snap.yaml skill->interface change

[Mark Shuttleworth]

On 01/03/16 12:17, Michael Vogt wrote:
> as announced by Gustavo in [1] we are working on a new "interfaces"
> based system that replaces the previous "capabilities" system.
>
> If you are using snapcraft, this change will happen automatically and
> transparently with the next release (and you just ignore the rest of
> the mail :)

Thanks Michael

For those of you following along at arms length, the background for this
evolution has been our desire to find a very clean language to describe:

 * kernel and other security requirements for snaps and their apps
 * services exported from snap to snap
 * files and other content exported between snaps from the same publisher

That language has shaped up very nicely. An "interface" is a convention,
and a plug is something that provides the services described by that
convention, and a slot is a space that can consume a plug from another snap.

This will address many of the common questions and requests I've seen
from folks working with snaps. For example, it will enable groups using
very large common libraries to share those libraries between their own
snaps (but not across vendor boundaries). It will enable vendors to
build snaps that export REST APIs to other snaps, for example "set
waypoints for the drone" style APIs. And it will allow you to build
ecosystems of snaps that use the services your snaps export.

There is one last piece to finalise, which is the initial set of
security services. Those have largely been ad-hoc to date, but we want
to kick off the Ubuntu Core 16 GA with a nice set of 10-20 security
services which cover the cases we have seen today, and can be well
documented. Over time we will probably evolve to a more granular set of
security services, but the starting set should be 10-20 relatively broad
ones. We'll have that nailed by April.

The current plan is that Ubuntu Core 16 would be GA within about 6 weeks
of the release of Ubuntu 16.04 LTS. Your feedback during the coming
weeks (especially once we've got a draft of the security plugs) will
really help to make that first GA an amazing release.

I have to say we were blown away by the feedback at MWC - it seems that
people really love the idea of snappy. I was amazed and delighted with
the cool things various entrepreneurs and giants like Samsung are doing
with it, and very much want this first major release to serve your
needs. So please do take a look at the 16.04 images and latest snapcraft
as we get over the hump of these transitions, and file bugs / requests
as needed.

Mark