deb-heat/heat/engine/constraints.py
Ethan Lynn 11c1b62052 Remove deprecated function i18n.install('heat')
Since i18n.install() is deprecated, remove it from heat codes and
import i18n._() to where it needed.

blueprint oslo-i18n
Change-Id: Icefada18b5a33112b425cd90d31d3a6a5f06188a
2014-10-13 10:31:28 +08:00

583 lines
19 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 numbers
import re
from oslo.utils import strutils
import six
from heat.common import exception
from heat.common.i18n import _
from heat.engine import resources
class Schema(collections.Mapping):
"""
Schema base class for validating properties or parameters.
Schema objects are serialisable to dictionaries following a superset of
the HOT input Parameter schema using dict().
Serialises to JSON in the form::
{
'type': 'list',
'required': False
'constraints': [
{
'length': {'min': 1},
'description': 'List must not be empty'
}
],
'schema': {
'*': {
'type': 'string'
}
},
'description': 'An example list property.'
}
"""
KEYS = (
TYPE, DESCRIPTION, DEFAULT, SCHEMA, REQUIRED, CONSTRAINTS,
) = (
'type', 'description', 'default', 'schema', 'required', 'constraints',
)
# Keywords for data types; each Schema subclass can define its respective
# type name used in templates
TYPE_KEYS = (
INTEGER_TYPE, STRING_TYPE, NUMBER_TYPE, BOOLEAN_TYPE, MAP_TYPE,
LIST_TYPE,
) = (
'INTEGER', 'STRING', 'NUMBER', 'BOOLEAN', 'MAP',
'LIST',
)
# Default type names for data types used in templates; can be overridden by
# subclasses
TYPES = (
INTEGER, STRING, NUMBER, BOOLEAN, MAP, LIST,
) = (
'Integer', 'String', 'Number', 'Boolean', 'Map', 'List',
)
def __init__(self, data_type, description=None,
default=None, schema=None,
required=False, constraints=None, label=None):
self._len = None
self.label = label
self.type = data_type
if self.type not in self.TYPES:
raise exception.InvalidSchemaError(
message=_('Invalid type (%s)') % self.type)
self.description = description
self.required = required
if isinstance(schema, type(self)):
if self.type != self.LIST:
msg = _('Single schema valid only for '
'%(ltype)s, not %(utype)s') % dict(ltype=self.LIST,
utype=self.type)
raise exception.InvalidSchemaError(message=msg)
self.schema = AnyIndexDict(schema)
else:
self.schema = schema
if self.schema is not None and self.type not in (self.LIST,
self.MAP):
msg = _('Schema valid only for %(ltype)s or '
'%(mtype)s, not %(utype)s') % dict(ltype=self.LIST,
mtype=self.MAP,
utype=self.type)
raise exception.InvalidSchemaError(message=msg)
self.constraints = constraints or []
self.default = default
def validate(self, context=None):
'''
Validates the schema.
This method checks if the schema itself is valid, and if the
default value - if present - complies to the schema's constraints.
'''
for c in self.constraints:
if not self._is_valid_constraint(c):
err_msg = _('%(name)s constraint '
'invalid for %(utype)s') % dict(
name=type(c).__name__,
utype=self.type)
raise exception.InvalidSchemaError(message=err_msg)
self._validate_default(context)
# validated nested schema(ta)
if self.schema:
if isinstance(self.schema, AnyIndexDict):
self.schema.value.validate(context)
else:
for nested_schema in self.schema.values():
nested_schema.validate(context)
def _validate_default(self, context):
if self.default is not None:
try:
self.validate_constraints(self.default, context)
except (ValueError, TypeError) as exc:
raise exception.InvalidSchemaError(
message=_('Invalid default %(default)s (%(exc)s)') %
dict(default=self.default, exc=exc))
def set_default(self, default=None):
"""Set the default value for this Schema object."""
self.default = default
def _is_valid_constraint(self, constraint):
valid_types = getattr(constraint, 'valid_types', [])
return any(self.type == getattr(self, t, None) for t in valid_types)
@staticmethod
def str_to_num(value):
"""Convert a string representation of a number into a numeric type."""
if isinstance(value, numbers.Number):
return value
try:
return int(value)
except ValueError:
return float(value)
def to_schema_type(self, value):
"""Returns the value in the schema's data type."""
try:
# We have to be backwards-compatible for Integer and Number
# Schema types and try to convert string representations of
# number into "real" number types, therefore calling
# str_to_num below.
if self.type == self.INTEGER:
num = Schema.str_to_num(value)
if isinstance(num, float):
raise ValueError(_('%s is not an integer.') % num)
return num
elif self.type == self.NUMBER:
return Schema.str_to_num(value)
elif self.type == self.STRING:
return str(value)
elif self.type == self.BOOLEAN:
return strutils.bool_from_string(str(value), strict=True)
except ValueError:
raise ValueError(_('Value "%(val)s" is invalid for data type '
'"%(type)s".')
