Including tasks has a performance penalty when compared with importing
tasks. If the include has a condition associated with it, then the
overhead of the include may be lower than the overhead of skipping all
imported tasks. For unconditionally included tasks, switching to
import_tasks provides a clear benefit.

Benchmarking of include vs. import is available at [1].

This change switches from include_tasks to import_tasks where there is
no condition applied to the include.

[1] https://github.com/stackhpc/ansible-scaling/blob/master/doc/include-and-import.md#task-include-and-import

Partially-Implements: blueprint performance-improvements

Change-Id: Ia45af4a198e422773d9f009c7f7b2e32ce9e3b97

The idea is to factor out a role for deploying Nova related services
to cells. Since all deployments use cells, this role can be used
in both regular deployments which have just cell0 and cell1,
and deployments with many cells.

Partially Implements: blueprint support-nova-cells
Change-Id: Ib1f36ec0a773c384f2c1eac1843782a3e766045a

include is marked as deprecated since ansible 2.4[0]

[0] https://docs.ansible.com/ansible/2.4/include_module.html#deprecated



Co-Authored-By: confi-surya <singh.surya64mnnit@gmail.com>
Change-Id: Ic9d71e1865d1c728890625aeddf424a5734c0a8a

Co-Authored-By: Mauricio Lima <mauriciolimab@gmail.com>
Change-Id: Ib54136f9d4313db05f3711fc1c8d7a07d2186d6b
Partially-implements: blueprint better-reconfigure

do_reconfigure.yml is introduced to use serial directive. But we use
it in wrong. Now serial has moved to playbook file. So it is time to
remove the do_reconfigure.yml file

Closes-Bug: #1628152
Change-Id: I8d42d27e6bc302a0e575b0353956eaef9b2ca9fd

Useful for upgrade etc., which is preferablly done serially.

Example usage: tools/kolla-ansible deploy OR tools/kolla-ansible upgrade

Closes-Bug: #1576708

DocImpact

Change-Id: I34b2e16f8ce53e472a4682a4738c4ac0f5abf00c

Partially-Implements: blueprint ansible-aodh

Change-Id: I9e20f4bf5e7d8f37f243ae15746e2b7bb49eb20c