placement/placement/lib.py

244 lines
11 KiB
Python

# 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.
"""Symbols intended to be imported by both placement code and placement API
consumers. When placement is separated out, this module should be part of a
common library that both placement and its consumers can require."""
import re
import webob
from placement.i18n import _
from placement import microversion
from placement import util
# Querystring-related constants
_QS_RESOURCES = 'resources'
_QS_REQUIRED = 'required'
_QS_MEMBER_OF = 'member_of'
_QS_KEY_PATTERN = re.compile(
r"^(%s)([1-9][0-9]*)?$" % '|'.join(
(_QS_RESOURCES, _QS_REQUIRED, _QS_MEMBER_OF)))
class RequestGroup(object):
def __init__(self, use_same_provider=True, resources=None,
required_traits=None, forbidden_traits=None, member_of=None):
"""Create a grouping of resource and trait requests.
:param use_same_provider:
If True, (the default) this RequestGroup represents requests for
resources and traits which must be satisfied by a single resource
provider. If False, represents a request for resources and traits
in any resource provider in the same tree, or a sharing provider.
:param resources: A dict of { resource_class: amount, ... }
:param required_traits: A set of { trait_name, ... }
:param forbidden_traits: A set of { trait_name, ... }
:param member_of: A list of [ [aggregate_UUID],
[aggregate_UUID, aggregate_UUID] ... ]
"""
self.use_same_provider = use_same_provider
self.resources = resources or {}
self.required_traits = required_traits or set()
self.forbidden_traits = forbidden_traits or set()
self.member_of = member_of or []
def __str__(self):
ret = 'RequestGroup(use_same_provider=%s' % str(self.use_same_provider)
ret += ', resources={%s}' % ', '.join(
'%s:%d' % (rc, amount)
for rc, amount in sorted(list(self.resources.items())))
ret += ', traits=[%s]' % ', '.join(
sorted(self.required_traits) +
['!%s' % ft for ft in self.forbidden_traits])
ret += ', aggregates=[%s]' % ', '.join(
sorted('[%s]' % ', '.join(agglist)
for agglist in sorted(self.member_of)))
ret += ')'
return ret
@staticmethod
def dict_from_request(req):
"""Parse numbered resources, traits, and member_of groupings out of a
querystring dict found in a webob Request.
The input req contains a query string of the form:
?resources=$RESOURCE_CLASS_NAME:$AMOUNT,$RESOURCE_CLASS_NAME:$AMOUNT
&required=$TRAIT_NAME,$TRAIT_NAME&member_of=in:$AGG1_UUID,$AGG2_UUID
&resources1=$RESOURCE_CLASS_NAME:$AMOUNT,RESOURCE_CLASS_NAME:$AMOUNT
&required1=$TRAIT_NAME,$TRAIT_NAME&member_of1=$AGG_UUID
&resources2=$RESOURCE_CLASS_NAME:$AMOUNT,RESOURCE_CLASS_NAME:$AMOUNT
&required2=$TRAIT_NAME,$TRAIT_NAME&member_of2=$AGG_UUID
These are parsed in groups according to the numeric suffix of the key.
For each group, a RequestGroup instance is created containing that
group's resources, required traits, and member_of. For the (single)
group with no suffix, the RequestGroup.use_same_provider attribute is
False; for the numbered groups it is True.
If a trait in the required parameter is prefixed with ``!`` this
indicates that that trait must not be present on the resource
providers in the group. That is, the trait is forbidden. Forbidden
traits are only processed if ``allow_forbidden`` is True. This allows
the caller to control processing based on microversion handling.
The return is a dict, keyed by the numeric suffix of these RequestGroup
instances (or the empty string for the unnumbered group).
