Files
python-ganttclient/nova/scheduler/api.py
2011-05-23 16:19:12 -07:00

290 lines
9.9 KiB
Python

# Copyright (c) 2011 Openstack, LLC.
# 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.
"""
Handles all requests relating to schedulers.
"""
import novaclient
import traceback #nuke
from nova import db
from nova import exception
from nova import flags
from nova import log as logging
from nova import rpc
from eventlet import greenpool
FLAGS = flags.FLAGS
flags.DEFINE_bool('enable_zone_routing',
False,
'When True, routing to child zones will occur.')
LOG = logging.getLogger('nova.scheduler.api')
def _call_scheduler(method, context, params=None):
"""Generic handler for RPC calls to the scheduler.
:param params: Optional dictionary of arguments to be passed to the
scheduler worker
:retval: Result returned by scheduler worker
"""
if not params:
params = {}
queue = FLAGS.scheduler_topic
kwargs = {'method': method, 'args': params}
return rpc.call(context, queue, kwargs)
def get_zone_list(context):
"""Return a list of zones assoicated with this zone."""
items = _call_scheduler('get_zone_list', context)
for item in items:
item['api_url'] = item['api_url'].replace('\\/', '/')
if not items:
items = db.zone_get_all(context)
return items
def zone_get(context, zone_id):
return db.zone_get(context, zone_id)
def zone_delete(context, zone_id):
return db.zone_delete(context, zone_id)
def zone_create(context, data):
return db.zone_create(context, data)
def zone_update(context, zone_id, data):
return db.zone_update(context, zone_id, data)
def get_zone_capabilities(context):
"""Returns a dict of key, value capabilities for this zone."""
return _call_scheduler('get_zone_capabilities', context=context)
def select(context, specs=None):
"""Returns a list of hosts."""
return _call_scheduler('select', context=context,
params={"specs": specs})
def update_service_capabilities(context, service_name, host, capabilities):
"""Send an update to all the scheduler services informing them
of the capabilities of this service."""
kwargs = dict(method='update_service_capabilities',
args=dict(service_name=service_name, host=host,
capabilities=capabilities))
return rpc.fanout_cast(context, 'scheduler', kwargs)
def _wrap_method(function, self):
"""Wrap method to supply self."""
def _wrap(*args, **kwargs):
return function(self, *args, **kwargs)
return _wrap
def _process(func, zone):
"""Worker stub for green thread pool. Give the worker
an authenticated nova client and zone info."""
nova = novaclient.OpenStack(zone.username, zone.password, zone.api_url)
nova.authenticate()
return func(nova, zone)
def call_zone_method(context, method, errors_to_ignore=None, *args, **kwargs):
"""Returns a list of (zone, call_result) objects."""
if not isinstance(errors_to_ignore, (list, tuple)):
# This will also handle the default None
errors_to_ignore = [errors_to_ignore]
pool = greenpool.GreenPool()
results = []
for zone in db.zone_get_all(context):
try:
nova = novaclient.OpenStack(zone.username, zone.password,
zone.api_url)
nova.authenticate()
LOG.warn(_("*** AUTHENTICATED") % locals())#asdads
except novaclient.exceptions.BadRequest, e:
url = zone.api_url
LOG.warn(_("Failed request to zone; URL=%(url)s: %(e)s")
% locals())
#TODO (dabo) - add logic for failure counts per zone,
# with escalation after a given number of failures.
continue
zone_method = getattr(nova.zones, method)
def _error_trap(*args, **kwargs):
try:
LOG.warn(_("*** CALLING ZONE") % locals())#asdads
return zone_method(*args, **kwargs)
except Exception as e:
if type(e) in errors_to_ignore:
return None
ex = traceback.format_exc(e)
LOG.warn(_("*** CAUGHT EXCEPTION %(ex)s") % locals())#asdads
# TODO (dabo) - want to be able to re-raise here.
# Returning a string now; raising was causing issues.
# raise e
return "ERROR", "%s" % e
res = pool.spawn(_error_trap, *args, **kwargs)
results.append((zone, res))
pool.waitall()
return [(zone.id, res.wait()) for zone, res in results]
def child_zone_helper(zone_list, func):
"""Fire off a command to each zone in the list.
