s3action.py

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# -*- coding: utf-8 -*-
# @COPYRIGHT_begin
#
# Copyright [2010-2014] Institute of Nuclear Physics PAN, Krakow, Poland
#
# 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.
#
# @COPYRIGHT_end
import os
import urlparse
from ec2 import lookup
from ec2.base.action import Action, CLMException
from ec2.error import InvalidAction, MethodNotAllowed, InvalidArgument, InvalidURI, EC2Exception
from ec2.settings import BUCKETS_PATH
from ec2.helpers.auth import authenticate
from ec2.helpers.utils import get_path

##
# @package src.base.s3action
# S3 base action
# 
# @copyright Copyright (c) 2012 Institute of Nuclear Physics PAS <http://www.ifj.edu.pl/>
# @author Łukasz Chrząszcz <l.chrzaszcz@gmail.com>
# 

##
# Superclass for S3 API actions.
class S3Action(object):

    def __init__(self, parameters):
        self.parameters = parameters

        user_name = self.parameters['authorization'].split(' ')[1].split(':')[0]

        path = get_path(user_name, self.parameters['path_info'])

        # bucket_path = self.parameters['path_info']
        # slash = bucket_path.find('/')
        # if slash != -1:
        #     bucket_name = bucket_path[:slash+1]
        # else:
        #     bucket_name = bucket_path

        self.user_name = user_name
        self.path = path

    ##
    # Return an object of a concrete S3 action class.
    # 
    #         Args:
    #             parameters <dict> of the action
    #             cluster_manager <ClusterManager> the action will be run at
    #         
    def __new__(cls, parameters):
        concrete_class = None
        if cls == S3Action:
            if parameters['query_string']:
                qs_dict = urlparse.parse_qs(parameters['query_string'], keep_blank_values=True)
                for k, v in qs_dict.iteritems():
                    if len(v) == 1 and not v[0]:
                        raise MethodNotAllowed()  # we don't support any of the s3 commands defined by query string
                parameters['query_string'] = '' # we don't care about query string parameters and S3 doesn't use them for authorization

            path = os.path.normpath(parameters['path_info'])
            if path.startswith('/'):
                path = path[1:]
            if path.endswith('/'):
                path = path[:-1]

            path_parts = path.split('/')

            if len(path_parts) == 1:  # bucket
                if parameters['request_method'] == 'GET' or parameters['request_method'] == 'HEAD':
                    concrete_class_name = 'ListBucket'
            else:
                if parameters['request_method'] == 'PUT':
                    concrete_class_name = 'PutObject'
                if parameters['request_method'] == 'GET':
                    concrete_class_name = 'GetObject'

            for concrete_class in cls.__subclasses__():
                if concrete_class.__name__ == concrete_class_name:
                    break
        else:
            concrete_class = cls

        action = super(S3Action, cls).__new__(concrete_class, parameters)
        action.concrete_class_name = concrete_class_name
        return action


    def _get_template(self):
        name = '%s.xml' % self.concrete_class_name
        return lookup.get_template(name)

    def execute(self):
        authenticate(self.parameters)
        context = self._execute()

        # if body is dict then parse it to xml
        if context['body'].__class__ is dict:
            template = self._get_template()
            response = template.render(**context['body'])
        else:
            # if it isn't dict then pass that object directly
            response = context['body']

        result = {'body': response,
                  'headers': context.get('headers')}

        return result