xref: /tonic/examples/src/interceptor/server.rs (revision 9c1f2f94)
1 use tonic::{transport::Server, Request, Response, Status};
2 
3 use hello_world::greeter_server::{Greeter, GreeterServer};
4 use hello_world::{HelloReply, HelloRequest};
5 
6 pub mod hello_world {
7     tonic::include_proto!("helloworld");
8 }
9 
10 #[derive(Default)]
11 pub struct MyGreeter {}
12 
13 #[tonic::async_trait]
14 impl Greeter for MyGreeter {
say_hello( &self, request: Request<HelloRequest>, ) -> Result<Response<HelloReply>, Status>15     async fn say_hello(
16         &self,
17         request: Request<HelloRequest>,
18     ) -> Result<Response<HelloReply>, Status> {
19         let extension = request.extensions().get::<MyExtension>().unwrap();
20         println!("extension data = {}", extension.some_piece_of_data);
21 
22         let reply = hello_world::HelloReply {
23             message: format!("Hello {}!", request.into_inner().name),
24         };
25         Ok(Response::new(reply))
26     }
27 }
28 
29 #[tokio::main]
main() -> Result<(), Box<dyn std::error::Error>>30 async fn main() -> Result<(), Box<dyn std::error::Error>> {
31     let addr = "[::1]:50051".parse().unwrap();
32     let greeter = MyGreeter::default();
33 
34     // See examples/src/interceptor/client.rs for an example of how to create a
35     // named interceptor that can be returned from functions or stored in
36     // structs.
37     let svc = GreeterServer::with_interceptor(greeter, intercept);
38 
39     println!("GreeterServer listening on {}", addr);
40 
41     Server::builder().add_service(svc).serve(addr).await?;
42 
43     Ok(())
44 }
45 
46 /// This function will get called on each inbound request, if a `Status`
47 /// is returned, it will cancel the request and return that status to the
48 /// client.
intercept(mut req: Request<()>) -> Result<Request<()>, Status>49 fn intercept(mut req: Request<()>) -> Result<Request<()>, Status> {
50     println!("Intercepting request: {:?}", req);
51 
52     // Set an extension that can be retrieved by `say_hello`
53     req.extensions_mut().insert(MyExtension {
54         some_piece_of_data: "foo".to_string(),
55     });
56 
57     Ok(req)
58 }
59 
60 #[derive(Clone)]
61 struct MyExtension {
62     some_piece_of_data: String,
63 }
64