As an example, if qsdict represents the query string:
?resources=VCPU:2,MEMORY_MB:1024,DISK_GB=50
&required=HW_CPU_X86_VMX,CUSTOM_STORAGE_RAID
&member_of=in:9323b2b1-82c9-4e91-bdff-e95e808ef954,8592a199-7d73-4465-8df6-ab00a6243c82 # noqa
&resources1=SRIOV_NET_VF:2
&required1=CUSTOM_PHYSNET_PUBLIC,CUSTOM_SWITCH_A
&resources2=SRIOV_NET_VF:1
&required2=!CUSTOM_PHYSNET_PUBLIC
...the return value will be:
{ '': RequestGroup(
use_same_provider=False,
resources={
"VCPU": 2,
"MEMORY_MB": 1024,
"DISK_GB" 50,
},
required_traits=[
"HW_CPU_X86_VMX",
"CUSTOM_STORAGE_RAID",
],
member_of=[
[9323b2b1-82c9-4e91-bdff-e95e808ef954],
[8592a199-7d73-4465-8df6-ab00a6243c82,
ddbd9226-d6a6-475e-a85f-0609914dd058],
],
),
'1': RequestGroup(
use_same_provider=True,
resources={
"SRIOV_NET_VF": 2,
},
required_traits=[
"CUSTOM_PHYSNET_PUBLIC",
"CUSTOM_SWITCH_A",
],
),
'2': RequestGroup(
use_same_provider=True,
resources={
"SRIOV_NET_VF": 1,
},
forbidden_traits=[
"CUSTOM_PHYSNET_PUBLIC",
],
),
}
:param req: webob.Request object
:return: A dict, keyed by suffix, of RequestGroup instances.
:raises `webob.exc.HTTPBadRequest` if any value is malformed, or if a
trait list is given without corresponding resources.
"""
want_version = req.environ[microversion.MICROVERSION_ENVIRON]
# Control whether we handle forbidden traits.
allow_forbidden = want_version.matches((1, 22))
# dict of the form: { suffix: RequestGroup } to be returned
by_suffix = {}
def get_request_group(suffix):
if suffix not in by_suffix:
rq_grp = RequestGroup(use_same_provider=bool(suffix))
by_suffix[suffix] = rq_grp
return by_suffix[suffix]
for key, val in req.GET.items():
match = _QS_KEY_PATTERN.match(key)
if not match:
continue
# `prefix` is 'resources', 'required', or 'member_of'
# `suffix` is an integer string, or None
prefix, suffix = match.groups()
suffix = suffix or ''
request_group = get_request_group(suffix)
if prefix == _QS_RESOURCES:
request_group.resources = util.normalize_resources_qs_param(
val)
elif prefix == _QS_REQUIRED:
request_group.required_traits = util.normalize_traits_qs_param(
val, allow_forbidden=allow_forbidden)
elif prefix == _QS_MEMBER_OF:
# special handling of member_of qparam since we allow multiple
# member_of params at microversion 1.24.
# NOTE(jaypipes): Yes, this is inefficient to do this when
# there are multiple member_of query parameters, but we do this
# so we can error out if someone passes an "orphaned" member_of
# request group.
# TODO(jaypipes): Do validation of query parameters using
# JSONSchema
request_group.member_of = util.normalize_member_of_qs_params(
req, suffix)
# Ensure any group with 'required' or 'member_of' also has 'resources'.
orphans = [('required%s' % suff) for suff, group in by_suffix.items()
if group.required_traits and not group.resources]
if orphans:
msg = _(
'All traits parameters must be associated with resources. '
'Found the following orphaned traits keys: %s')
raise webob.exc.HTTPBadRequest(msg % ', '.join(orphans))
orphans = [('member_of%s' % suff) for suff, group in by_suffix.items()
if group.member_of and not group.resources]
if orphans:
msg = _('All member_of parameters must be associated with '
'resources. Found the following orphaned member_of '
'keys: %s')
raise webob.exc.HTTPBadRequest(msg % ', '.join(orphans))
# All request groups must have resources (which is almost, but not
# quite, verified by the orphan checks above).
if not all(grp.resources for grp in by_suffix.values()):
msg = _("All request groups must specify resources.")
raise webob.exc.HTTPBadRequest(msg)
# The above would still pass if there were no request groups
if not by_suffix:
msg = _(
"At least one request group (`resources` or `resources{N}`) "
"is required.")
raise webob.exc.HTTPBadRequest(msg)
# Make adjustments for forbidden traits by stripping forbidden out
# of required.
if allow_forbidden:
conflicting_traits = []
for suff, group in by_suffix.items():
forbidden = [trait for trait in group.required_traits
if trait.startswith('!')]
group.required_traits = (
group.required_traits - set(forbidden))
group.forbidden_traits = set([trait.lstrip('!') for trait in
forbidden])
conflicts = group.forbidden_traits & group.required_traits
if conflicts:
conflicting_traits.append('required%s: (%s)'
% (suff, ', '.join(conflicts)))
if conflicting_traits:
msg = _(
'Conflicting required and forbidden traits found in the '
'following traits keys: %s')
raise webob.exc.HTTPBadRequest(
msg % ', '.join(conflicting_traits))
return by_suffix