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# Copyright 2013 IBM Corp.
# Copyright 2011 OpenStack Foundation
# 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.
import inspect
import math
import time
from xml.dom import minidom
from lxml import etree
import six
import webob
from nova.api.openstack import xmlutil
from nova import exception
from nova.openstack.common import gettextutils
from nova.openstack.common.gettextutils import _
from nova.openstack.common import jsonutils
from nova.openstack.common import log as logging
from nova import utils
from nova import wsgi
XMLNS_V10 = 'http://docs.rackspacecloud.com/servers/api/v1.0'
XMLNS_V11 = 'http://docs.openstack.org/compute/api/v1.1'
XMLNS_ATOM = 'http://www.w3.org/2005/Atom'
LOG = logging.getLogger(__name__)
SUPPORTED_CONTENT_TYPES = (
'application/json',
'application/vnd.openstack.compute+json',
'application/xml',
'application/vnd.openstack.compute+xml',
)
_MEDIA_TYPE_MAP = {
'application/vnd.openstack.compute+json': 'json',
'application/json': 'json',
'application/vnd.openstack.compute+xml': 'xml',
'application/xml': 'xml',
'application/atom+xml': 'atom',
}
# These are typically automatically created by routes as either defaults
# collection or member methods.
_ROUTES_METHODS = [
'create',
'delete',
'show',
'update',
]
_METHODS_WITH_BODY = [
'POST',
'PUT',
]
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class Request(webob.Request):
"""Add some OpenStack API-specific logic to the base webob.Request."""
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def __init__(self, *args, **kwargs):
super(Request, self).__init__(*args, **kwargs)
self._extension_data = {'db_items': {}}
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def cache_db_items(self, key, items, item_key='id'):
"""Allow API methods to store objects from a DB query to be
used by API extensions within the same API request.
An instance of this class only lives for the lifetime of a
single API request, so there's no need to implement full
cache management.
"""
db_items = self._extension_data['db_items'].setdefault(key, {})
for item in items:
db_items[item[item_key]] = item
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def get_db_items(self, key):
"""Allow an API extension to get previously stored objects within
the same API request.
Note that the object data will be slightly stale.
"""
return self._extension_data['db_items'][key]
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def get_db_item(self, key, item_key):
"""Allow an API extension to get a previously stored object
within the same API request.
Note that the object data will be slightly stale.
"""
return self.get_db_items(key).get(item_key)
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def cache_db_instances(self, instances):
self.cache_db_items('instances', instances, 'uuid')
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def cache_db_instance(self, instance):
self.cache_db_items('instances', [instance], 'uuid')
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def get_db_instances(self):
return self.get_db_items('instances')
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def get_db_instance(self, instance_uuid):
return self.get_db_item('instances', instance_uuid)
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def cache_db_flavors(self, flavors):
self.cache_db_items('flavors', flavors, 'flavorid')
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def cache_db_flavor(self, flavor):
self.cache_db_items('flavors', [flavor], 'flavorid')
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def get_db_flavors(self):
return self.get_db_items('flavors')
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def get_db_flavor(self, flavorid):
return self.get_db_item('flavors', flavorid)
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def cache_db_compute_nodes(self, compute_nodes):
self.cache_db_items('compute_nodes', compute_nodes, 'id')
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def cache_db_compute_node(self, compute_node):
self.cache_db_items('compute_nodes', [compute_node], 'id')
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def get_db_compute_nodes(self):
return self.get_db_items('compute_nodes')
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def get_db_compute_node(self, id):
return self.get_db_item('compute_nodes', id)
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def best_match_content_type(self):
"""Determine the requested response content-type."""
if 'nova.best_content_type' not in self.environ:
# Calculate the best MIME type
content_type = None
# Check URL path suffix
parts = self.path.rsplit('.', 1)
if len(parts) > 1:
possible_type = 'application/' + parts[1]
if possible_type in SUPPORTED_CONTENT_TYPES:
content_type = possible_type
if not content_type:
content_type = self.accept.best_match(SUPPORTED_CONTENT_TYPES)
self.environ['nova.best_content_type'] = (content_type or
'application/json')
return self.environ['nova.best_content_type']
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def get_content_type(self):
"""Determine content type of the request body.
Does not do any body introspection, only checks header
"""
if "Content-Type" not in self.headers:
return None
content_type = self.content_type
# NOTE(markmc): text/plain is the default for eventlet and
# other webservers which use mimetools.Message.gettype()
# whereas twisted defaults to ''.
if not content_type or content_type == 'text/plain':
return None
if content_type not in SUPPORTED_CONTENT_TYPES:
raise exception.InvalidContentType(content_type=content_type)
return content_type
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def best_match_language(self):
"""Determine the best available language for the request.
