Basic container for X11 forwarding goodness

Dockerfile

FROM ubuntu
RUN apt update \
    && apt install -y firefox \
                      openssh-server \
                      xauth \
    && mkdir /var/run/sshd \
    && mkdir /root/.ssh \
    && chmod 700 /root/.ssh \
    && ssh-keygen -A \
    && sed -i "s/^.*PasswordAuthentication.*$/PasswordAuthentication no/" /etc/ssh/sshd_config \
    && sed -i "s/^.*X11Forwarding.*$/X11Forwarding yes/" /etc/ssh/sshd_config \
    && sed -i "s/^.*X11UseLocalhost.*$/X11UseLocalhost no/" /etc/ssh/sshd_config \
    && grep "^X11UseLocalhost" /etc/ssh/sshd_config || echo "X11UseLocalhost no" >> /etc/ssh/sshd_
config

RUN echo "YOUR_PUB_KEY_HERE" >> /root/.ssh/authorized_keys

ENTRYPOINT ["sh", "-c", "/usr/sbin/sshd && tail -f /dev/null"]

Very helpful stuff here but the the content has traveled some since the initial post. Steps I used:

1. @AutomationMusician's April 2018 post with the password file trick
2. @peter279k's suggestion to use FROM ubuntu:18.04 (edit: just tried again with 22.04 and it was fine) and his other steps on July 16, 2021. If you ssh in without filrefox on the end you can just type it at the terminal

Note that if you're working in a text editor that automatically adds a newline, like vim, don't add a blank line as it will do that for you (and the blank line will break it).

Might come back for the ssh keys-based method later.

I'm on MacOS and it's interesting to me that nowhere was the DISPLAY environment variable mentioned, or volume informations specified (e.g., '-v /tmp/.X11-unix:/tmp/.X11-unix'). These were huge red herrings in my attempts to figure this out.

Thanks. It also works for foreign architecture.