cinder/cinder/volume/drivers/vmware/api.py

309 lines
13 KiB
Python

# vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (c) 2013 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.
"""
Session and API call management for VMware ESX/VC server.
Provides abstraction over cinder.volume.drivers.vmware.vim.Vim SOAP calls.
"""
from eventlet import event
from cinder.openstack.common import log as logging
from cinder.openstack.common import loopingcall
from cinder.volume.drivers.vmware import error_util
from cinder.volume.drivers.vmware import vim
from cinder.volume.drivers.vmware import vim_util
LOG = logging.getLogger(__name__)
class Retry(object):
"""Decorator for retrying a function upon suggested exceptions.
The method retries for given number of times and the sleep
time increments till the max sleep time is reached.
If max retries is set to -1, then the decorated function is
invoked indefinitely till no exception is thrown or if
the caught exception is not in the list of suggested exceptions.
"""
def __init__(self, max_retry_count=-1, inc_sleep_time=10,
max_sleep_time=60, exceptions=()):
"""Initialize retry object based on input params.
:param max_retry_count: Max number of times, a function must be
retried when one of input 'exceptions'
is caught. The default -1 will always
retry the function till a non-exception
case, or an un-wanted error case arises.
:param inc_sleep_time: Incremental time in seconds for sleep time
between retrial
:param max_sleep_time: Max sleep time beyond which the sleep time will
not be incremented using param inc_sleep_time
and max_sleep_time will be used as sleep time
:param exceptions: Suggested exceptions for which the function must be
retried
"""
self._max_retry_count = max_retry_count
self._inc_sleep_time = inc_sleep_time
self._max_sleep_time = max_sleep_time
self._exceptions = exceptions
self._retry_count = 0
self._sleep_time = 0
def __call__(self, f):
def _func(done, *args, **kwargs):
try:
result = f(*args, **kwargs)
done.send(result)
except self._exceptions as excep:
LOG.exception(_("Failure while invoking function: "
"%(func)s. Error: %(excep)s.") %
{'func': f.__name__, 'excep': excep})
if (self._max_retry_count != -1 and
self._retry_count >= self._max_retry_count):
done.send_exception(excep)
else:
self._retry_count += 1
self._sleep_time += self._inc_sleep_time
return self._sleep_time
except Exception as excep:
done.send_exception(excep)
return 0
def func(*args, **kwargs):
done = event.Event()
loop = loopingcall.DynamicLoopingCall(_func, done, *args, **kwargs)
loop.start(periodic_interval_max=self._max_sleep_time)
result = done.wait()
loop.stop()
return result
return func
class VMwareAPISession(object):
"""Sets up a session with the server and handles all calls made to it."""
@Retry(exceptions=(Exception))
def __init__(self, server_ip, server_username, server_password,
api_retry_count, task_poll_interval, scheme='https',
create_session=True, wsdl_loc=None):
"""Constructs session object.
:param server_ip: IP address of ESX/VC server
:param server_username: Username of ESX/VC server admin user
:param server_password: Password for param server_username
:param api_retry_count: Number of times an API must be retried upon
session/connection related errors
:param task_poll_interval: Sleep time in seconds for polling an
on-going async task as part of the API call
:param scheme: http or https protocol
:param create_session: Boolean whether to set up connection at the
time of instance creation
:param wsdl_loc: WSDL file location for invoking SOAP calls on server
using suds
"""
self._server_ip = server_ip
self._server_username = server_username
self._server_password = server_password
self._wsdl_loc = wsdl_loc
self._api_retry_count = api_retry_count
self._task_poll_interval = task_poll_interval
self._scheme = scheme
self._session_id = None
self._vim = None
if create_session:
self.create_session()
@property
def vim(self):
if not self._vim:
self._vim = vim.Vim(protocol=self._scheme, host=self._server_ip,
wsdl_loc=self._wsdl_loc)
return self._vim
def create_session(self):
"""Establish session with the server."""
# Login and setup the session with the server for making
# API calls
session_manager = self.vim.service_content.sessionManager
session = self.vim.Login(session_manager,
userName=self._server_username,
password=self._server_password)
# Terminate the earlier session, if possible (For the sake of
# preserving sessions as there is a limit to the number of
# sessions we can have)
if self._session_id:
try:
self.vim.TerminateSession(session_manager,
sessionId=[self._session_id])
except Exception as excep:
# This exception is something we can live with. It is
# just an extra caution on our side. The session may
# have been cleared. We could have made a call to
# SessionIsActive, but that is an overhead because we
# anyway would have to call TerminateSession.
LOG.exception(_("Error while terminating session: %s.") %
excep)
self._session_id = session.key
LOG.info(_("Successfully established connection to the server."))
def __del__(self):
"""Logs-out the session."""
try:
self.vim.Logout(self.vim.service_content.sessionManager)
except Exception as excep:
LOG.exception(_("Error while logging out the user: %s.") %
excep)
def invoke_api(self, module, method, *args, **kwargs):
"""Wrapper method for invoking APIs.
