Source code for watcher.api.hooks

# -*- encoding: utf-8 -*-
#
# Copyright © 2012 New Dream Network, LLC (DreamHost)
#
# 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.


from oslo_config import cfg
from pecan import hooks
from six.moves import http_client

from watcher.common import context


class ContextHook(hooks.PecanHook):
    """Configures a request context and attaches it to the request.

    The following HTTP request headers are used:

    X-User:
        Used for context.user.

    X-User-Id:
        Used for context.user_id.

    X-Project-Name:
        Used for context.project.

    X-Project-Id:
        Used for context.project_id.

    X-Auth-Token:
        Used for context.auth_token.

    """

    def before(self, state):
        headers = state.request.headers
        user = headers.get('X-User')
        user_id = headers.get('X-User-Id')
        project = headers.get('X-Project-Name')
        project_id = headers.get('X-Project-Id')
        domain_id = headers.get('X-User-Domain-Id')
        domain_name = headers.get('X-User-Domain-Name')
        auth_token = headers.get('X-Storage-Token')
        auth_token = headers.get('X-Auth-Token', auth_token)
        show_deleted = headers.get('X-Show-Deleted')
        auth_token_info = state.request.environ.get('keystone.token_info')
        roles = (headers.get('X-Roles', None) and
                 headers.get('X-Roles').split(','))

        state.request.context = context.make_context(
            auth_token=auth_token,
            auth_token_info=auth_token_info,
            user=user,
            user_id=user_id,
            project=project,
            project_id=project_id,
            domain_id=domain_id,
            domain_name=domain_name,
            show_deleted=show_deleted,
            roles=roles)


class NoExceptionTracebackHook(hooks.PecanHook):
    """Workaround rpc.common: deserialize_remote_exception.

    deserialize_remote_exception builds rpc exception traceback into error
    message which is then sent to the client. Such behavior is a security
    concern so this hook is aimed to cut-off traceback from the error message.
    """
    # NOTE(max_lobur): 'after' hook used instead of 'on_error' because
    # 'on_error' never fired for wsme+pecan pair. wsme @wsexpose decorator
    # catches and handles all the errors, so 'on_error' dedicated for unhandled
    # exceptions never fired.
[docs]    def after(self, state):
        # Omit empty body. Some errors may not have body at this level yet.
        if not state.response.body:
            return

        # Do nothing if there is no error.
        # Status codes in the range 200 (OK) to 399 (400 = BAD_REQUEST) are not
        # an error.
        if (http_client.OK <= state.response.status_int <
                http_client.BAD_REQUEST):
            return

        json_body = state.response.json
        # Do not remove traceback when traceback config is set
        if cfg.CONF.debug:
            return

        faultstring = json_body.get('faultstring')
        traceback_marker = 'Traceback (most recent call last):'
        if faultstring and traceback_marker in faultstring:
            # Cut-off traceback.
            faultstring = faultstring.split(traceback_marker, 1)[0]
            # Remove trailing newlines and spaces if any.
            json_body['faultstring'] = faultstring.rstrip()
            # Replace the whole json. Cannot change original one because it's
            # generated on the fly.
            state.response.json = json_body