Source code for keystone.common.wsgi
# Copyright 2012 OpenStack Foundation
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2010 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.
"""Utility methods for working with WSGI servers."""
import functools
import itertools
import re
import wsgiref.util
import oslo_i18n
from oslo_log import log
from oslo_serialization import jsonutils
from oslo_utils import importutils
from oslo_utils import strutils
import routes.middleware
import six
from six.moves import http_client
import webob.dec
import webob.exc
from keystone.common import authorization
from keystone.common import json_home
from keystone.common import request as request_mod
from keystone.common import utils
import keystone.conf
from keystone import exception
from keystone.i18n import _
from keystone.models import token_model
CONF = keystone.conf.CONF
LOG = log.getLogger(__name__)
# Environment variable used to pass the request context
CONTEXT_ENV = 'openstack.context'
# Environment variable used to pass the request params
PARAMS_ENV = 'openstack.params'
JSON_ENCODE_CONTENT_TYPES = set(['application/json',
'application/json-home'])
[docs]def validate_token_bind(context, token_ref):
bind_mode = CONF.token.enforce_token_bind
if bind_mode == 'disabled':
return
if not isinstance(token_ref, token_model.KeystoneToken):
raise exception.UnexpectedError(_('token reference must be a '
'KeystoneToken type, got: %s') %
type(token_ref))
bind = token_ref.bind
# permissive and strict modes don't require there to be a bind
permissive = bind_mode in ('permissive', 'strict')
if not bind:
if permissive:
# no bind provided and none required
return
else:
msg = _('No bind information present in token.')
LOG.info(msg)
raise exception.Unauthorized(msg)
# get the named mode if bind_mode is not one of the known
name = None if permissive or bind_mode == 'required' else bind_mode
if name and name not in bind:
msg = (_('Named bind mode %(name)s not in bind information') %
{'name': name})
LOG.info(msg)
raise exception.Unauthorized(msg)
for bind_type, identifier in bind.items():
if bind_type == 'kerberos':
if (context['environment'].get('AUTH_TYPE', '').lower() !=
'negotiate'):
msg = _('Kerberos credentials required and not present')
LOG.info(msg)
raise exception.Unauthorized(msg)
if context['environment'].get('REMOTE_USER') != identifier:
msg = _('Kerberos credentials do not match those in bind')
LOG.info(msg)
raise exception.Unauthorized(msg)
LOG.info('Kerberos bind authentication successful')
elif bind_mode == 'permissive':
LOG.debug(("Ignoring unknown bind (due to permissive mode): "
"{%(bind_type)s: %(identifier)s}"), {
'bind_type': bind_type,
'identifier': identifier})
else:
msg = _('Could not verify unknown bind: {%(bind_type)s: '
'%(identifier)s}') % {
'bind_type': bind_type,
'identifier': identifier}
LOG.info(msg)
raise exception.Unauthorized(msg)
[docs]def best_match_language(req):
"""Determine the best available locale.
This returns best available locale based on the Accept-Language HTTP
header passed in the request.
"""
if not req.accept_language:
return None
return req.accept_language.best_match(
oslo_i18n.get_available_languages('keystone'))
[docs]class BaseApplication(object):
"""Base WSGI application wrapper. Subclasses need to implement __call__."""
[docs] @classmethod
def factory(cls, global_config, **local_config):
"""Used for paste app factories in paste.deploy config files.
Any local configuration (that is, values under the [app:APPNAME]
section of the paste config) will be passed into the `__init__` method
as kwargs.
A hypothetical configuration would look like:
[app:wadl]
latest_version = 1.3
paste.app_factory = keystone.fancy_api:Wadl.factory
which would result in a call to the `Wadl` class as
import keystone.fancy_api
keystone.fancy_api.Wadl(latest_version='1.3')
You could of course re-implement the `factory` method in subclasses,
but using the kwarg passing it shouldn't be necessary.
"""
return cls(**local_config)
def __call__(self, environ, start_response):
r"""Provide subclasses on how to implement __call__.
Probably like this:
@webob.dec.wsgify()
def __call__(self, req):
# Any of the following objects work as responses:
# Option 1: simple string
res = 'message\n'
# Option 2: a nicely formatted HTTP exception page
res = exc.HTTPForbidden(explanation='Nice try')
# Option 3: a webob Response object (in case you need to play with
# headers, or you want to be treated like an iterable, or or or)
res = Response();
res.app_iter = open('somefile')
# Option 4: any wsgi app to be run next
res = self.application
# Option 5: you can get a Response object for a wsgi app, too, to
# play with headers etc
res = req.get_response(self.application)
# You can then just return your response...
return res
# ... or set req.response and return None.
req.response = res
See the end of http://pythonpaste.org/webob/modules/dec.html
for more info.
