LXC bind run_as_root commands are obviously wrong

[Thierry Carrez]

The bind function (in nova/virt/disk/api.py) used by LXC calls "echo" as root in a wrong way:

utils.execute('echo', '>', cgroup_info, cgroups_path, run_as_root=True)

This is wrong because:
 * The order for the parameters is wrong
 * The command is not interpreted by shell so this doesn't actually redirect anything to cgroups_path
 * There is no rootwrap filter allowing 'echo' to be run as root

Somehow I doubt it works as expected. This should use tee with process_input instead, as in various other places in the same file.

[Thierry Carrez (ttx)]

Might have a shot at it if Chuck doesn't fix it before

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/5389

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/5389
Committed: http://github.com/openstack/nova/commit/51b3510387cafec87e39c2a52e8578a66f3488d4
Submitter: Jenkins
Branch: master

commit 51b3510387cafec87e39c2a52e8578a66f3488d4
Author: Thierry Carrez <email address hidden>
Date: Thu Mar 15 10:58:57 2012 +0100

    Fix LXC volume attach issue

    Fix erroneous use of echo to set permissions on LXC volume access.
    Fixes bug 943304.

    Note that based on input from the duplicate bug (948193), we set:
    b x:x rwm
    to /sys/fs/cgroup/devices/libvirt/lxc/x/devices.allow

    instead of:
    c x:x rwm
    to /sys/fs/cgroup/devices/sysdefault/libvirt/lxc/x/devices.allow

    Change-Id: Ia048d3f46799839b4b85c781bb50488e09ba9b5e