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Merge "docs: Add documentation for flavor extra specs"

tags/21.0.0.0rc1
Zuul 3 months ago
committed by Gerrit Code Review
parent
commit
c9421a3248
5 changed files with 471 additions and 10 deletions
  1. +231
    -0
      doc/ext/extra_specs.py
  2. +2
    -0
      doc/source/conf.py
  3. +212
    -0
      doc/source/configuration/extra-specs.rst
  4. +16
    -0
      doc/source/configuration/index.rst
  5. +10
    -10
      nova/api/validation/extra_specs/capabilities.py

+ 231
- 0
doc/ext/extra_specs.py View File

@@ -0,0 +1,231 @@
# Copyright 2020, Red Hat, 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.

"""Display extra specs in documentation.

Provides a single directive that can be used to list all extra specs validators
and, thus, document all extra specs that nova recognizes and supports.
"""

import typing as ty

from docutils import nodes
from docutils.parsers import rst
from docutils.parsers.rst import directives
from docutils import statemachine
from sphinx import addnodes
from sphinx import directives as sphinx_directives
from sphinx import domains
from sphinx import roles
from sphinx.util import logging
from sphinx.util import nodes as sphinx_nodes

from nova.api.validation.extra_specs import base
from nova.api.validation.extra_specs import validators

LOG = logging.getLogger(__name__)


class ExtraSpecXRefRole(roles.XRefRole):
"""Cross reference a extra spec.

Example::

:nova:extra-spec:`hw:cpu_policy`
"""

def __init__(self):
super(ExtraSpecXRefRole, self).__init__(
warn_dangling=True,
)

def process_link(self, env, refnode, has_explicit_title, title, target):
# The anchor for the extra spec link is the extra spec name
return target, target


class ExtraSpecDirective(sphinx_directives.ObjectDescription):
"""Document an individual extra spec.

Accepts one required argument - the extra spec name, including the group.

Example::

.. extra-spec:: hw:cpu_policy
"""

def handle_signature(self, sig, signode):
"""Transform an option description into RST nodes."""
# Insert a node into the output showing the extra spec name
signode += addnodes.desc_name(sig, sig)
signode['allnames'] = [sig]
return sig

def add_target_and_index(self, firstname, sig, signode):
cached_options = self.env.domaindata['nova']['extra_specs']
signode['ids'].append(sig)
self.state.document.note_explicit_target(signode)
# Store the location of the option definition for later use in
# resolving cross-references
cached_options[sig] = self.env.docname


def _indent(text):
if not text:
return text

padding = ' ' * 4
return padding + text


def _format_validator_group_help(
validators: ty.Dict[str, base.ExtraSpecValidator],
summary: bool,
):
"""Generate reStructuredText snippets for a group of validators."""
for validator in validators.values():
for line in _format_validator_help(validator, summary):
yield line


def _format_validator_help(
validator: base.ExtraSpecValidator,
summary: bool,
):
"""Generate reStucturedText snippets for the provided validator.

:param validator: A validator to document.
:type validator: nova.api.validation.extra_specs.base.ExtraSpecValidator
"""
yield f'.. nova:extra-spec:: {validator.name}'
yield ''

# NOTE(stephenfin): We don't print the pattern, if present, since it's too
# internal. Instead, the description should provide this information in a
# human-readable format
yield _indent(f':Type: {validator.value["type"].__name__}')

if validator.value.get('min') is not None:
yield _indent(f':Min: {validator.value["min"]}')

if validator.value.get('max') is not None:
yield _indent(f':Max: {validator.value["max"]}')

yield ''

if not summary:
for line in validator.description.splitlines():
yield _indent(line)

yield ''

if validator.deprecated:
yield _indent('.. warning::')
yield _indent(
'This extra spec has been deprecated and should not be used.'
)

yield ''


class ExtraSpecGroupDirective(rst.Directive):
"""Document extra specs belonging to the specified group.