"""
raise NotImplementedError('You must implement __call__')
[docs]class Application(BaseApplication):
@webob.dec.wsgify(RequestClass=request_mod.Request)
def __call__(self, req):
arg_dict = req.environ['wsgiorg.routing_args'][1]
action = arg_dict.pop('action')
del arg_dict['controller']
params = req.environ.get(PARAMS_ENV, {})
params.update(arg_dict)
# TODO(termie): do some basic normalization on methods
method = getattr(self, action)
# NOTE(morganfainberg): use the request method to normalize the
# response code between GET and HEAD requests. The HTTP status should
# be the same.
LOG.info('%(req_method)s %(uri)s', {
'req_method': req.method.upper(),
'uri': wsgiref.util.request_uri(req.environ),
})
params = self._normalize_dict(params)
try:
result = method(req, **params)
except exception.Unauthorized as e:
LOG.warning(
"Authorization failed. %(exception)s from "
"%(remote_addr)s",
{'exception': e, 'remote_addr': req.environ['REMOTE_ADDR']})
return render_exception(e,
context=req.context_dict,
user_locale=best_match_language(req))
except exception.Error as e:
if isinstance(e, exception.UnexpectedError):
LOG.exception(six.text_type(e))
else:
LOG.warning(six.text_type(e))
return render_exception(e,
context=req.context_dict,
user_locale=best_match_language(req))
except TypeError as e:
LOG.exception(six.text_type(e))
return render_exception(exception.ValidationError(e),
context=req.context_dict,
user_locale=best_match_language(req))
except Exception as e:
LOG.exception(six.text_type(e))
return render_exception(exception.UnexpectedError(exception=e),
context=req.context_dict,
user_locale=best_match_language(req))
if result is None:
return render_response(
status=(http_client.NO_CONTENT,
http_client.responses[http_client.NO_CONTENT]))
elif isinstance(result, six.string_types):
return result
elif isinstance(result, webob.Response):
return result
elif isinstance(result, webob.exc.WSGIHTTPException):
return result
response_code = self._get_response_code(req)
return render_response(body=result,
status=response_code,
method=req.method)
def _get_response_code(self, req):
req_method = req.environ['REQUEST_METHOD']
controller = importutils.import_class('keystone.common.controller')
code = None
if isinstance(self, controller.V3Controller) and req_method == 'POST':
code = (http_client.CREATED,
http_client.responses[http_client.CREATED])
return code
def _normalize_arg(self, arg):
return arg.replace(':', '_').replace('-', '_')
def _normalize_dict(self, d):
return {self._normalize_arg(k): v for (k, v) in d.items()}
[docs] def assert_admin(self, request):
"""Ensure the user is an admin.
:raises keystone.exception.Unauthorized: if a token could not be
found/authorized, a user is invalid, or a tenant is
invalid/not scoped.
:raises keystone.exception.Forbidden: if the user is not an admin and
does not have the admin role
"""
authorization.assert_admin(self, request)
def _attribute_is_empty(self, ref, attribute):
"""Determine if the attribute in ref is empty or None."""
return ref.get(attribute) is None or ref.get(attribute) == ''
def _require_attribute(self, ref, attribute):
"""Ensure the reference contains the specified attribute.
Raise a ValidationError if the given attribute is not present
"""
if self._attribute_is_empty(ref, attribute):
msg = _('%s field is required and cannot be empty') % attribute
raise exception.ValidationError(message=msg)
def _require_attributes(self, ref, attrs):
"""Ensure the reference contains the specified attributes.
