Source code for heat.engine.translation

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import functools

from oslo_log import log as logging
import six

from heat.common import exception
from heat.common.i18n import _
from heat.engine import function

LOG = logging.getLogger(__name__)


[docs]@functools.total_ordering class TranslationRule(object): """Translating mechanism one properties to another. Mechanism uses list of rules, each defines by this class, and can be executed. Working principe: during resource creating after properties defining resource take list of rules, specified by method translation_rules, which should be overloaded for each resource, if it's needed, and execute each rule using translate_properties method. Next operations are allowed: - ADD. This rule allows to add some value to list-type properties. Only list-type values can be added to such properties. Using for other cases is prohibited and will be returned with error. - REPLACE. This rule allows to replace some property value to another. Used for all types of properties. Note, that if property has list type, then value will be replaced for all elements of list, where it needed. If element in such property must be replaced by value of another element of this property, value_name must be defined. - DELETE. This rule allows to delete some property. If property has list type, then deleting affects value in all list elements. - RESOLVE. This rule allows to resolve some property using client and the finder function. Finders may require an additional entity key. """ RULE_KEYS = (ADD, REPLACE, DELETE, RESOLVE) = ('Add', 'Replace', 'Delete', 'Resolve') def __lt__(self, other): rules = [TranslationRule.ADD, TranslationRule.REPLACE, TranslationRule.RESOLVE, TranslationRule.DELETE] idx1 = rules.index(self.rule) idx2 = rules.index(other.rule) return idx1 < idx2 def __init__(self, properties, rule, translation_path, value=None, value_name=None, value_path=None, client_plugin=None, finder=None, entity=None, custom_value_path=None): """Add new rule for translating mechanism. :param properties: properties of resource :param rule: rule from RULE_KEYS :param translation_path: list with path to property, which value will be affected in rule. :param value: value which will be involved in rule :param value_name: value_name which used for replacing properties inside list-type properties. :param value_path: path to value, which should be used for translation. :param client_plugin: client plugin that would be used to resolve :param finder: finder method of the client plugin :param entity: some generic finders require an entity to resolve ex. neutron finder function. :param custom_value_path: list-type value path to translate property, which has no schema. """ self.properties = properties self.rule = rule self.translation_path = translation_path self.value = value or None self.value_name = value_name self.value_path = value_path self.client_plugin = client_plugin self.finder = finder self.entity = entity self.custom_value_path = custom_value_path self.validate()
[docs] def validate(self): if self.rule not in self.RULE_KEYS: raise ValueError(_('There is no rule %(rule)s. List of allowed ' 'rules is: %(rules)s.') % { 'rule': self.rule, 'rules': ', '.join(self.RULE_KEYS)}) if (not isinstance(self.translation_path, list) or len(self.translation_path) == 0): raise ValueError(_('"translation_path" should be non-empty list ' 'with path to translate.')) args = [self.value_path is not None, self.value is not None, self.value_name is not None] if args.count(True) > 1: raise ValueError(_('"value_path", "value" and "value_name" are ' 'mutually exclusive and cannot be specified ' 'at the same time.')) if (self.rule == self.ADD and self.value is not None and not isinstance(self.value, list)): raise ValueError(_('"value" must be list type when rule is Add.')) if (self.rule == self.RESOLVE and not (self.client_plugin or self.finder)): raise ValueError(_('"client_plugin" and "finder" should be ' 'specified for %s rule') % self.RESOLVE)
[docs] def get_value_absolute_path(self, full_value_name=False): path = [] if self.value_name: if full_value_name: path.extend(self.translation_path[:-1]) path.append(self.value_name) elif self.value_path: path.extend(self.value_path) if self.custom_value_path: path.extend(self.custom_value_path) return path
[docs]class Translation(object): """Mechanism for translating one properties to other. Mechanism allows to handle properties - update deprecated/hidden properties to new, resolve values, remove unnecessary. It uses list of TranslationRule objects as rules for translation. """ def __init__(self, properties=None): """Initialise translation mechanism. :param properties: Properties class object to resolve rule pathes. :var _rules: store specified rules by set_rules method. :var resolves_translations: key-pair dict, where key is string-type full path of property, value is a resolved value. :var is_active: indicate to not translate property, if property already in translation and just tries to get property value. This indicator escapes from infinite loop. :var store_translated_values: define storing resolved values. Useful for validation phase, where not all functions can be resolved (``get_attr`` for not created resource, for example). """ self.properties = properties self._rules = {} self.resolved_translations = {} self.is_active = True self.store_translated_values = True self._ignore_resolve_error = False self._deleted_props = [] self._replaced_props = []