Accepts one optional argument - the extra spec group - and one option -
whether to show a summary view only (omit descriptions). Example::

.. extra-specs:: hw_rng
:summary:
"""

required_arguments = 0
optional_arguments = 1
option_spec = {
'summary': directives.flag,
}
has_content = False

def run(self):
result = statemachine.ViewList()
source_name = self.state.document.current_source

group = self.arguments[0] if self.arguments else None
summary = self.options.get('summary', False)

if group:
group_validators = {
n.split(':', 1)[1]: v for n, v in validators.VALIDATORS.items()
if ':' in n and n.split(':', 1)[0].split('{')[0] == group
}
else:
group_validators = {
n: v for n, v in validators.VALIDATORS.items()
if ':' not in n
}

if not group_validators:
LOG.warning("No validators found for group '%s'", group or '')

for count, line in enumerate(
_format_validator_group_help(group_validators, summary)
):
result.append(line, source_name, count)
LOG.debug('%5d%s%s', count, ' ' if line else '', line)

node = nodes.section()
node.document = self.state.document

sphinx_nodes.nested_parse_with_titles(self.state, result, node)

return node.children


class NovaDomain(domains.Domain):
"""nova domain."""
name = 'nova'
label = 'nova'
object_types = {
'configoption': domains.ObjType(
'extra spec', 'spec',
),
}
directives = {
'extra-spec': ExtraSpecDirective,
}
roles = {
'extra-spec': ExtraSpecXRefRole(),
}
initial_data = {
'extra_specs': {},
}

def resolve_xref(
self, env, fromdocname, builder, typ, target, node, contnode,
):
"""Resolve cross-references"""
if typ == 'option':
return sphinx_nodes.make_refnode(
builder,
fromdocname,
env.domaindata['nova']['extra_specs'][target],
target,
contnode,
target,
)
return None


def setup(app):
app.add_domain(NovaDomain)
app.add_directive('extra-specs', ExtraSpecGroupDirective)

+ 2
- 0
doc/source/conf.py View File

@@ -41,6 +41,7 @@ extensions = [
'oslo_policy.sphinxext',
'ext.versioned_notifications',
'ext.feature_matrix',
'ext.extra_specs',
'sphinxcontrib.actdiag',
'sphinxcontrib.seqdiag',
'sphinxcontrib.rsvgconverter',
@@ -148,6 +149,7 @@ latex_use_xindy = False
openstack_projects = [
'ceilometer',
'cinder',
'cyborg',
'glance',
'horizon',
'ironic',


+ 212
- 0
doc/source/configuration/extra-specs.rst View File

@@ -0,0 +1,212 @@
===========
Extra Specs
===========

The following is an overview of all extra specs recognized by nova in its
default configuration.

.. note::

Other services and virt drivers may provide additional extra specs not
listed here. In addition, it is possible to register your own extra specs.
For more information on the latter, refer to :doc:`/user/filter-scheduler`.

Placement
---------

The following extra specs are used during scheduling to modify the request sent
to placement.

``resources``
~~~~~~~~~~~~~

The following extra specs are used to request an amount of the specified
resource from placement when scheduling. All extra specs expect an integer
value.

.. note::

Not all of the resource types listed below are supported by all virt
drivers.

.. extra-specs:: resources
:summary:

``trait``
~~~~~~~~~

The following extra specs are used to request a specified trait from placement
when scheduling. All extra specs expect one of the following values:

- ``required``
- ``forbidden``

.. note::

Not all of the traits listed below are supported by all virt drivers.

.. extra-specs:: trait
:summary:

Scheduler Filters
-----------------

The following extra specs are specific to various in-tree scheduler filters.

``aggregate_instance_extra_specs``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The following extra specs are used to specify metadata that must be present on
the aggregate of a host. If this metadata is not present or does not match the
expected value, the aggregate and all hosts within in will be rejected.

Requires the ``AggregateInstanceExtraSpecsFilter`` scheduler filter.

.. extra-specs:: aggregate_instance_extra_specs

``capabilities``
~~~~~~~~~~~~~~~~

The following extra specs are used to specify a host capability that must be
provided by the host compute service. If this capability is not present or does
not match the expected value, the host will be rejected.

Requires the ``ComputeCapabilitiesFilter`` scheduler filter.

All extra specs expect similar types of values:

* ``=`` (equal to or greater than as a number; same as vcpus case)
* ``==`` (equal to as a number)
* ``!=`` (not equal to as a number)
* ``>=`` (greater than or equal to as a number)
* ``<=`` (less than or equal to as a number)
* ``s==`` (equal to as a string)
* ``s!=`` (not equal to as a string)
* ``s>=`` (greater than or equal to as a string)
* ``s>`` (greater than as a string)
* ``s<=`` (less than or equal to as a string)
* ``s<`` (less than as a string)
* ``<in>`` (substring)
* ``<all-in>`` (all elements contained in collection)
* ``<or>`` (find one of these)
* A specific value, e.g. ``true``, ``123``, ``testing``

Examples are: ``>= 5``, ``s== 2.1.0``, ``<in> gcc``, ``<all-in> aes mmx``, and
``<or> fpu <or> gpu``

.. note::

Not all operators will apply to all types of values. For example, the ``==``
operator should not be used for a string value - use ``s==`` instead.

.. extra-specs:: capabilities
:summary:

Virt driver
-----------

The following extra specs are used as hints to configure internals of a
instance, from the bus used for paravirtualized devices to the amount of a
physical device to passthrough to the instance. Most of these are virt
driver-specific.

``quota``
~~~~~~~~~

The following extra specs are used to configure quotas for various
paravirtualized devices.

