[PROPOSAL] lock juju down to using charms from LTS and latest release only

[Clint Byrum]

Excerpts from Robbie Williamson's message of 2013-03-13 11:02:02 -0700:
> Hi all,
> 
> With all the discussion about rolling release, I got to thinking about
> our charms and how they tie to releases.  I wanted to propose that we
> limit the releases supported by juju to LTS plus the latest release.  My
> reasoning is that we need to ensure better charm consistency for
> supported releases, and the current approach isn't working well[1].
> With this proposal, we'd only ever need to care about two releases
> (maybe three):
> 
>   13.04: 12.04LTS (juju doesn't work with 10.04LTS) and 13.04
>   13.10: 12.04LTS and 13.10
>   14.04: 12.04LTS and 14.04LTS
>   14.10: 12.04LTS, 14.04LTS, 14.10
>    *or*
>   14.10: 14.04LTS and 14.10
> 
> I'm not sure we need to support two LTSes come 14.10, but then that
> means existing deployments with 12.04 are forced to upgrade to the next
> LTS to get continued free updates and support for their charms.  I think
> from a coding and complexity perspective, simply saying latest LTS plus
> current release is best.  Plus, for the 14.04 LTS release we would keep
> 12.04 supported for 6 months until 14.10, allowing time for updates.

Who exactly is "supporting" charms? What does the charm + release mean?

The combination of charm + release is an assertion by the
maintainer. "This charm works on that release". Nothing more. ~charmers
job is more to make sure that the charms conform to policy, than to test
if they work on every release. That is the maintainers' jobs. So if a
maintainer wants to keep a quantal charm working until quantal goes EOL,
that should be their prerogative. ~charmers only responsibility is to
remove or fix it if the bugs aren't being fixed.

Its not a huge burden on ~charmers doing these policy maintenance changes.
What is a burden is just managing the review queue. My suggestion would
be to unblock maintainers a bit by giving them more power as per the
other thread about this. Also more people should be encouraged to join
~charmers and help with said review queue.