300486546b
The current version of the nvp_api client does not load balance requests across multiple controllers. Instead, it just sends all the requests to one controller and if there is a controller failure it will failover to use another controller. This blueprint implements the ablility to utilize all controllers at once. blueprint nvp-api-client-loadbalance-request Change-Id: I331be2a23ae360a95786152d5f116359f690d9f3
280 lines
11 KiB
Python
280 lines
11 KiB
Python
# Copyright 2012 Nicira, Inc.
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# All Rights Reserved
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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#
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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#
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# @author: Aaron Rosen, Nicira Networks, Inc.
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from abc import ABCMeta
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from abc import abstractmethod
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import copy
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import httplib
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import logging
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import time
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import urlparse
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from quantum.plugins.nicira.nicira_nvp_plugin.api_client.common import (
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_conn_str)
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logging.basicConfig(level=logging.INFO)
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LOG = logging.getLogger(__name__)
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# Default parameters.
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DEFAULT_REQUEST_TIMEOUT = 30
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DEFAULT_HTTP_TIMEOUT = 10
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DEFAULT_RETRIES = 2
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DEFAULT_REDIRECTS = 2
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DEFAULT_API_REQUEST_POOL_SIZE = 1000
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DEFAULT_MAXIMUM_REQUEST_ID = 4294967295
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DOWNLOAD_TIMEOUT = 180 # The UI code has a coorespoind 190 sec timeout
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# for downloads, see: django/nvp_console/views.py
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class NvpApiRequest(object):
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'''An abstract baseclass for all ApiRequest implementations.
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This defines the interface and property structure for both eventlet and
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gevent-based ApiRequest classes.
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'''
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__metaclass__ = ABCMeta
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# List of allowed status codes.
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ALLOWED_STATUS_CODES = [
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httplib.OK,
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httplib.CREATED,
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httplib.NO_CONTENT,
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httplib.MOVED_PERMANENTLY,
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httplib.TEMPORARY_REDIRECT,
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httplib.BAD_REQUEST,
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httplib.UNAUTHORIZED,
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httplib.FORBIDDEN,
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httplib.NOT_FOUND,
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httplib.CONFLICT,
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httplib.INTERNAL_SERVER_ERROR,
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httplib.SERVICE_UNAVAILABLE
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]
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@abstractmethod
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def start(self):
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pass
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@abstractmethod
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def join(self):
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pass
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@abstractmethod
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def copy(self):
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pass
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def _issue_request(self):
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'''Issue a request to a provider.'''
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conn = (self._client_conn or
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self._api_client.acquire_connection(True,
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copy.copy(self._headers),
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rid=self._rid()))
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if conn is None:
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error = Exception("No API connections available")
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self._request_error = error
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return error
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url = self._url
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LOG.debug(_("[%d] Issuing - request '%s'"),
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self._rid(), self._request_str(conn, url))
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issued_time = time.time()
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is_conn_error = False
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is_conn_service_unavail = False
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try:
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redirects = 0
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while (redirects <= self._redirects):
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# Update connection with user specified request timeout,
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# the connect timeout is usually smaller so we only set
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# the request timeout after a connection is established
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if conn.sock is None:
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conn.connect()
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conn.sock.settimeout(self._http_timeout)
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elif conn.sock.gettimeout() != self._http_timeout:
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conn.sock.settimeout(self._http_timeout)
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headers = copy.copy(self._headers)
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cookie = self._api_client.auth_cookie(conn)
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if cookie:
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headers["Cookie"] = cookie
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gen = self._api_client.nvp_config_gen
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if gen:
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headers["X-Nvp-Wait-For-Config-Generation"] = gen
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LOG.debug(_("Setting %s request header: '%s'"),
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'X-Nvp-Wait-For-Config-Generation', gen)
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try:
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conn.request(self._method, url, self._body, headers)
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except Exception as e:
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LOG.warn(_("[%d] Exception issuing request: '%s'"),
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self._rid(), e)
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raise e
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response = conn.getresponse()
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response.body = response.read()
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response.headers = response.getheaders()
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LOG.debug(_("[%d] Completed request '%s': %s (%0.2f seconds)"),
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self._rid(), self._request_str(conn, url),
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response.status, time.time() - issued_time)
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new_gen = response.getheader('X-Nvp-Config-Generation', None)
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if new_gen:
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LOG.debug(_("Reading '%s' response header: '%s'"),
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'X-Nvp-config-Generation', new_gen)
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if (self._api_client.nvp_config_gen is None or
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self._api_client.nvp_config_gen < int(new_gen)):
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self._api_client.nvp_config_gen = int(new_gen)
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if response.status == httplib.UNAUTHORIZED:
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if cookie is None and self._url != "/ws.v1/login":
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# The connection still has no valid cookie despite
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# attemps to authenticate and the request has failed
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# with unauthorized status code. If this isn't a
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# a request to authenticate, we should abort the
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# request since there is no point in retrying.