:returns: the best language match or None if the 'Accept-Language'
header was not available in the request.
"""
if not self.accept_language:
return None
return self.accept_language.best_match(
gettextutils.get_available_languages('nova'))
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class ActionDispatcher(object):
"""Maps method name to local methods through action name."""
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def dispatch(self, *args, **kwargs):
"""Find and call local method."""
action = kwargs.pop('action', 'default')
action_method = getattr(self, str(action), self.default)
return action_method(*args, **kwargs)
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def default(self, data):
raise NotImplementedError()
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class TextDeserializer(ActionDispatcher):
"""Default request body deserialization."""
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def deserialize(self, datastring, action='default'):
return self.dispatch(datastring, action=action)
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def default(self, datastring):
return {}
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class JSONDeserializer(TextDeserializer):
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def _from_json(self, datastring):
try:
return jsonutils.loads(datastring)
except ValueError:
msg = _("cannot understand JSON")
raise exception.MalformedRequestBody(reason=msg)
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def default(self, datastring):
return {'body': self._from_json(datastring)}
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class XMLDeserializer(TextDeserializer):
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def __init__(self, metadata=None):
""":param metadata: information needed to deserialize xml into
a dictionary.
"""
super(XMLDeserializer, self).__init__()
self.metadata = metadata or {}
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def _from_xml(self, datastring):
plurals = set(self.metadata.get('plurals', {}))
node = xmlutil.safe_minidom_parse_string(datastring).childNodes[0]
return {node.nodeName: self._from_xml_node(node, plurals)}
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def _from_xml_node(self, node, listnames):
"""Convert a minidom node to a simple Python type.
:param listnames: list of XML node names whose subnodes should
be considered list items.
"""
if len(node.childNodes) == 1 and node.childNodes[0].nodeType == 3:
return node.childNodes[0].nodeValue
elif node.nodeName in listnames:
return [self._from_xml_node(n, listnames) for n in node.childNodes]
else:
result = dict()
for attr in node.attributes.keys():
if not attr.startswith("xmlns"):
result[attr] = node.attributes[attr].nodeValue
for child in node.childNodes:
if child.nodeType != node.TEXT_NODE:
result[child.nodeName] = self._from_xml_node(child,
listnames)
return result
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def find_first_child_named_in_namespace(self, parent, namespace, name):
"""Search a nodes children for the first child with a given name."""
for node in parent.childNodes:
if (node.localName == name and
node.namespaceURI and
node.namespaceURI == namespace):
return node
return None
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def find_first_child_named(self, parent, name):
"""Search a nodes children for the first child with a given name."""
for node in parent.childNodes:
if node.localName == name:
return node
return None
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def find_children_named(self, parent, name):
"""Return all of a nodes children who have the given name."""
for node in parent.childNodes:
if node.localName == name:
yield node
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def extract_text(self, node):
"""Get the text field contained by the given node."""
ret_val = ""
for child in node.childNodes:
if child.nodeType == child.TEXT_NODE:
ret_val += child.nodeValue
return ret_val
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def extract_elements(self, node):
"""Get only Element type childs from node."""
elements = []
for child in node.childNodes:
if child.nodeType == child.ELEMENT_NODE:
elements.append(child)
return elements
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def find_attribute_or_element(self, parent, name):
"""Get an attribute value; fallback to an element if not found."""
if parent.hasAttribute(name):
return parent.getAttribute(name)
node = self.find_first_child_named(parent, name)
if node:
return self.extract_text(node)
return None
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def default(self, datastring):
return {'body': self._from_xml(datastring)}
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class MetadataXMLDeserializer(XMLDeserializer):
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def extract_metadata(self, metadata_node):
"""Marshal the metadata attribute of a parsed request."""
metadata = {}
if metadata_node is not None:
for meta_node in self.find_children_named(metadata_node, "meta"):
key = meta_node.getAttribute("key")
metadata[key] = self.extract_text(meta_node)
return metadata
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class DictSerializer(ActionDispatcher):
"""Default request body serialization."""
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def serialize(self, data, action='default'):
return self.dispatch(data, action=action)
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def default(self, data):
return ""
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class JSONDictSerializer(DictSerializer):
"""Default JSON request body serialization."""
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def default(self, data):
return jsonutils.dumps(data)
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class XMLDictSerializer(DictSerializer):
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def __init__(self, metadata=None, xmlns=None):
""":param metadata: information needed to deserialize xml into
a dictionary.
