[vUDS blueprint 13.10] hardware images

[Scott Moser]

Hi All,
 I'd like to propose that we do some work on "hardware images" in the
13.10 cycle.  The end result is basically to a 'cloud-image' that works on
hardware the way our cloud-images currently work on virtual platforms.

 * Currently, we're making "ephemeral" images available for use in MAAS.
   These images are essentially cloud images with a -generic kernel
   inserted.  They're really close to what we'd end up with.

 * We did some work last cycle on a "fast path installer".  Installing
   ready-to-go images to disk is not terribly difficult.  If everything is
   working perfectly, its not much more than 'dd if=image of=disk'.

   We need to do some work on automation and production of these images
   so that they're available.

 * There is a growing interest in Openstack "Bare Metal" provisioning.
   We'd like to have Ubuntu images "just work" with openstack  bare metal
   the way our cloud images do with openstack kvm/xen.

There is some work that we'd need to do:
 * cloud-init datasource for bare metal.  Doing first boot customization
   is tricky without a datasource available.  We'll need to come up with
   some agreement between an "installer" and the created image on how to
   communicate first-boot customization.  Our current solution with the
   maas images and the fast path installer is Ubuntu specific (d-i
   preseeding / file writing "inside the image")
 * produce baremetal cloud images on similar build cycle to the
   cloud-images.
 * work with openstack to make sure our images are working perfectly
   there.
 * misc other things.  My first pass at just making dd'able images
   performed poorly because of filesystem alignment.  There might be
   things we can do to improve this.
 * boot work (EFI and secure boot)

One additional piece of work I'd like to consider is the return of the
'-server' kernel.  We currently have basically 2 kernel options for server
installation:
 * linux-image-virtual (~25M installed)
 * linux-image-generic (~155M installed)

there is certainly some set of modules that a "default server install"
could do without.  Ie, you probably aren't using a bluetooth headset,
audio, or wifi on your server install.  I've not done any digging at all,
but if there is a middle ground that makes a high percentage of server
hardware boot with a 60M footprint, then we could eventually consider
dropping -virtual for that kernel.

Since our "hardware images" will be mainly "cloud images with a hardware
kernel", we could potentially at some point join the two.

The -virtual kernel is very useful. Our images are a ~200M download and
come with a filesystem ~700M populated.  If we just swapped out -virtual
for -generic, we'd see ~15% size growth as a result, and at almost zero
percent growth in function.