OpenStack Orchestration (Heat)
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# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 OpenStack LLC.
# 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.
"""
This auth module is intended to allow Openstack client-tools to select from a
variety of authentication strategies, including NoAuth (the default), and
Keystone (an identity management system).
> auth_plugin = AuthPlugin(creds)
> auth_plugin.authenticate()
> auth_plugin.auth_token
abcdefg
> auth_plugin.management_url
http://service_endpoint/
"""
import httplib2
import json
import urlparse
from heat.common import exception
class BaseStrategy(object):
def __init__(self):
self.auth_token = None
# TODO(sirp): Should expose selecting public/internal/admin URL.
self.management_url = None
def authenticate(self):
raise NotImplementedError
@property
def is_authenticated(self):
raise NotImplementedError
@property
def strategy(self):
raise NotImplementedError
class NoAuthStrategy(BaseStrategy):
def authenticate(self):
pass
@property
def is_authenticated(self):
return True
@property
def strategy(self):
return 'noauth'
class KeystoneStrategy(BaseStrategy):
MAX_REDIRECTS = 10
def __init__(self, creds):
self.creds = creds
super(KeystoneStrategy, self).__init__()
def check_auth_params(self):
# Ensure that supplied credential parameters are as required
for required in ('username', 'password', 'auth_url',
'strategy'):
if required not in self.creds:
raise exception.MissingCredentialError(required=required)
if self.creds['strategy'] != 'keystone':
raise exception.BadAuthStrategy(expected='keystone',
received=self.creds['strategy'])
# For v2.0 also check tenant is present
if self.creds['auth_url'].rstrip('/').endswith('v2.0'):
if 'tenant' not in self.creds:
raise exception.MissingCredentialError(required='tenant')
def authenticate(self):
"""Authenticate with the Keystone service.
There are a few scenarios to consider here:
1. Which version of Keystone are we using? v1 which uses headers to
pass the credentials, or v2 which uses a JSON encoded request body?
2. Keystone may respond back with a redirection using a 305 status
code.
3. We may attempt a v1 auth when v2 is what's called for. In this
case, we rewrite the url to contain /v2.0/ and retry using the v2
protocol.
"""
def _authenticate(auth_url):
# If OS_AUTH_URL is missing a trailing slash add one
if not auth_url.endswith('/'):
auth_url += '/'
token_url = urlparse.urljoin(auth_url, "tokens")
# 1. Check Keystone version
is_v2 = auth_url.rstrip('/').endswith('v2.0')
if is_v2:
self._v2_auth(token_url)
else:
self._v1_auth(token_url)
self.check_auth_params()
auth_url = self.creds['auth_url']
for _ in range(self.MAX_REDIRECTS):
try:
_authenticate(auth_url)
except exception.AuthorizationRedirect as e:
# 2. Keystone may redirect us
auth_url = e.url
except exception.AuthorizationFailure:
# 3. In some configurations nova makes redirection to
# v2.0 keystone endpoint. Also, new location does not
# contain real endpoint, only hostname and port.
if 'v2.0' not in auth_url:
auth_url = urlparse.urljoin(auth_url, 'v2.0/')
else:
# If we sucessfully auth'd, then memorize the correct auth_url
# for future use.
self.creds['auth_url'] = auth_url
break
else:
# Guard against a redirection loop
raise exception.MaxRedirectsExceeded(redirects=self.MAX_REDIRECTS)
def _v1_auth(self, token_url):
creds = self.creds
headers = {}
headers['X-Auth-User'] = creds['username']
headers['X-Auth-Key'] = creds['password']
tenant = creds.get('tenant')
if tenant:
headers['X-Auth-Tenant'] = tenant
resp, resp_body = self._do_request(token_url, 'GET', headers=headers)
def _management_url(self, resp):
for url_header in ('x-image-management-url',
'x-server-management-url',
'x-heat'):
try:
return resp[url_header]
except KeyError as e:
not_found = e
raise not_found
if resp.status in (200, 204):
try:
self.management_url = _management_url(self, resp)
self.auth_token = resp['x-auth-token']
except KeyError:
raise exception.AuthorizationFailure()
elif resp.status == 305:
raise exception.AuthorizationRedirect(resp['location'])
elif resp.status == 400:
raise exception.AuthBadRequest(url=token_url)
elif resp.status == 401:
raise exception.NotAuthorized()
elif resp.status == 404:
raise exception.AuthUrlNotFound(url=token_url)
else:
raise Exception(_('Unexpected response: %s' % resp.status))
def _v2_auth(self, token_url):
def get_endpoint(service_catalog):
"""
Select an endpoint from the service catalog
We search the full service catalog for services
matching both type and region. If the client
supplied no region then any 'image' endpoint
is considered a match. There must be one -- and
only one -- successful match in the catalog,
otherwise we will raise an exception.
"""
# FIXME(sirp): for now just use the public url.
endpoint = None
region = self.creds.get('region')
for service in service_catalog:
if service['type'] == 'image':
for ep in service['endpoints']:
if region is None or region == ep['region']:
if endpoint is not None:
# This is a second match, abort
raise exception.RegionAmbiguity(region=region)
endpoint = ep
if endpoint is None:
raise exception.NoServiceEndpoint()
return endpoint['publicURL']
creds = self.creds
creds = {
"auth": {
"tenantName": creds['tenant'],
"passwordCredentials": {
"username": creds['username'],
"password": creds['password']
}
}
}
headers = {}
headers['Content-Type'] = 'application/json'
req_body = json.dumps(creds)
resp, resp_body = self._do_request(
token_url, 'POST', headers=headers, body=req_body)
if resp.status == 200:
resp_auth = json.loads(resp_body)['access']
self.management_url = get_endpoint(resp_auth['serviceCatalog'])
self.auth_token = resp_auth['token']['id']
elif resp.status == 305:
raise exception.RedirectException(resp['location'])
elif resp.status == 400:
raise exception.AuthBadRequest(url=token_url)
elif resp.status == 401:
raise exception.NotAuthorized()
elif resp.status == 404:
raise exception.AuthUrlNotFound(url=token_url)
else:
raise Exception(_('Unexpected response: %s') % resp.status)
@property
def is_authenticated(self):
return self.auth_token is not None
@property
def strategy(self):
return 'keystone'
@staticmethod
def _do_request(url, method, headers=None, body=None):
headers = headers or {}
conn = httplib2.Http()
conn.force_exception_to_status_code = True
headers['User-Agent'] = 'heat-client'
resp, resp_body = conn.request(url, method, headers=headers, body=body)
return resp, resp_body
def get_plugin_from_strategy(strategy, creds=None):
if strategy == 'noauth':
return NoAuthStrategy()
elif strategy == 'keystone':
return KeystoneStrategy(creds)
else:
raise Exception(_("Unknown auth strategy '%s'") % strategy)