在 WSL 2 上通过 Docker 连接到 TCP 服务器时遇到问题

Question

I'm using WSL2 on Windows 10 using an Ubuntu image, and Docker for Desktop Windows (2.2.2.0) with the WSL integration.

I have a super basic rust tcp server. I think the only relevant bit is:

let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
println!("Listening on 8080");
for stream in listener.incoming() {
    println!("Received connection");
    let stream = stream.unwrap();
    handle_connection(stream);
}

I can cargo install and run the binary without issue; the line above prints, I can curl localhost:8080 from WSL and see the response as I'd expect from the rest of the code.

I wanted to turn it into a docker image. Here's the Dockerfile.

FROM rust:1.40 as builder
COPY . .
RUN cargo install --path . --root .

FROM debian:buster-slim
COPY --from=builder ./bin/coolserver ./coolserver
EXPOSE 8080
ENTRYPOINT ["./coolserver"]

I then do:

docker build -t coolserver .
docker run -it --rm -p 8080:8080 coolserver

I see Listening on 8080 as expected (ie no panic), but attempting to curl localhost:8080 yields curl: (52) Empty reply from server . This, I don't know what to make of. Logging suggests my program gets to the point where it reaches listener.incoming() , but does not enter into the block.

To see if it was something to do with my setup (Docker for Desktop, WSL, etc.) or my Dockerfile, I followed the README for the docker-http-https-echo image, successfully. I can curl it on the specified ports.

I don't know how to debug further. Thanks in advance.

Answer 1

EXPOSE关键字是打开用于容器间通信的端口以使用来自主机的这些端口您必须在通过docker run运行 docker 时使用-p 8080:8080

Answer 2

@CarlosRafaelRamirez resolved it for me. It was as simple as binding to 0.0.0.0 rather than the loopback address 127.0.0.1 . More info here: https://pythonspeed.com/articles/docker-connection-refused/