Mistral evacuate plugin
=======================

This is a PoC for providing automatic evacuation for VMs in OpenStack cloud
using Mistral. It uses flavor extra specs and VM metadata to tell if given
instance should be evacuated. Extra spec is 'evacuation:evacuate' and VM
metadata is 'evacuate'. If one of them is set to True, instance will be
evacuated.

Installation
------------

#. Copy ``filter_vm_action.py`` and ``evacuate_vm_action.py``
   to the place reachable by python interpreter -
   see ``PYTHONPATH`` or ``sys.path`` for reference.
#. Append lines

   .. code:: ini

      [entry_points]
      mistral.actions =
          …
          custom.filter_vm = filter_vm_action:FilterVmAction
          custom.evacuate = evacuate_vm_action:EvacuateVmAction

   to ``setup.cfg`` file under Mistral repository
#. Run db-sync tool via either

   .. code:: shell-session

      $ tools/sync_db.sh --config-file <path-to-config>

   or

   .. code:: shell-session

      $ mistral-db-manage --config-file <path-to-config> populate

#. Register Mistral workflow:

   .. code:: shell-session

      $ mistral workflow-create host-evacuate.yaml

#. Create JSON file with content similar to:

   .. code:: json

     {
         "search_opts": {
             "host": "compute-hostanme"
         },
         "on_shared_storage": false
     }

#. Trigger the action via:

   .. code:: shell-session

      $ mistral execution-create host-evacuate input.json

   where ``input.json`` is a file created in previous step.