Possible race condition when two instances are deployed

[Serg Melikyan]

Murano uses Heat to allocate OpenStack resources by creating and updating one Heat stack. All changes to stack are stored in shared variable exposed via call to environment.stack.updateStack. Allocation of resources needed by Instance class is done in several calls to environment.stack.updateStack therefor in case of simultaneous deployment of two instances of class Instance race condition is possible.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/118570
Committed: https://git.openstack.org/cgit/stackforge/murano/commit/?id=9130ad2c7408b3d15b48ab6f0d37ee0dfec1ca65
Submitter: Jenkins
Branch: master

commit 9130ad2c7408b3d15b48ab6f0d37ee0dfec1ca65
Author: Serg Melikyan <email address hidden>
Date: Wed Sep 3 12:37:26 2014 +0400

    Fix race condition when two Instances are deployed

    Murano uses Heat to allocate OpenStack resources by creating and
    updating one Heat stack. All changes to stack are stored in shared
    variable exposed via call to environment.stack.updateStack.

    Allocation of resources needed by Instance class is done in several calls
    to environment.stack.updateStack therefor in case of simultaneous deployment
    of two instances of class Instance race condition is possible.

    Instance class was rewritten to have only one call to stack.updateStack
    that is going to eliminate possible race condition.

    P.S. This change also introduce new function mergeWith that can merge
    two dicts.

    Change-Id: Ib3b0be04e7d0b6107466bd5837278a12f01cf766
    Closes-Bug: #1364824