OpenStack host maintenance and upgrade in interaction with application on top of it

Gerrit User 22348 697acb82d3 Update patch set 1 ... Patch Set 1: Verified+1 Build succeeded (check pipeline). - openstack-tox-pep8 https://zuul.opendev.org/t/openstack/build/5a10da5d4f9349f4920af4b61cb670ce : SUCCESS in 2m 33s - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/01e457bb4d284e4ab4357c41a7f41f2e : SUCCESS in 3m 15s Patch-set: 1 Tag: autogenerated:zuul:check Label: Verified=+1		2019-12-19 08:54:08 +00:00