Merge lp://staging/~frankban/juju-quickstart/version-handling into lp://staging/juju-quickstart

Reviewers: mp+210395_code.launchpad.net,

Message:
Please take a look.

Description:
Improve version handling.

Modify the app.ensure_dependencies function
so that it returns the Juju version tuple.
This way we allow for reusing the version
through the app and we can avoid calling
"juju version" multiple times.

Support local environments by installing
the juju-local meta-package in place of
specific packages (e.g. lxc, mongo).
This way we don't have to update quickstart
if core devs introduce new local env
dependencies.

Fix the destroy-environment message displayed
at the end of the process. The -e flag is
included when an old Juju is used.

Tests: `make check`.

QA: no strictly required.
Use .venv/bin/python juju-quickstart, check everything
works well, check the destroy-environment message
at the end of the process.

https://code.launchpad.net/~frankban/juju-quickstart/version-handling/+merge/210395

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/74010044/

Affected files (+161, -159 lines):
   A [revision details]
   M quickstart/__init__.py
   M quickstart/app.py
   M quickstart/manage.py
   M quickstart/settings.py
   M quickstart/tests/test_app.py
   M quickstart/tests/test_manage.py
   M quickstart/tests/test_utils.py
   M quickstart/utils.py

LGTM will qa as well.

https://codereview.appspot.com/74010044/diff/1/quickstart/settings.py
File quickstart/settings.py (right):

https://codereview.appspot.com/74010044/diff/1/quickstart/settings.py#newcode34
quickstart/settings.py:34: # The path to the Juju command.
can/should we get this via `which juju`? I guess it shouldn't change.

https://codereview.appspot.com/74010044/

QA ok doing a local env post 1.17.2 thanks!

https://codereview.appspot.com/74010044/

Thank you for the review!

https://codereview.appspot.com/74010044/diff/1/quickstart/settings.py
File quickstart/settings.py (right):

https://codereview.appspot.com/74010044/diff/1/quickstart/settings.py#newcode34
quickstart/settings.py:34: # The path to the Juju command.
On 2014/03/11 13:24:24, rharding wrote:
> can/should we get this via `which juju`? I guess it shouldn't change.

We can but I am not sure we should. We call juju with sudo, and we use
the complete path for that security reason. AFAICT using `which` would
reintroduce the problem ,and at that point it would be easier to just
call `juju`.

https://codereview.appspot.com/74010044/

LGTM, thanks for the clean-up!

https://codereview.appspot.com/74010044/

*** Submitted:

Improve version handling.

Modify the app.ensure_dependencies function
so that it returns the Juju version tuple.
This way we allow for reusing the version
through the app and we can avoid calling
"juju version" multiple times.

Support local environments by installing
the juju-local meta-package in place of
specific packages (e.g. lxc, mongo).
This way we don't have to update quickstart
if core devs introduce new local env
dependencies.

Fix the destroy-environment message displayed
at the end of the process. The -e flag is
included when an old Juju is used.

Tests: `make check`.

QA: no strictly required.
Use .venv/bin/python juju-quickstart, check everything
works well, check the destroy-environment message
at the end of the process.

R=rharding, matthew.scott
CC=
https://codereview.appspot.com/74010044

https://codereview.appspot.com/74010044/

Thank you!

https://codereview.appspot.com/74010044/