openstack/python-keystoneclient
Code Issues Proposed changes

Versioned Endpoint hack for Sessions

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To maintain compatibility we must allow people to specify a versioned
URL in the service catalog but allow the plugins to return a different
URL to users.

We need this to be a general approach as other services will likely have
a similar problem with their catalog.

The expectation here is that a client will register the catalog hack at
import time rather than for every request.

Closes-Bug: #1335726
Change-Id: I244f0ec3acca39fd1b2a2c5883abc06ec10eddc7
This commit is contained in:
Jamie Lennox
2014-04-28 12:20:46 +10:00
parent 3305c7be4b
commit ec57b35bc8
5 changed files with 198 additions and 1 deletions
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54
keystoneclient/_discover.py
View File

@@ -22,6 +22,7 @@ raw data specified in version discovery responses.
"""
import logging
import re
from keystoneclient import exceptions
from keystoneclient import utils
@@ -262,3 +263,56 @@ class Discover(object):
"""
data = self.data_for(version, **kwargs)
return data['url'] if data else None
class _VersionHacks(object):
"""A container to abstract the list of version hacks.
This could be done as simply a dictionary but is abstracted like this to
make for easier testing.
"""
def __init__(self):
self._discovery_data = {}
def add_discover_hack(self, service_type, old, new=''):
"""Add a new hack for a service type.
:param str service_type: The service_type in the catalog.
:param re.RegexObject old: The pattern to use.
:param str new: What to replace the pattern with.
"""
hacks = self._discovery_data.setdefault(service_type, [])
hacks.append((old, new))
def get_discover_hack(self, service_type, url):
"""Apply the catalog hacks and figure out an unversioned endpoint.
:param str service_type: the service_type to look up.
:param str url: The original url that came from a service_catalog.
:return: Either the unversioned url or the one from the catalog to try.
"""
for old, new in self._discovery_data.get(service_type, []):
new_string, number_of_subs_made = old.subn(new, url)
if number_of_subs_made > 0:
return new_string
return url
_VERSION_HACKS = _VersionHacks()
_VERSION_HACKS.add_discover_hack('identity', re.compile('/v2.0/?$'), '/')
def get_catalog_discover_hack(service_type, url):
"""Apply the catalog hacks and figure out an unversioned endpoint.
This function is internal to keystoneclient.
:param str service_type: the service_type to look up.
:param str url: The original url that came from a service_catalog.
:return: Either the unversioned url or the one from the catalog to try.
"""
return _VERSION_HACKS.get_discover_hack(service_type, url)

9
keystoneclient/auth/identity/base.py
View File

@@ -201,8 +201,15 @@ class BaseIdentityPlugin(base.BaseAuthPlugin):
# defaulting to the most recent version.
return url
# NOTE(jamielennox): For backwards compatibility people might have a
# versioned endpoint in their catalog even though they want to use
# other endpoint versions. So we support a list of client defined
# situations where we can strip the version component from a URL before
# doing discovery.
hacked_url = _discover.get_catalog_discover_hack(service_type, url)
try:
disc = self.get_discovery(session, url, authenticated=False)
disc = self.get_discovery(session, hacked_url, authenticated=False)
except (exceptions.DiscoveryFailure,
exceptions.HTTPError,
exceptions.ConnectionError):

31
keystoneclient/discover.py
View File

@@ -266,3 +266,34 @@ class Discover(_discover.Discover):
"""
version_data = self._calculate_version(version, unstable)
return self._create_client(version_data, **kwargs)
def add_catalog_discover_hack(service_type, old, new):
"""Adds a version removal rule for a particular service.
Originally deployments of OpenStack would contain a versioned endpoint in
the catalog for different services. E.g. an identity service might look
like ``http://localhost:5000/v2.0``. This is a problem when we want to use
a different version like v3.0 as there is no way to tell where it is
located. We cannot simply change all service catalogs either so there must
be a way to handle the older style of catalog.
This function adds a rule for a given service type that if part of the URL
matches a given regular expression in *old* then it will be replaced with
the *new* value. This will replace all instances of old with new. It should
therefore contain a regex anchor.
For example the included rule states::
add_catalog_version_hack('identity', re.compile('/v2.0/?$'), '/')
so if the catalog retrieves an *identity* URL that ends with /v2.0 or
/v2.0/ then it should replace it simply with / to fix the user's catalog.
:param str service_type: The service type as defined in the catalog that
the rule will apply to.
:param re.RegexObject old: The regular expression to search for and replace
if found.
:param str new: The new string to replace the pattern with.
"""
_discover._VERSION_HACKS.add_discover_hack(service_type, old, new)