% {'val': value, 'type': self.type})
return value
def validate_constraints(self, value, context=None):
try:
for constraint in self.constraints:
constraint.validate(value, self, context)
except ValueError as ex:
raise exception.StackValidationFailed(message=six.text_type(ex))
def __getitem__(self, key):
if key == self.TYPE:
return self.type.lower()
elif key == self.DESCRIPTION:
if self.description is not None:
return self.description
elif key == self.DEFAULT:
if self.default is not None:
return self.default
elif key == self.SCHEMA:
if self.schema is not None:
return dict((n, dict(s)) for n, s in self.schema.items())
elif key == self.REQUIRED:
return self.required
elif key == self.CONSTRAINTS:
if self.constraints:
return [dict(c) for c in self.constraints]
raise KeyError(key)
def __iter__(self):
for k in self.KEYS:
try:
self[k]
except KeyError:
pass
else:
yield k
def __len__(self):
if self._len is None:
self._len = len(list(iter(self)))
return self._len
class AnyIndexDict(collections.Mapping):
"""
A Mapping that returns the same value for any integer index.
Used for storing the schema for a list. When converted to a dictionary,
it contains a single item with the key '*'.
"""
ANYTHING = '*'
def __init__(self, value):
self.value = value
def __getitem__(self, key):
if key != self.ANYTHING and not isinstance(key, (int, long)):
raise KeyError(_('Invalid key %s') % str(key))
return self.value
def __iter__(self):
yield self.ANYTHING
def __len__(self):
return 1
class Constraint(collections.Mapping):
"""
Parent class for constraints on allowable values for a Property.
Constraints are serialisable to dictionaries following the HOT input
Parameter constraints schema using dict().
"""
(DESCRIPTION,) = ('description',)
def __init__(self, description=None):
self.description = description
def __str__(self):
def desc():
if self.description:
yield self.description
yield self._str()
return '\n'.join(desc())
def validate(self, value, schema=None, context=None):
if not self._is_valid(value, schema, context):
if self.description:
err_msg = self.description
else:
err_msg = self._err_msg(value)
raise ValueError(err_msg)
@classmethod
def _name(cls):
return '_'.join(w.lower() for w in re.findall('[A-Z]?[a-z]+',
cls.__name__))
def __getitem__(self, key):
if key == self.DESCRIPTION:
if self.description is None:
raise KeyError(key)
return self.description
if key == self._name():
return self._constraint()
raise KeyError(key)
def __iter__(self):
if self.description is not None:
yield self.DESCRIPTION
yield self._name()
def __len__(self):
return 2 if self.description is not None else 1
class Range(Constraint):
"""
Constrain values within a range.
Serialises to JSON as::
{
'range': {'min': <min>, 'max': <max>},
'description': <description>
}
"""
(MIN, MAX) = ('min', 'max')
valid_types = (Schema.INTEGER_TYPE, Schema.NUMBER_TYPE,)
def __init__(self, min=None, max=None, description=None):
super(Range, self).__init__(description)
self.min = min
self.max = max
for param in (min, max):
if not isinstance(param, (float, int, long, type(None))):
raise exception.InvalidSchemaError(
message=_('min/max must be numeric'))
if min is max is None:
raise exception.InvalidSchemaError(
message=_('A range constraint must have a min value and/or '
'a max value specified.'))
def _str(self):
if self.max is None:
fmt = _('The value must be at least %(min)s.')
elif self.min is None:
fmt = _('The value must be no greater than %(max)s.')
else:
fmt = _('The value must be in the range %(min)s to %(max)s.')
return fmt % self._constraint()
def _err_msg(self, value):
return '%s is out of range (min: %s, max: %s)' % (value,
self.min,
self.max)
def _is_valid(self, value, schema, context):
value = Schema.str_to_num(value)
if self.min is not None:
if value < self.min:
return False
if self.max is not None:
if value > self.max:
return False
return True
def _constraint(self):
def constraints():
if self.min is not None:
yield self.MIN, self.min
if self.max is not None:
yield self.MAX, self.max
return dict(constraints())
class Length(Range):
"""
Constrain the length of values within a range.
