gRPC config - client interceptors (#24339)

Co-authored-by: Rick Anderson <3605364+Rick-Anderson@users.noreply.github.com>

aspnetcore/grpc/configuration.md

@@ -69,6 +69,10 @@ The following code:
 
 [!code-csharp[](~/grpc/configuration/sample/Program.cs?name=snippet&highlight=3-8)]
 
+Note that client interceptors aren't configured with `GrpcChannelOptions`. Instead, client interceptors are configured using the `Intercept` extension method with a channel. This extension method is in the `Grpc.Core.Interceptors` namespace.
+
+[!code-csharp[](~/grpc/configuration/sample/Program2.cs?name=snippet&highlight=4)]
+
 [!INCLUDE[](~/includes/gRPCazure.md)]
 
 ## Additional resources

aspnetcore/grpc/configuration/sample/Program2.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Threading.Tasks;
+using Greet;
+using Grpc.Core;
+using Grpc.Core.Interceptors;
+using Grpc.Net.Client;
+
+namespace GrpcGreeterClient
+{
+    class Program
+    {
+        #region snippet
+        static async Task Main(string[] args)
+        {
+            var channel = GrpcChannel.ForAddress("https://localhost:5001");
+            var callInvoker = channel.Intercept(new LoggingInterceptor());
+            var client = new Greeter.GreeterClient(callInvoker);
+
+            var reply = await client.SayHelloAsync(
+                              new HelloRequest { Name = "GreeterClient" });
+            Console.WriteLine("Greeting: " + reply.Message);
+        }
+        #endregion
+    }
+}