68
keystoneclient/tests/auth/test_identity_common.py
View File

@@ -286,3 +286,71 @@ class V2(CommonIdentityTests, utils.TestCase):
def stub_auth(self, **kwargs):
self.stub_url('POST', ['tokens'], **kwargs)
class CatalogHackTests(utils.TestCase):
TEST_URL = 'http://keystone.server:5000/v2.0'
OTHER_URL = 'http://other.server:5000/path'
IDENTITY = 'identity'
BASE_URL = 'http://keystone.server:5000/'
V2_URL = BASE_URL + 'v2.0'
V3_URL = BASE_URL + 'v3'
def test_getting_endpoints(self):
disc = fixture.DiscoveryList(href=self.BASE_URL)
self.stub_url('GET',
['/'],
base_url=self.BASE_URL,
json=disc)
token = fixture.V2Token()
service = token.add_service(self.IDENTITY)
service.add_endpoint(public=self.V2_URL,
admin=self.V2_URL,
internal=self.V2_URL)
self.stub_url('POST',
['tokens'],
base_url=self.V2_URL,
json=token)
v2_auth = v2.Password(self.V2_URL,
username=uuid.uuid4().hex,
password=uuid.uuid4().hex)
sess = session.Session(auth=v2_auth)
endpoint = sess.get_endpoint(service_type=self.IDENTITY,
interface='public',
version=(3, 0))
self.assertEqual(self.V3_URL, endpoint)
def test_returns_original_when_discover_fails(self):
token = fixture.V2Token()
service = token.add_service(self.IDENTITY)
service.add_endpoint(public=self.V2_URL,
admin=self.V2_URL,
internal=self.V2_URL)
self.stub_url('POST',
['tokens'],
base_url=self.V2_URL,
json=token)
self.stub_url('GET', [], base_url=self.BASE_URL, status_code=404)
v2_auth = v2.Password(self.V2_URL,
username=uuid.uuid4().hex,
password=uuid.uuid4().hex)
sess = session.Session(auth=v2_auth)
endpoint = sess.get_endpoint(service_type=self.IDENTITY,
interface='public',
version=(3, 0))
self.assertEqual(self.V2_URL, endpoint)

37
keystoneclient/tests/test_discovery.py
View File

@@ -10,6 +10,7 @@
# License for the specific language governing permissions and limitations
# under the License.
import re
import uuid
import six
@@ -772,6 +773,42 @@ class DiscoverQueryTests(utils.TestCase):
self.assertEqual(1, len(versions))
class CatalogHackTests(utils.TestCase):
TEST_URL = 'http://keystone.server:5000/v2.0'
OTHER_URL = 'http://other.server:5000/path'
IDENTITY = 'identity'
BASE_URL = 'http://keystone.server:5000/'
V2_URL = BASE_URL + 'v2.0'
V3_URL = BASE_URL + 'v3'
def setUp(self):
super(CatalogHackTests, self).setUp()
self.hacks = _discover._VersionHacks()
self.hacks.add_discover_hack(self.IDENTITY,
re.compile('/v2.0/?$'),
'/')
def test_version_hacks(self):
self.assertEqual(self.BASE_URL,
self.hacks.get_discover_hack(self.IDENTITY,
self.V2_URL))
self.assertEqual(self.BASE_URL,
self.hacks.get_discover_hack(self.IDENTITY,
self.V2_URL + '/'))
self.assertEqual(self.OTHER_URL,
self.hacks.get_discover_hack(self.IDENTITY,
self.OTHER_URL))
def test_ignored_non_service_type(self):
self.assertEqual(self.V2_URL,
self.hacks.get_discover_hack('other', self.V2_URL))
class DiscoverUtils(utils.TestCase):
def test_version_number(self):