tuskar/tuskar/common/context.py

# Copyright 2011 OpenStack Foundation
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.

"""RequestContext: context for requests that persist through all of nova."""

import copy
import uuid

from tuskar.common import exception
from tuskar.common import policy
from tuskar.openstack.common import local
from tuskar.openstack.common import log as logging
from tuskar.openstack.common import timeutils


LOG = logging.getLogger(__name__)


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


class RequestContext(object):
    """Security context and request information.

    Represents the user taking a given action within the system.

    """

    def __init__(self, user_id, project_id, is_admin=None, read_deleted="no",
                 roles=None, remote_address=None, timestamp=None,
                 request_id=None, auth_token=None, overwrite=True,
                 quota_class=None, user_name=None, project_name=None,
                 service_catalog=None, instance_lock_checked=False, **kwargs):
        """Initialize this RequestContext.

        :param read_deleted: 'no' indicates deleted records are hidden, 'yes'
            indicates deleted records are visible, 'only' indicates that
            *only* deleted records are visible.

        :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.
        """
        if kwargs:
            LOG.warn(_('Arguments dropped when creating context: %s') %
                    str(kwargs))

        self.user_id = user_id
        self.project_id = project_id
        self.roles = roles or []
        self.read_deleted = read_deleted
        self.remote_address = remote_address
        if not timestamp:
            timestamp = timeutils.utcnow()
        if isinstance(timestamp, basestring):
            timestamp = timeutils.parse_strtime(timestamp)
        self.timestamp = timestamp
        if not request_id:
            request_id = generate_request_id()
        self.request_id = request_id
        self.auth_token = auth_token

        if service_catalog:
            # Only include required parts of service_catalog
            self.service_catalog = [s for s in service_catalog
                if s.get('type') in ('volume')]
        else:
            # if list is empty or none
            self.service_catalog = []

        self.instance_lock_checked = instance_lock_checked

        # NOTE(markmc): this attribute is currently only used by the
        # rs_limits turnstile pre-processor.
        # See https://lists.launchpad.net/openstack/msg12200.html
        self.quota_class = quota_class
        self.user_name = user_name
        self.project_name = project_name
        self.is_admin = is_admin
        if self.is_admin is None:
            self.is_admin = policy.check_is_admin(self)
        if overwrite or not hasattr(local.store, 'context'):
            self.update_store()

    def _get_read_deleted(self):
        return self._read_deleted

    def _set_read_deleted(self, read_deleted):
        if read_deleted not in ('no', 'yes', 'only'):
            raise ValueError(_("read_deleted can only be one of 'no', "
                               "'yes' or 'only', not %r") % read_deleted)
        self._read_deleted = read_deleted

    def _del_read_deleted(self):
        del self._read_deleted

    read_deleted = property(_get_read_deleted, _set_read_deleted,
                            _del_read_deleted)

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

    def to_dict(self):
        return {'user_id': self.user_id,
                'project_id': self.project_id,
                'is_admin': self.is_admin,
                'read_deleted': self.read_deleted,
                'roles': self.roles,
                'remote_address': self.remote_address,
                'timestamp': timeutils.strtime(self.timestamp),
                'request_id': self.request_id,
                'auth_token': self.auth_token,
                'quota_class': self.quota_class,
                'user_name': self.user_name,
                'service_catalog': self.service_catalog,
                'project_name': self.project_name,
                'instance_lock_checked': self.instance_lock_checked,
                'tenant': self.tenant,
                'user': self.user}

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

    def elevated(self, read_deleted=None, overwrite=False):
        """Return a version of this context with admin flag set."""
        context = copy.copy(self)
        context.is_admin = True

        if 'admin' not in context.roles:
            context.roles.append('admin')

        if read_deleted is not None:
            context.read_deleted = read_deleted

        return context

    # NOTE(sirp): the openstack/common version of RequestContext uses
    # tenant/user whereas the Nova version uses project_id/user_id. We need
    # this shim in order to use context-aware code from openstack/common, like
    # logging, until we make the switch to using openstack/common's version of
    # RequestContext.
    @property
    def tenant(self):
        return self.project_id

    @property
    def user(self):
        return self.user_id


def get_admin_context(read_deleted="no"):
    return RequestContext(user_id=None,
                          project_id=None,
                          is_admin=True,
                          read_deleted=read_deleted,
                          overwrite=False)


def is_user_context(context):
    """Indicates if the request context is a normal user."""
    if not context:
        return False
    if context.is_admin:
        return False
    if not context.user_id or not context.project_id:
        return False
    return True


def require_admin_context(ctxt):
    """Raise exception.AdminRequired() if context is an admin context."""
    if not ctxt.is_admin:
        raise exception.AdminRequired()


def require_context(ctxt):
    """Raise exception.NotAuthorized() if context is not a user or an
    admin context.
    """
    if not ctxt.is_admin and not is_user_context(ctxt):
        raise exception.NotAuthorized()


def authorize_project_context(context, project_id):
    """Ensures a request has permission to access the given project."""
    if is_user_context(context):
        if not context.project_id:
            raise exception.NotAuthorized()
        elif context.project_id != project_id:
            raise exception.NotAuthorized()


def authorize_user_context(context, user_id):
    """Ensures a request has permission to access the given user."""
    if is_user_context(context):
        if not context.user_id:
            raise exception.NotAuthorized()
        elif context.user_id != user_id:
            raise exception.NotAuthorized()


def authorize_quota_class_context(context, class_name):
    """Ensures a request has permission to access the given quota class."""
    if is_user_context(context):
        if not context.quota_class:
            raise exception.NotAuthorized()
        elif context.quota_class != class_name:
            raise exception.NotAuthorized()