Module io.inverno.mod.grpc.client

module io.inverno.mod.grpc.client

The Inverno framework gRPC client module provides a gRPC client.

It defines the following sockets:

netService (required)
the Net service providing the ByteBuf allocator
configuration
the gRPC client module configuration
extensionRegistry
the Protocol buffer extension registry
messageCompressors
custom gRPC message compressors

It exposes the following beans:

configuration
the gRPC client module configuration
grpcClient
the gRPC client

A remote gRPC service method can be called by using an HTTP/2 client and transforming the client HTTP exchange into a client gRPC exchange as follows: 


 HttpClient httpClient = ... 
 h2Endpoint = httpClient.endpoint("localhost", 8080)
     .configuration(HttpClientConfigurationLoader.load(conf -> conf.http_protocol_versions(Set.of(HttpVersion.HTTP_2_0))))
     .build();
 
 HelloReply reply = h2Endpoint.exchange()
     .map(exchange -> (GrpcExchange.Unary<ExchangeContext, HelloRequest, HelloReply>)grpcClient.unary(
         exchange,
         GrpcServiceName.of("helloworld", "Greeter"), "SayHello",
         HelloRequest.getDefaultInstance(), HelloReply.getDefaultInstance()
     ))
     .flatMap(grpcExchange -> {
         grpcExchange.request().value(
             HelloRequest.newBuilder()
                 .setName("Bob")
                 .build()
         );
         return grpcExchange.response();
     })
     .flatMap(GrpcResponse.Unary::value)
     .block();

gRPC is only supported on top of the HTTP/2 protocol, the behaviour of an application using an HTTP/1.x client is undetermined.

It is recommended to rely on a protoc plugin for generating a proper gRPC client stub from Protocol buffer definitions.

Since:
1.9
Author:
Jeremy Kuhn