# 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 logging import six from keystoneclient import exceptions from keystoneclient import session as client_session from keystoneclient.v2_0 import client as v2_client from keystoneclient.v3 import client as v3_client _logger = logging.getLogger(__name__) class _KeystoneVersion(object): """A factory object that holds all the information to create a client. Instances of this class are callable objects that hold all the kwargs that were passed to discovery so that a user may simply call it to create a new client object. Additional arguments passed to the call will override or add to those provided to the object. """ _CLIENT_VERSIONS = {2: v2_client.Client, 3: v3_client.Client} def __init__(self, version, status, client_class=None, **kwargs): """Create a new discovered version object. :param tuple version: the version of the available API. :param string status: the stability of the API. :param Class client_class: the client class that should be used to instantiate against this version of the API. (optional, will be matched against known) :param dict **kwargs: Additional arguments that should be passed on to the client when it is constructed. """ self.version = version self.status = status self.client_class = client_class self.client_kwargs = kwargs if not self.client_class: try: self.client_class = self._CLIENT_VERSIONS[self.version[0]] except KeyError: raise exceptions.DiscoveryFailure("No client available " "for version: %s" % self.version) def __lt__(self, other): """Version Ordering. Versions are ordered by major, then minor version number, then 'stable' is deemed the highest possible status, then they are just treated alphabetically (alpha < beta etc) """ if self.version == other.version: if self.status == 'stable': return False elif other.status == 'stable': return True else: return self.status < other.status return self.version < other.version def __eq__(self, other): return self.version == other.version and self.status == other.status def create_client(self, **kwargs): if kwargs: client_kwargs = self.client_kwargs.copy() client_kwargs.update(kwargs) else: client_kwargs = self.client_kwargs return self.client_class(**client_kwargs) def __call__(self, **kwargs): return self.create_client(**kwargs) @property def _str_ver(self): ver = ".".join([str(v) for v in self.version]) if self.status != 'stable': ver = "%s-%s" % (ver, self.status) return ver def _normalize_version_number(version): """Turn a version representation into a tuple.""" # trim the v from a 'v2.0' or similar try: version = version.lstrip('v') except AttributeError: pass # if it's an integer or a numeric as a string then normalize it # to a string, this ensures 1 decimal point try: num = float(version) except Exception: pass else: version = str(num) # if it's a string (or an integer) from above break it on . try: return tuple(map(int, version.split("."))) except Exception: pass # last attempt, maybe it's a list or iterable. try: return tuple(map(int, version)) except Exception: pass raise TypeError("Invalid version specified: %s" % version) def available_versions(url, session=None, **kwargs): headers = {'Accept': 'application/json'} if not session: session = client_session.Session.construct(kwargs) resp = session.get(url, headers=headers) try: body_resp = resp.json() except ValueError: pass else: # In the event of querying a root URL we will get back a list of # available versions. try: return body_resp['versions']['values'] except (KeyError, TypeError): pass # Otherwise if we query an endpoint like /v2.0 then we will get back # just the one available version. try: return [body_resp['version']] except KeyError: pass raise exceptions.DiscoveryFailure("Invalid Response - Bad version" " data returned: %s" % resp.text) class Discover(object): """A means to discover and create clients depending on the supported API versions on the server. Querying the server is done on object creation and every subsequent method operates upon the data that was retrieved. """ def __init__(self, session=None, **kwargs): """Construct a new discovery object. The connection parameters associated with this method are the same format and name as those used by a client (see keystoneclient.v2_0.client.Client and keystoneclient.v3.client.Client). If not overridden in subsequent methods they will also be what is passed to the constructed client. In the event that auth_url and endpoint is provided then auth_url will be used in accordance with how the client operates. The initialization process also queries the server. :param Session session: A session object that will be used for communication. Clients will also be constructed with this session. :param string auth_url: Identity service endpoint for authorization. (optional) :param string endpoint: A user-supplied endpoint URL for the identity service. (optional) :param string original_ip: The original IP of the requesting user which will be sent to identity service in a 'Forwarded' header. (optional) DEPRECATED: use the session object. This is ignored if a session is provided. :param boolean debug: Enables debug logging of all request and responses to the identity service. default False (optional) DEPRECATED: use the session object. This is ignored if a session is provided. :param string cacert: Path to the Privacy Enhanced Mail (PEM) file which contains the trusted authority X.509 certificates needed to established SSL connection with the identity service. (optional) DEPRECATED: use the session object. This is ignored if a session is provided. :param string key: Path to the Privacy Enhanced Mail (PEM) file which contains the unencrypted client private key needed to established two-way SSL connection with the identity service. (optional) DEPRECATED: use the session object. This is ignored if a session is provided. :param string cert: Path to the Privacy Enhanced Mail (PEM) file which contains the corresponding X.509 client certificate needed to established two-way SSL connection with the identity service. (optional) DEPRECATED: use the session object. This is ignored if a session is provided. :param boolean insecure: Does not perform X.509 certificate validation when establishing SSL connection with identity service. default: False (optional) DEPRECATED: use the session object. This is ignored if a session is provided. """ if not session: session = client_session.Session.construct(kwargs) kwargs['session'] = session