Re: a work for lxc monitor network interface

[Serge Hallyn <serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>]

Quoting Libo Chen (clbchenlibo.chen-hv44wF8Li93QT0dZR+AlfA@public.gmane.org):
> On 2013/12/19 4:16, Serge Hallyn wrote:
> > Quoting Libo Chen (clbchenlibo.chen-hv44wF8Li93QT0dZR+AlfA@public.gmane.org):
> >> Hello LXC experts,
> >>
> >> 	lxc tool can set network interface by config, but it is static.
> >> In some scene, the network interface will be dynamic created on the host
> >> and need be shared to container, but it is not suitable to do by hand,
> >> so lxc can not work for it.
> >>
> >> 	I also know lxc_user_nic() can only do a part of work, but we have
> >> two more work:
> >> 1. grasp the netlink/uevent message about network interface online
> >> 2. config interface attached to container ip address .
> >>
> >> so it can not fully meet my requirements.
> >>
> >> 	I want there is a monitor can work for network interface hotplug.
> >>
> >> 1. read config form config file, it describe monitor which network interface
> >>    and what's the network configuration
> >> 2. grasp the netlink/uevent message about network interface online on the host
> >> 3. create veth pair, put veth attach to container and bridge
> >> 4. config the veth attached to container ipaddr
> >>
> >> 			
> >>          	          netlink  create veth pair
> >> monitor ---> read config  -------> veth0 attach to container --> config ipaddr
> >> 				   veth1 attach to bridge
> >>
> >> monitor may be the lxc-start or a child forked by lxc-start.
> >>
> >>
> >>  Is this reasonable?  If so, I'd like to do it.
> > 
> > I'm not quite clear on what you're trying to do, but it sounds like you
> > could use a udev rule, triggered on the nic creation, and use lxc-device
> > from inside that rule to attach the nic to the container.
> > 
> hi Serge,
> 
> using udev rule is a good idea, but not common. for instance android uses ueventd and
> busybox uses mdev, sometimes nothing at all.
> 
> so how about lxc itself provides this feature?

Just one more question - what would the configuration look like?
Especially, what would the monitor be looking for?  How would it
recognzie a link that came up as being the one which the container
should be attached to?  (We're constantly reminded that the names
cannot be unambiguously used to identify a physical link)