¡@
OpenStack Study: client.py**** CubicPower OpenStack Study ****
# 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 try: import sendfile # noqa SENDFILE_SUPPORTED = True except ImportError: SENDFILE_SUPPORTED = False 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 from glance.openstack.common import strutils LOG = logging.getLogger(__name__) # common chunk size for get and put CHUNKSIZE = 65536 VERSION_REGEX = re.compile(r"/?v[0-9\.]+")
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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/ """
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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)
**** CubicPower OpenStack Study **** 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, )
**** CubicPower OpenStack Study **** def __init__(self, host, port=None, timeout=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 timeout: Connection timeout. :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 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_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.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()
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** def set_auth_token(self, auth_tok): """ Updates the authentication token for this client connection. """ # FIXME(sirp): Nova image/glance.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 Glance to auth_token # 2. Change image/glance.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
**** CubicPower OpenStack Study **** def configure_from_url(self, url): """ Setups the connection based on the given url. The form is: """ 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()
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** def get_connection_type(self): """ Returns the proper connection type """ if self.use_ssl: return HTTPSClientAuthConnection else: return httplib.HTTPConnection
**** CubicPower OpenStack Study **** 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_unauthenticated
**** CubicPower OpenStack Study **** 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) # 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))
**** CubicPower OpenStack Study **** 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] = strutils.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
**** CubicPower OpenStack Study **** 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 = strutils.safe_encode return dict([(to_str(h), to_str(v)) for h, v in headers.iteritems()]) @handle_redirects
**** CubicPower OpenStack Study **** 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 {}) 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, 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 = self.image_iterator(c, headers, 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)
**** CubicPower OpenStack Study **** 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)
**** CubicPower OpenStack Study **** def _sendable(self, body): return (SENDFILE_SUPPORTED and hasattr(body, 'fileno') and self._seekable(body) and not self.use_ssl)
**** CubicPower OpenStack Study **** def _iterable(self, body): return isinstance(body, collections.Iterable)
**** CubicPower OpenStack Study **** 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)
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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
|