Not able to access code-server from inside a Docker Container

[qascade]

• Web Browser: Chrome
• Local OS: MacOS
• Remote OS: Ubuntu 20.04
• Remote Architecture: Amd64
• code-server --version: latest

I am trying to run code-server inside a ubuntu container and then trying to access it on host by exposing the internal port to external port but the page is not rendering

My Docker file

FROM ubuntu:20.04

USER root
RUN apt-get update
RUN apt-get install sudo gcc-multilib gdb -y
RUN apt-get install curl wget -y
RUN apt-get install radare2 -y
RUN useradd -rm -d /user/hacker -s /bin/bash -g root -G sudo -u 1001 hacker
#Basic Static Analysis Tools
RUN apt-get install strace ltrace -y
RUN apt-get install elfutils -y
RUN apt-get install nodejs -y
RUN apt-get install python3 python3-pip -y
RUN curl -fsSL https://code-server.dev/install.sh | sh
RUN echo 'hacker:hello' | chpasswd
USER hacker
RUN pip3 install pwntools
WORKDIR /user/hacker
RUN mkdir .config
WORKDIR /user/hacker/.config
RUN mkdir code-server
COPY ./config.yaml /user/hacker/.config/code-server/config.yaml
#For fixing gdb ascii error
RUN echo "export LC_CTYPE=C.UTF-8" >> .bashrc

WORKDIR /home/hacker/bin

#For installing gdb-gef plugin
RUN wget -O ~/.gdbinit-gef.py -q http://gef.blah.cat/py
RUN echo source ~/.gdbinit-gef.py >> ~/.gdbinit

RUN rm /home/hacker/bin/* &> /dev/null
COPY ./bin/stack1.c .
RUN gcc -w -o stack1 stack1.c
RUN rm stack1.c
EXPOSE 8080
ENTRYPOINT ["code-server","/home/hacker","--verbose"]

Steps to reproduce-

1. Run code-server inside the docker container whose PORT 8080 is exposed.
2. docker run -it -p 127.0.0.1:8085:8080 qascade/rev_engg_ubuntu:0.1

[qascade]

logs

[2022-05-18T18:28:46.634Z] trace child:26 got message {"message":{"type":"handshake","args":{"bind-addr":"127.0.0.1:8080","auth":"none","password":"hello","config":"/user/hacker/.config/code-server/config.yaml","_":["/home/hacker"],"verbose":true,"user-data-dir":"/user/hacker/.local/share/code-server","extensions-dir":"/user/hacker/.local/share/code-server/extensions","log":"trace","host":"127.0.0.1","port":8080,"proxy-domain":[],"usingEnvPassword":false,"usingEnvHashedPassword":false}}}
[2022-05-18T18:28:46.635Z] info  code-server 4.4.0 b088ec7adf9e17bc75215f79e21498eb40da03ed
[2022-05-18T18:28:46.636Z] info  Using user-data-dir ~/.local/share/code-server
[2022-05-18T18:28:46.636Z] trace Using extensions-dir ~/.local/share/code-server/extensions
[2022-05-18T18:28:46.648Z] info  Using config file ~/.config/code-server/config.yaml
[2022-05-18T18:28:46.648Z] info  HTTP server listening on http://127.0.0.1:8080/
[2022-05-18T18:28:46.648Z] info    - Authentication is disabled
[2022-05-18T18:28:46.648Z] info    - Not serving HTTPS

[jsjoeio]

What happens when you try to access it?

[jsjoeio]

Can you share a screenshot or browser logs?

[qascade]

Output of Docker Container

[2022-05-20T17:24:27.197Z] trace child:26 got message {"message":{"type":"handshake","args":{"bind-addr":"127.0.0.1:8080","auth":"none","password":"hello","config":"/user/hacker/.config/code-server/config.yaml","_":["/home/hacker"],"verbose":true,"user-data-dir":"/user/hacker/.local/share/code-server","extensions-dir":"/user/hacker/.local/share/code-server/extensions","log":"trace","host":"127.0.0.1","port":8080,"proxy-domain":[],"usingEnvPassword":false,"usingEnvHashedPassword":false}}}
[2022-05-20T17:24:27.199Z] info  code-server 4.4.0 b088ec7adf9e17bc75215f79e21498eb40da03ed
[2022-05-20T17:24:27.199Z] info  Using user-data-dir ~/.local/share/code-server
[2022-05-20T17:24:27.199Z] trace Using extensions-dir ~/.local/share/code-server/extensions
[2022-05-20T17:24:27.213Z] info  Using config file ~/.config/code-server/config.yaml
[2022-05-20T17:24:27.213Z] info  HTTP server listening on http://127.0.0.1:8080/
[2022-05-20T17:24:27.213Z] info    - Authentication is disabled
[2022-05-20T17:24:27.213Z] info    - Not serving HTTPS

Browser Output:

[jsjoeio]

Silly question: are the ports backwards? Should this be 127.0.0.1:8080:8085?

[qascade]

https://docs.docker.com/config/containers/container-networking/

Well the docker documentation says to use host port first, also in my experience while using other containers, host port has always come first while binding with the container port.

[qascade]

One things I am going to try is to try running this on different machine. But still, the problem lies is that packets are not recieved by code-serve instance. I might try to analyse the packets that are sent by the browser as well as in the container, it might be possible that code-server instance cannot process them for some reason. That's why it's not giving a response.

[jsjoeio]

Ah okay, makes sense.

Cool! Let us know what you find

[SimonUzL]

I had the same issue and in my case it helped to start code-sever with "code-server --bind-addr 0.0.0.0:8080".