swift/test/unit/common/middleware/helpers.py
Tim Burke 42adbe561f Respect X-Backend-Etag-Is-At headers from left of SLO
If a middleware left of SLO wants to override the ETag for a large
object, it will need to send a X-Backend-Etag-Is-At on GETs if it wants
to be at all performant. This would work fine coming out of the object
controller (which would look at the headers in the response, figure out
what's the real conditional etag, and pass it to swob.Response), and
even encryption (which would do the same), but at SLO, we'd just replace
the ETag, flag it as a conditional response, and let swob assume the
*SLO* ETag is the conditional one.

Now, SLO will jump through the same resolve_backend_etag_is_at hoops that
other parts of the proxy have to deal with. This allows If-Match and
If-None-Match to work correctly if/when swift3 stores an S3-compatible
multipart-upload ETag.

Change-Id: Ibbf59d38d7bcc9c485b1d5305548144025d77441
2018-03-26 23:50:43 +00:00

218 lines
7.8 KiB
Python

# Copyright (c) 2013 OpenStack Foundation
#
# 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.
# This stuff can't live in test/unit/__init__.py due to its swob dependency.
from collections import defaultdict, namedtuple
from hashlib import md5
from swift.common import swob
from swift.common.header_key_dict import HeaderKeyDict
from swift.common.request_helpers import is_user_meta, \
is_object_transient_sysmeta, resolve_etag_is_at_header
from swift.common.swob import HTTPNotImplemented
from swift.common.utils import split_path
from test.unit import FakeLogger, FakeRing
class LeakTrackingIter(object):
def __init__(self, inner_iter, mark_closed, path):
self.inner_iter = inner_iter
self.mark_closed = mark_closed
self.path = path
def __iter__(self):
for x in self.inner_iter:
yield x
def close(self):
self.mark_closed(self.path)
FakeSwiftCall = namedtuple('FakeSwiftCall', ['method', 'path', 'headers'])
class FakeSwift(object):
"""
A good-enough fake Swift proxy server to use in testing middleware.
"""
ALLOWED_METHODS = [
'PUT', 'POST', 'DELETE', 'GET', 'HEAD', 'OPTIONS', 'REPLICATE']
def __init__(self):
self._calls = []
self._unclosed_req_paths = defaultdict(int)
self.req_method_paths = []
self.swift_sources = []
self.txn_ids = []
self.uploaded = {}
# mapping of (method, path) --> (response class, headers, body)
self._responses = {}
self.logger = FakeLogger('fake-swift')
self.account_ring = FakeRing()
self.container_ring = FakeRing()
self.get_object_ring = lambda policy_index: FakeRing()
def _find_response(self, method, path):
resp = self._responses[(method, path)]
if isinstance(resp, list):
try:
resp = resp.pop(0)
except IndexError:
raise IndexError("Didn't find any more %r "
"in allowed responses" % (
(method, path),))
return resp
def __call__(self, env, start_response):
method = env['REQUEST_METHOD']
if method not in self.ALLOWED_METHODS:
raise HTTPNotImplemented()
path = env['PATH_INFO']
_, acc, cont, obj = split_path(env['PATH_INFO'], 0, 4,
rest_with_last=True)
if env.get('QUERY_STRING'):
path += '?' + env['QUERY_STRING']
if 'swift.authorize' in env:
resp = env['swift.authorize'](swob.Request(env))
if resp:
return resp(env, start_response)
req = swob.Request(env)
self.swift_sources.append(env.get('swift.source'))
self.txn_ids.append(env.get('swift.trans_id'))
try:
resp_class, raw_headers, body = self._find_response(method, path)
headers = HeaderKeyDict(raw_headers)
except KeyError:
if (env.get('QUERY_STRING')
and (method, env['PATH_INFO']) in self._responses):
resp_class, raw_headers, body = self._find_response(
method, env['PATH_INFO'])
headers = HeaderKeyDict(raw_headers)
elif method == 'HEAD' and ('GET', path) in self._responses:
resp_class, raw_headers, body = self._find_response(
'GET', path)
body = None
headers = HeaderKeyDict(raw_headers)
elif method == 'GET' and obj and path in self.uploaded:
resp_class = swob.HTTPOk
headers, body = self.uploaded[path]
else:
raise KeyError("Didn't find %r in allowed responses" % (
(method, path),))
# simulate object PUT
if method == 'PUT' and obj:
put_body = ''.join(iter(env['wsgi.input'].read, ''))
if 'swift.callback.update_footers' in env:
footers = HeaderKeyDict()
env['swift.callback.update_footers'](footers)
req.headers.update(footers)
etag = md5(put_body).hexdigest()
headers.setdefault('Etag', etag)
headers.setdefault('Content-Length', len(put_body))
# keep it for subsequent GET requests later
self.uploaded[path] = (dict(req.headers), put_body)
if "CONTENT_TYPE" in env:
self.uploaded[path][0]['Content-Type'] = env["CONTENT_TYPE"]
# simulate object POST
elif method == 'POST' and obj:
metadata, data = self.uploaded.get(path, ({}, None))
# select items to keep from existing...
new_metadata = dict(
(k, v) for k, v in metadata.items()
if (not is_user_meta('object', k) and not
is_object_transient_sysmeta(k)))
# apply from new
new_metadata.update(
dict((k, v) for k, v in req.headers.items()
if (is_user_meta('object', k) or
is_object_transient_sysmeta(k) or
k.lower == 'content-type')))
self.uploaded[path] = new_metadata, data
# note: tests may assume this copy of req_headers is case insensitive
# so we deliberately use a HeaderKeyDict
self._calls.append(
FakeSwiftCall(method, path, HeaderKeyDict(req.headers)))
# Apply conditional etag overrides
conditional_etag = resolve_etag_is_at_header(req, headers)
# range requests ought to work, hence conditional_response=True
if isinstance(body, list):
resp = resp_class(
req=req, headers=headers, app_iter=body,
conditional_response=req.method in ('GET', 'HEAD'),
conditional_etag=conditional_etag)
else:
resp = resp_class(
req=req, headers=headers, body=body,
conditional_response=req.method in ('GET', 'HEAD'),
conditional_etag=conditional_etag)
wsgi_iter = resp(env, start_response)
self.mark_opened(path)
return LeakTrackingIter(wsgi_iter, self.mark_closed, path)
def mark_opened(self, path):
self._unclosed_req_paths[path] += 1
def mark_closed(self, path):
self._unclosed_req_paths[path] -= 1
@property
def unclosed_requests(self):
return {path: count
for path, count in self._unclosed_req_paths.items()
if count > 0}
@property
def calls(self):
return [(method, path) for method, path, headers in self._calls]
@property
def headers(self):
return [headers for method, path, headers in self._calls]
@property
def calls_with_headers(self):
return self._calls
@property
def call_count(self):
return len(self._calls)
def register(self, method, path, response_class, headers, body=''):
self._responses[(method, path)] = (response_class, headers, body)
def register_responses(self, method, path, responses):
self._responses[(method, path)] = list(responses)
class FakeAppThatExcepts(object):
MESSAGE = "We take exception to that!"
def __init__(self, exception_class=Exception):
self.exception_class = exception_class
def __call__(self, env, start_response):
raise self.exception_class(self.MESSAGE)