132 lines
4.1 KiB
Python
132 lines
4.1 KiB
Python
# 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.
|
|
|
|
__version__ = '0.1.1'
|
|
|
|
import collections
|
|
|
|
|
|
ENVIRON_HTTP_HEADER_FMT = 'http_{}'
|
|
STANDARD_HEADER = 'openstack-api-version'
|
|
|
|
|
|
def get_version(headers, service_type, legacy_headers=None):
|
|
"""Parse a microversion out of headers
|
|
|
|
:param headers: The headers of a request, dict or list
|
|
:param service_type: The service type being looked for in the headers
|
|
:param legacy_headers: Other headers to look at for a version
|
|
:returns: a version string or "latest"
|
|
:raises: ValueError
|
|
|
|
If headers is not a dict we assume is an iterator of
|
|
tuple-like headers, which we will fold into a dict.
|
|
|
|
The flow is that we first look for the new standard singular
|
|
header:
|
|
|
|
* openstack-api-version: <service> <version>
|
|
|
|
If that's not present we fall back to the headers listed in
|
|
legacy_headers. These often look like this:
|
|
|
|
* openstack-<service>-api-version: <version>
|
|
* openstack-<legacy>-api-version: <version>
|
|
* x-openstack-<legacy>-api-version: <version>
|
|
|
|
Folded headers are joined by ','.
|
|
"""
|
|
|
|
folded_headers = fold_headers(headers)
|
|
|
|
version = check_standard_header(folded_headers, service_type)
|
|
if version:
|
|
return version
|
|
|
|
if legacy_headers:
|
|
version = check_legacy_headers(folded_headers, legacy_headers)
|
|
return version
|
|
|
|
return None
|
|
|
|
|
|
def check_legacy_headers(headers, legacy_headers):
|
|
"""Gather values from old headers."""
|
|
for legacy_header in legacy_headers:
|
|
try:
|
|
value = _extract_header_value(headers, legacy_header.lower())
|
|
return value.split(',')[-1].strip()
|
|
except KeyError:
|
|
pass
|
|
return None
|
|
|
|
|
|
def check_standard_header(headers, service_type):
|
|
"""Parse the standard header to get value for service."""
|
|
try:
|
|
header = _extract_header_value(headers, STANDARD_HEADER)
|
|
for header_value in reversed(header.split(',')):
|
|
try:
|
|
service, version = header_value.strip().split(None, 1)
|
|
if service.lower() == service_type.lower():
|
|
return version.strip()
|
|
except ValueError:
|
|
pass
|
|
except (KeyError, ValueError):
|
|
return None
|
|
|
|
|
|
def fold_headers(headers):
|
|
"""Turn a list of headers into a folded dict."""
|
|
# If it behaves like a dict, return it. Webob uses objects which
|
|
# are not dicts, but behave like them.
|
|
if hasattr(headers, 'keys'):
|
|
return dict((k.lower(), v) for k, v in headers.items())
|
|
header_dict = collections.defaultdict(list)
|
|
for header, value in headers:
|
|
header_dict[header.lower()].append(value.strip())
|
|
|
|
folded_headers = {}
|
|
for header, value in header_dict.items():
|
|
folded_headers[header] = ','.join(value)
|
|
|
|
return folded_headers
|
|
|
|
|
|
def headers_from_wsgi_environ(environ):
|
|
"""Extract all the HTTP_ keys and values from environ to a new dict.
|
|
|
|
Note that this does not change the keys in any way in the returned
|
|
dict. Nor is the incoming environ modified.
|
|
|
|
:param environ: A PEP 3333 compliant WSGI environ dict.
|
|
"""
|
|
return {key: environ[key] for key in environ if key.startswith('HTTP_')}
|
|
|
|
|
|
def _extract_header_value(headers, header_name):
|
|
"""Get the value of a header.
|
|
|
|
The provided headers is a dict. If a key doesn't exist for
|
|
header_name, try using the WSGI environ form of the name.
|
|
|
|
Raises KeyError if neither key is found.
|
|
"""
|
|
try:
|
|
value = headers[header_name]
|
|
except KeyError:
|
|
wsgi_header_name = ENVIRON_HTTP_HEADER_FMT.format(
|
|
header_name.replace('-', '_'))
|
|
value = headers[wsgi_header_name]
|
|
return value
|