Network error: [Errno 111] - Cannot interact with CoAP server outside a Docker Container about aiocoap

[chrysn]

I have little knowledge of what those WSL containers do, but can you confirm that the loopback address is even supposed to work across container boundaries?

You can test that easily by running sudo apt install socat on the Linux side, then running sudo socat - tcp-listen:80, and then pointing your web browser at http://127.0.0.1/ -- if forwarding works, you'll see the HTTP request in the Linux machine (and get an error in the browser); if not, socat will report nothing (and you'll get a different error).

[J0hn3ch]

Yes,

1. I enter inside the container of CoAP Server with this command: docker exec -it -u root ubuntu-coap-server bash

2. Next, as you write, I have installed inside the container, the tool socat with:
   apt install socat and running socat - tcp-listen:80.

3. From WSL in the Docker Host (so my machine) I run a curl http://127.0.0.1 and this is the result:

CoAP-Server-Container# socat - tcp-listen:80   |  Docker-Host-WSL$ curl -X GET http://127.0.0.1/
GET / HTTP/1.1                                 |  curl: (52) Empty reply from server     
Host: 127.0.0.1
User-Agent: curl/7.81.0
Accept: */*