glance/glance/common/client.py

592 lines
22 KiB
Python

# Copyright 2010-2011 OpenStack Foundation
# 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.
# HTTPSClientAuthConnection code comes courtesy of ActiveState website:
# http://code.activestate.com/recipes/
# 577548-https-httplib-client-connection-with-certificate-v/
import collections
import copy
import errno
import functools
import httplib
import os
import re
try:
from eventlet.green import socket
from eventlet.green import ssl
except ImportError:
import socket
import ssl
import osprofiler.web
try:
import sendfile # noqa
SENDFILE_SUPPORTED = True
except ImportError:
SENDFILE_SUPPORTED = False
from oslo.utils import encodeutils
import six
import six.moves.urllib.parse as urlparse
from six.moves import xrange
from glance.common import auth
from glance.common import exception
from glance.common import utils
import glance.openstack.common.log as logging
LOG = logging.getLogger(__name__)
# common chunk size for get and put
CHUNKSIZE = 65536
VERSION_REGEX = re.compile(r"/?v[0-9\.]+")
def handle_unauthenticated(func):
"""
Wrap a function to re-authenticate and retry.
"""
@functools.wraps(func)
def wrapped(self, *args, **kwargs):
try:
return func(self, *args, **kwargs)
except exception.NotAuthenticated:
self._authenticate(force_reauth=True)
return func(self, *args, **kwargs)
return wrapped
def handle_redirects(func):
"""
Wrap the _do_request function to handle HTTP redirects.
"""
MAX_REDIRECTS = 5
@functools.wraps(func)
def wrapped(self, method, url, body, headers):
for _ in xrange(MAX_REDIRECTS):
try:
return func(self, method, url, body, headers)
except exception.RedirectException as redirect:
if redirect.url is None:
raise exception.InvalidRedirect()
url = redirect.url
raise exception.MaxRedirectsExceeded(redirects=MAX_REDIRECTS)
return wrapped
class HTTPSClientAuthConnection(httplib.HTTPSConnection):
"""
Class to make a HTTPS connection, with support for
full client-based SSL Authentication
:see http://code.activestate.com/recipes/
577548-https-httplib-client-connection-with-certificate-v/
"""
def __init__(self, host, port, key_file, cert_file,
ca_file, timeout=None, insecure=False):
httplib.HTTPSConnection.__init__(self, host, port, key_file=key_file,
cert_file=cert_file)
self.key_file = key_file
self.cert_file = cert_file
self.ca_file = ca_file
self.timeout = timeout
self.insecure = insecure
def connect(self):
"""
Connect to a host on a given (SSL) port.
If ca_file is pointing somewhere, use it to check Server Certificate.
Redefined/copied and extended from httplib.py:1105 (Python 2.6.x).
This is needed to pass cert_reqs=ssl.CERT_REQUIRED as parameter to
ssl.wrap_socket(), which forces SSL to check server certificate against
our client certificate.
"""
sock = socket.create_connection((self.host, self.port), self.timeout)
if self._tunnel_host:
self.sock = sock
self._tunnel()
# Check CA file unless 'insecure' is specificed
if self.insecure is True:
self.sock = ssl.wrap_socket(sock, self.key_file, self.cert_file,
cert_reqs=ssl.CERT_NONE)
else:
self.sock = ssl.wrap_socket(sock, self.key_file, self.cert_file,
ca_certs=self.ca_file,
cert_reqs=ssl.CERT_REQUIRED)
class BaseClient(object):
"""A base client class"""
DEFAULT_PORT = 80
DEFAULT_DOC_ROOT = None
# Standard CA file locations for Debian/Ubuntu, RedHat/Fedora,
# Suse, FreeBSD/OpenBSD
DEFAULT_CA_FILE_PATH = ('/etc/ssl/certs/ca-certificates.crt:'
'/etc/pki/tls/certs/ca-bundle.crt:'
'/etc/ssl/ca-bundle.pem:'
'/etc/ssl/cert.pem')
OK_RESPONSE_CODES = (
httplib.OK,
httplib.CREATED,
httplib.ACCEPTED,
httplib.NO_CONTENT,
)
REDIRECT_RESPONSE_CODES = (
httplib.MOVED_PERMANENTLY,
httplib.FOUND,
httplib.SEE_OTHER,
httplib.USE_PROXY,
httplib.TEMPORARY_REDIRECT,
)
def __init__(self, host, port=None, timeout=None, use_ssl=False,
auth_token=None, creds=None, doc_root=None, key_file=None,
cert_file=None, ca_file=None, insecure=False,
configure_via_auth=True):
"""
Creates a new client to some service.
