heat/heat/common/context.py

# 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.

import uuid

from heat.openstack.common import local
from heat.common import exception
from heat.common import policy
from heat.common import wsgi
from heat.openstack.common import context
from heat.openstack.common import importutils
from heat.db import api as db_api


def generate_request_id():
    return 'req-' + str(uuid.uuid4())


class RequestContext(context.RequestContext):
    """
    Stores information about the security context under which the user
    accesses the system, as well as additional request information.
    """

    def __init__(self, auth_token=None, username=None, password=None,
                 aws_creds=None, tenant=None, user_id=None,
                 tenant_id=None, auth_url=None, roles=None, is_admin=None,
                 read_only=False, show_deleted=False,
                 overwrite=True, trust_id=None, trustor_user_id=None,
                 request_id=None, **kwargs):
        """
        :param overwrite: Set to False to ensure that the greenthread local
            copy of the index is not overwritten.

         :param kwargs: Extra arguments that might be present, but we ignore
            because they possibly came in from older rpc messages.
        """
        super(RequestContext, self).__init__(auth_token=auth_token,
                                             user=username, tenant=tenant,
                                             is_admin=is_admin,
                                             read_only=read_only,
                                             show_deleted=show_deleted,
                                             request_id=request_id)

        self.username = username
        self.user_id = user_id
        self.password = password
        self.aws_creds = aws_creds
        self.tenant_id = tenant_id
        self.auth_url = auth_url
        self.roles = roles or []
        if overwrite or not hasattr(local.store, 'context'):
            self.update_store()
        self._session = None
        self.trust_id = trust_id
        self.trustor_user_id = trustor_user_id
        self.policy = policy.Enforcer()

        if is_admin is None:
            self.is_admin = self.policy.check_is_admin(self)
        else:
            self.is_admin = is_admin

    def update_store(self):
        local.store.context = self

    @property
    def session(self):
        if self._session is None:
            self._session = db_api.get_session()
        return self._session

    def to_dict(self):
        return {'auth_token': self.auth_token,
                'username': self.username,
                'user_id': self.user_id,
                'password': self.password,
                'aws_creds': self.aws_creds,
                'tenant': self.tenant,
                'tenant_id': self.tenant_id,
                'trust_id': self.trust_id,
                'trustor_user_id': self.trustor_user_id,
                'auth_url': self.auth_url,
                'roles': self.roles,
                'is_admin': self.is_admin,
                'user': self.user,
                'request_id': self.request_id,
                'show_deleted': self.show_deleted}

    @classmethod
    def from_dict(cls, values):
        return cls(**values)


def get_admin_context(show_deleted=False):
    return RequestContext(is_admin=True, show_deleted=show_deleted)


class ContextMiddleware(wsgi.Middleware):

    def __init__(self, app, conf, **local_conf):
        # Determine the context class to use
        self.ctxcls = RequestContext
        if 'context_class' in local_conf:
            self.ctxcls = importutils.import_class(local_conf['context_class'])

        super(ContextMiddleware, self).__init__(app)

    def make_context(self, *args, **kwargs):
        """
        Create a context with the given arguments.
        """
        return self.ctxcls(*args, **kwargs)

    def process_request(self, req):
        """
        Extract any authentication information in the request and
        construct an appropriate context from it.
        """
        headers = req.headers

        try:
            username = None
            user_id = None
            password = None
            aws_creds = None

            if headers.get('X-Auth-User') is not None:
                username = headers.get('X-Auth-User')
                user_id = headers.get('X-User-Id')
                password = headers.get('X-Auth-Key')
            elif headers.get('X-Auth-EC2-Creds') is not None:
                aws_creds = headers.get('X-Auth-EC2-Creds')

            token = headers.get('X-Auth-Token')
            tenant = headers.get('X-Tenant-Name')
            tenant_id = headers.get('X-Tenant-Id')
            auth_url = headers.get('X-Auth-Url')
            roles = headers.get('X-Roles')
            if roles is not None:
                roles = roles.split(',')

        except Exception:
            raise exception.NotAuthenticated()

        req.context = self.make_context(auth_token=token,
                                        tenant=tenant, tenant_id=tenant_id,
                                        aws_creds=aws_creds,
                                        username=username,
                                        user_id=user_id,
                                        password=password,
                                        auth_url=auth_url, roles=roles)


def ContextMiddleware_filter_factory(global_conf, **local_conf):
    """
    Factory method for paste.deploy
    """
    conf = global_conf.copy()
    conf.update(local_conf)

    def filter(app):
        return ContextMiddleware(app, conf)

    return filter