fuel menu allow to run second copy of itself

[Sergey Vasilenko]

Detailed bug description:

fuel menu allow to run second copy of itself.
This leads to two negative results:
* different operators can make configuration changes consurently
* operator has ability do not end of master-node configuration before master-node operate

Steps to reproduce:
* boot ISO
* configure IP addresses by fuel-menu
* apply changes (do not exit from fuel menu!!!)
* ssh to master-node
* run fuel-menu
* configure another cluster options
* apply config and exit
After such steps there are no running nailgun, astute, etc...

Expected results:
  Fuel menu shouldn't allow to run second copy of itself

Actual result:
Multiple copy of fuel-menu can be running simultaneously.

Reproducibility:
  100%

Workaround:
  No

[Matthew Mosesohn (raytrac3r)]

Moving back to fuel-python in case someone else can work on this

[Dmitry Pyzhov (dpyzhov)]

Seems to be rare case caused by user mistake. Setting medium priority and moving to the Newton release.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/307682

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/307682
Committed: https://git.openstack.org/cgit/openstack/fuel-menu/commit/?id=3f84153673cc82b7d915b057adc68fc55eee9798
Submitter: Jenkins
Branch: master

commit 3f84153673cc82b7d915b057adc68fc55eee9798
Author: Dmitry Guryanov <email address hidden>
Date: Tue Apr 19 12:50:15 2016 +0300

    prevent running second copy of fuelmenu

    Create a file and take a lock on it before running main
    part of fuel-menu, so running two copies would be impossible.

    This patch adds an option -l, --lock-file to have ability to
    specify path to lock file.

    Change-Id: I8ab41e6e068caa0881e0affcbfb5695a9025b762
    Closes-Bug: #1566401