:param xmlns: XML namespace to include with serialized xml
"""
super(XMLDictSerializer, self).__init__()
self.metadata = metadata or {}
self.xmlns = xmlns
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def default(self, data):
# We expect data to contain a single key which is the XML root.
root_key = data.keys()[0]
doc = minidom.Document()
node = self._to_xml_node(doc, self.metadata, root_key, data[root_key])
return self.to_xml_string(node)
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def to_xml_string(self, node, has_atom=False):
self._add_xmlns(node, has_atom)
return node.toxml('UTF-8')
#NOTE (ameade): the has_atom should be removed after all of the
# xml serializers and view builders have been updated to the current
# spec that required all responses include the xmlns:atom, the has_atom
# flag is to prevent current tests from breaking
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def _add_xmlns(self, node, has_atom=False):
if self.xmlns is not None:
node.setAttribute('xmlns', self.xmlns)
if has_atom:
node.setAttribute('xmlns:atom', "http://www.w3.org/2005/Atom")
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def _to_xml_node(self, doc, metadata, nodename, data):
"""Recursive method to convert data members to XML nodes."""
result = doc.createElement(nodename)
# Set the xml namespace if one is specified
# TODO(justinsb): We could also use prefixes on the keys
xmlns = metadata.get('xmlns', None)
if xmlns:
result.setAttribute('xmlns', xmlns)
#TODO(bcwaldon): accomplish this without a type-check
if isinstance(data, list):
collections = metadata.get('list_collections', {})
if nodename in collections:
metadata = collections[nodename]
for item in data:
node = doc.createElement(metadata['item_name'])
node.setAttribute(metadata['item_key'], str(item))
result.appendChild(node)
return result
singular = metadata.get('plurals', {}).get(nodename, None)
if singular is None:
if nodename.endswith('s'):
singular = nodename[:-1]
else:
singular = 'item'
for item in data:
node = self._to_xml_node(doc, metadata, singular, item)
result.appendChild(node)
#TODO(bcwaldon): accomplish this without a type-check
elif isinstance(data, dict):
collections = metadata.get('dict_collections', {})
if nodename in collections:
metadata = collections[nodename]
for k, v in data.items():
node = doc.createElement(metadata['item_name'])
node.setAttribute(metadata['item_key'], str(k))
text = doc.createTextNode(str(v))
node.appendChild(text)
result.appendChild(node)
return result
attrs = metadata.get('attributes', {}).get(nodename, {})
for k, v in data.items():
if k in attrs:
result.setAttribute(k, str(v))
else:
if k == "deleted":
v = str(bool(v))
node = self._to_xml_node(doc, metadata, k, v)
result.appendChild(node)
else:
# Type is atom
node = doc.createTextNode(str(data))
result.appendChild(node)
return result
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def _create_link_nodes(self, xml_doc, links):
link_nodes = []
for link in links:
link_node = xml_doc.createElement('atom:link')
link_node.setAttribute('rel', link['rel'])
link_node.setAttribute('href', link['href'])
if 'type' in link:
link_node.setAttribute('type', link['type'])
link_nodes.append(link_node)
return link_nodes
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def _to_xml(self, root):
"""Convert the xml object to an xml string."""
return etree.tostring(root, encoding='UTF-8', xml_declaration=True)
def serializers(**serializers):
"""Attaches serializers to a method.
This decorator associates a dictionary of serializers with a
method. Note that the function attributes are directly
manipulated; the method is not wrapped.
"""
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def serializers(**serializers):
"""Attaches serializers to a method.
This decorator associates a dictionary of serializers with a
method. Note that the function attributes are directly
manipulated; the method is not wrapped.
"""
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def decorator(func):
if not hasattr(func, 'wsgi_serializers'):
func.wsgi_serializers = {}
func.wsgi_serializers.update(serializers)
return func
return decorator
def deserializers(**deserializers):
"""Attaches deserializers to a method.
This decorator associates a dictionary of deserializers with a
method. Note that the function attributes are directly
manipulated; the method is not wrapped.
"""
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def deserializers(**deserializers):
"""Attaches deserializers to a method.
This decorator associates a dictionary of deserializers with a
method. Note that the function attributes are directly
manipulated; the method is not wrapped.
"""
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def decorator(func):
if not hasattr(func, 'wsgi_deserializers'):
func.wsgi_deserializers = {}
func.wsgi_deserializers.update(deserializers)
return func
return decorator
def response(code):
"""Attaches response code to a method.
This decorator associates a response code with a method. Note
that the function attributes are directly manipulated; the method
is not wrapped.