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self._abort = True
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else:
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# If request is unauthorized, clear the session cookie
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# for the current provider so that subsequent requests
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# to the same provider triggers re-authentication.
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self._api_client.set_auth_cookie(conn, None)
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self._api_client.set_auth_cookie(conn, None)
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elif response.status == httplib.SERVICE_UNAVAILABLE:
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is_conn_service_unavail = True
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if response.status not in [httplib.MOVED_PERMANENTLY,
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httplib.TEMPORARY_REDIRECT]:
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break
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elif redirects >= self._redirects:
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LOG.info(_("[%d] Maximum redirects exceeded, aborting "
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"request"), self._rid())
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break
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redirects += 1
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conn, url = self._redirect_params(conn, response.headers,
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self._client_conn is None)
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if url is None:
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response.status = httplib.INTERNAL_SERVER_ERROR
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break
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LOG.info(_("[%d] Redirecting request to: '%s'"),
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self._rid(), self._request_str(conn, url))
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# If we receive any of these responses, then
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# our server did not process our request and may be in an
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# errored state. Raise an exception, which will cause the
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# the conn to be released with is_conn_error == True
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# which puts the conn on the back of the client's priority
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# queue.
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if response.status >= 500:
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LOG.warn(_("[%d] Request '%s %s' received: %s"),
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self._rid(), self._method, self._url,
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response.status)
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raise Exception('Server error return: %s' %
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response.status)
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return response
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except Exception as e:
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if isinstance(e, httplib.BadStatusLine):
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msg = "Invalid server response"
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else:
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msg = unicode(e)
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LOG.warn(_("[%d] Failed request '%s': '%s' (%0.2f seconds)"),
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self._rid(), self._request_str(conn, url), msg,
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time.time() - issued_time)
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self._request_error = e
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is_conn_error = True
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return e
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finally:
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# Make sure we release the original connection provided by the
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# acquire_connection() call above.
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if self._client_conn is None:
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self._api_client.release_connection(conn, is_conn_error,
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is_conn_service_unavail,
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rid=self._rid())
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def _redirect_params(self, conn, headers, allow_release_conn=False):
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"""Process redirect response, create new connection if necessary.
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Args:
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conn: connection that returned the redirect response
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headers: response headers of the redirect response
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allow_release_conn: if redirecting to a different server,
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release existing connection back to connection pool.
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Returns: Return tuple(conn, url) where conn is a connection object
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to the redirect target and url is the path of the API request
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"""
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url = None
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for name, value in headers:
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if name.lower() == "location":
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url = value
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break
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if not url:
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LOG.warn(_("[%d] Received redirect status without location header"
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" field"), self._rid())
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return (conn, None)
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# Accept location with the following format:
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# 1. /path, redirect to same node
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# 2. scheme://hostname:[port]/path where scheme is https or http
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# Reject others
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# 3. e.g. relative paths, unsupported scheme, unspecified host
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result = urlparse.urlparse(url)
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if not result.scheme and not result.hostname and result.path:
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if result.path[0] == "/":
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if result.query:
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url = "%s?%s" % (result.path, result.query)
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else:
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url = result.path
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return (conn, url) # case 1
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else:
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LOG.warn(_("[%d] Received invalid redirect location: '%s'"),
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self._rid(), url)
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return (conn, None) # case 3
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elif result.scheme not in ["http", "https"] or not result.hostname:
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LOG.warn(_("[%d] Received malformed redirect location: %s"),
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self._rid(), url)
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return (conn, None) # case 3
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# case 2, redirect location includes a scheme
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# so setup a new connection and authenticate
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if allow_release_conn:
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self._api_client.release_connection(conn)
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conn_params = (result.hostname, result.port, result.scheme == "https")
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conn = self._api_client.acquire_redirect_connection(conn_params, True,
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self._headers)
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if result.query:
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url = "%s?%s" % (result.path, result.query)
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else:
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url = result.path
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return (conn, url)
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def _rid(self):
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'''Return current request id.'''
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return self._request_id
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@property
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def request_error(self):
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'''Return any errors associated with this instance.'''
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return self._request_error
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def _request_str(self, conn, url):
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'''Return string representation of connection.'''
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return "%s %s/%s" % (self._method, _conn_str(conn), url)
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