| # Copyright 2015, Google Inc. |
| # All rights reserved. |
| # |
| # Redistribution and use in source and binary forms, with or without |
| # modification, are permitted provided that the following conditions are |
| # met: |
| # |
| # * Redistributions of source code must retain the above copyright |
| # notice, this list of conditions and the following disclaimer. |
| # * Redistributions in binary form must reproduce the above |
| # copyright notice, this list of conditions and the following disclaimer |
| # in the documentation and/or other materials provided with the |
| # distribution. |
| # * Neither the name of Google Inc. nor the names of its |
| # contributors may be used to endorse or promote products derived from |
| # this software without specific prior written permission. |
| # |
| # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| """Reference implementation for health checking in gRPC Python.""" |
| |
| import abc |
| import enum |
| import threading |
| |
| from grpc.health.v1 import health_pb2 |
| |
| |
| @enum.unique |
| class HealthStatus(enum.Enum): |
| """Statuses for a service mirroring the reference health.proto's values.""" |
| UNKNOWN = health_pb2.HealthCheckResponse.UNKNOWN |
| SERVING = health_pb2.HealthCheckResponse.SERVING |
| NOT_SERVING = health_pb2.HealthCheckResponse.NOT_SERVING |
| |
| |
| class _HealthServicer(health_pb2.EarlyAdopterHealthServicer): |
| """Servicer handling RPCs for service statuses.""" |
| |
| def __init__(self): |
| self._server_status_lock = threading.Lock() |
| self._server_status = {} |
| |
| def Check(self, request, context): |
| with self._server_status_lock: |
| if request.service not in self._server_status: |
| # TODO(atash): once the Python API has a way of setting the server |
| # status, bring us into conformance with the health check spec by |
| # returning the NOT_FOUND status here. |
| raise NotImplementedError() |
| else: |
| return health_pb2.HealthCheckResponse( |
| status=self._server_status[request.service].value) |
| |
| def set(service, status): |
| if not isinstance(status, HealthStatus): |
| raise TypeError('expected grpc.health.v1.health.HealthStatus ' |
| 'for argument `status` but got {}'.format(status)) |
| with self._server_status_lock: |
| self._server_status[service] = status |
| |
| |
| class HealthServer(health_pb2.EarlyAdopterHealthServer): |
| """Interface for the reference gRPC Python health server.""" |
| __metaclass__ = abc.ABCMeta |
| |
| @abc.abstractmethod |
| def start(self): |
| raise NotImplementedError() |
| |
| @abc.abstractmethod |
| def stop(self): |
| raise NotImplementedError() |
| |
| @abc.abstractmethod |
| def set(self, service, status): |
| """Set the status of the given service. |
| |
| Args: |
| service (str): service name of the service to set the reported status of |
| status (HealthStatus): status to set for the specified service |
| """ |
| raise NotImplementedError() |
| |
| |
| class _HealthServerImplementation(HealthServer): |
| """Implementation for the reference gRPC Python health server.""" |
| |
| def __init__(self, server, servicer): |
| self._server = server |
| self._servicer = servicer |
| |
| def start(self): |
| self._server.start() |
| |
| def stop(self): |
| self._server.stop() |
| |
| def set(self, service, status): |
| self._servicer.set(service, status) |
| |
| |
| def create_Health_server(port, private_key=None, certificate_chain=None): |
| """Get a HealthServer instance. |
| |
| Args: |
| port (int): port number passed through to health_pb2 server creation |
| routine. |
| private_key (str): to-be-created server's desired private key |
| certificate_chain (str): to-be-created server's desired certificate chain |
| |
| Returns: |
| An instance of HealthServer (conforming thus to |
| EarlyAdopterHealthServer and providing a method to set server status).""" |
| servicer = _HealthServicer() |
| server = health_pb2.early_adopter_create_Health_server( |
| servicer, port=port, private_key=private_key, |
| certificate_chain=certificate_chain) |
| return _HealthServerImplementation(server, servicer) |