# 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 eventlet
from oslo_log import log as logging
from oslo_serialization import jsonutils
from six.moves import http_client as httplib
from six.moves.urllib import parse
from vmware_nsx._i18n import _
from vmware_nsx.api_client import request
LOG = logging.getLogger(__name__)
USER_AGENT = "Neutron eventlet client/2.0"
class EventletApiRequest(request.ApiRequest):
'''Eventlet-based ApiRequest class.
This class will form the basis for eventlet-based ApiRequest classes
'''
# Maximum number of green threads present in the system at one time.
API_REQUEST_POOL_SIZE = request.DEFAULT_API_REQUEST_POOL_SIZE
# Pool of green threads. One green thread is allocated per incoming
# request. Incoming requests will block when the pool is empty.
API_REQUEST_POOL = eventlet.GreenPool(API_REQUEST_POOL_SIZE)
# A unique id is assigned to each incoming request. When the current
# request id reaches MAXIMUM_REQUEST_ID it wraps around back to 0.
MAXIMUM_REQUEST_ID = request.DEFAULT_MAXIMUM_REQUEST_ID
# The request id for the next incoming request.
CURRENT_REQUEST_ID = 0
def __init__(self, client_obj, url, method="GET", body=None,
headers=None,
retries=request.DEFAULT_RETRIES,
auto_login=True,
redirects=request.DEFAULT_REDIRECTS,
http_timeout=request.DEFAULT_HTTP_TIMEOUT, client_conn=None):
'''Constructor.'''
self._api_client = client_obj
self._url = url
self._method = method
self._body = body
self._headers = headers or {}
self._request_timeout = http_timeout * retries
self._retries = retries
self._auto_login = auto_login
self._redirects = redirects
self._http_timeout = http_timeout
self._client_conn = client_conn
self._request_error = None
if "User-Agent" not in self._headers:
self._headers["User-Agent"] = USER_AGENT
self._green_thread = None
# Retrieve and store this instance's unique request id.
self._request_id = EventletApiRequest.CURRENT_REQUEST_ID
# Update the class variable that tracks request id.
# Request IDs wrap around at MAXIMUM_REQUEST_ID
next_request_id = self._request_id + 1
next_request_id %= self.MAXIMUM_REQUEST_ID
EventletApiRequest.CURRENT_REQUEST_ID = next_request_id
@classmethod
def _spawn(cls, func, *args, **kwargs):
'''Allocate a green thread from the class pool.'''
return cls.API_REQUEST_POOL.spawn(func, *args, **kwargs)
def spawn(self, func, *args, **kwargs):
'''Spawn a new green thread with the supplied function and args.'''
return self.__class__._spawn(func, *args, **kwargs)
@classmethod
def joinall(cls):
'''Wait for all outstanding requests to complete.'''
return cls.API_REQUEST_POOL.waitall()
def join(self):
'''Wait for instance green thread to complete.'''
if self._green_thread is not None:
return self._green_thread.wait()
return Exception(_('Joining an invalid green thread'))
def start(self):
'''Start request processing.'''
self._green_thread = self.spawn(self._run)
def copy(self):
'''Return a copy of this request instance.'''
return EventletApiRequest(
self._api_client, self._url, self._method, self._body,
self._headers, self._retries,
self._auto_login, self._redirects, self._http_timeout)
def _run(self):
'''Method executed within green thread.'''
if self._request_timeout:
# No timeout exception escapes the with block.
with eventlet.timeout.Timeout(self._request_timeout, False):
return self._handle_request()
LOG.info('[%d] Request timeout.', self._rid())
self._request_error = Exception(_('Request timeout'))
return None
else:
return self._handle_request()
def _handle_request(self):
'''First level request handling.'''
attempt = 0
timeout = 0
response = None
while response is None and attempt <= self._retries:
eventlet.greenthread.sleep(timeout)
attempt += 1
req = self._issue_request()
# automatically raises any exceptions returned.
if isinstance(req, httplib.HTTPResponse):
timeout = 0
if attempt <= self._retries:
if req.status in (httplib.UNAUTHORIZED, httplib.FORBIDDEN):
continue
elif req.status == httplib.SERVICE_UNAVAILABLE:
timeout = 0.5
continue
# else fall through to return the error code
LOG.debug("[%(rid)d] Completed request '%(method)s %(url)s'"
": %(status)s",
{'rid': self._rid(), 'method': self._method,
'url': self._url, 'status': req.status})
self._request_error = None
response = req
else:
LOG.info('[%(rid)d] Error while handling request: '
'%(req)s',
{'rid': self._rid(), 'req': req})
self._request_error = req
response = None
return response
class LoginRequestEventlet(EventletApiRequest):
'''Process a login request.'''
def __init__(self, client_obj, user, password, client_conn=None,
headers=None):
if headers is None:
headers = {}
headers.update({"Content-Type": "application/x-www-form-urlencoded"})
body = parse.urlencode({"username": user, "password": password})
super(LoginRequestEventlet, self).__init__(
client_obj, "/ws.v1/login", "POST", body, headers,
auto_login=False, client_conn=client_conn)
def session_cookie(self):
if self.successful():
return self.value.getheader("Set-Cookie")
return None
class GetApiProvidersRequestEventlet(EventletApiRequest):
'''Get a list of API providers.'''
def __init__(self, client_obj):
url = "/ws.v1/control-cluster/node?fields=roles"
super(GetApiProvidersRequestEventlet, self).__init__(
client_obj, url, "GET", auto_login=True)
def api_providers(self):
"""Parse api_providers from response.
Returns: api_providers in [(host, port, is_ssl), ...] format
"""
def _provider_from_listen_addr(addr):
# (pssl|ptcp):<ip>:<port> => (host, port, is_ssl)
parts = addr.split(':')
return (parts[1], int(parts[2]), parts[0] == 'pssl')
try:
if self.successful():
ret = []
body = jsonutils.loads(self.value.body)
for node in body.get('results', []):
for role in node.get('roles', []):
if role.get('role') == 'api_provider':
addr = role.get('listen_addr')
if addr:
ret.append(_provider_from_listen_addr(addr))
return ret
except Exception as e:
LOG.warning("[%(rid)d] Failed to parse API provider: %(e)s",
{'rid': self._rid(), 'e': e})
# intentionally fall through
return None
class GenericRequestEventlet(EventletApiRequest):
'''Handle a generic request.'''
def __init__(self, client_obj, method, url, body, content_type,
auto_login=False,
http_timeout=request.DEFAULT_HTTP_TIMEOUT,
retries=request.DEFAULT_RETRIES,
redirects=request.DEFAULT_REDIRECTS):
headers = {"Content-Type": content_type}
super(GenericRequestEventlet, self).__init__(
client_obj, url, method, body, headers,
retries=retries,
auto_login=auto_login, redirects=redirects,
http_timeout=http_timeout)
def session_cookie(self):
if self.successful():
return self.value.getheader("Set-Cookie")
return None
request.ApiRequest.register(EventletApiRequest)