"""
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def response(code):
"""Attaches response code to a method.
This decorator associates a response code with a method. Note
that the function attributes are directly manipulated; the method
is not wrapped.
"""
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def decorator(func):
func.wsgi_code = code
return func
return decorator
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class ResponseObject(object):
"""Bundles a response object with appropriate serializers.
Object that app methods may return in order to bind alternate
serializers with a response object to be serialized. Its use is
optional.
"""
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def __init__(self, obj, code=None, headers=None, **serializers):
"""Binds serializers with an object.
Takes keyword arguments akin to the @serializer() decorator
for specifying serializers. Serializers specified will be
given preference over default serializers or method-specific
serializers on return.
"""
self.obj = obj
self.serializers = serializers
self._default_code = 200
self._code = code
self._headers = headers or {}
self.serializer = None
self.media_type = None
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def __getitem__(self, key):
"""Retrieves a header with the given name."""
return self._headers[key.lower()]
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def __setitem__(self, key, value):
"""Sets a header with the given name to the given value."""
self._headers[key.lower()] = value
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def __delitem__(self, key):
"""Deletes the header with the given name."""
del self._headers[key.lower()]
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def _bind_method_serializers(self, meth_serializers):
"""Binds method serializers with the response object.
Binds the method serializers with the response object.
Serializers specified to the constructor will take precedence
over serializers specified to this method.
:param meth_serializers: A dictionary with keys mapping to
response types and values containing
serializer objects.
"""
# We can't use update because that would be the wrong
# precedence
for mtype, serializer in meth_serializers.items():
self.serializers.setdefault(mtype, serializer)
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def get_serializer(self, content_type, default_serializers=None):
"""Returns the serializer for the wrapped object.
Returns the serializer for the wrapped object subject to the
indicated content type. If no serializer matching the content
type is attached, an appropriate serializer drawn from the
default serializers will be used. If no appropriate
serializer is available, raises InvalidContentType.
"""
default_serializers = default_serializers or {}
try:
mtype = _MEDIA_TYPE_MAP.get(content_type, content_type)
if mtype in self.serializers:
return mtype, self.serializers[mtype]
else:
return mtype, default_serializers[mtype]
except (KeyError, TypeError):
raise exception.InvalidContentType(content_type=content_type)
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def preserialize(self, content_type, default_serializers=None):
"""Prepares the serializer that will be used to serialize.
Determines the serializer that will be used and prepares an
instance of it for later call. This allows the serializer to
be accessed by extensions for, e.g., template extension.
"""
mtype, serializer = self.get_serializer(content_type,
default_serializers)
self.media_type = mtype
self.serializer = serializer()
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def attach(self, **kwargs):
"""Attach slave templates to serializers."""
if self.media_type in kwargs:
self.serializer.attach(kwargs[self.media_type])
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def serialize(self, request, content_type, default_serializers=None):
"""Serializes the wrapped object.
Utility method for serializing the wrapped object. Returns a
webob.Response object.
"""
if self.serializer:
serializer = self.serializer
else:
_mtype, _serializer = self.get_serializer(content_type,
default_serializers)
serializer = _serializer()
response = webob.Response()
response.status_int = self.code
for hdr, value in self._headers.items():
response.headers[hdr] = utils.utf8(str(value))
response.headers['Content-Type'] = utils.utf8(content_type)
if self.obj is not None:
response.body = serializer.serialize(self.obj)
return response
@property
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def code(self):
"""Retrieve the response status."""
return self._code or self._default_code
@property
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def headers(self):
"""Retrieve the headers."""
return self._headers.copy()
def action_peek_json(body):
"""Determine action to invoke."""
try:
decoded = jsonutils.loads(body)
except ValueError:
msg = _("cannot understand JSON")
raise exception.MalformedRequestBody(reason=msg)
# Make sure there's exactly one key...
if len(decoded) != 1:
msg = _("too many body keys")
raise exception.MalformedRequestBody(reason=msg)
# Return the action and the decoded body...
return decoded.keys()[0]
def action_peek_xml(body):
"""Determine action to invoke."""
dom = xmlutil.safe_minidom_parse_string(body)
action_node = dom.childNodes[0]
return action_node.tagName
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def action_peek_json(body):
"""Determine action to invoke."""
try:
decoded = jsonutils.loads(body)
except ValueError:
msg = _("cannot understand JSON")
raise exception.MalformedRequestBody(reason=msg)
# Make sure there's exactly one key...
if len(decoded) != 1:
msg = _("too many body keys")
raise exception.MalformedRequestBody(reason=msg)
# Return the action and the decoded body...
return decoded.keys()[0]
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def action_peek_xml(body):
"""Determine action to invoke."""
dom = xmlutil.safe_minidom_parse_string(body)
action_node = dom.childNodes[0]
return action_node.tagName
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class ResourceExceptionHandler(object):
"""Context manager to handle Resource exceptions.
