root / snf-django-lib / snf_django / lib / api / __init__.py @ f9d665e4
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# Copyright 2012, 2013 GRNET S.A. All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or
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# without modification, are permitted provided that the following
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# conditions are met:
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#
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# 1. Redistributions of source code must retain the above
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# copyright notice, this list of conditions and the following
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# disclaimer.
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#
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# 2. Redistributions in binary form must reproduce the above
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# copyright notice, this list of conditions and the following
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# disclaimer in the documentation and/or other materials
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# provided with the distribution.
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#
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# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
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# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
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# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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# POSSIBILITY OF SUCH DAMAGE.
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#
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# The views and conclusions contained in the software and
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# documentation are those of the authors and should not be
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# interpreted as representing official policies, either expressed
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# or implied, of GRNET S.A.
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import sys |
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from functools import wraps |
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from traceback import format_exc |
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from time import time |
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from logging import getLogger |
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from wsgiref.handlers import format_date_time |
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from django.http import HttpResponse |
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from django.utils import cache |
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from django.utils import simplejson as json |
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from django.template.loader import render_to_string |
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from django.views.decorators import csrf |
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from astakosclient import AstakosClient |
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from astakosclient.errors import AstakosClientException |
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from django.conf import settings |
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from snf_django.lib.api import faults |
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import itertools |
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log = getLogger(__name__) |
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django_logger = getLogger("django.request")
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def get_token(request): |
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"""Get the Authentication Token of a request."""
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token = request.GET.get("X-Auth-Token", None) |
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if not token: |
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token = request.META.get("HTTP_X_AUTH_TOKEN", None) |
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return token
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def api_method(http_method=None, token_required=True, user_required=True, |
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logger=None, format_allowed=True, astakos_auth_url=None, |
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serializations=None, strict_serlization=False): |
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"""Decorator function for views that implement an API method."""
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if not logger: |
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logger = log |
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serializations = serializations or ['json', 'xml'] |
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def decorator(func): |
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@wraps(func)
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def wrapper(request, *args, **kwargs): |
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try:
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# Get the requested serialization format
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serialization = get_serialization( |
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request, format_allowed, serializations[0])
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# If guessed serialization is not supported, fallback to
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# the default serialization or return an API error in case
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# strict serialization flag is set.
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if not serialization in serializations: |
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if strict_serlization:
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raise faults.BadRequest(("%s serialization not " |
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"supported") % serialization)
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serialization = serializations[0]
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request.serialization = serialization |
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# Check HTTP method
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if http_method and request.method != http_method: |
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raise faults.NotAllowed("Method not allowed", |
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allowed_methods=[http_method]) |
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# Get authentication token
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request.x_auth_token = None
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if token_required or user_required: |
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token = get_token(request) |
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if not token: |
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msg = "Access denied. No authentication token"
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raise faults.Unauthorized(msg)
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request.x_auth_token = token |
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# Authenticate
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if user_required:
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assert(token_required), "Can not get user without token" |
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astakos_url = astakos_auth_url |
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if astakos_url is None: |
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try:
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astakos_url = settings.ASTAKOS_AUTH_URL |
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except AttributeError: |
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logger.error("Cannot authenticate without having"
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" an Astakos Authentication URL")
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raise
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astakos = AstakosClient(token, astakos_url, |
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use_pool=True,
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retry=2,
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logger=logger) |
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user_info = astakos.authenticate() |
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request.user_uniq = user_info["access"]["user"]["id"] |
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request.user = user_info |
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# Get the response object
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response = func(request, *args, **kwargs) |
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# Fill in response variables
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update_response_headers(request, response) |
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return response
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except faults.Fault as fault: |
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if fault.code >= 500: |
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django_logger.error("Unexpected API Error: %s",
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request.path, |
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exc_info=sys.exc_info(), |
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extra={ |
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"status_code": fault.code,
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"request": request})
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return render_fault(request, fault)
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except AstakosClientException as err: |
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fault = faults.Fault(message=err.message, |
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details=err.details, |
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code=err.status) |
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if fault.code >= 500: |
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django_logger.error("Unexpected AstakosClient Error: %s",
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request.path, |
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exc_info=sys.exc_info(), |
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extra={ |
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"status_code": fault.code,
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"request": request})
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return render_fault(request, fault)
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except:
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django_logger.error("Internal Server Error: %s", request.path,
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exc_info=sys.exc_info(), |
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extra={ |
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"status_code": '500', |
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"request": request})
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fault = faults.InternalServerError("Unexpected error")
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return render_fault(request, fault)
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return csrf.csrf_exempt(wrapper)
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return decorator
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def get_serialization(request, format_allowed=True, |
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default_serialization="json"):
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"""Return the serialization format requested.
