To build an Allura vagrant box:

$ mkdir ~/vagrant_allura && cd ~/vagrant_allura

# Get the base box, see http://www.vagrantbox.es/
# 12.04 is LTS, so will be good to stick with for some time
$ vagrant box add ubuntu-1204-server-amd64 http://cloud-images.ubuntu.com/precise/current/precise-server-cloudimg-vagrant-amd64-disk1.box
$ vagrant init ubuntu-1204-server-amd64

# Get a copy of the provisioning scripts (note, Vagrantfile may change from release to release and may need manual updating)
$ cp -R /var/local/allura/vagrant/* .

# At this point you can make whatever changes you want to the provisioning
# scripts.  Currently, the .pp puppet file runs first and sets some stuff up
# and then allura_setup.sh runs and does more.

# Provision the box (this will take a while)
$ vagrant up

# If you get an error, you can run `vagrant ssh` to get in and debug, and then `vagrant destroy` to start over

# Package the Allura box
$ vagrant package --vagrantfile Vagrantfile.pkg

# Test your new box
$ mkdir ~/vagrant_allura_test && cd ~/vagrant_allura_test
$ vagrant box add allura ~/vagrant_allura/package.box
$ vagrant init allura
$ vagrant up
$ vagrant ssh

# Do whatever testing you want...

# If everything checks out, you can rename your package.box and upload it