Raise a ValidationError if any of the given attributes is not present
"""
missing_attrs = [attribute for attribute in attrs
if self._attribute_is_empty(ref, attribute)]
if missing_attrs:
msg = _('%s field(s) cannot be empty') % ', '.join(missing_attrs)
raise exception.ValidationError(message=msg)
[docs] @classmethod
def base_url(cls, context, endpoint_type):
url = CONF['%s_endpoint' % endpoint_type]
if url:
substitutions = dict(
itertools.chain(CONF.items(), CONF.eventlet_server.items()))
url = url % substitutions
elif 'environment' in context:
url = wsgiref.util.application_uri(context['environment'])
# remove version from the URL as it may be part of SCRIPT_NAME but
# it should not be part of base URL
url = re.sub(r'/v(3|(2\.0))/*$', '', url)
# now remove the standard port
url = utils.remove_standard_port(url)
else:
# if we don't have enough information to come up with a base URL,
# then fall back to localhost. This should never happen in
# production environment.
url = 'http://localhost:%d' % CONF.eventlet_server.public_port
return url.rstrip('/')
[docs]def middleware_exceptions(method):
@functools.wraps(method)
def _inner(self, request):
try:
return method(self, request)
except exception.Error as e:
LOG.warning(six.text_type(e))
return render_exception(e, request=request,
user_locale=best_match_language(request))
except TypeError as e:
LOG.exception(six.text_type(e))
return render_exception(exception.ValidationError(e),
request=request,
user_locale=best_match_language(request))
except Exception as e:
LOG.exception(six.text_type(e))
return render_exception(exception.UnexpectedError(exception=e),
request=request,
user_locale=best_match_language(request))
return _inner
[docs]class Middleware(Application):
"""Base WSGI middleware.
These classes require an application to be
initialized that will be called next. By default the middleware will
simply call its wrapped app, or you can override __call__ to customize its
behavior.
"""
[docs] @classmethod
def factory(cls, global_config):
"""Used for paste app factories in paste.deploy config files."""
def _factory(app):
return cls(app)
return _factory
def __init__(self, application):
super(Middleware, self).__init__()
self.application = application
[docs] def process_request(self, request):
"""Called on each request.
If this returns None, the next application down the stack will be
executed. If it returns a response then that response will be returned
and execution will stop here.
"""
return None
[docs] def process_response(self, request, response):
"""Do whatever you'd like to the response, based on the request."""
return response
@webob.dec.wsgify(RequestClass=request_mod.Request)
@middleware_exceptions
def __call__(self, request):
response = self.process_request(request)
if response:
return response
response = request.get_response(self.application)
return self.process_response(request, response)
[docs]class Debug(Middleware):
"""Helper class for debugging a WSGI application.
Can be inserted into any WSGI application chain to get information
about the request and response.
"""
@webob.dec.wsgify(RequestClass=request_mod.Request)
def __call__(self, req):
if not hasattr(LOG, 'isEnabledFor') or LOG.isEnabledFor(LOG.debug):
LOG.debug('%s %s %s', ('*' * 20), 'REQUEST ENVIRON', ('*' * 20))
for key, value in req.environ.items():
LOG.debug('%s = %s', key,
strutils.mask_password(value))
LOG.debug('')
LOG.debug('%s %s %s', ('*' * 20), 'REQUEST BODY', ('*' * 20))
for line in req.body_file:
LOG.debug('%s', strutils.mask_password(line))
LOG.debug('')
resp = req.get_response(self.application)
if not hasattr(LOG, 'isEnabledFor') or LOG.isEnabledFor(LOG.debug):
LOG.debug('%s %s %s', ('*' * 20), 'RESPONSE HEADERS', ('*' * 20))
for (key, value) in resp.headers.items():
LOG.debug('%s = %s', key, value)
LOG.debug('')
resp.app_iter = self.print_generator(resp.app_iter)
return resp
[docs] @staticmethod
def print_generator(app_iter):
"""Iterator that prints the contents of a wrapper string."""
LOG.debug('%s %s %s', ('*' * 20), 'RESPONSE BODY', ('*' * 20))
for part in app_iter:
LOG.debug(part)
yield part
[docs]class Router(object):
"""WSGI middleware that maps incoming requests to WSGI apps."""
def __init__(self, mapper):
"""Create a router for the given routes.Mapper.
Each route in `mapper` must specify a 'controller', which is a
WSGI app to call. You'll probably want to specify an 'action' as
well and have your controller be an object that can route
the request to the action-specific method.
Examples:
mapper = routes.Mapper()
sc = ServerController()
# Explicit mapping of one route to a controller+action
mapper.connect(None, '/svrlist', controller=sc, action='list')
# Actions are all implicitly defined
mapper.resource('server', 'servers', controller=sc)
# Pointing to an arbitrary WSGI app. You can specify the
# {path_info:.*} parameter so the target app can be handed just that
# section of the URL.
mapper.connect(None, '/v1.0/{path_info:.*}', controller=BlogApp())
"""
self.map = mapper
self._router = routes.middleware.RoutesMiddleware(self._dispatch,
self.map)
@webob.dec.wsgify(RequestClass=request_mod.Request)
def __call__(self, req):
"""Route the incoming request to a controller based on self.map.
