gRPC equivalent of WCF service discovery

Question

EDIT: I don't want to use Consul or ZooKeeper. I want to find the address of a web service on a local network.

What are the gRPC equivalents of service discovery classes in WCF, like: ServiceDiscoveryBehavior and UdpDiscoveryEndpoint and DiscoveryClient used in this example:

Service:

using (ServiceHost serviceHost = new ServiceHost(typeof(CalculatorService), baseAddress))
{
    // Add calculator endpoint
    serviceHost.AddServiceEndpoint(typeof(ICalculator), new WSHttpBinding(), string.Empty);

    // ** DISCOVERY ** //
    // Make the service discoverable by adding the discovery behavior
    ServiceDiscoveryBehavior discoveryBehavior = new ServiceDiscoveryBehavior();
    serviceHost.Description.Behaviors.Add(discoveryBehavior);

    // Send announcements on UDP multicast transport
    discoveryBehavior.AnnouncementEndpoints.Add(new UdpAnnouncementEndpoint());

    // ** DISCOVERY ** //
    // Add the discovery endpoint that specifies where to publish the services
    serviceHost.Description.Endpoints.Add(new UdpDiscoveryEndpoint());

    // Open the ServiceHost to create listeners and start listening for messages.
    serviceHost.Open();
}

Client:

{
    DiscoveryClient discoveryClient = new DiscoveryClient(new UdpDiscoveryEndpoint());

    Collection<EndpointDiscoveryMetadata> calculatorServices =   
        (Collection<EndpointDiscoveryMetadata>)
        discoveryClient.Find(new FindCriteria(typeof(ICalculator))).Endpoints;

    discoveryClient.Close();

    CalculatorClient client = new CalculatorClient();  
    client.Endpoint.Address = calculatorServices[0].Address;
}  

Answer 1

gRPC has no classes equivalent to ServiceDiscoveryBehavior, UdpDiscoveryEndpoint or DiscoveryClient.

You have to use System.Net.Sockets to write your own network discovery using UDP broadcast.

Service:

IPAddress ipAddress = Dns.GetHostEntry(Dns.GetHostName()).AddressList.
                      FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork);

Server grpcServer = new Server
{
    Services = { Simulator.BindService(new Service()) },
    Ports = { new ServerPort(ipAddress.ToString(), 8080, ServerCredentials.Insecure) }
};
grpcServer.Start();

Task.Run(() =>
{
    while (true)
    {
        UdpClient udpServer = new UdpClient(8888);
        IPEndPoint clientEndPoint = new IPEndPoint(IPAddress.Any, 0);
        byte[] clientRequestData = udpServer.Receive(ref clientEndPoint);
        string clientRequest = Encoding.ASCII.GetString(clientRequestData);
        Console.WriteLine($"Recived {clientRequest} from {clientEndPoint.Address}");

        byte[] responseData = Encoding.ASCII.GetBytes("Response");
        udpServer.Send(responseData, responseData.Length, clientEndPoint);
        udpServer.Close();
    }
});

Client:

UdpClient udpClient = new UdpClient { EnableBroadcast = true };
byte[] requestData = Encoding.ASCII.GetBytes("Request");
udpClient.Send(requestData, requestData.Length, new IPEndPoint(IPAddress.Broadcast, 8888));

IPEndPoint serverEndPoint = new IPEndPoint(IPAddress.Any, 0);
byte[] serverResponseData = udpClient.Receive(ref serverEndPoint);
string serverResponse = Encoding.ASCII.GetString(serverResponseData);
Console.WriteLine($"Recived {serverResponse} from {serverEndPoint.Address}");

IPAddress ipAddress = serverEndPoint.Address;
udpClient.Close();

var grpcChannel = new Channel(ipAddress.ToString(), 8080, ChannelCredentials.Insecure);
var grpcClient = new Client(grpcChannel);