The return is [novaclient return objects] from each child zone.
For example, if you are calling server.pause(), the list will
be whatever the response from server.pause() is. One entry
per child zone called."""
green_pool = greenpool.GreenPool()
return [result for result in green_pool.imap(
_wrap_method(_process, func), zone_list)]
def _issue_novaclient_command(nova, zone, collection, method_name, item_id):
"""Use novaclient to issue command to a single child zone.
One of these will be run in parallel for each child zone."""
manager = getattr(nova, collection)
result = None
try:
try:
result = manager.get(int(item_id))
except ValueError, e:
result = manager.find(name=item_id)
except novaclient.NotFound:
url = zone.api_url
LOG.debug(_("%(collection)s '%(item_id)s' not found on '%(url)s'" %
locals()))
return None
if method_name.lower() not in ['get', 'find']:
result = getattr(result, method_name)()
return result
def wrap_novaclient_function(f, collection, method_name, item_id):
"""Appends collection, method_name and item_id to the incoming
(nova, zone) call from child_zone_helper."""
def inner(nova, zone):
return f(nova, zone, collection, method_name, item_id)
return inner
class RedirectResult(exception.Error):
"""Used to the HTTP API know that these results are pre-cooked
and they can be returned to the caller directly."""
def __init__(self, results):
self.results = results
super(RedirectResult, self).__init__(
message=_("Uncaught Zone redirection exception"))
class reroute_compute(object):
"""Decorator used to indicate that the method should
delegate the call the child zones if the db query
can't find anything."""
def __init__(self, method_name):
self.method_name = method_name
def __call__(self, f):
def wrapped_f(*args, **kwargs):
collection, context, item_id = \
self.get_collection_context_and_id(args, kwargs)
try:
# Call the original function ...
return f(*args, **kwargs)
except exception.InstanceNotFound, e:
LOG.debug(_("Instance %(item_id)s not found "
"locally: '%(e)s'" % locals()))
if not FLAGS.enable_zone_routing:
raise
zones = db.zone_get_all(context)
if not zones:
raise
# Ask the children to provide an answer ...
LOG.debug(_("Asking child zones ..."))
result = self._call_child_zones(zones,
wrap_novaclient_function(_issue_novaclient_command,
collection, self.method_name, item_id))
# Scrub the results and raise another exception
# so the API layers can bail out gracefully ...
raise RedirectResult(self.unmarshall_result(result))
return wrapped_f
def _call_child_zones(self, zones, function):
"""Ask the child zones to perform this operation.
Broken out for testing."""
return child_zone_helper(zones, function)
def get_collection_context_and_id(self, args, kwargs):
"""Returns a tuple of (novaclient collection name, security
context and resource id. Derived class should override this."""
context = kwargs.get('context', None)
instance_id = kwargs.get('instance_id', None)
if len(args) > 0 and not context:
context = args[1]
if len(args) > 1 and not instance_id:
instance_id = args[2]
return ("servers", context, instance_id)
def unmarshall_result(self, zone_responses):
"""Result is a list of responses from each child zone.
Each decorator derivation is responsible to turning this
into a format expected by the calling method. For
example, this one is expected to return a single Server
dict {'server':{k:v}}. Others may return a list of them, like
{'servers':[{k,v}]}"""
reduced_response = []
for zone_response in zone_responses:
if not zone_response:
continue
server = zone_response.__dict__
for k in server.keys():
if k[0] == '_' or k == 'manager':
del server[k]
reduced_response.append(dict(server=server))
if reduced_response:
return reduced_response[0] # first for now.
return {}
def redirect_handler(f):
def new_f(*args, **kwargs):
try:
return f(*args, **kwargs)
except RedirectResult, e:
return e.results
return new_f