trove/reddwarf/common/wsgi.py

591 lines
21 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 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.
"""Wsgi helper utilities for reddwarf"""
import eventlet.wsgi
import paste.urlmap
import re
import traceback
import webob
import webob.dec
import webob.exc
from paste import deploy
from xml.dom import minidom
from reddwarf.common import context as rd_context
from reddwarf.common import exception
from reddwarf.common import utils
from reddwarf.openstack.common.gettextutils import _
from reddwarf.openstack.common import pastedeploy
from reddwarf.openstack.common import service
from reddwarf.openstack.common import wsgi as openstack_wsgi
from reddwarf.openstack.common import log as logging
from reddwarf.common import cfg
CONTEXT_KEY = 'reddwarf.context'
Router = openstack_wsgi.Router
Debug = openstack_wsgi.Debug
Middleware = openstack_wsgi.Middleware
JSONDictSerializer = openstack_wsgi.JSONDictSerializer
XMLDictSerializer = openstack_wsgi.XMLDictSerializer
XMLDeserializer = openstack_wsgi.XMLDeserializer
RequestDeserializer = openstack_wsgi.RequestDeserializer
eventlet.patcher.monkey_patch(all=False, socket=True)
LOG = logging.getLogger('reddwarf.common.wsgi')
CONF = cfg.CONF
XMLNS = 'http://docs.openstack.org/database/api/v1.0'
CUSTOM_PLURALS_METADATA = {'databases': '', 'users': ''}
CUSTOM_SERIALIZER_METADATA = {
'instance': {
'status': '',
'hostname': '',
'id': '',
'name': '',
'created': '',
'updated': '',
'host': '',
'server_id': '',
#mgmt/instance
'local_id': '',
'task_description': '',
'deleted': '',
'deleted_at': '',
'tenant_id': '',
},
'volume': {
'size': '',
'used': '',
#mgmt/instance
'id': '',
},
'flavor': {'id': '', 'ram': '', 'name': ''},
'link': {'href': '', 'rel': ''},
'database': {'name': ''},
'user': {'name': '', 'password': ''},
'account': {'id': ''},
# mgmt/host
'host': {'instanceCount': '', 'name': '', 'usedRAM': '', 'totalRAM': '',
'percentUsed': ''},
# mgmt/storage
'capacity': {'available': '', 'total': ''},
'provision': {'available': '', 'total': '', 'percent': ''},
'device': {'used': '', 'name': '', 'type': ''},
# mgmt/account
'account': {'id': '', 'num_instances': ''},
#mgmt/instance
'guest_status': {'state_description': ''},
#mgmt/instance/diagnostics
'diagnostics': {'vmHwm': '', 'vmPeak': '', 'vmSize': '', 'threads': '',
'version': '', 'vmRss': '', 'fdSize': ''},
#mgmt/instance/root
'root_history': {'enabled': '', 'id': '', 'user': ''},
}
def versioned_urlmap(*args, **kwargs):
urlmap = paste.urlmap.urlmap_factory(*args, **kwargs)
return VersionedURLMap(urlmap)
def launch(app_name, port, paste_config_file, data={},
host='0.0.0.0', backlog=128, threads=1000):
"""Launches a wsgi server based on the passed in paste_config_file.
Launch provides a easy way to create a paste app from the config
file and launch it via the service launcher. It takes care of
all of the plumbing. The only caveat is that the paste_config_file
must be a file that paste.deploy can find and handle. There is
a helper method in cfg.py that finds files.
Example:
conf_file = CONF.find_file(CONF.api_paste_config)
launcher = wsgi.launch('myapp', CONF.bind_port, conf_file)
launcher.wait()
"""
app = pastedeploy.paste_deploy_app(paste_config_file, app_name, data)
server = openstack_wsgi.Service(app, port, host=host,
backlog=backlog, threads=threads)
return service.launch(server)
class VersionedURLMap(object):
def __init__(self, urlmap):
self.urlmap = urlmap
def __call__(self, environ, start_response):
req = Request(environ)
if req.url_version is None and req.accept_version is not None:
version = "/v" + req.accept_version
http_exc = webob.exc.HTTPNotAcceptable(_("version not supported"))
app = self.urlmap.get(version, Fault(http_exc))
else:
app = self.urlmap
return app(environ, start_response)
class Request(openstack_wsgi.Request):
@property
def params(self):
return utils.stringify_keys(super(Request, self).params)
def best_match_content_type(self, supported_content_types=None):
"""Determine the most acceptable content-type.