If no match, return a 404.
"""
return self._router
@staticmethod
@webob.dec.wsgify(RequestClass=request_mod.Request)
def _dispatch(req):
"""Dispatch the request to the appropriate controller.
Called by self._router after matching the incoming request to a route
and putting the information into req.environ. Either returns 404
or the routed WSGI app's response.
"""
match = req.environ['wsgiorg.routing_args'][1]
if not match:
msg = (_('(%(url)s): The resource could not be found.') %
{'url': req.url})
return render_exception(exception.NotFound(msg),
request=req,
user_locale=best_match_language(req))
app = match['controller']
return app
[docs]class ComposingRouter(Router):
def __init__(self, mapper=None, routers=None):
if mapper is None:
mapper = routes.Mapper()
if routers is None:
routers = []
for router in routers:
router.add_routes(mapper)
super(ComposingRouter, self).__init__(mapper)
[docs]class ComposableRouter(Router):
"""Router that supports use by ComposingRouter."""
def __init__(self, mapper=None):
if mapper is None:
mapper = routes.Mapper()
self.add_routes(mapper)
super(ComposableRouter, self).__init__(mapper)
[docs]class ExtensionRouter(Router):
"""A router that allows extensions to supplement or overwrite routes.
Expects to be subclassed.
"""
def __init__(self, application, mapper=None):
if mapper is None:
mapper = routes.Mapper()
self.application = application
self.add_routes(mapper)
mapper.connect('/{path_info:.*}', controller=self.application)
super(ExtensionRouter, self).__init__(mapper)
[docs] @classmethod
def factory(cls, global_config, **local_config):
"""Used for paste app factories in paste.deploy config files.
Any local configuration (that is, values under the [filter:APPNAME]
section of the paste config) will be passed into the `__init__` method
as kwargs.
A hypothetical configuration would look like:
[filter:analytics]
redis_host = 127.0.0.1
paste.filter_factory = keystone.analytics:Analytics.factory
which would result in a call to the `Analytics` class as
import keystone.analytics
keystone.analytics.Analytics(app, redis_host='127.0.0.1')
You could of course re-implement the `factory` method in subclasses,
but using the kwarg passing it shouldn't be necessary.
"""
def _factory(app):
conf = global_config.copy()
conf.update(local_config)
return cls(app, **local_config)
return _factory
[docs]class RoutersBase(object):
"""Base class for Routers."""
def __init__(self):
self.v3_resources = []
[docs] def append_v3_routers(self, mapper, routers):
"""Append v3 routers.
Subclasses should override this method to map its routes.
Use self._add_resource() to map routes for a resource.
"""
def _add_resource(self, mapper, controller, path, rel,
get_action=None, head_action=None, get_head_action=None,
put_action=None, post_action=None, patch_action=None,
delete_action=None, get_post_action=None,
path_vars=None, status=json_home.Status.STABLE,
new_path=None):
if get_head_action:
getattr(controller, get_head_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=get_head_action,
conditions=dict(method=['GET', 'HEAD']))
if get_action:
getattr(controller, get_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=get_action,
conditions=dict(method=['GET']))
if head_action:
getattr(controller, head_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=head_action,
conditions=dict(method=['HEAD']))
if put_action:
getattr(controller, put_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=put_action,
conditions=dict(method=['PUT']))
if post_action:
getattr(controller, post_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=post_action,
conditions=dict(method=['POST']))
if patch_action:
getattr(controller, patch_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=patch_action,
conditions=dict(method=['PATCH']))
if delete_action:
getattr(controller, delete_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=delete_action,
conditions=dict(method=['DELETE']))
if get_post_action:
getattr(controller, get_post_action) # ensure the attribute exists
mapper.connect(path, controller=controller, action=get_post_action,
conditions=dict(method=['GET', 'POST']))
resource_data = dict()
if path_vars:
resource_data['href-template'] = new_path or path
resource_data['href-vars'] = path_vars
else:
resource_data['href'] = new_path or path
json_home.Status.update_resource_data(resource_data, status)
self.v3_resources.append((rel, resource_data))
[docs]class V3ExtensionRouter(ExtensionRouter, RoutersBase):
"""Base class for V3 extension router."""
