python-novaclient/novaclient/client.py
Boris Pavlovic 98934d7bf1 Fix session handling in novaclient
Prior to this patch, novaclient was handling sessions in an inconsistent
manner.

Every time we created a client instance, it would use a global
connection pool, which made it difficult to use in a process that is
meant to be forked.

Obviously sessions like the ones provided by the requests library that
will automatically cause connections to be kept alive should not be
implicit. This patch moves the novaclient back to the age of a single
session-less request call by default, but also adds two more
resource-reuse friendly options that a user needs to be explicit about.

The first one is that both v1_1 and v3 clients can now be used as
context managers,. where the session will be kept open (and thus the
connection kept-alive) for the duration of the with block. This is far
more ideal for a web worker use-case as the session can be made
request-long.

The second one is the per-instance session. This is very similar to what
we had up until now, except it is not a global object so forking is
possible as long as each child instantiates it's own client. The session
once created will be kept open for the duration of the client object
lifetime.

Please note: client instances are not thread safe. As can be seen from
above forking example - if you wish to use threading/multiprocessing,
you *must not* share client instances.

DocImpact

Related-bug: #1247056
Closes-Bug: #1297796
Co-authored-by: Nikola Dipanov <ndipanov@redhat.com>
Change-Id: Id59e48f61bb3f3c6223302355c849e1e99673410
2014-04-07 19:38:51 +02:00

