snap.yaml skill->interface change

[Michael Vogt]

Hello,

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 :)

Today the internal meta/snap.yaml changes that were part of this work
landed in git:

The previous "migration-skill" is now called the "old-security"
interfaces in `meta/snap.yaml`.

The changes you need to do in your meta/snap.yaml are very
straightforward, the "uses:" key is replaced with the "slots:" key and
the "type: migration-skill" with "interface: old-security". Here is an
example:

"""
name: foo
version: 1.0
apps:
 appname:
  command: a-command
  uses: [something]
uses:
 something:
  type: migration-skill
  caps:
   - network-client
"""

becomes:

"""
name: foo
version: 1.0
apps:
 appname:
  command: a-command
  slots: [something]
slots:
 something:
  interface: old-security
  caps:
   - network-client
"""

This change will take effect once the new snappy enters rolling 16.04
(which we expect to happen tomorrow).

Cheers,
 Michael


[1] https://lists.ubuntu.com/archives/snappy-devel/2016-February/001501.html