[lxc-users] Adding a host block device to a container

[Serge Hallyn]

Quoting Peter Steele (pwsteele at gmail.com):
> On 09/01/2015 07:25 AM, Serge Hallyn wrote:
> >FWIW there is a lxc-device command that will do the mknod for you,
> >but it won't be persistent (iirc).  Support for making that
> >persistent would be welcome.  I think that would come in three small
> >pieces:
> >
> >. have src/lxc/lxc_device optionally save the container configuration
> >   when done.
> >. have do_add_remove_node() manipulate a new list of devices to be
> >   created at container start.
> >. have src/lxc/conf.c:fill_autodev create devices which are in the new
> >   list
> 
> I definitely want this to be persistent, and in my case it's
> intended to be all part of an automation process. The containers are
> created programmatically and certain types of containers will be
> assigned certain block devices. Once this setup is done, the

In that case that's exactly what templates were meant to do.  So while
I'd still like to see lxc-device updated to support persistence, you
could do what you want by

1. creating a lxc.hook.autodev hook which creates the device you want
   using mknod,
2. adding lxc.hook.autodev = /usr/local/bin/my-dev-hook to the container
   configuration
3. adding the lxc.cgroup rule you need to the container configuration

You could add the two config additions to your global
/etc/lxc/default.conf, add them to the config you pass to
lxc-create -f, or set them in a new template you create and use
instead of /bin/true.