From 8049266e642e3a6a0782ab9eee5fee439f0acfcc Mon Sep 17 00:00:00 2001
From: Jan Tattermusch <jtattermusch@google.com>
Date: Tue, 2 Jun 2020 17:31:56 +0200
Subject: [PATCH] improvements

---
 examples/csharp/Xds/GreeterServer/Program.cs |  6 +-
 examples/csharp/Xds/README.md                | 90 +++++++++++++++++---
 2 files changed, 83 insertions(+), 13 deletions(-)

diff --git a/examples/csharp/Xds/GreeterServer/Program.cs b/examples/csharp/Xds/GreeterServer/Program.cs
index 030dd61c8b2..e7a2965739f 100644
--- a/examples/csharp/Xds/GreeterServer/Program.cs
+++ b/examples/csharp/Xds/GreeterServer/Program.cs
@@ -30,14 +30,14 @@ namespace GreeterServer
         // Server side handler of the SayHello RPC
         public override Task<HelloReply> SayHello(HelloRequest request, ServerCallContext context)
         {
-            String hostName = Dns.GetHostName();
+            String hostName = Dns.GetHostName();  // TODO: make hostname configurable
             return Task.FromResult(new HelloReply { Message = $"Hello {request.Name} from {hostName}!"});
         }
     }
 
     class Program
     {
-        const int Port = 50051;
+        const int Port = 50051;  // TODO: make port configurable
 
         public static void Main(string[] args)
         {
@@ -49,7 +49,7 @@ namespace GreeterServer
             Server server = new Server
             {
                 Services = { Greeter.BindService(greeterImpl), Health.BindService(healthServiceImpl), ServerReflection.BindService(reflectionImpl) },
-                Ports = { new ServerPort("localhost", Port, ServerCredentials.Insecure) }
+                Ports = { new ServerPort("localhost", Port, ServerCredentials.Insecure) }   // TODO: don't listen on just localhost
             };
             server.Start();
 
diff --git a/examples/csharp/Xds/README.md b/examples/csharp/Xds/README.md
index 7c09f307896..9b3f939dcf0 100644
--- a/examples/csharp/Xds/README.md
+++ b/examples/csharp/Xds/README.md
@@ -3,7 +3,7 @@ gRPC Hostname example (C#)
 
 BACKGROUND
 -------------
-This is a version of the helloworld example with a server whose response includes its hostname. It also supports health and reflection services. This makes it a good server to test infrastructure, like load balancing.
+This is a version of the helloworld example with a server whose response includes its hostname. It also supports health and reflection services. This makes it a good server to test infrastructure, such as XDS load balancing.
 
 PREREQUISITES
 -------------
@@ -13,17 +13,87 @@ PREREQUISITES
 You can also build the solution `Greeter.sln` using Visual Studio 2019,
 but it's not a requirement.
 
-BUILD AND RUN
+RUN THE EXAMPLE
 -------------
 
-- Build and run the server
+First, build and run the server, then verify the server is running and
+check the server is behaving as expected (more on that below).
 
-  ```
-  > dotnet run -p GreeterServer
-  ```
+```
+cd GreeterServer
+dotnet run
+```
 
-- Build and run the client
+After configuring your xDS server to track the gRPC server we just started,
+create a bootstrap file as desribed in [gRFC A27](https://github.com/grpc/proposal/blob/master/A27-xds-global-load-balancing.md):
 
-  ```
-  > dotnet run -p GreeterClient
-  ```
+```
+{
+  xds_servers": [
+    {
+      "server_uri": <string containing URI of xds server>,
+      "channel_creds": [
+        {
+          "type": <string containing channel cred type>,
+          "config": <JSON object containing config for the type>
+        }
+      ]
+    }
+  ],
+  "node": <JSON form of Node proto>
+}
+```
+
+Then point the `GRPC_XDS_BOOTSTRAP` environment variable at the bootstrap file:
+
+```
+export GRPC_XDS_BOOTSTRAP=/etc/xds-bootstrap.json
+```
+
+Finally, run your client:
+
+```
+cd GreeterClient
+dotnet run -- xds-experimental:///my-backend 
+```
+
+VERIFYING THE SERVER
+-------------
+
+`grpcurl` can be used to test your server. If you don't have it,
+install [`grpcurl`](https://github.com/fullstorydev/grpcurl/releases). This will allow
+you to manually test the service.
+
+Exercise your server's application-layer service:
+
+```sh
+> grpcurl --plaintext -d '{"name": "you"}' localhost:50051
+{
+  "message": "Hello you from jtatt.muc.corp.google.com!"
+}
+```
+
+Make sure that all of your server's services are available via reflection:
+
+```sh
+> grpcurl --plaintext localhost:50051 list
+grpc.health.v1.Health
+grpc.reflection.v1alpha.ServerReflection
+helloworld.Greeter
+```
+
+Make sure that your services are reporting healthy:
+
+```sh
+> grpcurl --plaintext -d '{"service": "helloworld.Greeter"}' localhost:50051
+grpc.health.v1.Health/Check
+{
+  "status": "SERVING"
+}
+
+> grpcurl --plaintext -d '{"service": ""}' localhost:50051
+grpc.health.v1.Health/Check
+{
+  "status": "SERVING"
+}
+```