url = kwargs.get('endpoint') or kwargs.get('auth_url') if not url: raise exceptions.DiscoveryFailure('Not enough information to ' 'determine URL. Provide either ' 'auth_url or endpoint') self._client_kwargs = kwargs self._available_versions = available_versions(url, session=session) def _get_client_constructor_kwargs(self, kwargs_dict={}, **kwargs): client_kwargs = self._client_kwargs.copy() client_kwargs.update(kwargs_dict) client_kwargs.update(**kwargs) return client_kwargs def available_versions(self, unstable=False): """Return a list of identity APIs available on the server and the data associated with them. :param bool unstable: Accept endpoints not marked 'stable'. (optional) :returns: A List of dictionaries as presented by the server. Each dict will contain the version and the URL to use for the version. It is a direct representation of the layout presented by the identity API. Example:: >>> from keystoneclient import discover >>> disc = discover.Discovery(auth_url='http://localhost:5000') >>> disc.available_versions() [{'id': 'v3.0', 'links': [{'href': u'http://127.0.0.1:5000/v3/', 'rel': u'self'}], 'media-types': [ {'base': 'application/json', 'type': 'application/vnd.openstack.identity-v3+json'}, {'base': 'application/xml', 'type': 'application/vnd.openstack.identity-v3+xml'}], 'status': 'stable', 'updated': '2013-03-06T00:00:00Z'}, {'id': 'v2.0', 'links': [{'href': u'http://127.0.0.1:5000/v2.0/', 'rel': u'self'}, {'href': u'...', 'rel': u'describedby', 'type': u'application/pdf'}], 'media-types': [ {'base': 'application/json', 'type': 'application/vnd.openstack.identity-v2.0+json'}, {'base': 'application/xml', 'type': 'application/vnd.openstack.identity-v2.0+xml'}], 'status': 'stable', 'updated': '2013-03-06T00:00:00Z'}] """ if unstable: # no need to determine the stable endpoints, just return everything return self._available_versions versions = [] for v in self._available_versions: try: status = v['status'] except KeyError: _logger.warning("Skipping over invalid version data. " "No stability status in version.") else: if status == 'stable': versions.append(v) return versions def _get_factory_from_response_entry(self, version_data, **kwargs): """Create a _KeystoneVersion factory object from a version response entry returned from a server. """ try: version_str = version_data['id'] status = version_data['status'] if not version_str.startswith('v'): raise exceptions.DiscoveryFailure('Skipping over invalid ' 'version string: %s. It ' 'should start with a v.' % version_str) for link in version_data['links']: # NOTE(jamielennox): there are plenty of links like with # documentation and such, we only care about the self # which is a link to the URL we should use. if link['rel'].lower() == 'self': version_number = _normalize_version_number(version_str) version_url = link['href'] break else: raise exceptions.DiscoveryFailure("Didn't find any links " "in version data.") except (KeyError, TypeError, ValueError): raise exceptions.DiscoveryFailure('Skipping over invalid ' 'version data.') # NOTE(jamielennox): the url might be the auth_url or the endpoint # depending on what was passed initially. Order is important, endpoint # needs to override auth_url. for url_type in ('auth_url', 'endpoint'): if self._client_kwargs.get(url_type, False): kwargs[url_type] = version_url else: kwargs[url_type] = None return _KeystoneVersion(status=status, version=version_number, **kwargs) def _available_clients(self, unstable=False, **kwargs): """Return a dictionary of factory functions for available API versions. :returns: A dictionary of available API endpoints with the version number as a tuple as the key, and a factory object that can be used to create an appropriate client as the value. To use the returned factory you simply call it with the parameters to pass to keystoneclient. These parameters will override those saved in the factory. Example:: >>> from keystoneclient import client >>> available_clients = client._available_clients(auth_url=url, ... **kwargs) >>> try: ... v2_factory = available_clients[(2, 0)] ... except KeyError: ... print "Version 2.0 unavailable" ... else: ... v2_client = v2_factory(token='abcdef') ... v2_client.tenants.list() :raises: DiscoveryFailure if the response is invalid :raises: VersionNotAvailable if a suitable client cannot be found. """ versions = dict() response_values = self.available_versions(unstable=unstable) client_kwargs = self._get_client_constructor_kwargs(kwargs_dict=kwargs) for version_data in response_values: try: v = self._get_factory_from_response_entry(version_data, **client_kwargs) except exceptions.DiscoveryFailure as e: _logger.warning("Invalid entry: %s", e, exc_info=True) else: versions[v.version] = v return versions def create_client(self, version=None, **kwargs): """Factory function to create a new identity service client. :param tuple version: The required version of the identity API. If specified the client will be selected such that the major version is equivalent and an endpoint provides at least the specified minor version. For example to specify the 3.1 API use (3, 1). (optional) :param bool unstable: Accept endpoints not marked 'stable'. (optional) :param kwargs: Additional arguments will override those provided to this object's constructor. :returns: An instantiated identity client object. :raises: DiscoveryFailure if the server response is invalid :raises: VersionNotAvailable if a suitable client cannot be found. """ versions = self._available_clients(**kwargs) chosen = None if version: version = _normalize_version_number(version) for keystone_version in six.itervalues(versions): # major versions must be the same (eg even though v2 is a lower # version than v3 we can't use it if v2 was requested) if version[0] != keystone_version.version[0]: continue # prevent selecting a minor version less than what is required if version <= keystone_version.version: chosen = keystone_version break elif versions: # if no version specified pick the latest one chosen = max(six.iteritems(versions))[1] if not chosen: msg = "Could not find a suitable endpoint" if version: msg = "%s for client version: %s" % (msg, version) if versions: available = ", ".join([v._str_ver for v in six.itervalues(versions)]) msg = "%s. Available_versions are: %s" % (msg, available) else: msg = "%s. No versions reported available" % msg raise exceptions.VersionNotAvailable(msg) return chosen.create_client()