api: Implement RelationUnitsWatcher in client API

api: Implement RelationUnitsWatcher in client API

This completes the implementation of UniterAPI
WatchRelationUnits() at the client-side API by
implementing the rest of the RelationUnitsWatcher.

I missed some server-side code neede, which is
added now. Also, as a consequence some of the
relation and relation unit client methods got
implemented, as well as client uniter tests
were extended to cover the upcoming relation
units tests.

https://code.launchpad.net/~dimitern/juju-core/120-api-relationunitswatcher-client/+merge/184044

(do not edit description out of merge proposal)

[dimitern, 2013-09-05 09:20:31]

Please take a look.

[fwereade, 2013-09-05 13:06:06]

LGTM, thanks.

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/relationunit.go
File state/api/uniter/relationunit.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/relationunit....
state/api/uniter/relationunit.go:118: // Watch returns a watcher that notifies
of changes to conterpart
s/conterpart/counterpart/

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter.go
File state/api/uniter/uniter.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter.go#new...
state/api/uniter/uniter.go:108: result, err := st.relation(tag, st.unitTag)
This bit still feels a bit funny, but I'm ok with it really. We'll figure out
the right way eventually, and I don't think churn will help.

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter_test.go
File state/api/uniter/uniter_test.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter_test.g...
state/api/uniter/uniter_test.go:41: mysqlUnit        *state.Unit
I think this is getting a bit big, maybe. I'd respond positively to a followup
that split out a few separate test suites.

https://codereview.appspot.com/13559043/diff/1/state/api/watcher/watcher.go
File state/api/watcher/watcher.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/watcher/watcher.go#n...
state/api/watcher/watcher.go:267: data, ok := <-w.in
commonWatcher closes w.in when dying, I guess? Nice.

[dimitern, 2013-09-05 13:19:33]

Please take a look.

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/relationunit.go
File state/api/uniter/relationunit.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/relationunit....
state/api/uniter/relationunit.go:118: // Watch returns a watcher that notifies
of changes to conterpart
On 2013/09/05 13:06:07, fwereade wrote:
> s/conterpart/counterpart/

Done.

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter.go
File state/api/uniter/uniter.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter.go#new...
state/api/uniter/uniter.go:108: result, err := st.relation(tag, st.unitTag)
On 2013/09/05 13:06:07, fwereade wrote:
> This bit still feels a bit funny, but I'm ok with it really. We'll figure out
> the right way eventually, and I don't think churn will help.

Yeah, I'm sure there'll be a few changes until we have the finished API.

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter_test.go
File state/api/uniter/uniter_test.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/uniter/uniter_test.g...
state/api/uniter/uniter_test.go:41: mysqlUnit        *state.Unit
On 2013/09/05 13:06:07, fwereade wrote:
> I think this is getting a bit big, maybe. I'd respond positively to a followup
> that split out a few separate test suites.

Yeah, will do.

https://codereview.appspot.com/13559043/diff/1/state/api/watcher/watcher.go
File state/api/watcher/watcher.go (right):

https://codereview.appspot.com/13559043/diff/1/state/api/watcher/watcher.go#n...
state/api/watcher/watcher.go:267: data, ok := <-w.in
On 2013/09/05 13:06:07, fwereade wrote:
> commonWatcher closes w.in when dying, I guess? Nice.

That's the way other watchers work and it seems fine to me so far.