def __init__(self, application, mapper=None):
self.v3_resources = list()
super(V3ExtensionRouter, self).__init__(application, mapper)
def _update_version_response(self, response_data):
response_data['resources'].update(self.v3_resources)
@webob.dec.wsgify(RequestClass=request_mod.Request)
def __call__(self, request):
if request.path_info != '/':
# Not a request for version info so forward to super.
return super(V3ExtensionRouter, self).__call__(request)
response = request.get_response(self.application)
if response.status_code != http_client.OK:
# The request failed, so don't update the response.
return response
if response.headers['Content-Type'] != 'application/json-home':
# Not a request for JSON Home document, so don't update the
# response.
return response
response_data = jsonutils.loads(response.body)
self._update_version_response(response_data)
response.body = jsonutils.dump_as_bytes(response_data,
cls=utils.SmarterEncoder)
return response
[docs]def render_response(body=None, status=None, headers=None, method=None):
"""Form a WSGI response."""
if headers is None:
headers = []
else:
headers = list(headers)
headers.append(('Vary', 'X-Auth-Token'))
if body is None:
body = b''
status = status or (http_client.NO_CONTENT,
http_client.responses[http_client.NO_CONTENT])
else:
content_types = [v for h, v in headers if h == 'Content-Type']
if content_types:
content_type = content_types[0]
else:
content_type = None
if content_type is None or content_type in JSON_ENCODE_CONTENT_TYPES:
body = jsonutils.dump_as_bytes(body, cls=utils.SmarterEncoder)
if content_type is None:
headers.append(('Content-Type', 'application/json'))
status = status or (http_client.OK,
http_client.responses[http_client.OK])
# NOTE(davechen): `mod_wsgi` follows the standards from pep-3333 and
# requires the value in response header to be binary type(str) on python2,
# unicode based string(str) on python3, or else keystone will not work
# under apache with `mod_wsgi`.
# keystone needs to check the data type of each header and convert the
# type if needed.
# see bug:
# https://bugs.launchpad.net/keystone/+bug/1528981
# see pep-3333:
# https://www.python.org/dev/peps/pep-3333/#a-note-on-string-types
# see source from mod_wsgi:
# https://github.com/GrahamDumpleton/mod_wsgi(methods:
# wsgi_convert_headers_to_bytes(...), wsgi_convert_string_to_bytes(...)
# and wsgi_validate_header_value(...)).
def _convert_to_str(headers):
str_headers = []
for header in headers:
str_header = []
for value in header:
if not isinstance(value, str):
str_header.append(str(value))
else:
str_header.append(value)
# convert the list to the immutable tuple to build the headers.
# header's key/value will be guaranteed to be str type.
str_headers.append(tuple(str_header))
return str_headers
headers = _convert_to_str(headers)
resp = webob.Response(body=body,
status='%d %s' % status,
headerlist=headers,
charset='utf-8')
if method and method.upper() == 'HEAD':
# NOTE(morganfainberg): HEAD requests should return the same status
# as a GET request and same headers (including content-type and
# content-length). The webob.Response object automatically changes
# content-length (and other headers) if the body is set to b''. Capture
# all headers and reset them on the response object after clearing the
# body. The body can only be set to a binary-type (not TextType or
# NoneType), so b'' is used here and should be compatible with
# both py2x and py3x.
stored_headers = resp.headers.copy()
resp.body = b''
for header, value in stored_headers.items():
resp.headers[header] = value
return resp
[docs]def render_exception(error, context=None, request=None, user_locale=None):
"""Form a WSGI response based on the current error."""
error_message = error.args[0]
message = oslo_i18n.translate(error_message, desired_locale=user_locale)
if message is error_message:
# translate() didn't do anything because it wasn't a Message,
# convert to a string.
message = six.text_type(message)
body = {'error': {
'code': error.code,
'title': error.title,
'message': message,
}}
headers = []
if isinstance(error, exception.AuthPluginException):
body['error']['identity'] = error.authentication
elif isinstance(error, exception.Unauthorized):
# NOTE(gyee): we only care about the request environment in the
# context. Also, its OK to pass the environment as it is read-only in
# Application.base_url()
local_context = {}
if request:
local_context = {'environment': request.environ}
elif context and 'environment' in context:
local_context = {'environment': context['environment']}
url = Application.base_url(local_context, 'public')
headers.append(('WWW-Authenticate', 'Keystone uri="%s"' % url))
return render_response(status=(error.code, error.title),
body=body,
headers=headers)
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