How are the Official Ubuntu Vagrant boxes built and published to Atlas?
You would be correct that the build process for Ubuntu images is all open!
For 16.04 and newer
Look at the livecd-rootfs package for how the images are built:
- https://code.launchpad.net/~ubuntu-core-dev/livecd-rootfs/trunk
- http://bazaar.launchpad.net/~ubuntu-core-dev/livecd-rootfs/trunk/view/head:/live-build/ubuntu-cpc/hooks/042-vagrant.binary
For older releases of Ubuntu
- https://code.launchpad.net/~ubuntu-on-ec2
- https://launchpad.net/vmbuilder
Specifically:
- https://code.launchpad.net/~ubuntu-on-ec2/vmbuilder/jenkins_kvm
And this is probably what you're looking for:
- http://bazaar.launchpad.net/~ubuntu-on-ec2/vmbuilder/jenkins_kvm/view/head:/jenkins/CloudImages_Vagrant.sh