boot an image on a node in maintenance mode

[Ruby Loo]

Operators may want the ability to boot an image on a node in maintenance mode. See email thread: http://lists.openstack.org/pipermail/openstack-dev/2014-March/030392.html.

To do this, might involve (ie, needs to be fleshed out):

14:12 rloo: devananda, lucasagomes, we just made some changes to return nodes that are powered off, not in maintenance, but that email suggests we might want to return maintenance too?
14:13 devananda: rloo: to do what that email discusses, we need the nova driver to not merely receive a list of nodes both in and not in maintenance
14:13 devananda: but also to differentiate those two sets and tag some extra_specs onto the nodes in maintenance
14:14 devananda: and validate that the nova scheduler won't match it on a normal request, but that, with the --force-hosts extension, it will
14:14 devananda: that'll be fun to test :)

[Dmitry Tantsur (divius)]

I think this change requires a spec

[Galyna Zholtkevych (gzholtkevych)]

Ruby Loo, please, can you be more specific on what to do for now?
It seems that some of your propositions are already implemented

Thank you!

[Julia Kreger (juliaashleykreger)]

I believe this is now invalid as the remaining needs, from what I can tell from the discussion, is the basic functionality along the lines as rescue mode. The RFE for rescue mode can be found at: https://bugs.launchpad.net/ironic/+bug/1526449

If anyone feels that it is still valid, we can always change it to wishlist.