cmd/jujud: allow for a clean exit

cmd/jujud: allow for a clean exit

When a unit or a machine dies, we want the
unit or machine agent to exit cleanly, so
prepare for the worker to return ErrDead in that
case, and exit cleanly when the unit or machine
is dead to start with.

https://code.launchpad.net/~rogpeppe/juju-core/093-jujud-lifecycle/+merge/126980

Requires: https://code.launchpad.net/~rogpeppe/juju-core/064-uniter-upgrade/+merge/126714

(do not edit description out of merge proposal)

[niemeyer, 2012-09-28 14:54:54]

LGTM

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/machine.go
File cmd/jujud/machine.go (right):

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/machine.go#newcode58
cmd/jujud/machine.go:58: if err == machiner.ErrDead {
Should this be worker.ErrDead?

Also:

log.Printf("machine is dead")

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/machine.go#newcode61
cmd/jujud/machine.go:61: log.Printf("machiner: %v", err)
This should be changed with your suggestion.

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/unit.go
File cmd/jujud/unit.go (right):

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/unit.go#newcode60
cmd/jujud/unit.go:60: if err == uniter.ErrDead {
Same as for machine.

https://codereview.appspot.com/6567067/diff/1/upstart/upstart.go
File upstart/upstart.go (right):

https://codereview.appspot.com/6567067/diff/1/upstart/upstart.go#newcode96
upstart/upstart.go:96: normal exit 0
Nice.

[rog, 2012-09-28 15:39:45]

for reasons best known to itself, the branch corrupted itself, so i'm submitting
in another CL: https://codereview.appspot.com/6574060

https://code.launchpad.net/~rogpeppe/juju-core/093-jujud-lifecycle/+merge/126998

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/machine.go
File cmd/jujud/machine.go (right):

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/machine.go#newcode58
cmd/jujud/machine.go:58: if err == machiner.ErrDead {
On 2012/09/28 14:54:54, niemeyer wrote:
> Should this be worker.ErrDead?
> 
> Also:
> 
> log.Printf("machine is dead")

Done.

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/machine.go#newcode61
cmd/jujud/machine.go:61: log.Printf("machiner: %v", err)
On 2012/09/28 14:54:54, niemeyer wrote:
> This should be changed with your suggestion.

Done.

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/unit.go
File cmd/jujud/unit.go (right):

https://codereview.appspot.com/6567067/diff/1/cmd/jujud/unit.go#newcode60
cmd/jujud/unit.go:60: if err == uniter.ErrDead {
On 2012/09/28 14:54:54, niemeyer wrote:
> Same as for machine.

Done.