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Valid formats are 'json' and 'xml' and 'text'
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"""
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if not format_allowed: |
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return "text" |
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# Try to get serialization from 'format' parameter
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_format = request.GET.get("format")
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if _format:
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if _format == "json": |
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return "json" |
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elif _format == "xml": |
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return "xml" |
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# Try to get serialization from path
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path = request.path |
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if path.endswith(".json"): |
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return "json" |
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elif path.endswith(".xml"): |
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return "xml" |
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for item in request.META.get("HTTP_ACCEPT", "").split(","): |
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accept, sep, rest = item.strip().partition(";")
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if accept == "application/json": |
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return "json" |
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elif accept == "application/xml": |
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return "xml" |
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return default_serialization
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def update_response_headers(request, response): |
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if not getattr(response, "override_serialization", False): |
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serialization = request.serialization |
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if serialization == "xml": |
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response["Content-Type"] = "application/xml; charset=UTF-8" |
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elif serialization == "json": |
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response["Content-Type"] = "application/json; charset=UTF-8" |
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elif serialization == "text": |
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response["Content-Type"] = "text/plain; charset=UTF-8" |
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else:
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raise ValueError("Unknown serialization format '%s'" % |
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serialization) |
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if settings.DEBUG or getattr(settings, "TEST", False): |
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response["Date"] = format_date_time(time())
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if not response.has_header("Content-Length"): |
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_base_content_is_iter = getattr(response, '_base_content_is_iter', |
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None)
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if (_base_content_is_iter is not None and not _base_content_is_iter): |
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response["Content-Length"] = len(response.content) |
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else:
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if not (response.has_header('Content-Type') and |
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response['Content-Type'].startswith(
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'multipart/byteranges')):
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# save response content from been consumed if it is an iterator
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response._container, data = itertools.tee(response._container) |
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response["Content-Length"] = len(str(data)) |
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cache.add_never_cache_headers(response) |
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# Fix Vary and Cache-Control Headers. Issue: #3448
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cache.patch_vary_headers(response, ('X-Auth-Token',))
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cache.patch_cache_control(response, no_cache=True, no_store=True, |
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must_revalidate=True)
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def render_fault(request, fault): |
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"""Render an API fault to an HTTP response."""
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# If running in debug mode add exception information to fault details
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if settings.DEBUG or getattr(settings, "TEST", False): |
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fault.details = format_exc() |
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try:
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serialization = request.serialization |
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except AttributeError: |
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request.serialization = "json"
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serialization = "json"
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# Serialize the fault data to xml or json
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if serialization == "xml": |
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data = render_to_string("fault.xml", {"fault": fault}) |
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else:
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d = {fault.name: {"code": fault.code,
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"message": fault.message,
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"details": fault.details}}
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data = json.dumps(d) |
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response = HttpResponse(data, status=fault.code) |
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if response.status_code == 405 and hasattr(fault, 'allowed_methods'): |
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response['Allow'] = ','.join(fault.allowed_methods) |
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update_response_headers(request, response) |
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return response
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@api_method(token_required=False, user_required=False) |
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def api_endpoint_not_found(request): |
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raise faults.BadRequest("API endpoint not found") |
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@api_method(token_required=False, user_required=False) |
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def api_method_not_allowed(request, allowed_methods): |
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raise faults.NotAllowed("Method not allowed", |
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allowed_methods=allowed_methods) |
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def allow_jsonp(key='callback'): |
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"""
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Wrapper to enable jsonp responses.
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"""
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def wrapper(func): |
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@wraps(func)
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def view_wrapper(request, *args, **kwargs): |
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response = func(request, *args, **kwargs) |
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if 'content-type' in response._headers and \ |
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response._headers['content-type'][1] == 'application/json': |
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callback_name = request.GET.get(key, None)
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if callback_name:
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response.content = "%s(%s)" % (callback_name,
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response.content) |
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response._headers['content-type'] = ('Content-Type', |
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'text/javascript')
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return response
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return view_wrapper
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return wrapper
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def user_in_groups(permitted_groups, logger=None): |
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"""Check that the request user belongs to one of permitted groups.
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Django view wrapper to check that the already identified request user
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belongs to one of the allowed groups.
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"""
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if not logger: |
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logger = log |
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def decorator(func): |
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@wraps(func)
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def wrapper(request, *args, **kwargs): |
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if hasattr(request, "user") and request.user is not None: |
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groups = request.user["access"]["user"]["roles"] |
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groups = [g["name"] for g in groups] |
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else:
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raise faults.Forbidden
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common_groups = set(groups) & set(permitted_groups) |
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if not common_groups: |
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msg = ("Not allowing access to '%s' by user '%s'. User does"
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" not belong to a valid group. User groups: %s,"
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" Required groups %s"
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% (request.path, request.user, groups, |
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permitted_groups)) |
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logger.error(msg) |
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raise faults.Forbidden
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logger.info("User '%s' in groups '%s' accessed view '%s'",
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request.user_uniq, groups, request.path) |
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return func(request, *args, **kwargs)
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return wrapper
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return decorator
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