Based on the query extension then the Accept header.
"""
parts = self.path.rsplit('.', 1)
if len(parts) > 1:
format = parts[1]
if format in ['json', 'xml']:
return 'application/{0}'.format(parts[1])
ctypes = {
'application/vnd.openstack.reddwarf+json': "application/json",
'application/vnd.openstack.reddwarf+xml': "application/xml",
'application/json': "application/json",
'application/xml': "application/xml",
}
bm = self.accept.best_match(ctypes.keys())
return ctypes.get(bm, 'application/json')
@utils.cached_property
def accept_version(self):
accept_header = self.headers.get('ACCEPT', "")
accept_version_re = re.compile(".*?application/vnd.openstack.reddwarf"
"(\+.+?)?;"
"version=(?P<version_no>\d+\.?\d*)")
match = accept_version_re.search(accept_header)
return match.group("version_no") if match else None
@utils.cached_property
def url_version(self):
versioned_url_re = re.compile("/v(?P<version_no>\d+\.?\d*)")
match = versioned_url_re.search(self.path)
return match.group("version_no") if match else None
class Result(object):
"""A result whose serialization is compatable with JSON and XML.
This class is used by ReddwarfResponseSerializer, which calls the
data method to grab a JSON or XML specific dictionary which it then
passes on to be serialized.
"""
def __init__(self, data, status=200):
self._data = data
self.status = status
def data(self, serialization_type):
"""Return an appropriate serialized type for the body.
In both cases a dictionary is returned. With JSON it maps directly,
while with XML the dictionary is expected to have a single key value
which becomes the root element.
"""
if (serialization_type == "application/xml" and
hasattr(self._data, "data_for_xml")):
return self._data.data_for_xml()
if hasattr(self._data, "data_for_json"):
return self._data.data_for_json()
return self._data
class Resource(openstack_wsgi.Resource):
def __init__(self, controller, deserializer, serializer,
exception_map=None):
exception_map = exception_map or {}
self.model_exception_map = self._invert_dict_list(exception_map)
super(Resource, self).__init__(controller, deserializer, serializer)
@webob.dec.wsgify(RequestClass=Request)
def __call__(self, request):
return super(Resource, self).__call__(request)
def execute_action(self, action, request, **action_args):
if getattr(self.controller, action, None) is None:
return Fault(webob.exc.HTTPNotFound())
try:
result = super(Resource, self).execute_action(
action,
request,
**action_args)
if type(result) is dict:
result = Result(result)
return result
except exception.ReddwarfError as reddwarf_error:
LOG.debug(traceback.format_exc())
httpError = self._get_http_error(reddwarf_error)
return Fault(httpError(str(reddwarf_error), request=request))
except webob.exc.HTTPError as http_error:
LOG.debug(traceback.format_exc())
return Fault(http_error)
except Exception as error:
LOG.exception(error)
return Fault(webob.exc.HTTPInternalServerError(
str(error),
request=request))
def _get_http_error(self, error):
return self.model_exception_map.get(type(error),
webob.exc.HTTPBadRequest)
def _invert_dict_list(self, exception_dict):
"""Flattens values of keys and inverts keys and values.
Example:
{'x': [1, 2, 3], 'y': [4, 5, 6]} converted to
{1: 'x', 2: 'x', 3: 'x', 4: 'y', 5: 'y', 6: 'y'}
"""
inverted_dict = {}
for key, value_list in exception_dict.items():
for value in value_list:
inverted_dict[value] = key
return inverted_dict
def serialize_response(self, action, action_result, accept):
# If an exception is raised here in the base class, it is swallowed,
# and the action_result is returned as-is. For us, that's bad news -
# we never want that to happen except in the case of webob types.
# So we override the behavior here so we can at least log it (raising
# an exception in the base class creates a circular reference issue).
try:
return super(Resource, self).serialize_response(
action, action_result, accept)
except Exception as ex:
# The super class code seems designed to either serialize things
# or pass them back if they're webobs.
if not isinstance(action_result, webob.Response):
LOG.error("unserializable result detected! "
"Exception type: %s Message: %s" % (type(ex), ex))
raise
class Controller(object):
"""Base controller that creates a Resource with default serializers."""
