
range(len(value)),
validate)]
def _get_bool(self, value):
if value is None:
value = self.has_default() and self.default() or False
if isinstance(value, bool):
return value
normalised = value.lower()
if normalised not in ['true', 'false']:
raise ValueError(_('"%s" is not a valid boolean') % normalised)
return normalised == 'true'
def get_value(self, value, validate=False):
"""Get value from raw value and sanitize according to data type."""
t = self.type()
if t == Schema.STRING:
_value = self._get_string(value)
elif t == Schema.INTEGER:
_value = self._get_integer(value)
elif t == Schema.NUMBER:
_value = self._get_number(value)
elif t == Schema.MAP:
_value = self._get_map(value, validate)
elif t == Schema.LIST:
_value = self._get_list(value, validate)
elif t == Schema.BOOLEAN:
_value = self._get_bool(value)
# property value resolves to None if resource it depends on is not
# created. So, if value is None skip constraint validation.
if value is not None and validate:
self.schema.validate_constraints(_value, self.context)
return _value
class Properties(collections.Mapping):
def __init__(self, schema, data, resolver=lambda d: d, parent_name=None,
context=None):
self.props = dict((k, Property(s, k, context))
for k, s in schema.items())
self.resolve = resolver
self.data = data
if parent_name is None:
self.error_prefix = ''
else:
self.error_prefix = '%s: ' % parent_name
self.context = context
@staticmethod
def schema_from_params(params_snippet):
"""
Convert a template snippet that defines parameters
into a properties schema
:param params_snippet: parameter definition from a template
:returns: an equivalent properties schema for the specified params
"""
if params_snippet:
return dict((n, Schema.from_parameter(p)) for n, p
in params_snippet.items())
return {}
def validate(self, with_value=True):
for (key, prop) in self.props.items():
# check that update_allowed and immutable
# do not contradict each other
if prop.update_allowed() and prop.immutable():
msg = _("Property %(prop)s: %(ua)s and %(im)s "
"cannot both be True") % {
'prop': key,
'ua': prop.schema.UPDATE_ALLOWED,
'im': prop.schema.IMMUTABLE}
raise exception.InvalidSchemaError(message=msg)
if with_value:
try:
self._get_property_value(key, validate=True)
except ValueError as e:
msg = _("Property error : %s") % e
raise exception.StackValidationFailed(message=msg)
# are there unimplemented Properties
if not prop.implemented() and key in self.data:
msg = _("Property %s not implemented yet") % key
raise exception.StackValidationFailed(message=msg)
for key in self.data:
if key not in self.props:
msg = _("Unknown Property %s") % key
raise exception.StackValidationFailed(message=msg)
def _get_property_value(self, key, validate=False):
if key not in self:
raise KeyError(_('%(prefix)sInvalid Property %(key)s') %
{'prefix': self.error_prefix, 'key': key})
prop = self.props[key]
if key in self.data:
try:
unresolved_value = self.data[key]
if validate:
deps = function.dependencies(unresolved_value)
if any(res.action == res.INIT for res in deps):
validate = False
value = self.resolve(unresolved_value)
return prop.get_value(value, validate)
# the resolver function could raise any number of exceptions,
# so handle this generically
except Exception as e:
raise ValueError('%s%s %s' % (self.error_prefix, key,
six.text_type(e)))
elif prop.has_default():
return prop.default()
elif prop.required():
raise ValueError(_('%(prefix)sProperty %(key)s not assigned') %
{'prefix': self.error_prefix, 'key': key})
def __getitem__(self, key):
return self._get_property_value(key)
def __len__(self):
return len(self.props)
def __contains__(self, key):
return key in self.props
def __iter__(self):
return iter(self.props)
@staticmethod
def _param_def_from_prop(schema):
"""
Return a template parameter definition corresponding to a property.
"""
param_type_map = {
schema.INTEGER: parameters.Schema.NUMBER,
schema.STRING: parameters.Schema.STRING,
schema.NUMBER: parameters.Schema.NUMBER,
schema.BOOLEAN: parameters.Schema.BOOLEAN,
schema.MAP: parameters.Schema.MAP,
schema.LIST: parameters.Schema.LIST,
}
def param_items():
yield parameters.TYPE, param_type_map[schema.type]
if schema.description is not None:
yield parameters.DESCRIPTION, schema.description
if schema.default is not None:
yield parameters.DEFAULT, schema.default
for constraint in schema.constraints:
if isinstance(constraint, constr.Length):
if constraint.min is not None:
yield parameters.MIN_LENGTH, constraint.min
if constraint.max is not None:
yield parameters.MAX_LENGTH, constraint.max
elif isinstance(constraint, constr.Range):
if constraint.min is not None:
yield parameters.MIN_VALUE, constraint.min
if constraint.max is not None:
yield parameters.MAX_VALUE, constraint.max
elif isinstance(constraint, constr.AllowedValues):
yield parameters.ALLOWED_VALUES, list(constraint.allowed)
elif isinstance(constraint, constr.AllowedPattern):
yield parameters.ALLOWED_PATTERN, constraint.pattern
if schema.type == schema.BOOLEAN:
yield parameters.ALLOWED_VALUES, ['True', 'true',
'False', 'false']
return dict(param_items())
@staticmethod
def _prop_def_from_prop(name, schema):
"""
Return a provider template property definition for a property.
"""
if schema.type == Schema.LIST:
return {'Fn::Split': [',', {'Ref': name}]}
else:
return {'Ref': name}
@classmethod
def schema_to_parameters_and_properties(cls, schema):
"""Generates properties with params resolved for a resource's
properties_schema.
:param schema: A resource type's properties_schema
:returns: A tuple of params and properties dicts
ex: input: {'foo': {'Type': 'String'}}
output: {'foo': {'Type': 'String'}},
{'foo': {'Ref': 'foo'}}
ex: input: {'foo': {'Type': 'List'}, 'bar': {'Type': 'Map'}}
output: {'foo': {'Type': 'CommaDelimitedList'}
'bar': {'Type': 'Json'}},
{'foo': {'Fn::Split': {'Ref': 'foo'}},
'bar': {'Ref': 'bar'}}
"""
def param_prop_def_items(name, schema):
param_def = cls._param_def_from_prop(schema)
prop_def = cls._prop_def_from_prop(name, schema)
return (name, param_def), (name, prop_def)
if not schema:
return {}, {}
param_prop_defs = [param_prop_def_items(n, s)
for n, s in six.iteritems(schemata(schema))
if s.implemented]
param_items, prop_items = zip(*param_prop_defs)
return dict(param_items), dict(prop_items)