Serialises to JSON as::
{
'length': {'min': <min>, 'max': <max>},
'description': <description>
}
"""
valid_types = (Schema.STRING_TYPE, Schema.LIST_TYPE, Schema.MAP_TYPE,)
def __init__(self, min=None, max=None, description=None):
if min is max is None:
raise exception.InvalidSchemaError(
message=_('A length constraint must have a min value and/or '
'a max value specified.'))
super(Length, self).__init__(min, max, description)
for param in (min, max):
if not isinstance(param, (int, long, type(None))):
msg = _('min/max length must be integral')
raise exception.InvalidSchemaError(message=msg)
def _str(self):
if self.max is None:
fmt = _('The length must be at least %(min)s.')
elif self.min is None:
fmt = _('The length must be no greater than %(max)s.')
else:
fmt = _('The length must be in the range %(min)s to %(max)s.')
return fmt % self._constraint()
def _err_msg(self, value):
return 'length (%d) is out of range (min: %s, max: %s)' % (len(value),
self.min,
self.max)
def _is_valid(self, value, schema, context):
return super(Length, self)._is_valid(len(value), schema, context)
class AllowedValues(Constraint):
"""
Constrain values to a predefined set.
Serialises to JSON as::
{
'allowed_values': [<allowed1>, <allowed2>, ...],
'description': <description>
}
"""
valid_types = (Schema.STRING_TYPE, Schema.INTEGER_TYPE, Schema.NUMBER_TYPE,
Schema.BOOLEAN_TYPE, Schema.LIST_TYPE,)
def __init__(self, allowed, description=None):
super(AllowedValues, self).__init__(description)
if (not isinstance(allowed, collections.Sequence) or
isinstance(allowed, basestring)):
raise exception.InvalidSchemaError(
message=_('AllowedValues must be a list'))
self.allowed = tuple(allowed)
def _str(self):
allowed = ', '.join(str(a) for a in self.allowed)
return _('Allowed values: %s') % allowed
def _err_msg(self, value):
allowed = '[%s]' % ', '.join(str(a) for a in self.allowed)
return '"%s" is not an allowed value %s' % (value, allowed)
def _is_valid(self, value, schema, context):
# For list values, check if all elements of the list are contained
# in allowed list.
if isinstance(value, list):
return all(v in self.allowed for v in value)
if schema is not None:
_allowed = tuple(schema.to_schema_type(v) for v in self.allowed)
return schema.to_schema_type(value) in _allowed
return value in self.allowed
def _constraint(self):
return list(self.allowed)
class AllowedPattern(Constraint):
"""
Constrain values to a predefined regular expression pattern.
Serialises to JSON as::
{
'allowed_pattern': <pattern>,
'description': <description>
}
"""
valid_types = (Schema.STRING_TYPE,)
def __init__(self, pattern, description=None):
super(AllowedPattern, self).__init__(description)
if not isinstance(pattern, basestring):
raise exception.InvalidSchemaError(
message=_('AllowedPattern must be a string'))
self.pattern = pattern
self.match = re.compile(pattern).match
def _str(self):
return _('Value must match pattern: %s') % self.pattern
def _err_msg(self, value):
return '"%s" does not match pattern "%s"' % (value, self.pattern)
def _is_valid(self, value, schema, context):
match = self.match(value)
return match is not None and match.end() == len(value)
def _constraint(self):
return self.pattern
class CustomConstraint(Constraint):
"""
A constraint delegating validation to an external class.
"""
valid_types = (Schema.STRING_TYPE, Schema.INTEGER_TYPE, Schema.NUMBER_TYPE,
Schema.BOOLEAN_TYPE, Schema.LIST_TYPE)
def __init__(self, name, description=None, environment=None):
super(CustomConstraint, self).__init__(description)
self.name = name
self._environment = environment
self._custom_constraint = None
def _constraint(self):
return self.name
@property
def custom_constraint(self):
if self._custom_constraint is None:
if self._environment is None:
self._environment = resources.global_env()
constraint_class = self._environment.get_constraint(self.name)
if constraint_class:
self._custom_constraint = constraint_class()
return self._custom_constraint
def _str(self):
message = getattr(self.custom_constraint, "message", None)
if not message:
message = _('Value must be of type %s') % self.name
return message
def _err_msg(self, value):
constraint = self.custom_constraint
if constraint is None:
return _('"%(value)s" does not validate %(name)s '
'(constraint not found)') % {
"value": value, "name": self.name}
error = getattr(constraint, "error", None)
if error:
return error(value)
return _('"%(value)s" does not validate %(name)s') % {
"value": value, "name": self.name}
def _is_valid(self, value, schema, context):
constraint = self.custom_constraint
if not constraint:
return False
return constraint.validate(value, context)
class BaseCustomConstraint(object):
"""A base class for validation using API clients.
It will provide a better error message, and reduce a bit of duplication.
Subclass must provide `expected_exceptions` and implement
`validate_with_client`.
"""
expected_exceptions = ()
_error_message = None
def error(self, value):
if self._error_message is None:
return _("Error validating value %(value)r") % {"value": value}
return _("Error validating value %(value)r: %(message)s") % {
"value": value, "message": self._error_message}
def validate(self, value, context):
try:
self.validate_with_client(context.clients, value)
except self.expected_exceptions as e:
self._error_message = str(e)
return False
else:
return True