deb-heat/heat/common/client.py
Ian Main a093e6d074 Fix auth failed exception handler
This patch fixes the auth failed exception handler so that we
get back a meaningful result when authentication fails.

Change-Id: I2f37daed3890fd685fa6f701938b675460e76b0c
Signed-off-by: Ian Main <imain@redhat.com>
2012-05-30 10:46:59 -07:00

615 lines
22 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# 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 errno
import functools
import httplib
import logging
import os
import urllib
import urlparse
try:
from eventlet.green import socket, ssl
except ImportError:
import socket
import ssl
try:
import sendfile
SENDFILE_SUPPORTED = True
except ImportError:
SENDFILE_SUPPORTED = False
from heat.common import auth
from heat.common import exception, utils
# common chunk size for get and put
CHUNKSIZE = 65536
def handle_unauthorized(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.NotAuthorized:
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 ImageBodyIterator(object):
"""
A class that acts as an iterator over an image file's
chunks of data. This is returned as part of the result
tuple from `heat.client.Client.get_image`
"""
def __init__(self, source):
"""
Constructs the object from a readable image source
(such as an HTTPResponse or file-like object)
"""
self.source = source
def __iter__(self):
"""
Exposes an iterator over the chunks of data in the
image file.
"""
while True:
chunk = self.source.read(CHUNKSIZE)
if chunk:
yield chunk
else:
break
class SendFileIterator:
"""
Emulate iterator pattern over sendfile, in order to allow
send progress be followed by wrapping the iteration.
"""
def __init__(self, connection, body):
self.connection = connection
self.body = body
self.offset = 0
self.sending = True
def __iter__(self):
class OfLength:
def __init__(self, len):
self.len = len
def __len__(self):
return self.len
while self.sending:
try:
sent = sendfile.sendfile(self.connection.sock.fileno(),
self.body.fileno(),
self.offset,
CHUNKSIZE)
except OSError as e:
# suprisingly, sendfile may fail transiently instead of
# blocking, in which case we select on the socket in order
# to wait on its return to a writeable state before resuming
# the send loop
if e.errno in (errno.EAGAIN, errno.EBUSY):
wlist = [self.connection.sock.fileno()]
rfds, wfds, efds = select.select([], wlist, [])
if wfds:
continue
raise
self.sending = (sent != 0)
self.offset += sent
yield OfLength(sent)
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, use_ssl=False, auth_tok=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 use_ssl: Should we use HTTPS?
:param auth_tok: 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
HEAT_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
HEAT_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
HEAT_CLIENT_CA_FILE is looked for.
:param insecure: Optional. If set then the server's certificate
will not be verified.
"""
self.host = host
self.port = port or self.DEFAULT_PORT
self.use_ssl = use_ssl
self.auth_tok = auth_tok
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.auth_plugin = self.make_auth_plugin(self.creds)
self.key_file = key_file
self.cert_file = cert_file
self.ca_file = ca_file
self.insecure = insecure
self.connect_kwargs = self.get_connect_kwargs()
def get_connect_kwargs(self):
connect_kwargs = {}
if self.use_ssl:
if self.key_file is None:
self.key_file = os.environ.get('HEAT_CLIENT_KEY_FILE')
if self.cert_file is None:
self.cert_file = os.environ.get('HEAT_CLIENT_CERT_FILE')
if self.ca_file is None:
self.ca_file = os.environ.get('HEAT_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 "
"HEAT_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 "
"HEAT_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 set_auth_token(self, auth_tok):
"""
Updates the authentication token for this client connection.
"""
# FIXME(sirp): Nova image/heat.py currently calls this. Since this
# method isn't really doing anything useful[1], we should go ahead and
# rip it out, first in Nova, then here. Steps:
#
# 1. Change auth_tok in heat to auth_token
# 2. Change image/heat.py in Nova to use client.auth_token
# 3. Remove this method
#
# [1] http://mail.python.org/pipermail/tutor/2003-October/025932.html
self.auth_tok = auth_tok
def configure_from_url(self, url):
"""
Setups the connection based on the given url.
The form is:
<http|https>://<host>:port/doc_root
"""
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
# 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):
"""
Returns an instantiated authentication plugin.
"""
strategy = creds.get('strategy', 'noauth')
plugin = auth.get_plugin_from_strategy(strategy, creds)
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_tok = 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_unauthorized
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_tok:
self._authenticate()
url = self._construct_url(action, params)
return self._do_request(method=method, url=url, body=body,
headers=headers)
def _construct_url(self, action, params=None):
"""
Create a URL object we can use to pass to _do_request().
"""
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]
query = urllib.urlencode(params)
else:
query = None
return urlparse.ParseResult(scheme, netloc, path, '', query, '')
@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/heat 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 = headers or {}
if 'x-auth-token' not in headers and self.auth_tok:
headers['x-auth-token'] = self.auth_tok
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, basestring)
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)
for header, value in headers.items():
c.putheader(header, value)
iter = self.image_iterator(c, headers, body)
if self._sendable(body):
# 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.NotAuthorized()
elif status_code == httplib.FORBIDDEN:
raise exception.NotAuthorized()
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(reason=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("Internal Server error: %s" % res.read())
elif status_code == httplib.SERVICE_UNAVAILABLE:
raise exception.ServiceUnavailable(retry=_retry(res))
elif status_code == httplib.REQUEST_URI_TOO_LONG:
raise exception.RequestUriTooLong(body=res.read())
else:
raise Exception("Unknown error occurred! %s" % res.read())
except (socket.error, IOError), e:
raise exception.ClientConnectionError(e)
def _seekable(self, body):
# pipes are not seekable, avoids sendfile() failure on e.g.
# cat /path/to/image | heat add ...
# or where add command is launched via popen
try:
os.lseek(body.fileno(), 0, os.SEEK_SET)
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 image_iterator(self, connection, headers, body):
if self._sendable(body):
return SendFileIterator(connection, body)
elif self._iterable(body):
return utils.chunkreadable(body)
else:
return ImageBodyIterator(body)
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
"""
result = {}
for param in actual_params:
if param in allowed_params:
result[param] = actual_params[param]
elif 'Parameters.member.' in param:
result[param] = actual_params[param]
return result