Merge lp://staging/~frankban/charms/precise/juju-gui/bug-1132905-log-hook into lp://staging/~juju-gui/charms/precise/juju-gui/trunk

Reviewers: mp+150413_code.launchpad.net,

Message:
Please take a look.

Description:
Add and use a log_hook context manager.

Replace the current calls to log_entry and log_exit in the __main__ of
the hooks with a log_hook context manager, simplifying the code a bit.

Avoiding log_entry and log_exit also temporarily works around a problem
they have with the juju-core handling of strings starting with "--" in
juju-log.

https://code.launchpad.net/~frankban/charms/precise/juju-gui/bug-1132905-log-hook/+merge/150413

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/7379050/

Affected files:
   A [revision details]
   M hooks/config-changed
   M hooks/install
   M hooks/start
   M hooks/stop
   M hooks/utils.py
   M tests/test_utils.py

LGTM.

Nice tests.

Thanks!

https://codereview.appspot.com/7379050/diff/1/hooks/config-changed
File hooks/config-changed (right):

https://codereview.appspot.com/7379050/diff/1/hooks/config-changed#newcode135
hooks/config-changed:135: with log_hook():
Nice!

https://codereview.appspot.com/7379050/

*** Submitted:

Add and use a log_hook context manager.

Replace the current calls to log_entry and log_exit in the __main__ of
the hooks with a log_hook context manager, simplifying the code a bit.

Avoiding log_entry and log_exit also temporarily works around a problem
they have with the juju-core handling of strings starting with "--" in
juju-log.

R=gary.poster
CC=
https://codereview.appspot.com/7379050

https://codereview.appspot.com/7379050/