ironic.common.json_rpc.client

Source code for ironic.common.json_rpc.client

# 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.

"""A simple JSON RPC client.

This client is compatible with any JSON RPC 2.0 implementation, including ours.
"""

from oslo_config import cfg
from oslo_log import log
from oslo_utils import importutils
from oslo_utils import strutils
from oslo_utils import uuidutils

from ironic.common import exception
from ironic.common.i18n import _
from ironic.common import json_rpc
from ironic.common import keystone


CONF = cfg.CONF
LOG = log.getLogger(__name__)
_SESSION = None


def _get_session():
    global _SESSION

    if _SESSION is None:
        if json_rpc.require_authentication():
            auth = keystone.get_auth('json_rpc')
        else:
            auth = None

        _SESSION = keystone.get_session('json_rpc', auth=auth)
        _SESSION.headers = {
            'Content-Type': 'application/json'
        }

    return _SESSION


[docs]class Client(object): """JSON RPC client with ironic exception handling.""" def __init__(self, serializer, version_cap=None): self.serializer = serializer self.version_cap = version_cap
[docs] def can_send_version(self, version): return _can_send_version(version, self.version_cap)
[docs] def prepare(self, topic, version=None): host = topic.split('.', 1)[1] return _CallContext(host, self.serializer, version=version, version_cap=self.version_cap)
class _CallContext(object): """Wrapper object for compatibility with oslo.messaging API.""" def __init__(self, host, serializer, version=None, version_cap=None): self.host = host self.serializer = serializer self.version = version self.version_cap = version_cap def _handle_error(self, error): if not error: return message = error['message'] try: cls = error['data']['class'] except KeyError: LOG.error("Unexpected error from RPC: %s", error) raise exception.IronicException( _("Unexpected error raised by RPC")) else: if not cls.startswith('ironic.common.exception.'): # NOTE(dtantsur): protect against arbitrary code execution LOG.error("Unexpected error from RPC: %s", error) raise exception.IronicException( _("Unexpected error raised by RPC")) raise importutils.import_object(cls, message, code=error.get('code', 500)) def call(self, context, method, version=None, **kwargs): """Call conductor RPC. Versioned objects are automatically serialized and deserialized. :param context: Security context. :param method: Method name. :param version: RPC API version to use. :param kwargs: Keyword arguments to pass. :return: RPC result (if any). """ return self._request(context, method, cast=False, version=version, **kwargs) def cast(self, context, method, version=None, **kwargs): """Call conductor RPC asynchronously. Versioned objects are automatically serialized and deserialized. :param context: Security context. :param method: Method name. :param version: RPC API version to use. :param kwargs: Keyword arguments to pass. :return: None """ return self._request(context, method, cast=True, version=version, **kwargs) def _request(self, context, method, cast=False, version=None, **kwargs): """Call conductor RPC. Versioned objects are automatically serialized and deserialized. :param context: Security context. :param method: Method name. :param cast: If true, use a JSON RPC notification. :param version: RPC API version to use. :param kwargs: Keyword arguments to pass. :return: RPC result (if any). """ params = {key: self.serializer.serialize_entity(context, value) for key, value in kwargs.items()} params['context'] = context.to_dict() if version is None: version = self.version if version is not None: _check_version(version, self.version_cap) params['rpc.version'] = version body = { "jsonrpc": "2.0", "method": method, "params": params, } if not cast: body['id'] = context.request_id or uuidutils.generate_uuid() LOG.debug("RPC %s with %s", method, strutils.mask_dict_password(body)) scheme = 'http' if CONF.json_rpc.use_ssl: scheme = 'https' url = '%s://%s:%d' % (scheme, self.host, CONF.json_rpc.port) result = _get_session().post(url, json=body) LOG.debug('RPC %s returned %s', method, strutils.mask_password(result.text or '<None>')) if not cast: result = result.json() self._handle_error(result.get('error')) result = self.serializer.deserialize_entity(context, result['result']) return result def _can_send_version(requested, version_cap): if requested is None or version_cap is None: return True requested_parts = [int(item) for item in requested.split('.', 1)] version_cap_parts = [int(item) for item in version_cap.split('.', 1)] if requested_parts[0] != version_cap_parts[0]: return False # major version mismatch else: return requested_parts[1] <= version_cap_parts[1] def _check_version(requested, version_cap): if not _can_send_version(requested, version_cap): raise RuntimeError(_("Cannot send RPC request: requested version " "%(requested)s, maximum allowed version is " "%(version_cap)s") % {'requested': requested, 'version_cap': version_cap})
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