539 lines
20 KiB
Python

# Copyright 2010 Jacob Kaplan-Moss
# Copyright 2011 OpenStack Foundation
# Copyright 2011 Piston Cloud Computing, Inc.
# 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.
"""
OpenStack Client interface. Handles the REST calls and responses.
"""
import logging
import time
import requests
from requests import adapters
try:
import json
except ImportError:
import simplejson as json
from six.moves.urllib import parse
from novaclient import exceptions
from novaclient.openstack.common.gettextutils import _
from novaclient.openstack.common import network_utils
from novaclient import service_catalog
from novaclient import utils
class _ClientConnectionPool(object):
def __init__(self):
self._adapters = {}
def get(self, url):
"""
Store and reuse HTTP adapters per Service URL.
"""
if url not in self._adapters:
self._adapters[url] = adapters.HTTPAdapter()
return self._adapters[url]
class HTTPClient(object):
USER_AGENT = 'python-novaclient'
def __init__(self, user, password, projectid=None, auth_url=None,
insecure=False, timeout=None, proxy_tenant_id=None,
proxy_token=None, region_name=None,
endpoint_type='publicURL', service_type=None,
service_name=None, volume_service_name=None,
timings=False, bypass_url=None,
os_cache=False, no_cache=True,
http_log_debug=False, auth_system='keystone',
auth_plugin=None, auth_token=None,
cacert=None, tenant_id=None, user_id=None,
connection_pool=False):
self.user = user
self.user_id = user_id
self.password = password
self.projectid = projectid
self.tenant_id = tenant_id
self._connection_pool = (_ClientConnectionPool()
if connection_pool else None)
# This will be called by #_get_password if self.password is None.
# EG if a password can only be obtained by prompting the user, but a
# token is available, you don't want to prompt until the token has
# been proven invalid
self.password_func = None
if auth_system and auth_system != 'keystone' and not auth_plugin:
raise exceptions.AuthSystemNotFound(auth_system)
if not auth_url and auth_system and auth_system != 'keystone':
auth_url = auth_plugin.get_auth_url()
if not auth_url:
raise exceptions.EndpointNotFound()
self.auth_url = auth_url.rstrip('/') if auth_url else auth_url
self.version = 'v1.1'
self.region_name = region_name
self.endpoint_type = endpoint_type
self.service_type = service_type
self.service_name = service_name
self.volume_service_name = volume_service_name
self.timings = timings
self.bypass_url = bypass_url.rstrip('/') if bypass_url else bypass_url
self.os_cache = os_cache or not no_cache
self.http_log_debug = http_log_debug
if timeout is not None:
self.timeout = float(timeout)
else:
self.timeout = None
self.times = [] # [("item", starttime, endtime), ...]
self.management_url = self.bypass_url or None
self.auth_token = auth_token
self.proxy_token = proxy_token
self.proxy_tenant_id = proxy_tenant_id
self.keyring_saver = None
self.keyring_saved = False
if insecure:
self.verify_cert = False
else:
if cacert:
self.verify_cert = cacert
else:
self.verify_cert = True
self.auth_system = auth_system
self.auth_plugin = auth_plugin
self._session = None
self._current_url = None
self._logger = logging.getLogger(__name__)
if self.http_log_debug and not self._logger.handlers:
# Logging level is already set on the root logger
ch = logging.StreamHandler()
self._logger.addHandler(ch)
self._logger.propagate = False
if hasattr(requests, 'logging'):
rql = requests.logging.getLogger(requests.__name__)
rql.addHandler(ch)
# Since we have already setup the root logger on debug, we
# have to set it up here on WARNING (its original level)
# otherwise we will get all the requests logging messages
rql.setLevel(logging.WARNING)
def use_token_cache(self, use_it):
self.os_cache = use_it
def unauthenticate(self):
"""Forget all of our authentication information."""
self.management_url = None
self.auth_token = None
def set_management_url(self, url):
self.management_url = url
def get_timings(self):
return self.times
def reset_timings(self):
self.times = []
def http_log_req(self, method, url, kwargs):
if not self.http_log_debug:
return
string_parts = ['curl -i']
if not kwargs.get('verify', True):
string_parts.append(' --insecure')
string_parts.append(" '%s'" % url)
string_parts.append(' -X %s' % method)
for element in kwargs['headers']:
header = ' -H "%s: %s"' % (element, kwargs['headers'][element])
string_parts.append(header)
if 'data' in kwargs:
string_parts.append(" -d '%s'" % (kwargs['data']))
self._logger.debug("\nREQ: %s\n" % "".join(string_parts))
def http_log_resp(self, resp):
if not self.http_log_debug:
return
self._logger.debug(_("RESP: [%(status)s] %(headers)s\nRESP BODY: "
"%(text)s\n"), {'status': resp.status_code,
'headers': resp.headers,
'text': resp.text})
def open_session(self):
if not self._connection_pool:
self._session = requests.Session()
def close_session(self):
if self._session and not self._connection_pool:
self._session.close()
self._session = None
def _get_session(self, url):
if self._connection_pool:
magic_tuple = parse.urlsplit(url)
scheme, netloc, path, query, frag = magic_tuple
service_url = '%s://%s' % (scheme, netloc)
if self._current_url != service_url:
# Invalidate Session object in case the url is somehow changed
if self._session:
self._session.close()
self._current_url = service_url
self._logger.debug(
"New session created for: (%s)" % service_url)
self._session = requests.Session()
self._session.mount(service_url,
self._connection_pool.get(service_url))
return self._session
elif self._session:
return self._session
def request(self, url, method, **kwargs):
kwargs.setdefault('headers', kwargs.get('headers', {}))
kwargs['headers']['User-Agent'] = self.USER_AGENT
kwargs['headers']['Accept'] = 'application/json'
if 'body' in kwargs:
kwargs['headers']['Content-Type'] = 'application/json'
kwargs['data'] = json.dumps(kwargs['body'])
del kwargs['body']
if self.timeout is not None:
kwargs.setdefault('timeout', self.timeout)
kwargs['verify'] = self.verify_cert
self.http_log_req(method, url, kwargs)
request_func = requests.request
session = self._get_session(url)
if session:
request_func = session.request
resp = request_func(
method,
url,
**kwargs)
self.http_log_resp(resp)
if resp.text:
# TODO(dtroyer): verify the note below in a requests context
# NOTE(alaski): Because force_exceptions_to_status_code=True
# httplib2 returns a connection refused event as a 400 response.
# To determine if it is a bad request or refused connection we need
# to check the body. httplib2 tests check for 'Connection refused'
# or 'actively refused' in the body, so that's what we'll do.
if resp.status_code == 400:
if ('Connection refused' in resp.text or
'actively refused' in resp.text):
raise exceptions.ConnectionRefused(resp.text)
try:
body = json.loads(resp.text)
except ValueError:
body = None
else:
body = None
if resp.status_code >= 400:
raise exceptions.from_response(resp, body, url, method)
return resp, body
def _time_request(self, url, method, **kwargs):
start_time = time.time()
resp, body = self.request(url, method, **kwargs)
self.times.append(("%s %s" % (method, url),
start_time, time.time()))
return resp, body
def _cs_request(self, url, method, **kwargs):
if not self.management_url:
self.authenticate()
# Perform the request once. If we get a 401 back then it
# might be because the auth token expired, so try to
# re-authenticate and try again. If it still fails, bail.
try:
kwargs.setdefault('headers', {})['X-Auth-Token'] = self.auth_token
if self.projectid:
kwargs['headers']['X-Auth-Project-Id'] = self.projectid
resp, body = self._time_request(self.management_url + url, method,
**kwargs)
return resp, body
except exceptions.Unauthorized as e:
try:
# first discard auth token, to avoid the possibly expired
# token being re-used in the re-authentication attempt
self.unauthenticate()
# overwrite bad token
self.keyring_saved = False
self.authenticate()
kwargs['headers']['X-Auth-Token'] = self.auth_token
resp, body = self._time_request(self.management_url + url,
method, **kwargs)
return resp, body
except exceptions.Unauthorized:
raise e
def _get_password(self):
if not self.password and self.password_func:
self.password = self.password_func()
return self.password
def get(self, url, **kwargs):
return self._cs_request(url, 'GET', **kwargs)
def post(self, url, **kwargs):
return self._cs_request(url, 'POST', **kwargs)
def put(self, url, **kwargs):
return self._cs_request(url, 'PUT', **kwargs)
def delete(self, url, **kwargs):
return self._cs_request(url, 'DELETE', **kwargs)
def _extract_service_catalog(self, url, resp, body, extract_token=True):
"""See what the auth service told us and process the response.
We may get redirected to another site, fail or actually get
back a service catalog with a token and our endpoints.
"""
# content must always present
if resp.status_code == 200 or resp.status_code == 201:
try:
self.auth_url = url
self.service_catalog = \
service_catalog.ServiceCatalog(body)
if extract_token:
self.auth_token = self.service_catalog.get_token()
self.tenant_id = self.service_catalog.get_tenant_id()
management_url = self.service_catalog.url_for(
attr='region',
filter_value=self.region_name,
endpoint_type=self.endpoint_type,
service_type=self.service_type,
service_name=self.service_name,
volume_service_name=self.volume_service_name,)
self.management_url = management_url.rstrip('/')
return None
except exceptions.AmbiguousEndpoints:
print(_("Found more than one valid endpoint. Use a more "
"restrictive filter"))
raise
except KeyError:
raise exceptions.AuthorizationFailure()
except exceptions.EndpointNotFound:
print(_("Could not find any suitable endpoint. Correct "
"region?"))
raise
elif resp.status_code == 305:
return resp.headers['location']
else:
raise exceptions.from_response(resp, body, url)
def _fetch_endpoints_from_auth(self, url):
"""We have a token, but don't know the final endpoint for
the region. We have to go back to the auth service and
ask again. This request requires an admin-level token