:param host: The host where service resides
:param port: The port where service resides
:param timeout: Connection timeout.
:param use_ssl: Should we use HTTPS?
:param auth_token: The auth token to pass to the server
:param creds: The credentials to pass to the auth plugin
:param doc_root: Prefix for all URLs we request from host
:param key_file: Optional PEM-formatted file that contains the private
key.
If use_ssl is True, and this param is None (the
default), then an environ variable
GLANCE_CLIENT_KEY_FILE is looked for. If no such
environ variable is found, ClientConnectionError
will be raised.
:param cert_file: Optional PEM-formatted certificate chain file.
If use_ssl is True, and this param is None (the
default), then an environ variable
GLANCE_CLIENT_CERT_FILE is looked for. If no such
environ variable is found, ClientConnectionError
will be raised.
:param ca_file: Optional CA cert file to use in SSL connections
If use_ssl is True, and this param is None (the
default), then an environ variable
GLANCE_CLIENT_CA_FILE is looked for.
:param insecure: Optional. If set then the server's certificate
will not be verified.
:param configure_via_auth: Optional. Defaults to True. If set, the
URL returned from the service catalog for the image
endpoint will **override** the URL supplied to in
the host parameter.
"""
self.host = host
self.port = port or self.DEFAULT_PORT
self.timeout = timeout
# A value of '0' implies never timeout
if timeout == 0:
self.timeout = None
self.use_ssl = use_ssl
self.auth_token = auth_token
self.creds = creds or {}
self.connection = None
self.configure_via_auth = configure_via_auth
# doc_root can be a nullstring, which is valid, and why we
# cannot simply do doc_root or self.DEFAULT_DOC_ROOT below.
self.doc_root = (doc_root if doc_root is not None
else self.DEFAULT_DOC_ROOT)
self.key_file = key_file
self.cert_file = cert_file
self.ca_file = ca_file
self.insecure = insecure
self.auth_plugin = self.make_auth_plugin(self.creds, self.insecure)
self.connect_kwargs = self.get_connect_kwargs()
def get_connect_kwargs(self):
connect_kwargs = {}
# Both secure and insecure connections have a timeout option
connect_kwargs['timeout'] = self.timeout
if self.use_ssl:
if self.key_file is None:
self.key_file = os.environ.get('GLANCE_CLIENT_KEY_FILE')
if self.cert_file is None:
self.cert_file = os.environ.get('GLANCE_CLIENT_CERT_FILE')
if self.ca_file is None:
self.ca_file = os.environ.get('GLANCE_CLIENT_CA_FILE')
# Check that key_file/cert_file are either both set or both unset
if self.cert_file is not None and self.key_file is None:
msg = _("You have selected to use SSL in connecting, "
"and you have supplied a cert, "
"however you have failed to supply either a "
"key_file parameter or set the "
"GLANCE_CLIENT_KEY_FILE environ variable")
raise exception.ClientConnectionError(msg)
if self.key_file is not None and self.cert_file is None:
msg = _("You have selected to use SSL in connecting, "
"and you have supplied a key, "
"however you have failed to supply either a "
"cert_file parameter or set the "
"GLANCE_CLIENT_CERT_FILE environ variable")
raise exception.ClientConnectionError(msg)
if (self.key_file is not None and
not os.path.exists(self.key_file)):
msg = _("The key file you specified %s does not "
"exist") % self.key_file
raise exception.ClientConnectionError(msg)
connect_kwargs['key_file'] = self.key_file
if (self.cert_file is not None and
not os.path.exists(self.cert_file)):
msg = _("The cert file you specified %s does not "
"exist") % self.cert_file
raise exception.ClientConnectionError(msg)
connect_kwargs['cert_file'] = self.cert_file
if (self.ca_file is not None and
not os.path.exists(self.ca_file)):
msg = _("The CA file you specified %s does not "
"exist") % self.ca_file
raise exception.ClientConnectionError(msg)
if self.ca_file is None:
for ca in self.DEFAULT_CA_FILE_PATH.split(":"):
if os.path.exists(ca):
self.ca_file = ca
break
connect_kwargs['ca_file'] = self.ca_file
connect_kwargs['insecure'] = self.insecure
return connect_kwargs
def configure_from_url(self, url):
"""
Setups the connection based on the given url.