exclude_attr = []
exception_map = {
webob.exc.HTTPUnprocessableEntity: [
exception.UnprocessableEntity,
],
webob.exc.HTTPUnauthorized: [
exception.Forbidden,
],
webob.exc.HTTPBadRequest: [
exception.InvalidModelError,
exception.BadRequest,
exception.CannotResizeToSameSize,
exception.BadValue,
exception.DatabaseAlreadyExists,
exception.UserAlreadyExists,
],
webob.exc.HTTPNotFound: [
exception.NotFound,
exception.ComputeInstanceNotFound,
exception.ModelNotFoundError,
exception.UserNotFound,
exception.DatabaseNotFound,
],
webob.exc.HTTPConflict: [],
webob.exc.HTTPRequestEntityTooLarge: [
exception.OverLimit,
exception.QuotaExceeded,
exception.VolumeQuotaExceeded,
],
webob.exc.HTTPServerError: [
exception.VolumeCreationFailure,
exception.UpdateGuestError,
],
}
def create_resource(self):
serializer = ReddwarfResponseSerializer(
body_serializers={'application/xml': ReddwarfXMLDictSerializer()})
return Resource(
self,
ReddwarfRequestDeserializer(),
serializer,
self.exception_map)
def _extract_limits(self, params):
return dict([(key, params[key]) for key in params.keys()
if key in ["limit", "marker"]])
def _extract_required_params(self, params, model_name):
params = params or {}
model_params = params.get(model_name, {})
return utils.stringify_keys(utils.exclude(model_params,
*self.exclude_attr))
class ReddwarfRequestDeserializer(RequestDeserializer):
"""Break up a Request object into more useful pieces."""
def __init__(self, body_deserializers=None, headers_deserializer=None,
supported_content_types=None):
super(ReddwarfRequestDeserializer, self).__init__(
body_deserializers,
headers_deserializer,
supported_content_types)
self.body_deserializers['application/xml'] = ReddwarfXMLDeserializer()
class ReddwarfXMLDeserializer(XMLDeserializer):
def __init__(self, metadata=None):
"""
:param metadata: information needed to deserialize xml into
a dictionary.
"""
if metadata is None:
metadata = {}
metadata['plurals'] = CUSTOM_PLURALS_METADATA
super(ReddwarfXMLDeserializer, self).__init__(metadata)
def default(self, datastring):
# Sanitize the newlines
# hub-cap: This feels wrong but minidom keeps the newlines
# and spaces as childNodes which is expected behavior.
return {'body': self._from_xml(re.sub(r'((?<=>)\s+)*\n*(\s+(?=<))*',
'', datastring))}
class ReddwarfXMLDictSerializer(openstack_wsgi.XMLDictSerializer):
def __init__(self, metadata=None, xmlns=None):
super(ReddwarfXMLDictSerializer, self).__init__(metadata, XMLNS)
def default(self, data):
# We expect data to be a dictionary containing a single key as the XML
# root, or two keys, the later being "links."
# We expect data to contain a single key which is the XML root,
has_links = False
root_key = None
for key in data:
if key == "links":
has_links = True
elif root_key is None:
root_key = key
else:
msg = "Xml issue: multiple root keys found in dict!: %s" % data
LOG.error(msg)
raise RuntimeError(msg)
if root_key is None:
msg = "Missing root key in dict: %s" % data
LOG.error(msg)
raise RuntimeError(msg)
doc = minidom.Document()
node = self._to_xml_node(doc, self.metadata, root_key, data[root_key])
if has_links:
# Create a links element, and mix it into the node element.
links_node = self._to_xml_node(doc, self.metadata,
'links', data['links'])
node.appendChild(links_node)
return self.to_xml_string(node)
def _to_xml_node(self, doc, metadata, nodename, data):
metadata['attributes'] = CUSTOM_SERIALIZER_METADATA
if hasattr(data, "to_xml"):
return data.to_xml()
return super(ReddwarfXMLDictSerializer, self)._to_xml_node(
doc,
metadata,
nodename,
data)
class ReddwarfResponseSerializer(openstack_wsgi.ResponseSerializer):
def serialize_body(self, response, data, content_type, action):
"""Overrides body serialization in openstack_wsgi.ResponseSerializer.
If the "data" argument is the Result class, its data
method is called and *that* is passed to the superclass implementation
instead of the actual data.
