Write troubleshooting docs for "no valid host found" nova error when used with ironic

[Dmitry Tantsur]

In bare metal case this error happens much more often, so lets document it. We have something for tripleo that can be reused/copied/linked to: http://docs.openstack.org/developer/tripleo-docs/troubleshooting/troubleshooting-overcloud.html#no-valid-host-found-error (just throw away references to "profiles").

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/239206

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/239206
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=c30879be2e1acdcefe8819b6c69ec294320cb415
Submitter: Jenkins
Branch: master

commit c30879be2e1acdcefe8819b6c69ec294320cb415
Author: Shuquan Huang <[e-mail]>
Date: Sun Oct 25 10:57:44 2015 +0800

    Add troubleshooting docs for "no valid host found"

    In bare metal case this error happens much more often, we
    are adding a new troubleshooting document and add it as
    part of this new document.

    Change-Id: I155b5c7160fbefe61c6a7bcdc5aa51452c8b8ab7
    Closes-bug: #1503735