Here we retry the API calls for exceptions which may come because
of session overload.
Make sure if a Vim instance is being passed here, this session's
Vim (self.vim) instance is used, as we retry establishing session
in case of session timedout.
:param module: Module invoking the VI SDK calls
:param method: Method in the module that invokes the VI SDK call
:param args: Arguments to the method
:param kwargs: Keyword arguments to the method
:return: Response of the API call
"""
@Retry(max_retry_count=self._api_retry_count,
exceptions=(error_util.VimException))
def _invoke_api(module, method, *args, **kwargs):
last_fault_list = []
while True:
try:
api_method = getattr(module, method)
return api_method(*args, **kwargs)
except error_util.VimFaultException as excep:
if error_util.NOT_AUTHENTICATED not in excep.fault_list:
raise excep
# If it is a not-authenticated fault, we re-authenticate
# the user and retry the API invocation.
# Because of the idle session returning an empty
# RetrieveProperties response and also the same is
# returned when there is an empty answer to a query
# (e.g. no VMs on the host), we have no way to
# differentiate.
# So if the previous response was also an empty
# response and after creating a new session, we get
# the same empty response, then we are sure of the
# response being an empty response.
if error_util.NOT_AUTHENTICATED in last_fault_list:
return []
last_fault_list = excep.fault_list
LOG.exception(_("Not authenticated error occurred. "
"Will create session and try "
"API call again: %s.") % excep)
self.create_session()
return _invoke_api(module, method, *args, **kwargs)
def wait_for_task(self, task):
"""Return a deferred that will give the result of the given task.
The task is polled until it completes. The method returns the task
information upon successful completion.
:param task: Managed object reference of the task
:return: Task info upon successful completion of the task
"""
done = event.Event()
loop = loopingcall.FixedIntervalLoopingCall(self._poll_task,
task, done)
loop.start(self._task_poll_interval)
task_info = done.wait()
loop.stop()
return task_info
def _poll_task(self, task, done):
"""Poll the given task.
If the task completes successfully then returns task info.
In case of error sends back appropriate error.
:param task: Managed object reference of the task
:param event: Event that captures task status
"""
try:
task_info = self.invoke_api(vim_util, 'get_object_property',
self.vim, task, 'info')
if task_info.state in ['queued', 'running']:
# If task already completed on server, it will not return
# the progress.
if hasattr(task_info, 'progress'):
LOG.debug(_("Task: %(task)s progress: %(prog)s.") %
{'task': task, 'prog': task_info.progress})
return
elif task_info.state == 'success':
LOG.debug(_("Task %s status: success.") % task)
done.send(task_info)
else:
error_msg = str(task_info.error.localizedMessage)
LOG.exception(_("Task: %(task)s failed with error: %(err)s.") %
{'task': task, 'err': error_msg})
done.send_exception(error_util.VimFaultException([],
error_msg))
except Exception as excep:
LOG.exception(_("Task: %(task)s failed with error: %(err)s.") %
{'task': task, 'err': excep})
done.send_exception(excep)
def wait_for_lease_ready(self, lease):
done = event.Event()
loop = loopingcall.FixedIntervalLoopingCall(self._poll_lease,
lease,
done)
loop.start(self._task_poll_interval)
done.wait()
loop.stop()
def _poll_lease(self, lease, done):
try:
state = self.invoke_api(vim_util, 'get_object_property',
self.vim, lease, 'state')
if state == 'ready':
# done
LOG.debug(_("Lease is ready."))
done.send()
return
elif state == 'initializing':
LOG.debug(_("Lease initializing..."))
return
elif state == 'error':
error_msg = self.invoke_api(vim_util, 'get_object_property',
self.vim, lease, 'error')
LOG.exception(error_msg)
excep = error_util.VimFaultException([], error_msg)
done.send_exception(excep)
else:
# unknown state - complain
error_msg = _("Error: unknown lease state %s.") % state
raise error_util.VimFaultException([], error_msg)
except Exception as excep:
LOG.exception(excep)
done.send_exception(excep)