[Bug 1748581] Re: ubuntu-release-upgrader will need to know how to switch snaps between Ubuntu release channels during an upgrade

[Steve Langasek]

On Tue, Aug 21, 2018 at 07:33:56PM -0000, Stéphane Graber wrote:
> In the case where a snap is already installed, the upgrader should check
> what track and channel is in use for the snap, then attempt to switch to
> an "ubuntu-XX.XX" branch of that track/channel combination if it exists,
> if it doesn't, assume the user knows what they're doing and leave them
> alone.

Indeed, I'd go a step further and say that the channel should only be
switched if the user is already currently on a /ubuntu-XX.YY branch where
XX.YY is the Ubuntu release installed prior to the upgrade.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to ubuntu-release-upgrader in
Ubuntu.
https://bugs.launchpad.net/bugs/1748581

Title:
  ubuntu-release-upgrader will need to know how to switch snaps between
  Ubuntu release channels during an upgrade

Status in ubuntu-release-upgrader package in Ubuntu:
  Fix Released
Status in ubuntu-release-upgrader source package in Cosmic:
  Fix Released

Bug description:
  As part of the plan for including snaps in Ubuntu images by default
  (https://wiki.ubuntu.com/UbuntuSeededSnaps), we intend for the snap
  installs to be pinned to (possibly empty) per-Ubuntu-release channels
  in the Snap Store.

  This means that as part of a dist upgrade, ubuntu-release-upgrader
  will need to switch the channels of any relevant installed snaps from
  the channel for one release, to the channel for the next release, with
  snap refresh.

  (In many cases both channels will be empty and this will involve
  downloading no new snaps, just changing the pin on the client.)

  Since 18.04 is the first release with snaps by default, this doesn't
  need to be implemented in 18.04; but will need to be supported by the
  release upgrader in 18.10 at latest.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1748581/+subscriptions