Few years ago I found a nice open source chess game named Lucas Chess. The program is written in Python but unfortunately the game was targeted to the Windows Platform. Since then the community around Lucas Chess has done many steps towards supporting Linux platforms. Right now the git repo provides instructions on how LucasChess can be installed on the Linux platform ( specifically on a Debian based platform i.e. Debian/Ubuntu/Mint etc ) .
Nevertheless, this issue reveals that many attempts to install LucasChess on Linux had no results. The issue made me wonder if we can create a docker container for serving GUI purposes. Furthermore I saw the challenge to provide the installation details with the infrastructure as code approach. To take it one step further I was wondering whether a local development environment can be provided by a docker container. For example the java development environment image contains your favorite IDE, your preferred jdk etc. On the other hand the Angular development environment is going to bundle with the respective tools. It seems that Docker has not only revolutionized the DevOps landscape but also the development environment landscape.
The simple idea for running a GUI application inside a docker container is sharing the host’s X11 socket. The socket directories described here .
Based on the above idea we need to pass the parameters bellow in order to do the trick. Those params are :
-v /tmp/.X11-unix:/tmp/.X11-unix
This makes the unix domain socket available in the container
-e DISPLAY=unix$DISPLAY
This environmental variable tells the container which display to use (using the unix domain socket).
The container must belong to the host network .
The Dockerfile for the lucas chess base image :
FROM ubuntu:18.04
RUN apt-get update && apt-get install -y git sudo apt-utils
RUN export uid=1000 gid=1000 && \
mkdir -p /home/developer && \
echo "developer:x:${uid}:${gid}:Developer,,,:/home/developer:/bin/bash" >> /etc/passwd && \
echo "developer:x:${uid}:" >> /etc/group && \
echo "developer ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/developer && \
chmod 0440 /etc/sudoers.d/developer && \
chown ${uid}:${gid} -R /home/developer
RUN apt-get install -y python-pip \
python-dev \
python-qt4 \
python-pyaudio
RUN pip install setuptools && \
pip install psutil && \
pip install chardet && \
pip install 'python-chess<0.24' && \
pip install Pillow && \
pip install PhotoHash && \
pip install Cython && \
pip install scandir
USER developer
ENV HOME /home/developer
RUN cd ${HOME} && git clone https://github.com/lukasmonk/lucaschess.git lucaschess
WORKDIR /home/developer/lucaschess
RUN chmod -R 755 *
RUN chmod -R +x *
RUN sed -i 's/LCEngine2.so/LCEngine4.so/' LCEngine/xcython_linux.sh
RUN cd LCEngine/irina && ./xmk_linux.sh
RUN cd LCEngine && ./xcython_linux.sh
ENV LD_LIBRARY_PATH /home/developer/lucaschess/Engines/Linux64/_tools
RUN chmod +x -R Engines/Linux64/
USER root
RUN apt-get install -y stockfish
User developer
RUN ln -s /usr/games/stockfish ${HOME}/stockfish.exe
ENTRYPOINT ["python2.7", "Lucas.py"]
The usual command in order to build the image
docker build -t lucaschess
The command to start the container
docker run --name lucaschess --network host -it --rm -e DISPLAY=$DISPLAY -e QT_X11_NO_MITSHM=1 -v /tmp/.X11-unix:/tmp/.X11-unix lucaschess
The command above declares that the environmental variable QT_X11_NO_MITSHM has the value 1.
If we omit this environmental variable we are going to get the following error
X Error: BadShmSeg (invalid shared segment parameter) 128 Extension: 130 (MIT-SHM) Minor opcode: 3 (X_ShmPutImage) Resource id: 0x2c00012
A blank window is going to pop up. The MIT-SHM is a X Window System extension for exchange of image data between client and server using shared memory.
The “QT_X11_NO_MITSHM” – stops Qt from using the MIT-SHM X11 extension. ( maybe it would be wiser to define this parameter in the dockerfile ).
Above you can see the screenshots. The board created in the container but displayed in the host.
This link contains an example also on how you can create an Java Development Environment with a docker image containing Netbeans and Openjdk.