# Copyright 2012 VMware, 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.
#
import abc
import copy
import socket
import time
import eventlet
from oslo_log import log as logging
from oslo_utils import excutils
import six
from six.moves import http_client as httplib
import six.moves.urllib.parse as urlparse
from vmware_nsx._i18n import _
from vmware_nsx import api_client
LOG = logging.getLogger(__name__)
DEFAULT_HTTP_TIMEOUT = 30
DEFAULT_RETRIES = 2
DEFAULT_REDIRECTS = 2
DEFAULT_API_REQUEST_POOL_SIZE = 1000
DEFAULT_MAXIMUM_REQUEST_ID = 4294967295
DOWNLOAD_TIMEOUT = 180
@six.add_metaclass(abc.ABCMeta)
class ApiRequest(object):
'''An abstract baseclass for all ApiRequest implementations.
This defines the interface and property structure for both eventlet and
gevent-based ApiRequest classes.
'''
# List of allowed status codes.
ALLOWED_STATUS_CODES = [
httplib.OK,
httplib.CREATED,
httplib.NO_CONTENT,
httplib.MOVED_PERMANENTLY,
httplib.TEMPORARY_REDIRECT,
httplib.BAD_REQUEST,
httplib.UNAUTHORIZED,
httplib.FORBIDDEN,
httplib.NOT_FOUND,
httplib.CONFLICT,
httplib.INTERNAL_SERVER_ERROR,
httplib.SERVICE_UNAVAILABLE
]
@abc.abstractmethod
def start(self):
pass
@abc.abstractmethod
def join(self):
pass
@abc.abstractmethod
def copy(self):
pass
def _issue_request(self):
'''Issue a request to a provider.'''
conn = (self._client_conn or
self._api_client.acquire_connection(True,
copy.copy(self._headers),
rid=self._rid()))
if conn is None:
error = Exception(_("No API connections available"))
self._request_error = error
return error
url = self._url
LOG.debug("[%(rid)d] Issuing - request url: %(conn)s "
"body: %(body)s",
{'rid': self._rid(), 'conn': self._request_str(conn, url),
'body': self._body})
issued_time = time.time()
is_conn_error = False
is_conn_service_unavail = False
response = None
try:
redirects = 0
while (redirects <= self._redirects):
# Update connection with user specified request timeout,
# the connect timeout is usually smaller so we only set
# the request timeout after a connection is established
if conn.sock is None:
conn.connect()
conn.sock.settimeout(self._http_timeout)
elif conn.sock.gettimeout() != self._http_timeout:
conn.sock.settimeout(self._http_timeout)
headers = copy.copy(self._headers)
cookie = self._api_client.auth_cookie(conn)
if cookie:
headers["Cookie"] = cookie
gen = self._api_client.config_gen
if gen:
headers["X-Nvp-Wait-For-Config-Generation"] = gen
LOG.debug("Setting X-Nvp-Wait-For-Config-Generation "
"request header: '%s'", gen)
try:
conn.request(self._method, url, self._body, headers)
except Exception as e:
with excutils.save_and_reraise_exception():
LOG.warning("[%(rid)d] Exception issuing request: "
"%(e)s",
{'rid': self._rid(), 'e': e})
response = conn.getresponse()
response.body = response.read()
response.headers = response.getheaders()
elapsed_time = time.time() - issued_time
LOG.debug("[%(rid)d] Completed request '%(conn)s': "
"%(status)s (%(elapsed)s seconds)",
{'rid': self._rid(),
'conn': self._request_str(conn, url),
'status': response.status,
'elapsed': elapsed_time})
new_gen = response.getheader('X-Nvp-Config-Generation', None)
if new_gen:
LOG.debug("Reading X-Nvp-config-Generation response "
"header: '%s'", new_gen)
if (self._api_client.config_gen is None or
self._api_client.config_gen < int(new_gen)):
self._api_client.config_gen = int(new_gen)
if response.status == httplib.UNAUTHORIZED:
