openstacksdk/openstack/proxy.py

297 lines
13 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.
from openstack import exceptions
from openstack import resource
# The _check_resource decorator is used on BaseProxy methods to ensure that
# the `actual` argument is in fact the type of the `expected` argument.
# It does so under two cases:
# 1. When strict=False, if and only if `actual` is a Resource instance,
# it is checked to see that it's an instance of the `expected` class.
# This allows `actual` to be other types, such as strings, when it makes
# sense to accept a raw id value.
# 2. When strict=True, `actual` must be an instance of the `expected` class.
def _check_resource(strict=False):
def wrap(method):
def check(self, expected, actual=None, *args, **kwargs):
if (strict and actual is not None and not
isinstance(actual, resource.Resource)):
raise ValueError("A %s must be passed" % expected.__name__)
elif (isinstance(actual, resource.Resource) and not
isinstance(actual, expected)):
raise ValueError("Expected %s but received %s" % (
expected.__name__, actual.__class__.__name__))
return method(self, expected, actual, *args, **kwargs)
return check
return wrap
class BaseProxy(object):
def __init__(self, session):
self.session = session
def _get_resource(self, resource_type, value, path_args=None):
"""Get a resource object to work on
:param resource_type: The type of resource to operate on. This should
be a subclass of
:class:`~openstack.resource.Resource` with a
``from_id`` method.
:param value: The ID of a resource or an object of ``resource_type``
class if using an existing instance, or None to create a
new instance.
:param path_args: A dict containing arguments for forming the request
URL, if needed.
"""
if value is None:
# Create a bare resource
res = resource_type()
elif not isinstance(value, resource_type):
# Create from an ID
args = {resource_type.id_attribute:
resource.Resource.get_id(value)}
res = resource_type.existing(**args)
else:
# An existing resource instance
res = value
# Set any intermediate path arguments, but don't overwrite Nones.
if path_args is not None:
res.update_attrs(ignore_none=True, **path_args)
return res
def _find(self, resource_type, name_or_id, path_args=None,
ignore_missing=True):
"""Find a resource
:param name_or_id: The name or ID of a resource to find.
:param bool ignore_missing: When set to ``False``
:class:`~openstack.exceptions.ResourceNotFound` will be
raised when the resource does not exist.
When set to ``True``, None will be returned when
attempting to find a nonexistent resource.
:returns: An instance of ``resource_type`` or None
"""
return resource_type.find(self.session, name_or_id,
path_args=path_args,
ignore_missing=ignore_missing)
@_check_resource(strict=False)
def _delete(self, resource_type, value, path_args=None,
ignore_missing=True):
"""Delete a resource
:param resource_type: The type of resource to delete. This should
be a :class:`~openstack.resource.Resource`
subclass with a ``from_id`` method.
:param value: The value to delete. Can be either the ID of a
resource or a :class:`~openstack.resource.Resource`
subclass.
:param path_args: A dict containing arguments for forming the request
URL, if needed.
:param bool ignore_missing: When set to ``False``
:class:`~openstack.exceptions.ResourceNotFound` will be
raised when the resource does not exist.
When set to ``True``, no exception will be set when
attempting to delete a nonexistent resource.
:returns: The result of the ``delete``
:raises: ``ValueError`` if ``value`` is a
:class:`~openstack.resource.Resource` that doesn't match
the ``resource_type``.
:class:`~openstack.exceptions.ResourceNotFound` when
ignore_missing if ``False`` and a nonexistent resource
is attempted to be deleted.
"""
res = self._get_resource(resource_type, value, path_args)
try:
rv = res.delete(self.session)
except exceptions.NotFoundException as e:
if ignore_missing:
return None
else:
# Reraise with a more specific type and message
raise exceptions.ResourceNotFound(
message="No %s found for %s" %
(resource_type.__name__, value),
details=e.details, response=e.response,
request_id=e.request_id, url=e.url, method=e.method,
http_status=e.http_status, cause=e.cause)
return rv
@_check_resource(strict=False)
def _update(self, resource_type, value, path_args=None, **attrs):
"""Update a resource
:param resource_type: The type of resource to update.
:type resource_type: :class:`~openstack.resource.Resource`
:param value: The resource to update. This must either be a
:class:`~openstack.resource.Resource` or an id
that corresponds to a resource.
:param path_args: A dict containing arguments for forming the request
URL, if needed.
:param **attrs: Attributes to update on a Resource object.
These attributes will be used in conjunction with
``resource_type``.
:returns: The result of the ``update``
:rtype: :class:`~openstack.resource.Resource`
"""
res = self._get_resource(resource_type, value, path_args)
res.update_attrs(attrs)
return res.update(self.session)
def _create(self, resource_type, path_args=None, **attrs):
"""Create a resource from attributes
:param resource_type: The type of resource to create.