They are only supported by the libvirt virt driver.

.. extra-specs:: quota

``accel``
~~~~~~~~~

The following extra specs are used to configure attachment of various
accelerators to an instance. For more information, refer to :cyborg-doc:`the
Cyborg documentation <>`.

They are only supported by the libvirt virt driver.

.. extra-specs:: accel

``pci_passthrough``
~~~~~~~~~~~~~~~~~~~

The following extra specs are used to configure passthrough of a host PCI
device to an instance. This requires prior host configuration. For more
information, refer to :doc:`/admin/pci-passthrough`.

They are only supported by the libvirt virt driver.

.. extra-specs:: pci_passthrough

``hw``
~~~~~~

The following extra specs are used to configure various attributes of
instances. Some of the extra specs act as feature flags, while others tweak for
example the guest-visible CPU topology of the instance.

Except where otherwise stated, they are only supported by the libvirt virt
driver.

.. extra-specs:: hw

``hw_rng``
~~~~~~~~~~

The following extra specs are used to configure a random number generator for
an instance.

They are only supported by the libvirt virt driver.

.. extra-specs:: hw_rng

``hw_video``
~~~~~~~~~~~~

The following extra specs are used to configure attributes of the default guest
video device.

They are only supported by the libvirt virt driver.

.. extra-specs:: hw_video

``os``
~~~~~~

The following extra specs are used to configure various attributes of
instances when using the HyperV virt driver.

They are only supported by the HyperV virt driver.

.. extra-specs:: os

``powervm``
~~~~~~~~~~~

The following extra specs are used to configure various attributes of
instances when using the PowerVM virt driver.

They are only supported by the PowerVM virt driver.

.. extra-specs:: powervm

``vmware``
~~~~~~~~~~

The following extra specs are used to configure various attributes of
instances when using the VMWare virt driver.

They are only supported by the VMWare virt driver.

.. extra-specs:: vmware

Others (uncategorized)
----------------------

The following extra specs are not part of a group.

.. extra-specs::

+ 16
- 0
doc/source/configuration/index.rst View File

@@ -75,3 +75,19 @@ permissions on REST API actions.
:hidden:

sample-policy

Extra Specs
-----------

Nova uses *flavor extra specs* as a way to provide additional information to
instances beyond basic information like amount of RAM or disk. This information
can range from hints for the scheduler to hypervisor-specific configuration
instructions for the instance.

* :doc:`Extra Spec Reference <extra-specs>`: A complete reference for all extra
specs currently recognized and supported by nova.

.. toctree::
:hidden:

extra-specs

+ 10
- 10
nova/api/validation/extra_specs/capabilities.py View File

@@ -18,17 +18,8 @@ These are used by the ``ComputeCapabilitiesFilter`` scheduler filter. Note that
we explicitly do not allow the unnamespaced variant of extra specs since this
has been deprecated since Grizzly (commit 8ce8e4b6c0d). Users that insist on
using these can disable extra spec validation.
"""

from nova.api.validation.extra_specs import base


DESCRIPTION = """\
Specify that the '{capability}' capability provided by the host compute service
satisfy the provided filter value. Requires the ``ComputeCapabilitiesFilter``
scheduler filter.

The value can be one of the following:
For all extra specs, the value can be one of the following:

* ``=`` (equal to or greater than as a number; same as vcpus case)
* ``==`` (equal to as a number)
@@ -50,6 +41,15 @@ Examples are: ``>= 5``, ``s== 2.1.0``, ``<in> gcc``, ``<all-in> aes mmx``, and
``<or> fpu <or> gpu``
"""

from nova.api.validation.extra_specs import base


DESCRIPTION = """\
Specify that the '{capability}' capability provided by the host compute service
satisfy the provided filter value. Requires the ``ComputeCapabilitiesFilter``
scheduler filter.
"""

EXTRA_SPEC_VALIDATORS = []

# non-nested capabilities (from 'nova.objects.compute_node.ComputeNode' and


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