Synnefo

# Copyright (C) 2012, 2013 GRNET S.A. All rights reserved.

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

#

# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

import logging

import urlparse

import httplib

import urllib

from copy import copy

import simplejson

import objpool.http

# --------------------------------------------------------------------

# Astakos Client Exception

class AstakosClientException(Exception):

    def __init__(self, message, status=0):

        self.message = message

        self.status = status

    def __str__(self):

        return repr(self.message)

# --------------------------------------------------------------------

# Astakos Client Class

def getTokenFromCookie(request, cookie_name):

    """Extract token from the cookie name provided

    Cookie should be in the same form as astakos

    service sets its cookie contents:

        <user_uniq>|<user_token>

    """

    try:

        cookie_content = urllib.unquote(request.COOKIE.get(cookie_name, None))

        return cookie_content.split("|")[1]

    except:

        return None

class AstakosClient():

    """AstakosClient Class Implementation"""

    # ----------------------------------

    def __init__(self, astakos_url, use_pool=False, retry=0, logger=None):

        """Intialize AstakosClient Class

        Keyword arguments:

        astakos_url -- i.e https://accounts.example.com (string)

        use_pool    -- use objpool for http requests (boolean)

        retry       -- how many time to retry (integer)

        logger      -- pass a different logger

        """

        if logger is None:

            logger = logging.getLogger("astakosclient")

        logger.debug("Intialize AstakosClient: astakos_url = %s, "

                     "use_pool = %s" % (astakos_url, use_pool))

        if not astakos_url:

            m = "Astakos url not given"

            logger.error(m)

            raise ValueError(m)

        # Check for supported scheme

        p = urlparse.urlparse(astakos_url)

        conn_class = _scheme_to_class(p.scheme, use_pool)

        if conn_class is None:

            m = "Unsupported scheme: %s" % p.scheme

            logger.error(m)

            raise ValueError(m)

        # Save astakos_url etc. in our class

        self.retry = retry

        self.logger = logger

        self.netloc = p.netloc

        self.scheme = p.scheme

        self.conn_class = conn_class

    # ----------------------------------

    def retry(func):

        def decorator(self, *args, **kwargs):

            attemps = 0

            while True:

                try:

                    return func(self, *args, **kwargs)

                except AstakosClientException as err:

                    is_last_attempt = attemps == self.retry

                    if is_last_attempt:

                        raise err

                    if err.status == 401 or err.status == 404:

                        # In case of Unauthorized response

                        # or Not Found return immediately

                        raise err

                    attemps += 1

        return decorator

    # ----------------------------------

    @retry

    def _callAstakos(self, token, request_path,

                     headers=None, body=None, method="GET"):

        """Make the actual call to Astakos Service"""

        self.logger.debug(

            "Make a %s request to %s with headers %s "

            "and body %s" % (method, request_path, headers, body))

        # Check Input

        if not token:

            m = "Token not given"

            self.logger.error(m)

            raise ValueError(m)

        if headers is None:

            headers = {}

        if body is None:

            body = {}

        # Build request's header and body

        kwargs = {}

        kwargs['headers'] = copy(headers)

        kwargs['headers']['X-Auth-Token'] = token

        if body:

            kwargs['body'] = copy(body)

            kwargs['headers'].setdefault(

                'content-type', 'application/octet-stream')

        kwargs['headers'].setdefault('content-length',

                                     len(body) if body else 0)

        # Get the connection object

        conn = self.conn_class(self.netloc)

        # Send request

        try:

            (data, status) = _doRequest(conn, method, request_path, **kwargs)

        except Exception as err:

            self.logger.error("Failed to send request: %s" % err)

            raise AstakosClientException(str(err))

        finally:

            conn.close()

        # Return

        self.logger.debug("Request returned with status %s" % status)

        if status < 200 or status >= 300:

            raise AstakosClientException(data, status)

        return simplejson.loads(unicode(data))

    # ------------------------

    def authenticate(self, token, usage=False):

        """Check if user is authenticated Astakos user

        Keyword arguments:

        token   -- user's token (string)

        usage   -- return usage information for user (boolean)

        In case of success return user information (json parsed format).

        Otherwise raise an AstakosClientException.

        """

        # Send request

        auth_path = "/im/authenticate"

        if usage:

            auth_path += "?usage=1"

        return self._callAstakos(token, auth_path)

    # ----------------------------------

    def getDisplayNames(self, token, uuids):

        """Return a uuid_catalog dictionary for the given uuids

        Keyword arguments:

        token   -- user's token (string)

        uuids   -- list of user ids (list of strings)

        The returned uuid_catalog is a dictionary with uuids as

        keys and the corresponding user names as values

        """

        req_headers = {'content-type': 'application/json'}

        req_body = simplejson.dumps({'uuids': uuids})

        req_path = "/user_catalogs"

        data = self._callAstakos(

            token, req_path, req_headers, req_body, "POST")

        # XXX: check if exists

        return data.get("uuid_catalog")

    def getDisplayName(self, token, uuid):

        """Return the displayName of a uuid (see getDisplayNames)"""

        if not uuid:

            m = "No uuid was given"

            self.logger.error(m)

            raise ValueError(m)

        uuid_dict = self.getDisplayNames(token, [uuid])

        # XXX: check if exists

        return uuid_dict.get(uuid)

# --------------------------------------------------------------------

# Private functions

def _scheme_to_class(scheme, use_pool):

    """Return the appropriate conn class for given scheme"""

    if scheme == "http":

        if use_pool:

            return _objpoolHttpScheme

        else:

            return httplib.HTTPConnection

    elif scheme == "https":

        if use_pool:

            return _objpoolHttpsScheme

        else:

            return httplib.HTTPSConnection

    else:

        return None

def _objpoolHttpScheme(netloc):

    """Intialize the appropriate objpool.http class"""

    return objpool.http.get_http_connection(netloc, "http")

def _objpoolHttpsScheme(netloc):

    """Intialize the appropriate objpool.http class"""

    return objpool.http.get_http_connection(netloc, "https")

def _doRequest(conn, method, url, **kwargs):

    """The actual request. This function can easily be mocked"""

    conn.request(method, url, **kwargs)

    response = conn.getresponse()

    length = response.getheader('content-length', None)

    data = response.read(length)

    status = int(response.status)

    return (data, status)