Used when processing exceptions generated by API implementation
methods (or their extensions). Converts most exceptions to Fault
exceptions, with the appropriate logging.
"""
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def __enter__(self):
return None
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def __exit__(self, ex_type, ex_value, ex_traceback):
if not ex_value:
return True
if isinstance(ex_value, exception.NotAuthorized):
raise Fault(webob.exc.HTTPForbidden(
explanation=ex_value.format_message()))
elif isinstance(ex_value, exception.Invalid):
raise Fault(exception.ConvertedException(
code=ex_value.code,
explanation=ex_value.format_message()))
# Under python 2.6, TypeError's exception value is actually a string,
# so test # here via ex_type instead:
# http://bugs.python.org/issue7853
elif issubclass(ex_type, TypeError):
exc_info = (ex_type, ex_value, ex_traceback)
LOG.error(_('Exception handling resource: %s') % ex_value,
exc_info=exc_info)
raise Fault(webob.exc.HTTPBadRequest())
elif isinstance(ex_value, Fault):
LOG.info(_("Fault thrown: %s"), unicode(ex_value))
raise ex_value
elif isinstance(ex_value, webob.exc.HTTPException):
LOG.info(_("HTTP exception thrown: %s"), unicode(ex_value))
raise Fault(ex_value)
# We didn't handle the exception
return False
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class Resource(wsgi.Application):
"""WSGI app that handles (de)serialization and controller dispatch.
WSGI app that reads routing information supplied by RoutesMiddleware
and calls the requested action method upon its controller. All
controller action methods must accept a 'req' argument, which is the
incoming wsgi.Request. If the operation is a PUT or POST, the controller
method must also accept a 'body' argument (the deserialized request body).
They may raise a webob.exc exception or return a dict, which will be
serialized by requested content type.
Exceptions derived from webob.exc.HTTPException will be automatically
wrapped in Fault() to provide API friendly error responses.
"""
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def __init__(self, controller, action_peek=None, inherits=None,
**deserializers):
""":param controller: object that implement methods created by routes
lib
:param action_peek: dictionary of routines for peeking into an
action request body to determine the
desired action
:param inherits: another resource object that this resource should
inherit extensions from. Any action extensions that
are applied to the parent resource will also apply
to this resource.
"""
self.controller = controller
default_deserializers = dict(xml=XMLDeserializer,
json=JSONDeserializer)
default_deserializers.update(deserializers)
self.default_deserializers = default_deserializers
self.default_serializers = dict(xml=XMLDictSerializer,
json=JSONDictSerializer)
self.action_peek = dict(xml=action_peek_xml,
json=action_peek_json)
self.action_peek.update(action_peek or {})
# Copy over the actions dictionary
self.wsgi_actions = {}
if controller:
self.register_actions(controller)
# Save a mapping of extensions
self.wsgi_extensions = {}
self.wsgi_action_extensions = {}
self.inherits = inherits
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def register_actions(self, controller):
"""Registers controller actions with this resource."""
actions = getattr(controller, 'wsgi_actions', {})
for key, method_name in actions.items():
self.wsgi_actions[key] = getattr(controller, method_name)
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def register_extensions(self, controller):
"""Registers controller extensions with this resource."""
extensions = getattr(controller, 'wsgi_extensions', [])
for method_name, action_name in extensions:
# Look up the extending method
extension = getattr(controller, method_name)
if action_name:
# Extending an action...
if action_name not in self.wsgi_action_extensions:
self.wsgi_action_extensions[action_name] = []
self.wsgi_action_extensions[action_name].append(extension)
else:
# Extending a regular method
if method_name not in self.wsgi_extensions:
self.wsgi_extensions[method_name] = []
self.wsgi_extensions[method_name].append(extension)
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def get_action_args(self, request_environment):
"""Parse dictionary created by routes library."""
