To build an Allura vagrant box:
$ mkdir ~/vagrant_allura && cd ~/vagrant_allura
# Get the base box
$ vagrant box add ubuntu-1110-server-amd64 http://timhuegdon.com/vagrant-boxes/ubuntu-11.10.box
$ vagrant init
# Get a copy of the provisioning scripts
$ cp /var/local/allura/vagrant/* .
# At this point you can make whatever changes you want to the provisioning
# scripts
# Provision the box (this will take a while)
$ vagrant up
# Package the Allura box
$ vagrant package --vagrantfile Vagrantfile.pkg
# Test your new box
$ mkdir ~/vagrant_allura_test and cd ~/vagrant_allura_test
$ vagrant box add allura ~/vagrant_allura/package.box
$ vagrant init
$ vagrant ssh
# Do whatever testing you want...
# If everything checks out, you can rename your package.box and upload it