VCS code duplication and subordinate

[Patrick Hetu]

> Sure, but how will it make sure that the service is restarted when new content is found?

In the python-django charm I'm using a timestamp variable (an idea
from someone on IRC) that triggers the reloading of the wsgi server
when configuration change.

See: http://bazaar.launchpad.net/~charmers/charms/precise/python-django/trunk/view/head:/hooks/config-changed#L133

> It's also possible to add this to a standard library of charm tools, rather than do it in a subordinate.

I was thinking about one subordinate charm per vcs because I didn't
wanted to install all vcs
when I'm just using one of them. But that's a minor issue.

> This might be a good time to mention there's a VCS Charm Helper

Yeah, extending and using those helpers would the solve the
dependencies problem.

I'm also copying those helpers too in all my new charms to avoid repetition
and I just realized they are pretty much all in charm-tools. Maybe we
could split
the python version of those helpers in a python-charm-tools package an
make them importable
python code?

http://bazaar.launchpad.net/~charmers/charms/precise/postgresql/trunk/view/head:/hooks/hooks.py
 (first half of the file)
http://bazaar.launchpad.net/~charmers/charms/precise/postgresql/trunk/view/head:/hooks/helpers.py

Patrick