# NOTE(Vek): Check for get_action_args() override in the
# controller
if hasattr(self.controller, 'get_action_args'):
return self.controller.get_action_args(request_environment)
try:
args = request_environment['wsgiorg.routing_args'][1].copy()
except (KeyError, IndexError, AttributeError):
return {}
try:
del args['controller']
except KeyError:
pass
try:
del args['format']
except KeyError:
pass
return args
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def get_body(self, request):
try:
content_type = request.get_content_type()
except exception.InvalidContentType:
LOG.debug(_("Unrecognized Content-Type provided in request"))
return None, ''
return content_type, request.body
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def deserialize(self, meth, content_type, body):
meth_deserializers = getattr(meth, 'wsgi_deserializers', {})
try:
mtype = _MEDIA_TYPE_MAP.get(content_type, content_type)
if mtype in meth_deserializers:
deserializer = meth_deserializers[mtype]
else:
deserializer = self.default_deserializers[mtype]
except (KeyError, TypeError):
raise exception.InvalidContentType(content_type=content_type)
if (hasattr(deserializer, 'want_controller')
and deserializer.want_controller):
return deserializer(self.controller).deserialize(body)
else:
return deserializer().deserialize(body)
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def pre_process_extensions(self, extensions, request, action_args):
# List of callables for post-processing extensions
post = []
for ext in extensions:
if inspect.isgeneratorfunction(ext):
response = None
# If it's a generator function, the part before the
# yield is the preprocessing stage
try:
with ResourceExceptionHandler():
gen = ext(req=request, **action_args)
response = gen.next()
except Fault as ex:
response = ex
# We had a response...
if response:
return response, []
# No response, queue up generator for post-processing
post.append(gen)
else:
# Regular functions only perform post-processing
post.append(ext)
# Run post-processing in the reverse order
return None, reversed(post)
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def post_process_extensions(self, extensions, resp_obj, request,
action_args):
for ext in extensions:
response = None
if inspect.isgenerator(ext):
# If it's a generator, run the second half of
# processing
try:
with ResourceExceptionHandler():
response = ext.send(resp_obj)
except StopIteration:
# Normal exit of generator
continue
except Fault as ex:
response = ex
else:
# Regular functions get post-processing...
try:
with ResourceExceptionHandler():
response = ext(req=request, resp_obj=resp_obj,
**action_args)
except Fault as ex:
response = ex
# We had a response...
if response:
return response
return None
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def _should_have_body(self, request):
return request.method in _METHODS_WITH_BODY
@webob.dec.wsgify(RequestClass=Request)
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def __call__(self, request):
"""WSGI method that controls (de)serialization and method dispatch."""
# Identify the action, its arguments, and the requested
# content type
action_args = self.get_action_args(request.environ)
action = action_args.pop('action', None)
content_type, body = self.get_body(request)
accept = request.best_match_content_type()
# NOTE(Vek): Splitting the function up this way allows for
# auditing by external tools that wrap the existing
# function. If we try to audit __call__(), we can
# run into troubles due to the @webob.dec.wsgify()
# decorator.
return self._process_stack(request, action, action_args,
content_type, body, accept)
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def _process_stack(self, request, action, action_args,
content_type, body, accept):
"""Implement the processing stack."""
# Get the implementing method
try:
meth, extensions = self.get_method(request, action,
content_type, body)
except (AttributeError, TypeError):
return Fault(webob.exc.HTTPNotFound())
except KeyError as ex:
msg = _("There is no such action: %s") % ex.args[0]
return Fault(webob.exc.HTTPBadRequest(explanation=msg))
except exception.MalformedRequestBody:
msg = _("Malformed request body")
return Fault(webob.exc.HTTPBadRequest(explanation=msg))
if body:
msg = _("Action: '%(action)s', body: "
"%(body)s") % {'action': action,
'body': unicode(body, 'utf-8')}
LOG.debug(logging.mask_password(msg))
LOG.debug(_("Calling method '%(meth)s' (Content-type='%(ctype)s', "
"Accept='%(accept)s')"),
{'meth': str(meth),
'ctype': content_type,
'accept': accept})
