Websocket CORS error

[el-myz]

Hi,
-- the intial version of this question contained an error on my side, this is the edited version --
I am using the main branch version of axum. I have a local front-end development server on localhost:5173 and I am trying to connect to my axum server on, let's say, 0.0.0.0:3000.
Following the examples I could manage to send HTTP requests to my server, but my web socket on ws://0.0.0.0:3000/ws fails with the client side error message:

[Error] WebSocket connection to 'ws://0.0.0.0:3000/ws failed: The server did not accept the WebSocket handshake.

I am building the route like this:

pub fn create_route() -> Router {
    Router::new()
        .route("/ws", get(launch_ws))
        .route("/fake", get(fake))
        .layer(CorsLayer::very_permissive())
}

And hosting the server like this:

let app = Router::new()
        .merge(create_route())
        .layer(
            TraceLayer::new_for_http()
                .make_span_with(DefaultMakeSpan::default().include_headers(true)),
        );
        // .layer(cors);
    tokio::spawn(async move {
        axum::serve(
            listener,
            app.into_make_service_with_connect_info::<SocketAddr>(),
        )
        .await
    });

On the client I am just:

    const URL = `ws://localhost:45921/launch_comm`;
    ws = new WebSocket(URL);

Here is the log output. Note the output that is printed out one minute after the initial request

2023-09-19T07:00:56.696253Z TRACE hyper::proto::h1::conn: 200: Conn::read_head
2023-09-19T07:00:56.696314Z TRACE hyper::proto::h1::conn: 723: flushed({role=server}): State { reading: Init, writing: Init, keep_alive: Busy }
2023-09-19T07:00:56.696372Z TRACE hyper::proto::h1::conn: 200: Conn::read_head
2023-09-19T07:00:56.696409Z TRACE hyper::proto::h1::io: 257: received 484 bytes
2023-09-19T07:00:56.696477Z TRACE parse_headers: hyper::proto::h1::role: 147: Request.parse bytes=484
2023-09-19T07:00:56.696533Z TRACE parse_headers: hyper::proto::h1::role: 152: Request.parse Complete(484)
2023-09-19T07:00:56.696611Z DEBUG hyper::proto::h1::io: 203: parsed 12 headers
2023-09-19T07:00:56.696640Z DEBUG hyper::proto::h1::conn: 231: incoming body is empty
2023-09-19T07:00:56.696651Z TRACE hyper::proto::h1::conn: 785: {role=server}: prepare possible HTTP upgrade
2023-09-19T07:00:56.696769Z DEBUG request{method=GET uri=/launch_comm version=HTTP/1.1 headers={"host": "localhost:45921", "user-agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.0 Safari/605.1.15", "origin": "http://localhost:5173", "pragma": "no-cache", "cache-control": "no-cache", "upgrade": "websocket", "connection": "Upgrade", "sec-websocket-key": "vmePGm49tfp5mXdLFL9qxA==", "sec-websocket-version": "13", "sec-websocket-extensions": "permessage-deflate; client_max_window_bits", "accept-encoding": "gzip, deflate", "accept-language": "C"}}: tower_http::trace::on_request: 80: started processing request
2023-09-19T07:00:56.696878Z DEBUG request{method=GET uri=/launch_comm version=HTTP/1.1 headers={"host": "localhost:45921", "user-agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.0 Safari/605.1.15", "origin": "http://localhost:5173", "pragma": "no-cache", "cache-control": "no-cache", "upgrade": "websocket", "connection": "Upgrade", "sec-websocket-key": "vmePGm49tfp5mXdLFL9qxA==", "sec-websocket-version": "13", "sec-websocket-extensions": "permessage-deflate; client_max_window_bits", "accept-encoding": "gzip, deflate", "accept-language": "C"}}: tower_http::trace::on_response: 114: finished processing request latency=0 ms status=404
2023-09-19T07:00:56.696950Z TRACE encode_headers: hyper::proto::h1::role: 341: Server::encode status=404, body=None, req_method=Some(GET)
2023-09-19T07:00:56.697047Z DEBUG hyper::proto::h1::io: 308: flushed 263 bytes
2023-09-19T07:00:56.697077Z TRACE hyper::proto::h1::conn: 723: flushed({role=server}): State { reading: Init, writing: Init, keep_alive: Idle }


2023-09-19T07:01:56.710355Z TRACE hyper::proto::h1::conn: 200: Conn::read_head
2023-09-19T07:01:56.710418Z TRACE hyper::proto::h1::io: 257: received 0 bytes
2023-09-19T07:01:56.710430Z TRACE hyper::proto::h1::io: 235: parse eof
2023-09-19T07:01:56.710440Z TRACE hyper::proto::h1::conn: 947: State::close_read()
2023-09-19T07:01:56.710466Z DEBUG hyper::proto::h1::conn: 290: read eof
2023-09-19T07:01:56.710517Z TRACE hyper::proto::h1::conn: 953: State::close_write()
2023-09-19T07:01:56.710530Z TRACE hyper::proto::h1::conn: 947: State::close_read()
2023-09-19T07:01:56.710554Z TRACE hyper::proto::h1::conn: 953: State::close_write()
2023-09-19T07:01:56.710570Z TRACE hyper::proto::h1::conn: 723: flushed({role=server}): State { reading: Closed, writing: Closed, keep_alive: Disabled }
2023-09-19T07:01:56.710603Z TRACE hyper::upgrade: 236: pending upgrade fulfill

Can anyone help me with this problem?
Of course once I figure it out I want to set the CORS policy in a more restrictive manner.

[jplatte]

Can you try with CorsLayer::very_permissive? That has a few more allowances, maybe it helps somehow.

[el-myz]

Hi,
thank you very much for the quick response.
Unfortunately this also did not work. I will edit my question to include the JS code that tries to establish the web socket connection in case that helps to find the reason why I can not make it work,

[ttys3]

it seems related to js code.

you'd better put the whole demo to a repo. so people can help you

[el-myz]

Hi,
I have worked on a minimal example and it worked there even without the CORS settings. Turns out, websockets are not part of the CORS rules set.
Here is the running minimal example for anyone who might be interested in this: https://github.com/myz-dev/ws_cors
It is just a combination of existing axum examples.
Thank you for your messages.

[el-myz]

I also noticed that the CORS example is not up to date with the main branch. So it tries to use the 0.6 way of serving serve(app, 4000).await;.
Would a PR to fix this be too early as 0.7 is still being developed?

[davidpdrsn]

Please read the big message at the top of the readme. The main branch has breaking changes that are not published yet.

[el-myz]

Hi, thank you for the reply.
I understand. I wanted to ask if a contribution at this point trying to get all the examples to work with main would make sense or if it would make more sense to wait a little longer.