Hello World example doesn't work (Failed to connect)

[hyperium]

Hello World example doesn't work (Failed to connect)

[simonask]

As further info, I can add that a dtruss indicates that both bind, listen and accept get called, after which select is called from inside sys_common::net::await (the standard Rust TCP stack).

[seanmonstar]

can you run your server with RUST_LOG=hyper=debug?

[simonask]

Sure thing:

$ RUST_LOG=hyper=debug target/rust-web
DEBUG:hyper::::server: binding to 127.0.0.1:3000

And that's it… 😦

EDIT: Trying to connect produces no additional output.

[seanmonstar]

Hm, it may not even be getting through the TCP layer.

Does the example in the TCP docs work? http://doc.rust-lang.org/std/io/net/tcp/struct.TcpListener.html

[simonask]

Hm, it does not! That would suggest a bug in Rust, right?

[seanmonstar]

I believe so!

[simonask]

Wait a second, my mistake — the example from TcpListener does in fact work (as opposed to my telnet invocation skills). The following outputs "Hello, World!" to a connecting telnet instance:

fn main() {
  let listener = TcpListener::bind("127.0.0.1:3000");
  // bind the listener to the specified address
  let mut acceptor = listener.listen();

  fn handle_client(mut stream: TcpStream) {
      stream.write(b"Hello, World!");
  }

  // accept connections and process them, spawning a new tasks for each one
  for stream in acceptor.incoming() {
      match stream {
          Err(e) => { /* connection failed */ }
          Ok(stream) => spawn(proc() {
              // connection succeeded
              handle_client(stream)
          })
      }
  }

  // close the socket server
  drop(acceptor);
}

[seanmonstar]

Oh ok. So, the request with curl just says connection refused, but the server doesn't crash nor output any more info?

[simonask]

Exactly.

[seanmonstar]

So, it should either output DEBUG: incoming stream or an ERROR: connection failed: https://github.com/hyperium/hyper/blob/master/src/server/mod.rs#L103

If it's not getting there, I'm left wondering if the error is happening inside rust-intertwine...

[simonask]

As you can probably tell, I'm new to Rust, but I'd be happy to help debugging in whatever ways I can. But I guess first of all: Are you or anyone else able to reproduce this behaviour?

[seanmonstar]

I'm able to access the example server with cargo run --example server and can curl it.

[simonask]

Alright, I had the same issue with the example, but then I tried curl with a Rails app I had lying around, and it gave the same result. Apparently curl fails on all requests to localhost on my machine. wget and browsers work without issue. I have no clue as to why I'm seeing this behaviour, but the problem seems to be with curl, and neither Rust nor Hyper.

It seems I had the following line in my /etc/hosts:

::1        localhost

which caused curl to attempt an IPv6 connection to localhost, which neither Rust nor Ruby were listening on.

[seanmonstar]

Whew. Glad it's worked out.

On Mon, Nov 10, 2014, 11:30 AM Simon Ask Ulsnes [email protected]
wrote:

Alright, I had the same issue with the example, but then I tried curl
with a Rails app I had lying around, and it gave the same result.
Apparently curl fails on all requests to localhost on my machine. wget
and browsers work without issue. I have no clue as to why I'm seeing this
behaviour, but the problem seems to be with curl, and neither Rust nor
Hyper.

It seems I had the following line in my /etc/hosts:

::1 localhost

which caused curl to attempt an IPv6 connection to localhost, which
neither Rust nor Ruby were listening on.

—
Reply to this email directly or view it on GitHub
#109 (comment).

[simonask]

Me too — really, really sorry to have wasted your time!