"""
if isinstance(data, Result):
data = data.data(content_type)
super(ReddwarfResponseSerializer, self).serialize_body(
response,
data,
content_type,
action)
def serialize_headers(self, response, data, action):
super(ReddwarfResponseSerializer, self).serialize_headers(
response,
data,
action)
if isinstance(data, Result):
response.status = data.status
class Fault(webob.exc.HTTPException):
"""Error codes for API faults."""
code_wrapper = {
400: webob.exc.HTTPBadRequest,
401: webob.exc.HTTPUnauthorized,
403: webob.exc.HTTPUnauthorized,
404: webob.exc.HTTPNotFound,
}
resp_codes = [int(code) for code in code_wrapper.keys()]
def __init__(self, exception):
"""Create a Fault for the given webob.exc.exception."""
self.wrapped_exc = exception
@staticmethod
def _get_error_name(exc):
# Displays a Red Dwarf specific error name instead of a webob exc name.
named_exceptions = {
'HTTPBadRequest': 'badRequest',
'HTTPUnauthorized': 'unauthorized',
'HTTPForbidden': 'forbidden',
'HTTPNotFound': 'itemNotFound',
'HTTPMethodNotAllowed': 'badMethod',
'HTTPRequestEntityTooLarge': 'overLimit',
'HTTPUnsupportedMediaType': 'badMediaType',
'HTTPInternalServerError': 'instanceFault',
'HTTPNotImplemented': 'notImplemented',
'HTTPServiceUnavailable': 'serviceUnavailable',
}
name = exc.__class__.__name__
if name in named_exceptions:
return named_exceptions[name]
# If the exception isn't in our list, at least strip off the
# HTTP from the name, and then drop the case on the first letter.
name = name.split("HTTP").pop()
name = name[:1].lower() + name[1:]
return name
@webob.dec.wsgify(RequestClass=Request)
def __call__(self, req):
"""Generate a WSGI response based on the exception passed to ctor."""
# Replace the body with fault details.
fault_name = Fault._get_error_name(self.wrapped_exc)
fault_data = {
fault_name: {
'code': self.wrapped_exc.status_int,
}
}
if self.wrapped_exc.detail:
fault_data[fault_name]['message'] = self.wrapped_exc.detail
else:
fault_data[fault_name]['message'] = self.wrapped_exc.explanation
# 'code' is an attribute on the fault tag itself
metadata = {'attributes': {fault_name: 'code'}}
content_type = req.best_match_content_type()
serializer = {
'application/xml': openstack_wsgi.XMLDictSerializer(metadata),
'application/json': openstack_wsgi.JSONDictSerializer(),
}[content_type]
self.wrapped_exc.body = serializer.serialize(fault_data, content_type)
self.wrapped_exc.content_type = content_type
return self.wrapped_exc
class ContextMiddleware(openstack_wsgi.Middleware):
def __init__(self, application):
self.admin_roles = CONF.admin_roles
super(ContextMiddleware, self).__init__(application)
def _extract_limits(self, params):
return dict([(key, params[key]) for key in params.keys()
if key in ["limit", "marker"]])
def process_request(self, request):
tenant_id = request.headers.get('X-Tenant-Id', None)
auth_tok = request.headers["X-Auth-Token"]
user = request.headers.get('X-User', None)
roles = request.headers.get('X-Role', '').split(',')
is_admin = False
for role in roles:
if role.lower() in self.admin_roles:
is_admin = True
break
limits = self._extract_limits(request.params)
context = rd_context.ReddwarfContext(auth_tok=auth_tok,
tenant=tenant_id,
user=user,
is_admin=is_admin,
limit=limits.get('limit'),
marker=limits.get('marker'))
request.environ[CONTEXT_KEY] = context
@classmethod
def factory(cls, global_config, **local_config):
def _factory(app):
LOG.debug(_("Created context middleware with config: %s") %
local_config)
return cls(app)
return _factory
class FaultWrapper(openstack_wsgi.Middleware):
"""Calls down the middleware stack, making exceptions into faults."""
@webob.dec.wsgify(RequestClass=openstack_wsgi.Request)
def __call__(self, req):
try:
resp = req.get_response(self.application)
if resp.status_int in Fault.resp_codes:
for (header, value) in resp._headerlist:
if header == "Content-Type" and \
value == "text/plain; charset=UTF-8":
return Fault(Fault.code_wrapper[resp.status_int]())
return resp
return resp
except Exception as ex:
LOG.exception(_("Caught error: %s"), unicode(ex))
exc = webob.exc.HTTPInternalServerError()
return Fault(exc)
@classmethod
def factory(cls, global_config, **local_config):
def _factory(app):
return cls(app)
return _factory