Comment 4 for bug 1630891

from stable/newton branch:

commit c3ed3574a5c0aa59c9e68e6ac4ab2bff1fce3ca0
Author: Chuck Short <email address hidden>
Date: Thu Oct 6 09:08:37 2016 -0400

    Reset vifs after reboot

    When a host is rebooted instances are set into a shutdown instance
    state, which is the correct thing.

    However when a user tries to restart an instance, LXD will fail
    to restart the container because the bridge is not present.

    This is due to the fact that when the instance status transition
    from shutdown to active the compute daemon tries to run the
    plug_vifs method, which was not present in the driver.

    To correct this we re-add the the plug_vifs and unplug_vifs
    method.

    LP: #1630891

    Change-Id: Iae80f4667debab4d1e21d67d882ed52ef59cf15b
    Signed-off-by: Chuck Short <email address hidden>