debian base gui

debian-base-gui

EarthWalkSoftware/debian-base-gui builds upon EarthWalkSoftware/debian-base to include basic X11 client graphics packages to leverage the docker host's display.

A docker image for EarthWalkSoftware/debian-base-gui is available from EarthWalk Software.

Docker Tags

docker pull will pull the latest image by default, but you can specify other versions (or tags) in the Docker Tags link, above. For a description of how the debian-base-gui tags work, go to the Docker Tags page of the EarthWalk Software debian-base-gui Wiki.

Packages

Among the additional packages are

dbus-x11
dmz-cursor-theme
file
fonts-dejavu
fonts-liberation
hicolor-icon-theme
libdbus-glib-1-2
libglib2.0
libstdc++6
libx11-xcb-dev
libx11-xcb1
libxrender1
libxt6
xauth
xz-utils

Creating a container

The following command will create a docker container named gui and start a console version of bash:

docker run -it \
           -e DISPLAY=unix${DISPLAY} \
           -v /tmp/.X11-unix:/tmp/.X11-unix \
           -v /tmp/.docker.xauth:/tmp/.docker.xauth \
           -v ${HOME}/.Xauthority:${HOME}/.Xauthority \
           -v /etc/localtime:/etc/localtime:ro \
           --rm \
           --name=gui \
       earthwalksoftware/debian-base-gui /bin/bash

Docker RUN options

The following settings are (the minimum) required docker RUN options for all containers created using, or deriving FROM, the earthwalksoftware/debian-base-gui docker image:

Environment variables

DISPLAY
Used to set the docker host's display to use. Normally, set to the default host display

-e DISPLAY=unix${DISPLAY}

Volumes

X11-unix
Maps the docker container's X11 driver to the docker host's X11 driver. Normally set to

-v /tmp/.X11-unix:/tmp/.X11-unix
docker.xauth
Maps the docker container's xauth file to the docker host's xauth file. Normally set to

-v /tmp/.docker.xauth:/tmp/.docker.xauth
.Xauthority
Maps the docker container's .Xauthority file to the docker host's .Xauthority file. Normally set to

-v ${HOME}/.Xauthority:${HOME}/.Xauthority

Simple tests

Test 1

Copy the docker command above (Creating a container) and paste it into a docker host command line to create a temporary docker container named gui. At the bash prompt (#), enter the following command:

apt-get update
apt-get install mousepad  
/usr/bin/mousepad

A graphical dialog should appear containing the mousepad editor main window. Exit the mousepad program, then exit the container (exit 2 times).

Test 2

Add a new volume to the command above, mapping a local folder container text documents (e.g., $HOME/Documents) to an arbitrary folder in the container (e.g., /documents):

-v ${HOME}/Documents:/documents

Perform the steps in Test 1 to open the mousepad application. Using the mousepad file manager, browse to the new folder (/documents) and open a text document there.

locale

The following locale is automatically created in the image:

locale-gen en_US
update-locale LANG=C.UTF-8 LC_MESSAGES=POSIX

This setting may be changed in the Dockerfile (using the RUN command) when building a new container from the earthwalksoftware/debian-base-gui image,

The name's too long! (or, how to localize a docker image from a repository)

So, rename it to something shorter.

Pull the image down to the local docker host:

docker pull earthwalksoftware/debian-base-gui:latest

Tag the new image with a shorter name (e.g. - debian-base-gui:latest):

docker tag earthwalksoftware/debian-base-gui:latest debian-base-gui:latest

Remove the original image tag:

docker rmi earthwalksoftware/debian-base-gui:latest

View docker images

docker images

The debian-base-gui:latest image is now located on the local docker host, and may be referred to as debian-base-gui.

Security concerns

This implementation does not do much to harden the docker host-container interface. It is fairly light-weight and intended for use on secure internal and/or external LANs and/or vLANs.

When using the X11 server over a WAN (e.g., Internet), additional steps to isolate the docker container from the docker host must be taken. Docker offers many RUN-time options for controlling the host-container interface, and can be explored at the Docker Docs site:

https://docs.docker.com/engine/reference/run/#operator-exclusive-options

Alternatively, a more robust and secure solution, such as x11docker and x11docker-gui, is worthy of investigation:

https://github.com/mviereck/x11docker