# Now, deserialize the request body...
try:
contents = {}
if self._should_have_body(request):
#allow empty body with PUT and POST
if request.content_length == 0:
contents = {'body': None}
else:
contents = self.deserialize(meth, content_type, body)
except exception.InvalidContentType:
msg = _("Unsupported Content-Type")
return Fault(webob.exc.HTTPBadRequest(explanation=msg))
except exception.MalformedRequestBody:
msg = _("Malformed request body")
return Fault(webob.exc.HTTPBadRequest(explanation=msg))
# Update the action args
action_args.update(contents)
project_id = action_args.pop("project_id", None)
context = request.environ.get('nova.context')
if (context and project_id and (project_id != context.project_id)):
msg = _("Malformed request URL: URL's project_id '%(project_id)s'"
" doesn't match Context's project_id"
" '%(context_project_id)s'") % \
{'project_id': project_id,
'context_project_id': context.project_id}
return Fault(webob.exc.HTTPBadRequest(explanation=msg))
# Run pre-processing extensions
response, post = self.pre_process_extensions(extensions,
request, action_args)
if not response:
try:
with ResourceExceptionHandler():
action_result = self.dispatch(meth, request, action_args)
except Fault as ex:
response = ex
if not response:
# No exceptions; convert action_result into a
# ResponseObject
resp_obj = None
if type(action_result) is dict or action_result is None:
resp_obj = ResponseObject(action_result)
elif isinstance(action_result, ResponseObject):
resp_obj = action_result
else:
response = action_result
# Run post-processing extensions
if resp_obj:
# Do a preserialize to set up the response object
serializers = getattr(meth, 'wsgi_serializers', {})
resp_obj._bind_method_serializers(serializers)
if hasattr(meth, 'wsgi_code'):
resp_obj._default_code = meth.wsgi_code
resp_obj.preserialize(accept, self.default_serializers)
# Process post-processing extensions
response = self.post_process_extensions(post, resp_obj,
request, action_args)
if resp_obj and not response:
response = resp_obj.serialize(request, accept,
self.default_serializers)
if hasattr(response, 'headers'):
if context:
response.headers.add('x-compute-request-id',
context.request_id)
for hdr, val in response.headers.items():
# Headers must be utf-8 strings
response.headers[hdr] = utils.utf8(str(val))
return response
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def get_method(self, request, action, content_type, body):
meth, extensions = self._get_method(request,
action,
content_type,
body)
if self.inherits:
_meth, parent_ext = self.inherits.get_method(request,
action,
content_type,
body)
extensions.extend(parent_ext)
return meth, extensions
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def _get_method(self, request, action, content_type, body):
"""Look up the action-specific method and its extensions."""
# Look up the method
try:
if not self.controller:
meth = getattr(self, action)
else:
meth = getattr(self.controller, action)
except AttributeError:
if (not self.wsgi_actions or
action not in _ROUTES_METHODS + ['action']):
# Propagate the error
raise
else:
return meth, self.wsgi_extensions.get(action, [])
if action == 'action':
# OK, it's an action; figure out which action...
mtype = _MEDIA_TYPE_MAP.get(content_type)
action_name = self.action_peek[mtype](body)
else:
action_name = action
# Look up the action method
return (self.wsgi_actions[action_name],
self.wsgi_action_extensions.get(action_name, []))
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def dispatch(self, method, request, action_args):
"""Dispatch a call to the action-specific method."""
return method(req=request, **action_args)
def action(name):
"""Mark a function as an action.
The given name will be taken as the action key in the body.
This is also overloaded to allow extensions to provide
non-extending definitions of create and delete operations.
"""
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def action(name):
"""Mark a function as an action.
The given name will be taken as the action key in the body.
This is also overloaded to allow extensions to provide
non-extending definitions of create and delete operations.
"""
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def decorator(func):
func.wsgi_action = name
return func
return decorator
def extends(*args, **kwargs):
"""Indicate a function extends an operation.
Can be used as either::
@extends
def index(...):
pass
or as::
@extends(action='resize')
def _action_resize(...):
pass
"""
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def index(...):
pass
or as::
@extends(action='resize')
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def _action_resize(...):
pass
"""
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def decorator(func):
# Store enough information to find what we're extending
func.wsgi_extends = (func.__name__, kwargs.get('action'))
return func
# If we have positional arguments, call the decorator
if args:
return decorator(*args)
# OK, return the decorator instead
return decorator
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class ControllerMetaclass(type):
"""Controller metaclass.
This metaclass automates the task of assembling a dictionary
mapping action keys to method names.
"""
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def __new__(mcs, name, bases, cls_dict):
"""Adds the wsgi_actions dictionary to the class."""
# Find all actions
actions = {}
extensions = []
# start with wsgi actions from base classes
for base in bases:
actions.update(getattr(base, 'wsgi_actions', {}))
for key, value in cls_dict.items():
if not callable(value):
continue
if getattr(value, 'wsgi_action', None):
actions[value.wsgi_action] = key
elif getattr(value, 'wsgi_extends', None):
extensions.append(value.wsgi_extends)
# Add the actions and extensions to the class dict
cls_dict['wsgi_actions'] = actions
cls_dict['wsgi_extensions'] = extensions
return super(ControllerMetaclass, mcs).__new__(mcs, name, bases,
cls_dict)
@six.add_metaclass(ControllerMetaclass)
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class Controller(object):
"""Default controller."""
