upstart: make use of Out field

upstart: make use of Out field

Upstart confs for agents now include an Out value, which allows us to record
panics (and any other useful output, eg when an agent entriely fails to
start).

https://code.launchpad.net/~fwereade/juju-core/trivial-agent-output/+merge/130498

(do not edit description out of merge proposal)

[fwereade, 2012-10-19 08:42:38]

Please take a look.

[TheMue, 2012-10-19 08:44:47]

LGTM

[niemeyer, 2012-10-25 06:58:06]

LGTM, but please consider if this makes sense:

https://codereview.appspot.com/6737050/diff/1/container/container_test.go
File container/container_test.go (right):

https://codereview.appspot.com/6737050/diff/1/container/container_test.go#new...
container/container_test.go:78: ` >> /var/log/juju/unit-dummy-0\.out 2>&1\n`+
If it's an append operation (which sounds sensible), can't we use .log itself
for it?  What happens in that case?

[fwereade, 2012-10-25 07:19:51]

On 2012/10/25 06:58:06, niemeyer wrote:
> LGTM, but please consider if this makes sense:
> 
> https://codereview.appspot.com/6737050/diff/1/container/container_test.go
> File container/container_test.go (right):
> 
>
https://codereview.appspot.com/6737050/diff/1/container/container_test.go#new...
> container/container_test.go:78: ` >> /var/log/juju/unit-dummy-0\.out 2>&1\n`+
> If it's an append operation (which sounds sensible), can't we use .log itself
> for it?  What happens in that case?

When jujud has already opened the log file, and then panics, we just lose the
panic output. So I think we do need this...

[fwereade, 2012-10-25 07:35:04]

*** Submitted:

upstart: make use of Out field

Upstart confs for agents now include an Out value, which allows us to record
panics (and any other useful output, eg when an agent entriely fails to
start).

R=TheMue, niemeyer
CC=
https://codereview.appspot.com/6737050