I’m working on a learning project in which I developed 2 APIs Buyer and Seller and containerized it using Docker. To setup communication between these 2 APIs, I wanted to use KubeMQ RPC. I referred their cookbook and wrote a simple SendRequestAsync and SubscribeRequest.

public async Task<Response> SendRequest()
{
    Channel = new Channel(new ChannelParameters
    {
         RequestsType = RequestType.Query,
         Timeout = 10000,
         ChannelName = "SampleChannel",
         ClientID = "MyAPI",
         KubeMQAddress = "localhost:50000"
      });
       var result = await Channel.SendRequestAsync(new KubeMQ.SDK.csharp.CommandQuery.Request
       {
           Metadata = "MyMetadata",
           Body = Converter.ToByteArray("A Simple Request from Buyer.")
       });
        //Async
       if (result.Executed)
           return result;
       return null;
}

    private void SubscribeToChannel()
    {
        SubscribeRequest subscribeRequest = new SubscribeRequest(SubscribeType.Queries, "MyAPI", "SampleChannel", EventsStoreType.Undefined, 0);
                _responder.SubscribeToRequests(subscribeRequest, HandleIncomingRequests, HandleIncomingError);
    }

    private Response HandleIncomingRequests(RequestReceive request)
    {
                // Convert the request Body to a string
     string strBody = Converter.FromByteArray(request.Body).ToString();
                _logger.LogDebug($"Respond to Request. ID:'{request.RequestID}', Channel:'{request.Channel}', Body:'{strBody}'");
    
     // Create the Response object
     Response response = new Response(request)
     {
           Body = Converter.ToByteArray("OK"),
           Error = "None",
           ClientID = this.ClientID,
           Executed = true,
           Metadata = "OK",
     };
     return response;
}
private void HandleIncomingError(Exception ex)
{
    _logger.LogWarning($"Received Exception :{ex}");
}

My docker.yaml reads as below

services:
  kubemq:
    image: kubemq/kubemq:latest
    container_name: kubemq
    ports:
      - "8080:8080"
      - "9090:9090"
      - "50000:50000"
    environment:
      - KUBEMQ_HOST=kubemq
      - KUBEMQ_TOKEN=<<MyToken>>
    networks:
      - backend
    volumes:
      - kubemq_vol:/store
networks:
  backend:
volumes:
  kubemq_vol:

I am simply trying to send a message and get a response. But I’m getting the below error:

Grpc.Core.RpcException: Status(StatusCode="Unavailable", Detail="failed to connect to all addresses", DebugException="Grpc.Core.Internal.CoreErrorDetailException: {"created":"@1654251803.063997885","description":"Failed to pick subchannel","file":"/var/local/git/grpc/src/core/ext/filters/client_channel/client_channel.cc","file_line":5420,"referenced_errors":[{"created":"@1654251803.063991635","description":"failed to connect to all addresses","file":"/var/local/git/grpc/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc","file_line":398,"grpc_status":14}]}")
   at Grpc.Core.Internal.AsyncCall`2.UnaryCall(TRequest msg)
   at Grpc.Core.Calls.BlockingUnaryCall[TRequest,TResponse](CallInvocationDetails`2 call, TRequest req)
   at Grpc.Core.DefaultCallInvoker.BlockingUnaryCall[TRequest,TResponse](Method`2 method, String host, CallOptions options, TRequest request)
   at Grpc.Core.Interceptors.InterceptingCallInvoker.<BlockingUnaryCall>b__3_0[TRequest,TResponse](TRequest req, ClientInterceptorContext`2 ctx)
   at Grpc.Core.ClientBase.ClientBaseConfiguration.ClientBaseConfigurationInterceptor.BlockingUnaryCall[TRequest,TResponse](TRequest request, ClientInterceptorContext`2 context, BlockingUnaryCallContinuation`2 continuation)

I’m new to docker, KubeMQ and Microservices. So I’m maybe doing something wrong here. Any inputs is appreciated.
I didn’t find a lot of articles/questions on KubeMQ when compared to Kafka or RabbitMQ. I have to continue using KubeMQ since I can’t change the requirement now.