change seeds to keep upstart as init system on Ubuntu Touch

[Martin Pitt]

As per https://blueprints.launchpad.net/ubuntu/+spec/core-1411-systemd-migration we want to switch vivid from upstart to systemd, which will happen in ubuntu-minimal. Currently ubuntu-touch also uses ubuntu-minimal, but we can't switch ubuntu-touch to systemd yet.

So we need to give touch its own minimal, by copying platform.vivid's required seed to ubuntu-touch.vivid, and then either build a new ubuntu-touch-minimal, or just fold it into the existing ubuntu-touch metapackage. (Opinions?)

[Martin Pitt (pitti)]

As a first attempt I changed the ubuntu-touch.vivid seeds like this: http://paste.ubuntu.com/10524862/ (forking/copying required and essential.

Then I added the new ubuntu-minimal-touch binary and the minimal-touch seed to ubuntu-touch-meta: http://paste.ubuntu.com/10524878/

This causes the following autogenerated changes: http://paste.ubuntu.com/10524893/ The problem is this:

+minimal-touch ubuntu-touch-minimal-touch

which obviously doesn't match the intended package name ubuntu-touch-minimal (or ubuntu-minimal-touch would also be okay), and hence the generated dependencies of the new u-m-t metapackage are empty.

[Martin Pitt (pitti)]

Colin points out that ubuntu-minimal is Priority: important and hence gets into debootstrap. That's the mechanism how ubuntu-minimal is installed (as it doesn't have any reverse dependencies, in particular not ubuntu-{standard,touch,desktop}. So we might need to consider alternative ways.

 One option would be to move ubuntu-minimal from "upstart" to "init", and promote "init" to required. init currently Pre-Depends: upstart | systemd-sysv, so for now this wouldn't change anything. But we need to explicitly seed "upstart" in touch then. The main thing to figure out is whether the image build process gets along with removing systemd-sysv and installing upstart.

[Martin Pitt (pitti)]

Updated plan:

Right now:
 - Switch ubuntu-minimal to "init" (no-op as init's preferred alternative is upstart).
 - Add "upstart" dependency to ubuntu-touch, as an extra precaution; lots of packages in -touch actually depend on upstart, but let's be explicit. (No-op right now, but this will prepare us for doing the switch)
 - Explicitly uninstall systemd-sysv in livecd-rootfs (http://paste.ubuntu.com/10525503/) to convince apt to uninstall systemd-sysv and install upstart.

When we do the switch:

 - Upload "init" with flipped dependencies (systemd-sysv | upstart)
 - Add "systemd-sysv" to ubuntu-standard for switching upgrades.

[Launchpad Janitor (janitor)]

This bug was fixed in the package livecd-rootfs - 2.290

---------------
livecd-rootfs (2.290) vivid; urgency=medium

  * touch: Explicitly uninstall systemd-sysv, to help apt to install upstart
    when the preferred "init" alternative is systemd-sysv. Also explicitly
    install packagekit to help the problem resolver. Thanks Colin Watson!
    (LP: #1428026)
 -- Martin Pitt <email address hidden> Wed, 04 Mar 2015 12:04:22 +0100

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-touch-meta - 1.211

---------------
ubuntu-touch-meta (1.211) vivid; urgency=medium

  * Refreshed dependencies
  * Added upstart to desktop, touch. This ensures that we keep upstart on
    Touch even when we switch Ubuntu to systemd. (LP: #1428026)
 -- Martin Pitt <email address hidden> Wed, 04 Mar 2015 11:57:55 +0100

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-meta - 1.331

---------------
ubuntu-meta (1.331) vivid; urgency=medium

  * Refreshed dependencies
  * minimal: Replace upstart with init. (LP: #1428026)
 -- Martin Pitt <email address hidden> Wed, 04 Mar 2015 13:38:29 +0100