to work. The proxy token supplied could be from a low-level enduser.
We can't get this from the keystone service endpoint, we have to use
the admin endpoint.
This will overwrite our admin token with the user token.
"""
# GET ...:5001/v2.0/tokens/#####/endpoints
url = '/'.join([url, 'tokens', '%s?belongsTo=%s'
% (self.proxy_token, self.proxy_tenant_id)])
self._logger.debug(_("Using Endpoint URL: %s") % url)
resp, body = self._time_request(
url, "GET", headers={'X-Auth-Token': self.auth_token})
return self._extract_service_catalog(url, resp, body,
extract_token=False)
def authenticate(self):
magic_tuple = network_utils.urlsplit(self.auth_url)
scheme, netloc, path, query, frag = magic_tuple
port = magic_tuple.port
if port is None:
port = 80
path_parts = path.split('/')
for part in path_parts:
if len(part) > 0 and part[0] == 'v':
self.version = part
break
if self.auth_token and self.management_url:
self._save_keys()
return
# TODO(sandy): Assume admin endpoint is 35357 for now.
# Ideally this is going to have to be provided by the service catalog.
new_netloc = netloc.replace(':%d' % port, ':%d' % (35357,))
admin_url = parse.urlunsplit(
(scheme, new_netloc, path, query, frag))
auth_url = self.auth_url
if self.version == "v2.0": # FIXME(chris): This should be better.
while auth_url:
if not self.auth_system or self.auth_system == 'keystone':
auth_url = self._v2_auth(auth_url)
else:
auth_url = self._plugin_auth(auth_url)
# Are we acting on behalf of another user via an
# existing token? If so, our actual endpoints may
# be different than that of the admin token.
if self.proxy_token:
if self.bypass_url:
self.set_management_url(self.bypass_url)
else:
self._fetch_endpoints_from_auth(admin_url)
# Since keystone no longer returns the user token
# with the endpoints any more, we need to replace
# our service account token with the user token.
self.auth_token = self.proxy_token
else:
try:
while auth_url:
auth_url = self._v1_auth(auth_url)
# In some configurations nova makes redirection to
# v2.0 keystone endpoint. Also, new location does not contain
# real endpoint, only hostname and port.
except exceptions.AuthorizationFailure:
if auth_url.find('v2.0') < 0:
auth_url = auth_url + '/v2.0'
self._v2_auth(auth_url)
if self.bypass_url:
self.set_management_url(self.bypass_url)
elif not self.management_url:
raise exceptions.Unauthorized('Nova Client')
self._save_keys()
def _save_keys(self):
# Store the token/mgmt url in the keyring for later requests.
if (self.keyring_saver and self.os_cache and not self.keyring_saved
and self.auth_token and self.management_url
and self.tenant_id):
self.keyring_saver.save(self.auth_token,
self.management_url,
self.tenant_id)
# Don't save it again
self.keyring_saved = True
def _v1_auth(self, url):
if self.proxy_token:
raise exceptions.NoTokenLookupException()
headers = {'X-Auth-User': self.user,
'X-Auth-Key': self._get_password()}
if self.projectid:
headers['X-Auth-Project-Id'] = self.projectid
resp, body = self._time_request(url, 'GET', headers=headers)
if resp.status_code in (200, 204): # in some cases we get No Content
try:
mgmt_header = 'x-server-management-url'
self.management_url = resp.headers[mgmt_header].rstrip('/')
self.auth_token = resp.headers['x-auth-token']
self.auth_url = url
except (KeyError, TypeError):
raise exceptions.AuthorizationFailure()
elif resp.status_code == 305:
return resp.headers['location']
else:
raise exceptions.from_response(resp, body, url)
def _plugin_auth(self, auth_url):
return self.auth_plugin.authenticate(self, auth_url)
def _v2_auth(self, url):
"""Authenticate against a v2.0 auth service."""
if self.auth_token:
body = {"auth": {
"token": {"id": self.auth_token}}}
elif self.user_id:
body = {"auth": {
"passwordCredentials": {"userId": self.user_id,
"password": self._get_password()}}}
else:
body = {"auth": {
"passwordCredentials": {"username": self.user,
"password": self._get_password()}}}
if self.tenant_id:
body['auth']['tenantId'] = self.tenant_id
elif self.projectid:
body['auth']['tenantName'] = self.projectid
return self._authenticate(url, body)
def _authenticate(self, url, body, **kwargs):
"""Authenticate and extract the service catalog."""
method = "POST"
token_url = url + "/tokens"
# Make sure we follow redirects when trying to reach Keystone
resp, respbody = self._time_request(
token_url,
method,
body=body,
allow_redirects=True,
**kwargs)
return self._extract_service_catalog(url, resp, respbody)
def get_client_class(version):
version_map = {
'1.1': 'novaclient.v1_1.client.Client',
'2': 'novaclient.v1_1.client.Client',
'3': 'novaclient.v3.client.Client',
}
try:
client_path = version_map[str(version)]
except (KeyError, ValueError):
msg = _("Invalid client version '%(version)s'. must be one of: "
"%(keys)s") % {'version': version,
'keys': ', '.join(version_map.keys())}
raise exceptions.UnsupportedVersion(msg)
return utils.import_class(client_path)
def Client(version, *args, **kwargs):
client_class = get_client_class(version)
return client_class(*args, **kwargs)