The form is:
<http|https>://<host>:port/doc_root
"""
LOG.debug("Configuring from URL: %s", url)
parsed = urlparse.urlparse(url)
self.use_ssl = parsed.scheme == 'https'
self.host = parsed.hostname
self.port = parsed.port or 80
self.doc_root = parsed.path.rstrip('/')
# We need to ensure a version identifier is appended to the doc_root
if not VERSION_REGEX.match(self.doc_root):
if self.DEFAULT_DOC_ROOT:
doc_root = self.DEFAULT_DOC_ROOT.lstrip('/')
self.doc_root += '/' + doc_root
msg = ("Appending doc_root %(doc_root)s to URL %(url)s" %
{'doc_root': doc_root, 'url': url})
LOG.debug(msg)
# ensure connection kwargs are re-evaluated after the service catalog
# publicURL is parsed for potential SSL usage
self.connect_kwargs = self.get_connect_kwargs()
def make_auth_plugin(self, creds, insecure):
"""
Returns an instantiated authentication plugin.
"""
strategy = creds.get('strategy', 'noauth')
plugin = auth.get_plugin_from_strategy(strategy, creds, insecure,
self.configure_via_auth)
return plugin
def get_connection_type(self):
"""
Returns the proper connection type
"""
if self.use_ssl:
return HTTPSClientAuthConnection
else:
return httplib.HTTPConnection
def _authenticate(self, force_reauth=False):
"""
Use the authentication plugin to authenticate and set the auth token.
:param force_reauth: For re-authentication to bypass cache.
"""
auth_plugin = self.auth_plugin
if not auth_plugin.is_authenticated or force_reauth:
auth_plugin.authenticate()
self.auth_token = auth_plugin.auth_token
management_url = auth_plugin.management_url
if management_url and self.configure_via_auth:
self.configure_from_url(management_url)
@handle_unauthenticated
def do_request(self, method, action, body=None, headers=None,
params=None):
"""
Make a request, returning an HTTP response object.
:param method: HTTP verb (GET, POST, PUT, etc.)
:param action: Requested path to append to self.doc_root
:param body: Data to send in the body of the request
:param headers: Headers to send with the request
:param params: Key/value pairs to use in query string
:returns: HTTP response object
"""
if not self.auth_token:
self._authenticate()
url = self._construct_url(action, params)
# NOTE(ameade): We need to copy these kwargs since they can be altered
# in _do_request but we need the originals if handle_unauthenticated
# calls this function again.
return self._do_request(method=method, url=url,
body=copy.deepcopy(body),
headers=copy.deepcopy(headers))
def _construct_url(self, action, params=None):
"""
Create a URL object we can use to pass to _do_request().
"""
action = urlparse.quote(action)
path = '/'.join([self.doc_root or '', action.lstrip('/')])
scheme = "https" if self.use_ssl else "http"
netloc = "%s:%d" % (self.host, self.port)
if isinstance(params, dict):
for (key, value) in params.items():
if value is None:
del params[key]
continue
if not isinstance(value, six.string_types):
value = str(value)
params[key] = encodeutils.safe_encode(value)
query = urlparse.urlencode(params)
else:
query = None
url = urlparse.ParseResult(scheme, netloc, path, '', query, '')
log_msg = _("Constructed URL: %s")
LOG.debug(log_msg, url.geturl())
return url
def _encode_headers(self, headers):
"""
Encodes headers.
Note: This should be used right before
sending anything out.
:param headers: Headers to encode
:returns: Dictionary with encoded headers'
names and values
"""
to_str = encodeutils.safe_encode
return dict([(to_str(h), to_str(v)) for h, v in
six.iteritems(headers)])
@handle_redirects
def _do_request(self, method, url, body, headers):
"""
Connects to the server and issues a request. Handles converting
any returned HTTP error status codes to OpenStack/Glance exceptions
and closing the server connection. Returns the result data, or
raises an appropriate exception.
:param method: HTTP method ("GET", "POST", "PUT", etc...)
:param url: urlparse.ParsedResult object with URL information
:param body: data to send (as string, filelike or iterable),
or None (default)
:param headers: mapping of key/value pairs to add as headers
:note
If the body param has a read attribute, and method is either
POST or PUT, this method will automatically conduct a chunked-transfer
encoding and use the body as a file object or iterable, transferring
chunks of data using the connection's send() method. This allows large
objects to be transferred efficiently without buffering the entire
body in memory.
