Comment 13 for bug 1669473

Reviewed: https://review.openstack.org/440739
Committed: https://git.openstack.org/cgit/openstack-dev/devstack/commit/?id=f15224c740b880842e8d34e9a6c2ad08ba34448f
Submitter: Jenkins
Branch: master

commit f15224c740b880842e8d34e9a6c2ad08ba34448f
Author: Matt Riedemann <email address hidden>
Date: Thu Mar 2 12:45:47 2017 -0500

    Create cell1 cell before n-api starts

    Change ac5fdb4c4090efd682cc5c55aa30ec433da29fc7 introduced
    a problem for gnocchi CI because the deployments steps
    are now:

    1. create cell0
    2. start nova-api (with multiple workers)
    3. install ceilometer via extras
    4. ceilometer calls nova-api to list servers; at this point
       nova-api getes the list of cells and caches them, which
       will just be cell0
    5. create cell1 via simple_cell_setup which also discovers
       the n-cpu node so we can schedule instances
    6. gnocchi tests create and list instances and at this point it hits
       an n-api worker that only has cell0 cached so it does not
       find some test servers it created and fails.

    The cell0 and cell1 cells should be created in the nova_api db
    before starting n-api so that when we first list instances, we
    store both cells in the cache that's in n-api. This deployment
    order is also how the nova docs describe rolling out cells v2
    but the way we were doing this devstack wasn't following that,
    or accounting for when devstack plugins are loaded via extras.

    This change creates the main cell1 cell earlier in the setup
    before n-api is started, and then changes to just run
    discover_hosts at the end after n-cpu is running (which is what
    simple_cell_setup and map_cell_and_hosts would do implicitly).

    Change-Id: I38eab6707340253a10159a169ae61d34784c2d28
    Related-Bug: #1669473