os-migrateLive fault but rest api raise a incorrect conflict message

[Eli Qiao]

when do a live migration which the instance is in a state like this
taget@liyong:~/devstack$ nova list
+--------------------------------------+-------+--------+------------+-------------+----------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+-------+--------+------------+-------------+----------------------+
| 1d114104-9a62-49ba-b209-6a42beff4133 | test1 | ACTIVE | - | NOSTATE | private_net=10.0.0.9 |
+--------------------------------------+-------+--------+------------+-------------+----------------------+

rest api raise conflictRequest, this is correct, but the message is not correct.

(0, '{"conflictingRequest": {"message": "Instance 1d114104-9a62-49ba-b209-6a42beff4133 is in an invalid state for \'os-migrateLive\'", "code": 409}}', ' % Total % Received % Xferd Average Speed Time Time Time Current\n Dload Upload Total Spent Left Speed\n\r 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0\r100 92 0 0 100 92 0 76 0:00:01 0:00:01 --:--:-- 76\r100 233 100 141 100 92 78 51 0:00:01 0:00:01 --:--:-- 78\r100 233 100 141 100 92 78 51 0:00:01 0:00:01 --:--:-- 78\n')

in live_migrate.py, we check if instance in active state, it do the right thing.

    def _check_instance_is_active(self):
        if self.instance.power_state not in (power_state.RUNNING,
                                             power_state.PAUSED):
            raise exception.InstanceInvalidState(
                    instance_uuid = self.instance.uuid,
                    attr = 'power_state',
                    state = self.instance.power_state,
                    method = 'live migrate')

but in this case, power_state is an Integer zero,
the logic in raise_http_conflict_for_instance_invalid_state

by checking code of raise_http_conflict_for_instance_invalid_state

def raise_http_conflict_for_instance_invalid_state(exc, action, server_id):
    """Raises a webob.exc.HTTPConflict instance containing a message
    appropriate to return via the API based on the original
    InstanceInvalidState exception.
    """
    attr = exc.kwargs.get('attr')
    state = exc.kwargs.get('state')
    not_launched = exc.kwargs.get('not_launched')
    if attr and state: <<<<<<<<<<<<<------------ should go this condition but state is zero.
        msg = _("Cannot '%(action)s' instance %(server_id)s while it is in "
                "%(attr)s %(state)s") % {'action': action, 'attr': attr,
                                         'state': state,
                                         'server_id': server_id}

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/168211

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/168211
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=70f3c8d3d33a12ee002753f7867c6c12d2b0fc84
Submitter: Jenkins
Branch: master

commit 70f3c8d3d33a12ee002753f7867c6c12d2b0fc84
Author: Eli Qiao <email address hidden>
Date: Fri Mar 27 10:15:38 2015 +0800

    Fix incorrect http_conflict error message

    instance power state may be integer zero, in that case the error message would
    be no correct.

    BTW, this patch remove 'not_launched' from kwargs since no other code set this
    parameter into kwargs.

    Closes-bug: 1437111
    Change-Id: Id2fb561a79d627eb8c6b41e4fe3549dc69dc7d99