CONF.allow_migrate_to_same_host doesn't work

[zhangtralon]

there are such codes in the “resize” function from nova/compute/api.py

 if not CONF.allow_resize_to_same_host:
            filter_properties['ignore_hosts'].append(instance['host'])
 # Here when flavor_id is None, the process is considered as migrate.

if (not flavor_id and not CONF.allow_migrate_to_same_host):
          filter_properties['ignore_hosts'].append(instance['host'])

When running the "migrate" operation and the CONF.allow_resize_to_same_host is set as "false",the CONF.allow_migrate_to_same_host will not work
At the same time, I find the CONF.allow_migrate_to_same_host isn't checked in the _prep_resize function from nova/compute/manager.py.
the code part is as follows:

same_host = instance['host'] == self.host
    if same_host and not CONF.allow_resize_to_same_host:
         self._set_instance_error_state(context, instance)
         msg = _('destination same as source!')
         raise exception.MigrationError(msg)

So, I think that using two configuration items here can occur conflict, maybe we can
take out a configuration item!

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/118604

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/118604
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=9b224641295af3763d011816d6399565ac7b98de
Submitter: Jenkins
Branch: master

commit 9b224641295af3763d011816d6399565ac7b98de
Author: <email address hidden> <email address hidden>
Date: Wed Sep 3 19:12:16 2014 +0800

    remove the CONF.allow_migrate_to_same_host

    When running the "migrate" operation and the
    CONF.allow_resize_to_same_host is set as "false",
    the CONF.allow_migrate_to_same_host doesn't work
    in the function 'resize' from nova/compute/api.py.
    At the same time, there is no checking the
    CONF.allow_migrate_to_same_host in the function
    _prep_resize from nova/compute/manager.py

    DocImpact: remove the CONF.allow_migrate_to_same_host
    Change-Id: I4c54c7c6e0e5e37cc46c52350ba4ce2047325ef9
    Closes-Bug: #1364851

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/189798

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/189798
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=8895dca4588f8a196b7a7ee8d33dc117f73249ed
Submitter: Jenkins
Branch: master

commit 8895dca4588f8a196b7a7ee8d33dc117f73249ed
Author: Alessandro Pilotti <email address hidden>
Date: Tue Jun 9 19:04:39 2015 +0300

    Hyper-V: sets supports_migrate_to_same_host capability

    Commit 9b224641295af3763d011816d6399565ac7b98de removed
    CONF.allow_migrate_to_same_host and introduced the
    supports_migrate_to_same_host capability in compute drivers.

    This commit adds the capability to the Hyper-V driver.

    Change-Id: Iadfe3a3870235705af458bb2d35d0569ba212291
    Partial-Bug: #1364851