spinoff from https://github.com/toopher/toopher-docker Docker hub doesn't publish 32-bit CentOS builds, so this sets up a Docker Automated Build to create our own.
To build the image, merely invoke docker as follows:
docker build .
To build the tarball that is referenced in the Dockerfile
we use Vagrant to build up a CentOS VM that can run through docker's mkimage-yum
steps. Here's how that's done:
vagrant up
vagrant ssh
cd /vagrant
sudo ./make-docker-image.sh
exit
vagrant -f destroy
This will dump the tarball back in this directory where it can then be used to build the docker image as described above.