GrpcController

Implements: IOpenable, IConfigurable, IRegisterable, IUnreferenceable

Description

The GrpcController class allows you to create controllers that receive remote calls via the GRPC protocol.

Configuration parameters

• dependencies:
  • endpoint: override for GRPC Endpoint dependency
  • controller: override for Controller dependency
• connection(s):
  • discovery_key: (optional) key to retrieve the connection from IDiscovery
  • protocol: connection protocol: http or https
  • host: host name or IP address
  • port: port number
  • uri: resource URI or connection string with all parameters in it
• credentials:
  • ssl_key_file: SSL private key in PEM
  • ssl_crt_file: SSL certificate in PEM
  • ssl_ca_file: certificate authorities (root cerfiticates) in PEM

References

• *:discovery:*:*:1.0 - (optional) IDiscovery services
• *:logger:*:*:1.0 - (optional) ILogger components to pass log messages
• *:counters:*:*:1.0 - (optional) ICounters components to pass collected measurementsand as specified by the counter’s source.

Constructors

Creates a new instance of the controller.

GrpcController(controller_name: str)

• controller_name: str - controller’s name.

Fields

Abstract methods

register

Registers all controller routes in the HTTP endpoint.

This method is called by the controller and must be overriden in child classes.

abstractmethod register()

Instance methods

_apply_validation

TODO: add description

_apply_validation(schema: Schema, action: Callable[[InvokeRequest, ServicerContext], Any]): Callable[[InvokeRequest, ServicerContext], Any]

• schema: Schema - TODO: add description
• action: Callable[[InvokeRequest, ServicerContext], Any] - TODO: add description
• returns: Callable[[InvokeRequest, ServicerContext], Any] - TODO: add description

_apply_interceptors

TODO: add description

_apply_interceptors(action: Callable[[InvokeRequest, ServicerContext], Any]): Callable[[InvokeRequest, ServicerContext], Any]

• action: Callable[[InvokeRequest, ServicerContext], Any] - TODO: add description
• returns: Callable[[InvokeRequest, ServicerContext], Any] - TODO: add description

close

Closes the component and frees used resources.

close(context: Optional[IContext])

• context: IContext - (optional) a context to trace execution through a call chainn.

configure

Configures component by passing configuration parameters.

configure(config: ConfigParams)

• config: ConfigParams - configuration parameters to be set.

is_open

Checks if the component is open.

is_open(): bool

• returns: bool -True if the endpoint is open with an actively listening GRPC server.

_instrument

Adds instrumentation to log calls and measures call time. It returns a CounterTiming object that is used to end the time measurement.

_instrument(context: Optional[IContext], name: str): InstrumentTiming

• context: IContext - (optional) a context to trace execution through a call chain.
• name: str - method name.
• returns: InstrumentTiming - CounterTiming object used to end the time measurement.

_instrument_error

Adds instrumentation to error handling.

_instrument_error(context: Optional[IContext], name: str, err: Exception, reerror=False)

• context: IContext - (optional) a context to trace execution through a call chain.
• name: str - method name.
• err: Exception - occured error
• reerror: bool - if True - throw error

open

Opens the component.

open(context: Optional[IContext])

• context: IContext - (optional) a context to trace execution through a call chain.

_register_interceptor

Registers a middleware for methods in GRPC endpoint.

_register_interceptor(interceptor: Callable[[InvokeRequest, ServicerContext, Callable], Any])

• interceptor: Callable[[InvokeRequest, ServicerContext, Callable], Any] - middleware action to perform at the given route.

_register_method

Registers a middleware for methods in GRPC endpoint.

_register_method(name: str, schema: Schema, action: Callable[[InvokeRequest, ServicerContext], Any])

• name: str - method name
• schema: Schema - validation schema to validate received parameters.
• action: Callable[[InvokeRequest, ServicerContext], Any] - action function that is called when operation is invoked.

_register_method_with_auth

Registers a method with authorization.

_register_method_with_auth(name: str, schema: Schema, authorize: Callable[[InvokeRequest, ServicerContext, Callable], Any], action: Callable[[InvokeRequest, ServicerContext, Callable], Any])

• name: str - a method name
• schema: Schema - a validation schema to validate received parameters.
• authorize: Callable[[InvokeRequest, ServicerContext, Callable], Any] - an authorization interceptor
• action: Callable[[InvokeRequest, ServicerContext, Callable], Any] - an action function that is called when operation is invoked.

set_references

Sets references to dependent components.

set_references(references: IReferences)

• references: IReferences - references to locate the component dependencies.

unset_references

Unsets (clears) previously set references to dependent components.

unset_references()

Examples

class MyGrpcController(GrpcController, my_data_pb2_grpc.MyDataController):

    __controller: IMyController

    ...

    def __init__(self):
        suoer().__init__('.. controller name ...')
        self._dependency_resolver.put(
            "controller",
            Descriptor("mygroup","controller","*","*","1.0")
        )

    def add_servicer_to_server(self, server):
        my_data_pb2_grpc.add_MyDataServicer_to_server(self, server)

    def set_references(self, references):
        super().set_references(references)
        self._controller = this._dependency_resolver.get_required("controller")

    def __number_of_calls_interceptor(self, request: InvokeRequest, context: ServicerContext,
                            next: Callable[[InvokeRequest, ServicerContext], Any]): Any:
        self.__number_of_calls += 1
        return next(request, context)

    def __method(request: InvokeRequest, context: ServicerContext):
        context = request.context
        id = request.id
        return self._controller.get_my_data(context, id)

    def register(self):
        self._register_interceptor(self.__number_of_calls_interceptor)
        self._register_method("get_mydata", None, method)
        
        ...

controller = MyGrpcController()
controller.configure(ConfigParams.from_tuples(
    "connection.protocol", "http",
    "connection.host", "localhost",
    "connection.port", 8080
))

controller.set_references(References.from_tuples(
   Descriptor("mygroup","controller","default","default","1.0"), controller
))

controller.open("123")