New image organization and snap format

[Michael Vogt]

On Tue, Nov 24, 2015 at 02:30:04PM +0100, Michael Vogt wrote:
> On Wed, Nov 11, 2015 at 04:26:13PM -0200, Gustavo Niemeyer wrote:
> > This is (perhaps) the last major change which I'd like to raise attention
> > to, and it's perhaps one of the most disruptive and exciting ones too.
> > 
> > In the coming weeks we'll be landing relevant changes related to how the
> > ubuntu core image itself is organized, and also to the packaged format of
> > snaps. The new format is not backwards compatible, but there are relevant
> > benefits that will become apparent as that work lands and unrolls. Michael
> > Vogt is leading these changes for quite some time now, and we're expecting
> > them to become visible in the following weeks.
> 
> We made some good progress here in the last few weeks and there is an
> experimental "all-snap" image available at:
[..]

The all-snap image [1] has reached a new milestone, I pushed a new amd64
image to:

  https://people.canonical.com/~mvo/all-snaps/

that boot directly from the squashfs kernel-snap using the grub loop
mount support (no need to extract the kernel anymore). It also uses a
squashfs based gadget snap and follows the snap package names
discussed during the most recent snappy sprint.

Here is what it looks like on amd64:

"""
ubuntu at localhost:~$ snappy list
Name               Date       Version   Developer
canonical-linux-pc 2015-12-14 4.3.0-2-1 canonical
ubuntu-core        2015-12-17 16.04.0-2 canonical
canonical-pc       2015-12-17 2.1       canonical
"""

Note that when looking at /boot/grub there is no unpacked
kernel/initramfs anymore:

"""
ubuntu at localhost:~$ ls /boot/grub/
fonts  grub.cfg  grubenv  i386-pc  install.yaml  locale  x86_64-efi
"""

I also pushed a new rpi2 all-snap image which looks like this:
"""
ubuntu at localhost:~$ snappy list
Name                   Date       Version      Developer 
canonical-linux-raspi2 2015-12-17 4.2.0-1014-2 canonical 
ubuntu-core-armhf      2015-12-17 16.04.0-2    canonical 
canonical-pi2          2015-12-17 2.2          canonical 
"""
There we do have to unpack the kernel/initrd as uboot does not support
squashfs4.

Updates from the store should work on both images (as long as we keep
the snap package names :) But be warned that this is all pretty new
stuff.

Enjoy the new images!

Cheers,
 Michael


[1] Created with lp:~snappy-dev/goget-ubuntu-touch/all-snaps