Passwords can easily be accidentally regenerated by users of python-tripleoclient

[Dougal Matthews]

Description of problem:
The command `openstack overcloud deploy` generates passwords when it is first executed and stores them in a file. If the user then changes to another directory and re-runs the deploy, it will perform a stack update but generate the passwords again.

Steps to Reproduce:
1. openstack overcloud deploy
2. cd /tmp (or anywhere other than the current directory)
3. openstack overcloud deploy

Actual results:
Passwords are re-generated and sent to Heat again, which attempts to reconfigure the passwords on all services. This doesn't seem to be fully supported by tripleo-heat-templates at the moment.

Expected results:
Passwords should never be generated on a stack update, the command should complain loudly that the password file can't be found.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/275661

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/275661
Committed: https://git.openstack.org/cgit/openstack/python-tripleoclient/commit/?id=8f9b01e516d0dde43a840a847c257b19c20b5228
Submitter: Jenkins
Branch: master

commit 8f9b01e516d0dde43a840a847c257b19c20b5228
Author: Dougal Matthews <email address hidden>
Date: Wed Feb 3 11:35:43 2016 +0000

    Don't regenerate the overcloud passwords if the Heat stack exists

    If the user is in the incorrect directory (one different from
    where they originally deployed), the function to generate
    passwords will create a new password file with random passwords.
    This will then be sent to Heat and it will attempt to reconfigure
    the passwords for all services (which currently isn't fully
    supported and can leave users with a non-functioning overcloud).
    The issue can be replicated with:

        openstack overcloud deploy --templates
        cd /tmp (or any other different directory)
        openstack overcloud deploy --templates

    This changes the behaviour to display an error if the password
    file can't be found, but the Heat stack already exists.

    Closes-Bug: #1541342
    Change-Id: I2ce63c254c10d6382d626b2f5436019971a26952