This adds another interface like external_deploy_tasks, but instead
of running on each deploy step, the tasks are run after the deploy
is completed, so it's useful for per-service bootstrapping such
as is under development for octavia in:
https://review.openstack.org/#/c/508195https://review.openstack.org/#/c/515402/
These reviews could potentially be reworked to use this interface,
which would avoid the issue where the configuration needs to happen
after all the openstack services are deployed and configured.
As an example, here is how you could create a temp file post deploy:
external_post_deploy_tasks:
- name: Test something happens post-deploy
copy:
dest: /tmp/debugpostdeploy
content: "done"
Change-Id: Iff3190a7d5a238c8647a4ac474821aeda5f2b1f8