:type resource_type: :class:`~openstack.resource.Resource`
:param path_args: A dict containing arguments for forming the request
URL, if needed.
:param **attrs: Attributes from which to create a Resource object.
These attributes will be used in conjunction with
``resource_type``.
:returns: The result of the ``create``
:rtype: :class:`~openstack.resource.Resource`
"""
res = resource_type.new(**attrs)
if path_args is not None:
res.update_attrs(path_args)
return res.create(self.session)
@_check_resource(strict=False)
def _get(self, resource_type, value=None, path_args=None, args=None):
"""Get a resource
:param resource_type: The type of resource to get.
:type resource_type: :class:`~openstack.resource.Resource`
:param value: The value to get. Can be either the ID of a
resource or a :class:`~openstack.resource.Resource`
subclass.
:param path_args: A dict containing arguments for forming the request
URL, if needed.
:param args: A optional dict containing arguments that will be
translated into query strings when forming the request URL.
:returns: The result of the ``get``
:rtype: :class:`~openstack.resource.Resource`
"""
res = self._get_resource(resource_type, value, path_args)
try:
return res.get(self.session, args=args)
except exceptions.NotFoundException as e:
raise exceptions.ResourceNotFound(
message="No %s found for %s" %
(resource_type.__name__, value),
details=e.details, response=e.response,
request_id=e.request_id, url=e.url, method=e.method,
http_status=e.http_status, cause=e.cause)
def _list(self, resource_type, value=None, paginated=False,
path_args=None, **query):
"""List a resource
:param resource_type: The type of resource to delete. This should
be a :class:`~openstack.resource.Resource`
subclass with a ``from_id`` method.
:param value: The resource to list. It can be the ID of a resource, or
a :class:`~openstack.resource.Resource` object. When set
to None, a new bare resource is created.
:param bool paginated: When set to ``False``, expect all of the data
to be returned in one response. When set to
``True``, the resource supports data being
returned across multiple pages.
:param path_args: A dictionary containing arguments for use when
forming the request URL for resource retrieval.
:param kwargs **query: Keyword arguments that are sent to the list
method, which are then attached as query
parameters on the request URL.
:returns: A generator of Resource objects.
:raises: ``ValueError`` if ``value`` is a
:class:`~openstack.resource.Resource` that doesn't match
the ``resource_type``.
"""
res = self._get_resource(resource_type, value, path_args)
query = res.convert_ids(query)
return res.list(self.session, path_args=path_args, paginated=paginated,
params=query)
def _head(self, resource_type, value=None, path_args=None):
"""Retrieve a resource's header
:param resource_type: The type of resource to retrieve.
:type resource_type: :class:`~openstack.resource.Resource`
:param value: The value of a specific resource to retreive headers
for. Can be either the ID of a resource,
a :class:`~openstack.resource.Resource` subclass,
or ``None``.
:param path_args: A dict containing arguments for forming the request
URL, if needed.
:returns: The result of the ``head`` call
:rtype: :class:`~openstack.resource.Resource`
"""
res = self._get_resource(resource_type, value, path_args)
return res.head(self.session)
def wait_for_status(self, value, status, failures=[], interval=2,
wait=120):
"""Wait for a resource to be in a particular status.
:param value: The resource to wait on to reach the status. The
resource must have a status attribute.
:type value: :class:`~openstack.resource.Resource`
:param status: Desired status of the resource.
:param list failures: Statuses that would indicate the transition
failed such as 'ERROR'.
:param interval: Number of seconds to wait between checks.
:param wait: Maximum number of seconds to wait for the change.
:return: Method returns resource on success.
:raises: :class:`~openstack.exceptions.ResourceTimeout` transition
to status failed to occur in wait seconds.
:raises: :class:`~openstack.exceptions.ResourceFailure` resource
transitioned to one of the failure states.
:raises: :class:`~AttributeError` if the resource does not have a
status attribute
"""
return resource.wait_for_status(self.session, value, status,
failures, interval, wait)
def wait_for_delete(self, value, interval=2, wait=120):
"""Wait for the resource to be deleted.
:param value: The resource to wait on to be deleted.
:type value: :class:`~openstack.resource.Resource`
:param interval: Number of seconds to wait between checks.
:param wait: Maximum number of seconds to wait for the delete.
:return: Method returns resource on success.
:raises: :class:`~openstack.exceptions.ResourceTimeout` transition
to delete failed to occur in wait seconds.
"""
return resource.wait_for_delete(self.session, value, interval, wait)