"""
if url.query:
path = url.path + "?" + url.query
else:
path = url.path
try:
connection_type = self.get_connection_type()
headers = self._encode_headers(headers or {})
headers.update(osprofiler.web.get_trace_id_headers())
if 'x-auth-token' not in headers and self.auth_token:
headers['x-auth-token'] = self.auth_token
c = connection_type(url.hostname, url.port, **self.connect_kwargs)
def _pushing(method):
return method.lower() in ('post', 'put')
def _simple(body):
return body is None or isinstance(body, six.string_types)
def _filelike(body):
return hasattr(body, 'read')
def _sendbody(connection, iter):
connection.endheaders()
for sent in iter:
# iterator has done the heavy lifting
pass
def _chunkbody(connection, iter):
connection.putheader('Transfer-Encoding', 'chunked')
connection.endheaders()
for chunk in iter:
connection.send('%x\r\n%s\r\n' % (len(chunk), chunk))
connection.send('0\r\n\r\n')
# Do a simple request or a chunked request, depending
# on whether the body param is file-like or iterable and
# the method is PUT or POST
#
if not _pushing(method) or _simple(body):
# Simple request...
c.request(method, path, body, headers)
elif _filelike(body) or self._iterable(body):
c.putrequest(method, path)
use_sendfile = self._sendable(body)
# According to HTTP/1.1, Content-Length and Transfer-Encoding
# conflict.
for header, value in headers.items():
if use_sendfile or header.lower() != 'content-length':
c.putheader(header, str(value))
iter = utils.chunkreadable(body)
if use_sendfile:
# send actual file without copying into userspace
_sendbody(c, iter)
else:
# otherwise iterate and chunk
_chunkbody(c, iter)
else:
raise TypeError('Unsupported image type: %s' % body.__class__)
res = c.getresponse()
def _retry(res):
return res.getheader('Retry-After')
status_code = self.get_status_code(res)
if status_code in self.OK_RESPONSE_CODES:
return res
elif status_code in self.REDIRECT_RESPONSE_CODES:
raise exception.RedirectException(res.getheader('Location'))
elif status_code == httplib.UNAUTHORIZED:
raise exception.NotAuthenticated(res.read())
elif status_code == httplib.FORBIDDEN:
raise exception.Forbidden(res.read())
elif status_code == httplib.NOT_FOUND:
raise exception.NotFound(res.read())
elif status_code == httplib.CONFLICT:
raise exception.Duplicate(res.read())
elif status_code == httplib.BAD_REQUEST:
raise exception.Invalid(res.read())
elif status_code == httplib.MULTIPLE_CHOICES:
raise exception.MultipleChoices(body=res.read())
elif status_code == httplib.REQUEST_ENTITY_TOO_LARGE:
raise exception.LimitExceeded(retry=_retry(res),
body=res.read())
elif status_code == httplib.INTERNAL_SERVER_ERROR:
raise exception.ServerError()
elif status_code == httplib.SERVICE_UNAVAILABLE:
raise exception.ServiceUnavailable(retry=_retry(res))
else:
raise exception.UnexpectedStatus(status=status_code,
body=res.read())
except (socket.error, IOError) as e:
raise exception.ClientConnectionError(e)
def _seekable(self, body):
# pipes are not seekable, avoids sendfile() failure on e.g.
# cat /path/to/image | glance add ...
# or where add command is launched via popen
try:
os.lseek(body.fileno(), 0, os.SEEK_CUR)
return True
except OSError as e:
return (e.errno != errno.ESPIPE)
def _sendable(self, body):
return (SENDFILE_SUPPORTED and
hasattr(body, 'fileno') and
self._seekable(body) and
not self.use_ssl)
def _iterable(self, body):
return isinstance(body, collections.Iterable)
def get_status_code(self, response):
"""
Returns the integer status code from the response, which
can be either a Webob.Response (used in testing) or httplib.Response
"""
if hasattr(response, 'status_int'):
return response.status_int
else:
return response.status
def _extract_params(self, actual_params, allowed_params):
"""
Extract a subset of keys from a dictionary. The filters key
will also be extracted, and each of its values will be returned
as an individual param.
:param actual_params: dict of keys to filter
:param allowed_params: list of keys that 'actual_params' will be
reduced to
:retval subset of 'params' dict
"""
try:
# expect 'filters' param to be a dict here
result = dict(actual_params.get('filters'))
except TypeError:
result = {}
for allowed_param in allowed_params:
if allowed_param in actual_params:
result[allowed_param] = actual_params[allowed_param]
return result