Do not land code on blocked branches

Sun May 3 13:36:55 UTC 2015

Just to follow up one small point, Rick. The reason Juju has to fix the API
and restore the old behavior is because even if Quickstart fixed itself,
anyone running an older version is going to break with a newer Juju API,
which is why we require API stability, and only changing things by bumping
the version. :)

John
=:->

On Sun, May 3, 2015 at 4:38 PM, Ian Booth <ian.booth at canonical.com> wrote:

> My email was poorly worded, sorry. It's main purpose was to reply the the
> email
> from QA to let the QA folks know that an incompatibility was discovered
> which
> explains the CI test failures holding up the 1.24 release, and that a
> solution
> was in progress.
>
> John's analysis is correct. I am almost done restoring the Juju 1.16
> behaviour
> to reinstate compatibility with quickstart as it stands today. Any
> quickstart
> changes are not urgent therefore. The root cause is that Juju 1.16
> behaviour was
> removed and even though Juju clients are fine with this, existing external
> clients may inadvertently be relying on such deprecated behaviour.
>
> The difficulty is that right up until 1.18, the first point from which we
> were
> required to retain backwards compatibility "forever", quite a lot of
> functionality was deprecated. It's hard to know which external (non Juju)
> clients depend on such behaviour. That's why we have CI tests for the
> important
> clients like quickstart and deployer. So in this case, the CI tests have
> done
> their job :-)
>
> On 03/05/15 22:11, John Meinel wrote:
> > Just going off the bits that Ian pointed to, the section of code was if
> you
> > called ServiceDeploy with a CharmStore URL (eg cs:mysql) but you had not
> > already called AddCharm.
> >
> > The "juju" cli client already knows to call Client.AddCharm with the
> given
> > URL, whereas the internal api/client/client.go does a double check if it
> > gets called with a charm URL that isn't already in state.
> >
> > Now, I don't know how Quickstart would be triggering
> > apiserver/client/client.go
> > The error here: in traceback looks like:
> > connecting to wss://
> > 52.6.157.186:17070/environment/47724da5-9b38-4141-8f92-03d8f4225de9/api
> > environment type: ec2
> > bootstrap node series: trusty
> > charm URL: cs:trusty/juju-gui-27
> > requesting juju-gui deployment
> > juju-quickstart: error: bad API response: charm "cs:trusty/juju-gui-27"
> not
> > found
> > 2015-05-01 18:28:59 ERROR Command '('juju', '--show-log', 'quickstart',
> > '-e', 'aws-quickstart-bundle', '--constraints', 'mem=2G', '--no-browser',
> > '/var/lib/jenkins/repository/landscape-scalable.yaml')' returned non-zero
> > exit status 1
> > Traceback (most recent call last):
> >   File "/var/lib/jenkins/juju-ci-tools/quickstart_deploy.py", line 51, in
> > run
> >     for step in self.iter_steps():
> >   File "/var/lib/jenkins/juju-ci-tools/quickstart_deploy.py", line 70, in
> > iter_steps
> >     self.client.quickstart(self.bundle_path)
> >   File "/mnt/jenkinshome/juju-ci-tools/jujupy.py", line 335, in
> quickstart
> >     self.juju('quickstart', args, self.env.needs_sudo())
> >   File "/mnt/jenkinshome/juju-ci-tools/jujupy.py", line 294, in juju
> >     return subprocess.check_call(args, env=env)
> >   File "/usr/lib/python2.7/subprocess.py", line 511, in check_call
> >     raise CalledProcessError(retcode, cmd)
> >
> >
> > So it would appear that we had code to allow users to call
> > Client.ServiceDeploy(cs:mysql) and the server would lookup the charm and
> > deploy it for the user, but we stopped doing that as a Juju CLI since
> 1.16.
> >
> > However, I think this is *our* bad because this is a very important
> client
> > (quickstart and probably others) that has been relying on this behavior
> in
> > all our recent releases.
> >
> > Compat with juju-cli != compatibility with Juju API users.
> >
> > AFAIK we don't have a great way to respond to clients that behavior is
> > deprecated, but we can bump the Version of the API and change the
> behavior.
> > We definitely should have done that here rather than just remove the
> > behavior.
> >
> > John
> > =:->
> >
> > On Sun, May 3, 2015 at 3:59 PM, Richard Harding <
> rick.harding at canonical.com>
> > wrote:
> >
> >> On Sun, 03 May 2015, Ian Booth wrote:
> >>
> >>>>
> >>>> Curtis has filed three new bugs for these so far, and there appears to
> >>>> be one or two more to come:
> >>>>
> >>>> <https://bugs.launchpad.net/juju-core/+bug/1450912>
> >>>
> >>> The issue here is that quickstart is relying on Juju 1.16 behaviour.
> >> There was a
> >>> block of code with a comment:
> >>>
> >>> // Remove this whole if block when 1.16 compatibility is dropped.
> >>>
> >>> The code block was removed because 1.18 was our minimum compatibility
> >> version.
> >>> But it seems we have to restore the 1.16 behaviour. Note that this is
> >> not an
> >>> upgraded environment where we need to retain compatibility with older
> >>> deployments. It is a fresh 1.24 install which should be able to rely on
> >> 1.18 and
> >>> later behaviour only.
> >>
> >> Ian, can you be more specific on the chunk of code that was removed or
> >> branch I can look at for this? I'll happily file a bug and update
> >> quickstart, we just need to know what's changed there. Having a branch
> in
> >> hand or a bug will assist us in getting that updated as fast as
> possible.
> >>
> >> In searching through the quickstart code there's no hard requirement or
> >> notes on 1.16.
> >>
> >> Thanks
> >>
> >> --
> >>
> >> Rick Harding
> >>
> >> Juju UI Engineering
> >> https://launchpad.net/~rharding
> >> @mitechie
> >>
> >> --
> >> Juju-dev mailing list
> >> Juju-dev at lists.ubuntu.com
> >> Modify settings or unsubscribe at:
> >> https://lists.ubuntu.com/mailman/listinfo/juju-dev
> >>
> >
>
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