chore: Reorganize examples and interop crates (#180)

* chore: Reorganize examples and interop crates

* fix interop tests

examples/src/tls_client_auth/server.rs

@@ -0,0 +1,51 @@
+pub mod pb {
+    tonic::include_proto!("grpc.examples.echo");
+}
+
+use futures::Stream;
+use pb::{EchoRequest, EchoResponse};
+use std::pin::Pin;
+use tonic::transport::{Certificate, Identity, Server, ServerTlsConfig};
+use tonic::{Request, Response, Status};
+
+type EchoResult<T> = Result<Response<T>, Status>;
+type ResponseStream = Pin<Box<dyn Stream<Item = Result<EchoResponse, Status>> + Send + Sync>>;
+
+#[derive(Default)]
+pub struct EchoServer;
+
+#[tonic::async_trait]
+impl pb::echo_server::Echo for EchoServer {
+    async fn unary_echo(&self, request: Request<EchoRequest>) -> EchoResult<EchoResponse> {
+        let message = request.into_inner().message;
+        Ok(Response::new(EchoResponse { message }))
+    }
+
+    type ServerStreamingEchoStream = ResponseStream;
+    type BidirectionalStreamingEchoStream = ResponseStream;
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let cert = tokio::fs::read("tonic-examples/data/tls/server.pem").await?;
+    let key = tokio::fs::read("tonic-examples/data/tls/server.key").await?;
+    let server_identity = Identity::from_pem(cert, key);
+
+    let client_ca_cert = tokio::fs::read("tonic-examples/data/tls/client_ca.pem").await?;
+    let client_ca_cert = Certificate::from_pem(client_ca_cert);
+
+    let addr = "[::1]:50051".parse().unwrap();
+    let server = EchoServer::default();
+
+    let tls = ServerTlsConfig::with_rustls()
+        .identity(server_identity)
+        .client_ca_root(client_ca_cert);
+
+    Server::builder()
+        .tls_config(tls)
+        .add_service(pb::echo_server::EchoServer::new(server))
+        .serve(addr)
+        .await?;
+
+    Ok(())
+}