[docs] def set_rules(self, rules, client_resolve=True, ignore_resolve_error=False): if not rules: return self._rules = {} self.store_translated_values = client_resolve self._ignore_resolve_error = ignore_resolve_error for rule in rules: if not client_resolve and rule.rule == TranslationRule.RESOLVE: continue key = '.'.join(rule.translation_path) self._rules.setdefault(key, set()).add(rule) if rule.rule == TranslationRule.DELETE: self._deleted_props.append(key) if rule.rule == TranslationRule.REPLACE: path = '.'.join(rule.get_value_absolute_path(True)) self._replaced_props.append(path)
[docs] def is_deleted(self, key): return (self.is_active and self.cast_key_to_rule(key) in self._deleted_props)
[docs] def is_replaced(self, key): return (self.is_active and self.cast_key_to_rule(key) in self._replaced_props)
[docs] def cast_key_to_rule(self, key): return '.'.join([item for item in key.split('.') if not item.isdigit()])
[docs] def has_translation(self, key): key = self.cast_key_to_rule(key) return (self.is_active and (key in self._rules or key in self.resolved_translations))
[docs] def translate(self, key, prop_value=None, prop_data=None, validate=False): if key in self.resolved_translations: return self.resolved_translations[key] result = prop_value if self._rules.get(self.cast_key_to_rule(key)) is None: return result for rule in sorted(self._rules.get(self.cast_key_to_rule(key))): if rule.rule == TranslationRule.DELETE: if self.store_translated_values: self.resolved_translations[key] = None result = None if rule.rule == TranslationRule.REPLACE: result = self.replace(key, rule, result, prop_data, validate) if rule.rule == TranslationRule.ADD: result = self.add(key, rule, result, prop_data, validate) if rule.rule == TranslationRule.RESOLVE: resolved_value = resolve_and_find(result, rule.client_plugin, rule.finder, rule.entity, self._ignore_resolve_error) if self.store_translated_values: self.resolved_translations[key] = resolved_value result = resolved_value return result
[docs] def add(self, key, add_rule, prop_value=None, prop_data=None, validate=False): value_path = add_rule.get_value_absolute_path() if prop_value is None: prop_value = [] if not isinstance(prop_value, list): raise ValueError(_('Incorrect translation rule using - cannot ' 'resolve Add rule for non-list translation ' 'value "%s".') % key) translation_value = prop_value if add_rule.value: translation_value.extend(add_rule.value) elif value_path: if self.has_translation('.'.join(value_path)): self.translate('.'.join(value_path), prop_data=prop_data) self.is_active = False value = get_value(value_path, prop_data if add_rule.value_name else self.properties, validate) self.is_active = True if value is not None: translation_value.extend(value if isinstance(value, list) else [value]) if self.store_translated_values: self.resolved_translations[key] = translation_value return translation_value
[docs] def replace(self, key, replace_rule, prop_value=None, prop_data=None, validate=False): value = None value_path = replace_rule.get_value_absolute_path(full_value_name=True) short_path = replace_rule.get_value_absolute_path() if value_path: if replace_rule.value_name is not None: prop_path = key.split('.')[:-1] prop_path.extend(short_path) prop_path = '.'.join(prop_path) subpath = short_path else: prop_path = '.'.join(value_path) subpath = value_path props = prop_data if replace_rule.value_name else self.properties self.is_active = False value = get_value(subpath, props, validate) self.is_active = True if self.has_translation(prop_path): self.translate(prop_path, value, prop_data=prop_data) if value and prop_value: raise exception.StackValidationFailed( message=_('Cannot define the following properties at ' 'the same time: %s') % ', '.join( [self.cast_key_to_rule(key), '.'.join(value_path)])) elif replace_rule.value is not None: value = replace_rule.value result = value if value is not None else prop_value if self.store_translated_values: self.resolved_translations[key] = result if value_path: if replace_rule.value_name: value_path = (key.split('.')[:-1] + short_path) self.resolved_translations['.'.join(value_path)] = None return result
[docs]def get_value(path, props, validate=False): if not props: return None key = path[0] if isinstance(props, dict): prop = props.get(key) else: prop = props._get_property_value(key, validate) if len(path[1:]) == 0: return prop elif prop is None: return None elif isinstance(prop, list): values = [] for item in prop: values.append(get_value(path[1:], item)) return values elif isinstance(prop, dict): return get_value(path[1:], prop)
[docs]def resolve_and_find(value, cplugin, finder, entity=None, ignore_resolve_error=False): if isinstance(value, function.Function): value = function.resolve(value) if value: if isinstance(value, list): resolved_value = [] for item in value: resolved_value.append(resolve_and_find(item, cplugin, finder, entity, ignore_resolve_error)) return resolved_value finder = getattr(cplugin, finder) try: if entity: return finder(entity, value) else: return finder(value) except Exception as ex: if ignore_resolve_error: LOG.info("Ignoring error in RESOLVE translation: %s", six.text_type(ex)) return value raise