[Bug] Getting connect ECONNREFUSED when app is running on localhost

[15m43lk4155y]

Is there an existing issue for this?

• I have searched the existing issues

OS/Web Information

• Web Browser: Chrome
• Local OS: Ubuntu
• Docker image: codercom/code-server
• code-server --version: 4.91.1

Steps to Reproduce

1. docker container running locally with the image built using the following Dockerfile:

FROM codercom/code-server:4.91.1

CMD ["dumb-init", "code-server", "--proxy-domain", "{{port}}.customdomain.tld", "--port", "8443", "--auth", "none"]

3. local DNS pointing customdomain.tld to 127.0.0.1
4. NGINX reverse proxy that points to the code-server instance with two .conf files:

server {
    listen 80;
    server_name customdomain.tld;
    location / {
        proxy_pass http://container_ip:8443;
        proxy_set_header Host $host;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection upgrade;
        proxy_set_header Accept-Encoding gzip;
    }
}

and

server {
    listen 80;
    server_name ~^(\d+)\.customdomain\.tld$;
    location / {
        proxy_pass http://container_ip:8443;
        proxy_set_header Host $host;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection upgrade;
        proxy_set_header Accept-Encoding gzip;
    }
}

5. run http server in the code server terminal using python -m http.server -b localhost then open 8000.customdomain.tld in the browser

Expected

It should show the http server correctly

Actual

the following error displays:

Note that when running python -m http.server -b 127.0.0.1 the server is shown correctly as per the following image:

Logs

No response

Screenshot/Video

No response

Does this bug reproduce in native VS Code?

I did not test native VS Code

Does this bug reproduce in GitHub Codespaces?

I did not test GitHub Codespaces

Are you accessing code-server over a secure context?

• I am using a secure context.

Notes

This was tested using an angular app as well (since the host is localhost by default in it) and the same happens when I set the host in ng serve to 127.0.0.1 the app is shown correctly when I leave it by default (aka localhost) it doesn't

[code-asher]

Huh, I would expect both localhost and 127.0.0.1 to be inaccessible if they are inside the Docker container but 127.0.0.1 works for the Angular app? Does code-server work if you bind code-server to 0.0.0.0?

CMD ["dumb-init", "code-server", "--proxy-domain", "{{port}}.customdomain.tld", "--auth", "none", "--bind-addr", "0.0.0.0:8443"]

[code-asher]

Oh sorry I misunderstood, you are getting that error through code-server's built-in proxy. 8000.customdomain.tld will try to proxy whatever is on port 8000, so this error means nothing is running at the address 0.0.0.0:8000.

[code-asher]

If 127.0.0.1 works but not localhost, is it possible the Angular app is binding to ipv6?

[15m43lk4155y]

Huh, I would expect both localhost and 127.0.0.1 to be inaccessible if they are inside the Docker container but 127.0.0.1 works for the Angular app? Does code-server work if you bind code-server to 0.0.0.0?

CMD ["dumb-init", "code-server", "--proxy-domain", "{{port}}.customdomain.tld", "--auth", "none", "--bind-addr", "0.0.0.0:8443"]

Sorry for the miss I do actually bind it to 0.0.0.0 (what I gave is an earlier version of the Dockerfile, what I am using now is the following):
CMD ["dumb-init", "code-server", "--auth", "none", "--bind-addr", "0.0.0.0:8443", "--proxy-domain", "{{port}}.customdomain.tld"]

If 127.0.0.1 works but not localhost, is it possible the Angular app is binding to ipv6?

Well upon further tests I found out that this might be the case given the following tests:

The following displays the server correctly on 8000.customdomain.tld

The following displays the server correctly on 8000.customdomain.tld

The following gives connect ECONNREFUSED 0.0.0.0:8000 on 8000.customdomain.tld

So the issue as I understand is that the built-in proxy forwards the request to 0.0.0.0 even when the running server is binding to ipv6?

[15m43lk4155y]

@code-asher can you please give me an update on this issue on the light of my recent comment

[nomaddevops]

Hello there,
I'm experiencing the exact same issue running backstage (https://github.com/backstage/backstage)
don't really know why but the proxy return econnrefused.

If i'm running curl from my code-server instance this is working
For the record i'm running code-server under microk8s

[code-asher]

Hey, sorry for the delayed response.

So the issue as I understand is that the built-in proxy forwards the request to 0.0.0.0 even when the running server is binding to ipv6?

I think this is the case, yes. Possibly we should forward to localhost instead of 0.0.0.0.

[code-asher]

don't really know why but the proxy return econnrefused.

Maybe this is the same thing, can you make Backstage listen on 127.0.0.1 explicitly?

[nomaddevops]

don't really know why but the proxy return econnrefused.

Maybe this is the same thing, can you make Backstage listen on 127.0.0.1 explicitly?

Hey @code-asher sorry for my late response

I've just try it out, it looks like i'm being redirect but webpack return an invalid host header, this more related to how backstage is launch from my point of view