Add the api server parts for the logger worker.

Add the api server parts for the logger worker.

There are two things this needs to do: watch the environment to see if the
logging config changes, and return the logging config for agents.


I kept the mutliple entities option on the server side as it may be used by
the Juju GUI.

https://code.launchpad.net/~thumper/juju-core/logger-api-server/+merge/185401

(do not edit description out of merge proposal)

[thumper, 2013-09-13 01:59:47]

Please take a look.

[wallyworld, 2013-09-13 02:16:38]

LGTM with the test issue fixed for TestWatchLoggingConfig

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger.go
File state/apiserver/logger/logger.go (right):

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger....
state/apiserver/logger/logger.go:44: var _ Logger = (*LoggerAPI)(nil)
I'd like to see this and the above struct moved to the top, just beneath the
interface definition so they are all together. Just a suggestion.

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger....
state/apiserver/logger/logger.go:46: // WatchLoggingConfig starts a watcher to
track changes to the logging config.
"to the logging config for the agents specified."

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger....
state/apiserver/logger/logger.go:76: // from state.
really? why not exit early?

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger_...
File state/apiserver/logger/logger_test.go (right):

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger_...
state/apiserver/logger/logger_test.go:50: c.Assert(err, gc.IsNil)
Not part of this work I know, but surely there's a common set up test function
for these sorts of api tests. This looks like cut and paste boilerplate

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger_...
state/apiserver/logger/logger_test.go:109: statetesting.AssertStop(c, w)
Can we test the content of the change to ensure it matches what has been set

[thumper, 2013-09-13 03:45:52]

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger.go
File state/apiserver/logger/logger.go (right):

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger....
state/apiserver/logger/logger.go:44: var _ Logger = (*LoggerAPI)(nil)
On 2013/09/13 02:16:38, wallyworld wrote:
> I'd like to see this and the above struct moved to the top, just beneath the
> interface definition so they are all together. Just a suggestion.

Done.

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger....
state/apiserver/logger/logger.go:46: // WatchLoggingConfig starts a watcher to
track changes to the logging config.
On 2013/09/13 02:16:38, wallyworld wrote:
> "to the logging config for the agents specified."

Done.

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger....
state/apiserver/logger/logger.go:76: // from state.
On 2013/09/13 02:16:38, wallyworld wrote:
> really? why not exit early?

Early exit added and unfunny comment removed.

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger_...
File state/apiserver/logger/logger_test.go (right):

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger_...
state/apiserver/logger/logger_test.go:50: c.Assert(err, gc.IsNil)
On 2013/09/13 02:16:38, wallyworld wrote:
> Not part of this work I know, but surely there's a common set up test function
> for these sorts of api tests. This looks like cut and paste boilerplate

Yes there should be, but there isn't.  And a little out of scope for this
branch.

https://codereview.appspot.com/13690043/diff/1/state/apiserver/logger/logger_...
state/apiserver/logger/logger_test.go:109: statetesting.AssertStop(c, w)
On 2013/09/13 02:16:38, wallyworld wrote:
> Can we test the content of the change to ensure it matches what has been set

Nope, because it doesn't tell us.