On Thu, Nov 06, 2014 at 09:43:51AM -0500, Stéphane Graber wrote: > On Thu, Nov 06, 2014 at 03:56:05AM -0600, Tycho Andersen wrote: > > Hi all, > > > > I have a couple questions about exactly how `lxd move` [1] would be > > implemented. > > > > First, is the --stateful argument necessary? Can we just drop it and > > make it implied if the container is running? > > > > Second, are we sure we want to support changing the hostname of a > > running container (lxc move c1 c2)? That seems to me to look inside > > the container a bit too much (plus it has the added complication of > > changing the hostname of a container when applications might not be > > expecting it). > > > > Tycho > > > > [1]: > > https://github.com/lxc/lxd/blob/master/specs/command-line-user-experience.md#move > > Hi Tycho, > > Since you can't do a stateful migration with a stopped container and > can't do a stateless migration with a running container, I agree that > --stateful doesn't make sense and can be dropped. > Can you send a branch for that?
Yes, I will send a branch tomorrow. > Now as for the hostname, that's a trickier one. LXC currently does that > kind of change on clone and rename and I think it's useful to have to > provide a good user experience. > > But I also agree that we should keep detailed knowledge about the inside > of the container as far away from lxd as possible. > > > So how about this: > > Define a lxd specific hook, say "lxd.hook.name_changed" which if it's > set in the config will be run against the container on initial container > creation and whenever the container name changes. > > The hook would be passed the old hostname and the new one as argument > (or NONE if called at container creation) and would then be able to sed > all the relevant files. > > This would allow us to keep detailed knowledge of the rootfs structure > within the image. This sounds fine, to me. However, didn't at some point we talk about having a /dev/lxd that we passed containers events about what was happening on the outside? This seems like a prime candidate for some type of event like that. > > > As for changing the hostname under the feet of the running applications, > I'm not too concerned about this since plenty of distros already do so > whenever your DHCP server sends you a different hostname. So it's > already a common thing in the real world and something that applications > should cope with. Fair enough. I was just thinking that if we don't actually call sethostname maybe things would get confused. Tycho > > -- > Stéphane Graber > Ubuntu developer > http://www.ubuntu.com > _______________________________________________ > lxc-devel mailing list > lxc-devel@lists.linuxcontainers.org > http://lists.linuxcontainers.org/listinfo/lxc-devel _______________________________________________ lxc-devel mailing list lxc-devel@lists.linuxcontainers.org http://lists.linuxcontainers.org/listinfo/lxc-devel
