You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

358 lines
12 KiB

# 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
# 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.
"""The passive components to version discovery.
The Discover object in contains functions that can create objects
on your behalf. These functions are not usable from within the keystoneauth1
library because you will get dependency resolution issues.
The Discover object in this file provides the querying components of Discovery.
This includes functions like url_for which allow you to retrieve URLs and the
raw data specified in version discovery responses.
import re
from positional import positional
from keystoneauth1 import _utils as utils
from keystoneauth1 import exceptions
_LOGGER = utils.get_logger(__name__)
def get_version_data(session, url, authenticated=None):
"""Retrieve raw version data from a url."""
headers = {'Accept': 'application/json'}
resp = session.get(url, headers=headers, authenticated=authenticated)
body_resp = resp.json()
except ValueError:
# In the event of querying a root URL we will get back a list of
# available versions.
return body_resp['versions']['values']
except (KeyError, TypeError):
# Most servers don't have a 'values' element so accept a simple
# versions dict if available.
return body_resp['versions']
except KeyError:
# Otherwise if we query an endpoint like /v2.0 then we will get back
# just the one available version.
return [body_resp['version']]
except KeyError:
err_text = resp.text[:50] + '...' if len(resp.text) > 50 else resp.text
raise exceptions.DiscoveryFailure('Invalid Response - Bad version data '
'returned: %s' % err_text)
def normalize_version_number(version):
"""Turn a version representation into a tuple."""
# trim the v from a 'v2.0' or similar
version = version.lstrip('v')
except AttributeError:
# if it's an integer or a numeric as a string then normalize it
# to a string, this ensures 1 decimal point
num = float(version)
except Exception:
version = str(num)
# if it's a string (or an integer) from above break it on .
return tuple(map(int, version.split('.')))
except Exception:
# last attempt, maybe it's a list or iterable.
return tuple(map(int, version))
except Exception:
raise TypeError('Invalid version specified: %s' % version)
def version_match(required, candidate):
"""Test that an available version satisfies the required version.
To be suitable a version must be of the same major version as required
and be at least a match in minor/patch level.
eg. 3.3 is a match for a required 3.1 but 4.1 is not.
:param tuple required: the version that must be met.
:param tuple candidate: the version to test against required.
:returns: True if candidate is suitable False otherwise.
:rtype: bool
# major versions must be the same (e.g. even though v2 is a lower
# version than v3 we can't use it if v2 was requested)
if candidate[0] != required[0]:
return False
# prevent selecting a minor version less than what is required
if candidate < required:
return False
return True
class Discover(object):
CURRENT_STATUSES = ('stable', 'current', 'supported')
DEPRECATED_STATUSES = ('deprecated',)
EXPERIMENTAL_STATUSES = ('experimental',)
def __init__(self, session, url, authenticated=None):
self._data = get_version_data(session, url,
def raw_version_data(self, allow_experimental=False,
allow_deprecated=True, allow_unknown=False):
"""Get raw version information from URL.
Raw data indicates that only minimal validation processing is performed
on the data, so what is returned here will be the data in the same
format it was received from the endpoint.
:param bool allow_experimental: Allow experimental version endpoints.
:param bool allow_deprecated: Allow deprecated version endpoints.
:param bool allow_unknown: Allow endpoints with an unrecognised status.
:returns: The endpoints returned from the server that match the
:rtype: list
versions = []
for v in self._data:
status = v['status']
except KeyError:
_LOGGER.warning('Skipping over invalid version data. '
'No stability status in version.')
status = status.lower()
if status in self.CURRENT_STATUSES:
elif status in self.DEPRECATED_STATUSES:
if allow_deprecated:
elif status in self.EXPERIMENTAL_STATUSES:
if allow_experimental:
elif allow_unknown:
return versions
def version_data(self, reverse=False, **kwargs):
"""Get normalized version data.
Return version data in a structured way.
:param bool reverse: Reverse the list. reverse=true will mean the
returned list is sorted from newest to oldest
:returns: A list of version data dictionaries sorted by version number.
Each data element in the returned list is a dictionary
consisting of at least:
:version tuple: The normalized version of the endpoint.
:url str: The url for the endpoint.
:raw_status str: The status as provided by the server
:rtype: list(dict)
data = self.raw_version_data(**kwargs)
versions = []
for v in data:
version_str = v['id']
except KeyError:'Skipping invalid version data. Missing ID.')
links = v['links']
except KeyError:'Skipping invalid version data. Missing links')
version_number = normalize_version_number(version_str)
for link in links:
rel = link['rel']
url = link['href']
except (KeyError, TypeError):'Skipping invalid version link. '
'Missing link URL or relationship.')
if rel.lower() == 'self':
else:'Skipping invalid version data. '
'Missing link to endpoint.')
versions.append({'version': version_number,
'url': url,
'raw_status': v['status']})
versions.sort(key=lambda v: v['version'], reverse=reverse)
return versions
def data_for(self, version, **kwargs):
"""Return endpoint data for a version.
:param tuple version: The version is always a minimum version in the
same major release as there should be no compatibility issues with
using a version newer than the one asked for.
:returns: the endpoint data for a URL that matches the required version
(the format is described in version_data) or None if no
:rtype: dict
version = normalize_version_number(version)
for data in self.version_data(reverse=True, **kwargs):
if version_match(version, data['version']):
return data
return None
def url_for(self, version, **kwargs):
"""Get the endpoint url for a version.
:param tuple version: The version is always a minimum version in the
same major release as there should be no compatibility issues with
using a version newer than the one asked for.
:returns: The url for the specified version or None if no match.
:rtype: str
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.
:returns: 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/?$'), '/')
def _get_catalog_discover_hack(service_type, url):
"""Apply the catalog hacks and figure out an unversioned endpoint.
This function is internal to keystoneauth1.
:param str service_type: the service_type to look up.
:param str url: The original url that came from a service_catalog.
:returns: Either the unversioned url or the one from the catalog to try.
return _VERSION_HACKS.get_discover_hack(service_type, url)
def add_catalog_discover_hack(service_type, old, new):
"""Add a version removal rule for a particular service.
Originally deployments of OpenStack would contain a versioned endpoint in
the catalog for different services. E.g. an identity service might look
like ``http://localhost:5000/v2.0``. This is a problem when we want to use
a different version like v3.0 as there is no way to tell where it is
located. We cannot simply change all service catalogs either so there must
be a way to handle the older style of catalog.
This function adds a rule for a given service type that if part of the URL
matches a given regular expression in *old* then it will be replaced with
the *new* value. This will replace all instances of old with new. It should
therefore contain a regex anchor.
For example the included rule states::
add_catalog_version_hack('identity', re.compile('/v2.0/?$'), '/')
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.
_VERSION_HACKS.add_discover_hack(service_type, old, new)