# vim: tabstop=4 shiftwidth=4 softtabstop=4 # Copyright 2012 Nicira, Inc. # 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. # # @author: Somik Behera, Nicira Networks, Inc. import httplib # basic HTTP library for HTTPS connections import logging from quantum.plugins.nicira.nicira_nvp_plugin.api_client import ( client_eventlet, request_eventlet) LOG = logging.getLogger("NVPApiHelper") LOG.setLevel(logging.INFO) def _find_nvp_version_in_headers(headers): # be safe if headers is None - do not cause a failure for (header_name, header_value) in (headers or ()): try: if header_name == 'server': return header_value.split('/')[1] except IndexError: LOG.warning(_("Unable to fetch NVP version from response " "headers:%s"), headers) class NVPApiHelper(client_eventlet.NvpApiClientEventlet): ''' Helper class to do basic login, cookie management, and provide base method to send HTTP requests. Implements new eventlet-based framework derived from the management console nvp_gevent_client module. ''' def __init__(self, api_providers, user, password, request_timeout, http_timeout, retries, redirects, concurrent_connections=3, nvp_gen_timeout=-1): '''Constructor. :param api_providers: a list of tuples in the form: (host, port, is_ssl=True). Passed on to NvpClientEventlet. :param user: the login username. :param password: the login password. :param concurrent_connections: the number of concurrent connections. :param request_timeout: all operations (including retries, redirects from unresponsive controllers, etc) should finish within this timeout. :param http_timeout: how long to wait before aborting an unresponsive controller (and allow for retries to another controller in the cluster) :param retries: the number of concurrent connections. :param redirects: the number of concurrent connections. ''' client_eventlet.NvpApiClientEventlet.__init__( self, api_providers, user, password, concurrent_connections, nvp_gen_timeout) self._request_timeout = request_timeout self._http_timeout = http_timeout self._retries = retries self._redirects = redirects self._nvp_version = None # NOTE(salvatore-orlando): This method is not used anymore. Login is now # performed automatically inside the request eventlet if necessary. def login(self, user=None, password=None): '''Login to NVP controller. Assumes same password is used for all controllers. :param user: NVP controller user (usually admin). Provided for backwards compatability. In the normal mode of operation this should be None. :param password: NVP controller password. Provided for backwards compatability. In the normal mode of operation this should be None. :returns: Does not return a value. ''' if user: self._user = user if password: self._password = password return client_eventlet.NvpApiClientEventlet._login(self) def request(self, method, url, body="", content_type="application/json"): '''Issues request to controller.''' g = request_eventlet.NvpGenericRequestEventlet( self, method, url, body, content_type, auto_login=True, request_timeout=self._request_timeout, http_timeout=self._http_timeout, retries=self._retries, redirects=self._redirects) g.start() response = g.join() LOG.debug(_('NVPApiHelper.request() returns "%s"'), response) # response is a modified HTTPResponse object or None. # response.read() will not work on response as the underlying library # request_eventlet.NvpApiRequestEventlet has already called this # method in order to extract the body and headers for processing. # NvpApiRequestEventlet derived classes call .read() and # .getheaders() on the HTTPResponse objects and store the results in # the response object's .body and .headers data members for future # access. if response is None: # Timeout. LOG.error(_('Request timed out: %(method)s to %(url)s'), locals()) raise RequestTimeout() status = response.status if status == httplib.UNAUTHORIZED: raise UnAuthorizedRequest() # Fail-fast: Check for exception conditions and raise the # appropriate exceptions for known error codes. if status in self.error_codes: LOG.error(_("Received error code: %s"), status) LOG.error(_("Server Error Message: %s"), response.body) self.error_codes[status](self) # Continue processing for non-error condition. if (status != httplib.OK and status != httplib.CREATED and status != httplib.NO_CONTENT): LOG.error(_("%(method)s to %(url)s, unexpected response code: " "%(status)d (content = '%(body)s')"), {'method': method, 'url': url, 'status': response.status, 'body': response.body}) return None if not self._nvp_version: self._nvp_version = _find_nvp_version_in_headers(response.headers) return response.body def get_nvp_version(self): if not self._nvp_version: # generate a simple request (/ws.v1/log) # this will cause nvp_version to be fetched # don't bother about response self.request('GET', '/ws.v1/log') return self._nvp_version def fourZeroFour(self): raise ResourceNotFound() def fourZeroNine(self): raise Conflict() def fiveZeroThree(self): raise ServiceUnavailable() def fourZeroThree(self): raise Forbidden() def zero(self): raise NvpApiException() # TODO(del): ensure error_codes are handled/raised appropriately # in api_client. error_codes = {404: fourZeroFour, 409: fourZeroNine, 503: fiveZeroThree, 403: fourZeroThree, 301: zero, 307: zero, 400: zero, 500: zero, 503: zero} class NvpApiException(Exception): ''' Base NvpApiClient Exception To correctly use this class, inherit from it and define a 'message' property. That message will get printf'd with the keyword arguments provided to the constructor. ''' message = _("An unknown exception occurred.") def __init__(self, **kwargs): try: self._error_string = self.message % kwargs except Exception: # at least get the core message out if something happened self._error_string = self.message def __str__(self): return self._error_string class UnAuthorizedRequest(NvpApiException): message = _("Server denied session's authentication credentials.") class ResourceNotFound(NvpApiException): message = _("An entity referenced in the request was not found.") class Conflict(NvpApiException): message = _("Request conflicts with configuration on a different " "entity.") class ServiceUnavailable(NvpApiException): message = _("Request could not completed because the associated " "resource could not be reached.") class Forbidden(NvpApiException): message = _("The request is forbidden from accessing the " "referenced resource.") class RequestTimeout(NvpApiException): message = _("The request has timed out.")