# Copyright 2010 Jacob Kaplan-Moss # Copyright 2012 OpenStack Foundation # Copyright 2013 Rackspace Hosting # All Rights Reserved. # # 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. """ Base utilities to build API operation managers and objects on top of. """ import abc import contextlib import hashlib import os import six from six.moves.urllib import parse from troveclient.apiclient import base from troveclient.apiclient import exceptions from troveclient import common from troveclient import utils # Python 2.4 compat try: all except NameError: def all(iterable): return True not in (not x for x in iterable) def getid(obj): """Retrieves an id from object or integer. Abstracts the common pattern of allowing both an object or an object's ID as a parameter when dealing with relationships. """ try: return obj.id except AttributeError: return obj class Manager(utils.HookableMixin): """Manager defining CRUD operations for API. Managers interact with a particular type of API (servers, flavors, images, etc.) and provide CRUD operations for them. """ resource_class = None def __init__(self, api): self.api = api def _paginated(self, url, response_key, limit=None, marker=None, query_strings=None): query_strings = query_strings or {} url = common.append_query_strings(url, limit=limit, marker=marker, **query_strings) resp, body = self.api.client.get(url) if not body: raise Exception("Call to " + url + " did not return a body.") links = body.get('links', []) next_links = [link['href'] for link in links if link['rel'] == 'next'] next_marker = None for link in next_links: # Extract the marker from the url. parsed_url = parse.urlparse(link) query_dict = dict(parse.parse_qsl(parsed_url.query)) next_marker = query_dict.get('marker') data = [self.resource_class(self, res) for res in body[response_key]] return common.Paginated(data, next_marker=next_marker, links=links) def _list(self, url, response_key, obj_class=None, body=None): resp = None if body: resp, body = self.api.client.post(url, body=body) else: resp, body = self.api.client.get(url) if obj_class is None: obj_class = self.resource_class data = body[response_key] # NOTE(ja): keystone returns values as list as {'values': [ ... ]} # unlike other services which just return the list... if isinstance(data, dict): try: data = data['values'] except KeyError: pass with self.completion_cache('human_id', obj_class, mode="w"): with self.completion_cache('uuid', obj_class, mode="w"): return [obj_class(self, res, loaded=True) for res in data if res] @contextlib.contextmanager def completion_cache(self, cache_type, obj_class, mode): """Bash-completion cache. The completion cache store items that can be used for bash autocompletion, like UUIDs or human-friendly IDs. A resource listing will clear and repopulate the cache. A resource create will append to the cache. Delete is not handled because listings are assumed to be performed often enough to keep the cache reasonably up-to-date. """ base_dir = utils.env('TROVECLIENT_UUID_CACHE_DIR', default="~/.troveclient") # NOTE(sirp): Keep separate UUID caches for each username + endpoint # pair username = utils.env('OS_USERNAME', 'TROVE_USERNAME') url = utils.env('OS_URL', 'NOVA_URL') uniqifier = hashlib.md5(username.encode('utf-8') + url.encode('utf-8')).hexdigest() cache_dir = os.path.expanduser(os.path.join(base_dir, uniqifier)) try: os.makedirs(cache_dir, 0o755) except OSError: # NOTE(kiall): This is typically either permission denied while # attempting to create the directory, or the directory # already exists. Either way, don't fail. pass resource = obj_class.__name__.lower() filename = "%s-%s-cache" % (resource, cache_type.replace('_', '-')) path = os.path.join(cache_dir, filename) cache_attr = "_%s_cache" % cache_type try: setattr(self, cache_attr, open(path, mode)) except IOError: # NOTE(kiall): This is typically a permission denied while # attempting to write the cache file. pass try: yield finally: cache = getattr(self, cache_attr, None) if cache: cache.close() delattr(self, cache_attr) def write_to_completion_cache(self, cache_type, val): cache = getattr(self, "_%s_cache" % cache_type, None) if cache: cache.write("%s\n" % val) def _get(self, url, response_key=None): resp, body = self.api.client.get(url) if response_key: return self.resource_class(self, body[response_key], loaded=True) else: return self.resource_class(self, body, loaded=True) def _create(self, url, body, response_key, return_raw=False, **kwargs): self.run_hooks('modify_body_for_create', body, **kwargs) resp, body = self.api.client.post(url, body=body) if body: if return_raw: return body[response_key] with self.completion_cache('human_id', self.resource_class, mode="a"): with self.completion_cache('uuid', self.resource_class, mode="a"): return self.resource_class(self, body[response_key]) def _delete(self, url): resp, body = self.api.client.delete(url) return resp, body def _update(self, url, body, **kwargs): self.run_hooks('modify_body_for_update', body, **kwargs) resp, body = self.api.client.put(url, body=body) return body def _edit(self, url, body): resp, body = self.api.client.patch(url, body=body) return body class ManagerWithFind(six.with_metaclass(abc.ABCMeta, Manager)): """Like a `Manager`, but with additional `find()`/`findall()` methods.""" @abc.abstractmethod def list(self): pass def find(self, **kwargs): """Find a single item with attributes matching ``**kwargs``. This isn't very efficient: it loads the entire list then filters on the Python side. """ matches = self.findall(**kwargs) num_matches = len(matches) if num_matches == 0: msg = "No %s matching %s." % (self.resource_class.__name__, kwargs) raise exceptions.NotFound(404, msg) elif num_matches > 1: raise exceptions.NoUniqueMatch else: return matches[0] def findall(self, **kwargs): """Find all items with attributes matching ``**kwargs``. This isn't very efficient: it loads the entire list then filters on the Python side. """ found = [] searches = list(kwargs.items()) for obj in self.list(): try: if all(getattr(obj, attr) == value for (attr, value) in searches): found.append(self.get(obj.id)) except AttributeError: continue return found class Resource(base.Resource): """A resource represents a particular instance of an object like server. This is pretty much just a bag for attributes. :param manager: Manager object :param info: dictionary representing resource attributes :param loaded: prevent lazy-loading if set to True """ HUMAN_ID = False def __init__(self, manager, info, loaded=False): super(Resource, self).__init__(manager, info, loaded) # NOTE(sirp): ensure `id` is already present because if it isn't we'll # enter an infinite loop of __getattr__ -> get -> __init__ -> # __getattr__ -> ... if 'id' in self.__dict__ and len(str(self.id)) == 36: self.manager.write_to_completion_cache('uuid', self.id) human_id = self.human_id if human_id: self.manager.write_to_completion_cache('human_id', human_id)