_view_builder_class = None
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def __init__(self, view_builder=None):
"""Initialize controller with a view builder instance."""
if view_builder:
self._view_builder = view_builder
elif self._view_builder_class:
self._view_builder = self._view_builder_class()
else:
self._view_builder = None
@staticmethod
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def is_valid_body(body, entity_name):
if not (body and entity_name in body):
return False
def is_dict(d):
try:
d.get(None)
return True
except AttributeError:
return False
if not is_dict(body[entity_name]):
return False
return True
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def is_dict(d):
try:
d.get(None)
return True
except AttributeError:
return False
if not is_dict(body[entity_name]):
return False
return True
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class Fault(webob.exc.HTTPException):
"""Wrap webob.exc.HTTPException to provide API friendly response."""
_fault_names = {
400: "badRequest",
401: "unauthorized",
403: "forbidden",
404: "itemNotFound",
405: "badMethod",
409: "conflictingRequest",
413: "overLimit",
415: "badMediaType",
429: "overLimit",
501: "notImplemented",
503: "serviceUnavailable"}
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def __init__(self, exception):
"""Create a Fault for the given webob.exc.exception."""
self.wrapped_exc = exception
for key, value in self.wrapped_exc.headers.items():
self.wrapped_exc.headers[key] = str(value)
self.status_int = exception.status_int
@webob.dec.wsgify(RequestClass=Request)
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def __call__(self, req):
"""Generate a WSGI response based on the exception passed to ctor."""
user_locale = req.best_match_language()
# Replace the body with fault details.
code = self.wrapped_exc.status_int
fault_name = self._fault_names.get(code, "computeFault")
explanation = self.wrapped_exc.explanation
LOG.debug(_("Returning %(code)s to user: %(explanation)s"),
{'code': code, 'explanation': explanation})
explanation = gettextutils.translate(explanation,
user_locale)
fault_data = {
fault_name: {
'code': code,
'message': explanation}}
if code == 413 or code == 429:
retry = self.wrapped_exc.headers.get('Retry-After', None)
if retry:
fault_data[fault_name]['retryAfter'] = retry
# 'code' is an attribute on the fault tag itself
metadata = {'attributes': {fault_name: 'code'}}
xml_serializer = XMLDictSerializer(metadata, XMLNS_V11)
content_type = req.best_match_content_type()
serializer = {
'application/xml': xml_serializer,
'application/json': JSONDictSerializer(),
}[content_type]
self.wrapped_exc.body = serializer.serialize(fault_data)
self.wrapped_exc.content_type = content_type
_set_request_id_header(req, self.wrapped_exc.headers)
return self.wrapped_exc
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def __str__(self):
return self.wrapped_exc.__str__()
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class RateLimitFault(webob.exc.HTTPException):
"""Rate-limited request response."""
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def __init__(self, message, details, retry_time):
"""Initialize new `RateLimitFault` with relevant information."""
hdrs = RateLimitFault._retry_after(retry_time)
self.wrapped_exc = webob.exc.HTTPTooManyRequests(headers=hdrs)
self.content = {
"overLimit": {
"code": self.wrapped_exc.status_int,
"message": message,
"details": details,
"retryAfter": hdrs['Retry-After'],
},
}
@staticmethod
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def _retry_after(retry_time):
delay = int(math.ceil(retry_time - time.time()))
retry_after = delay if delay > 0 else 0
headers = {'Retry-After': '%d' % retry_after}
return headers
@webob.dec.wsgify(RequestClass=Request)
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def __call__(self, request):
"""Return the wrapped exception with a serialized body conforming
to our error format.
"""
user_locale = request.best_match_language()
content_type = request.best_match_content_type()
metadata = {"attributes": {"overLimit": ["code", "retryAfter"]}}
self.content['overLimit']['message'] = \
gettextutils.translate(
self.content['overLimit']['message'],
user_locale)
self.content['overLimit']['details'] = \
gettextutils.translate(
self.content['overLimit']['details'],
user_locale)
xml_serializer = XMLDictSerializer(metadata, XMLNS_V11)
serializer = {
'application/xml': xml_serializer,
'application/json': JSONDictSerializer(),
}[content_type]
content = serializer.serialize(self.content)
self.wrapped_exc.body = content
self.wrapped_exc.content_type = content_type
return self.wrapped_exc
def _set_request_id_header(req, headers):
context = req.environ.get('nova.context')
if context:
headers['x-compute-request-id'] = context.request_id
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def _set_request_id_header(req, headers):
context = req.environ.get('nova.context')
if context:
headers['x-compute-request-id'] = context.request_id