# If request is unauthorized, clear the session cookie
# for the current provider so that subsequent requests
# to the same provider triggers re-authentication.
self._api_client.set_auth_cookie(conn, None)
elif response.status == httplib.SERVICE_UNAVAILABLE:
is_conn_service_unavail = True
if response.status not in [httplib.MOVED_PERMANENTLY,
httplib.TEMPORARY_REDIRECT]:
break
elif redirects >= self._redirects:
LOG.info("[%d] Maximum redirects exceeded, aborting "
"request", self._rid())
break
redirects += 1
conn, url = self._redirect_params(conn, response.headers,
self._client_conn is None)
if url is None:
response.status = httplib.INTERNAL_SERVER_ERROR
break
LOG.info("[%(rid)d] Redirecting request to: %(conn)s",
{'rid': self._rid(),
'conn': self._request_str(conn, url)})
# yield here, just in case we are not out of the loop yet
eventlet.greenthread.sleep(0)
# If we receive any of these responses, then
# our server did not process our request and may be in an
# errored state. Raise an exception, which will cause the
# conn to be released with is_conn_error == True
# which puts the conn on the back of the client's priority
# queue.
if (response.status == httplib.INTERNAL_SERVER_ERROR and
response.status > httplib.NOT_IMPLEMENTED):
LOG.warning("[%(rid)d] Request '%(method)s %(url)s' "
"received: %(status)s",
{'rid': self._rid(), 'method': self._method,
'url': self._url, 'status': response.status})
raise Exception(_('Server error return: %s'), response.status)
return response
except socket.error:
is_conn_service_unavail = True
except Exception as e:
if isinstance(e, httplib.BadStatusLine):
msg = (_("Invalid server response"))
else:
msg = str(e)
if response is None:
elapsed_time = time.time() - issued_time
LOG.warning("[%(rid)d] Failed request '%(conn)s': '%(msg)s' "
"(%(elapsed)s seconds)",
{'rid': self._rid(),
'conn': self._request_str(conn, url),
'msg': msg, 'elapsed': elapsed_time})
self._request_error = e
is_conn_error = True
return e
finally:
# Make sure we release the original connection provided by the
# acquire_connection() call above.
if self._client_conn is None:
self._api_client.release_connection(conn, is_conn_error,
is_conn_service_unavail,
rid=self._rid())
def _redirect_params(self, conn, headers, allow_release_conn=False):
"""Process redirect response, create new connection if necessary.
Args:
conn: connection that returned the redirect response
headers: response headers of the redirect response
allow_release_conn: if redirecting to a different server,
release existing connection back to connection pool.
Returns: Return tuple(conn, url) where conn is a connection object
to the redirect target and url is the path of the API request
"""
url = None
for name, value in headers:
if name.lower() == "location":
url = value
break
if not url:
LOG.warning("[%d] Received redirect status without location "
"header field", self._rid())
return (conn, None)
# Accept location with the following format:
# 1. /path, redirect to same node
# 2. scheme://hostname:[port]/path where scheme is https or http
# Reject others
# 3. e.g. relative paths, unsupported scheme, unspecified host
result = urlparse.urlparse(url)
if not result.scheme and not result.hostname and result.path:
if result.path[0] == "/":
if result.query:
url = "%s?%s" % (result.path, result.query)
else:
url = result.path
return (conn, url) # case 1
else:
LOG.warning("[%(rid)d] Received invalid redirect "
"location: '%(url)s'",
{'rid': self._rid(), 'url': url})
return (conn, None) # case 3
elif result.scheme not in ["http", "https"] or not result.hostname:
LOG.warning("[%(rid)d] Received malformed redirect "
"location: %(url)s",
{'rid': self._rid(), 'url': url})
return (conn, None) # case 3
# case 2, redirect location includes a scheme
# so setup a new connection and authenticate
if allow_release_conn:
self._api_client.release_connection(conn)
conn_params = (result.hostname, result.port, result.scheme == "https")
conn = self._api_client.acquire_redirect_connection(conn_params, True,
self._headers)
if result.query:
url = "%s?%s" % (result.path, result.query)
else:
url = result.path
return (conn, url)
def _rid(self):
'''Return current request id.'''
return self._request_id
@property
def request_error(self):
'''Return any errors associated with this instance.'''
return self._request_error
def _request_str(self, conn, url):
'''Return string representation of connection.'''
return "%s %s/%s" % (self._method, api_client.ctrl_conn_to_str(conn),
url)