These images are clones of dovetailautomata/mk-cross-builder with some additions.
They are for cross-building for i386 | armhf | raspbian on an amd64 platform
To use them to build Machinekit packages
1) Pull the appropriate image:tag for the architecture you are targeting
2) cd to a blank directory in a terminal and run
docker run --rm -it --privileged -v /tmp/.X11-unix:/tmp/.X11-unix -v /dev/dri:/dev/dri -v $HOME:$HOME -e HOME -v $PWD:$PWD -w $PWD -e DISPLAY arceye/mk-cross-builder:<tag> /bin/bash
3) From inside the container run
where the tag is the architecture tag of the image eg. armhf