examples/python/errors/client.py

# Copyright 2019 The gRPC Authors
#
# 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.
"""This example handles rich error status in client-side."""

from __future__ import print_function
import logging

import grpc
from grpc_status import rpc_status
from google.rpc import error_details_pb2

from examples import helloworld_pb2
from examples import helloworld_pb2_grpc

_LOGGER = logging.getLogger(__name__)


def process(stub):
    try:
        response = stub.SayHello(helloworld_pb2.HelloRequest(name='Alice'))
        _LOGGER.info('Call success: %s', response.message)
    except grpc.RpcError as rpc_error:
        _LOGGER.error('Call failure: %s', rpc_error)
        status = rpc_status.from_call(rpc_error)
        for detail in status.details:
            if detail.Is(error_details_pb2.QuotaFailure.DESCRIPTOR):
                info = error_details_pb2.QuotaFailure()
                detail.Unpack(info)
                _LOGGER.error('Quota failure: %s', info)
            else:
                raise RuntimeError('Unexpected failure: %s' % detail)


def main():
    # NOTE(gRPC Python Team): .close() is possible on a channel and should be
    # used in circumstances in which the with statement does not fit the needs
    # of the code.
    with grpc.insecure_channel('localhost:50051') as channel:
        stub = helloworld_pb2_grpc.GreeterStub(channel)
        process(stub)


if __name__ == '__main__':
    logging.basicConfig()
    main()