On Mon, Aug 31, 2015 at 09:53:03PM +0200, Christian Brauner wrote: > On Mon Aug 31, 2015 at 04:08:33PM +0000, Serge Hallyn wrote: > > Quoting Stéphane Graber (stgraber at ubuntu.com): > > > On Mon, Aug 31, 2015 at 01:43:07PM +0000, Serge Hallyn wrote: > > > > Quoting Christian Brauner (christianvanbrauner at gmail.com): > > > > > On Fri, Aug 28, 2015 at 12:46:17AM +0200, Christian Brauner wrote: > > > > > > On Thu, Aug 27, 2015 at 03:41:03PM -0400, Stéphane Graber wrote: > > > > > > > On Sun, Aug 16, 2015 at 04:46:31PM +0000, Serge Hallyn wrote: > > > > > > > > Quoting Christian Brauner (christianvanbrauner at gmail.com): > > > > > > > > Hey, > > > > > > > > > > > > > > > > I'll leave this to Stéphane, as he's pretty keen on leaving the > > > > > > > > # > > > > > > > > commands > > > > > > > > low. As you say we might eventually be able to deprecate > > > > > > > > lxc-clone, > > > > > > > > and > > > > > > > > lxc-copy might eventually be a nice hook for migration. > > > > > > > > > > > > > > That'd be fine with me I think, bonus point if we can somehow > > > > > > > merge > > > > > > > lxc-start-ephemeral in there and kill two birds with one stone > > > > > > > (lxc-clone & lxc-start-ephemeral). > > > > > > > > > > > > > > The timeline for this would be having lxc-copy in 1.2 with both > > > > > > > lxc-clone and lxc-start-ephemeral doing arg swapping + re-exec > > > > > > > tricks > > > > > > > with a warning that they'll go away for good in 2.0. > > > > > > > > > > > > > > How does that sound? > > > > > > > > > > > > Sounds good! I'm on it! > > > > > > > > > > > > Christian > > > > > > > > > > In the current python implementation of lxc-start-ephemeral we > > > > > generate > > > > > a > > > > > pre-mount and post-stop script. The post-stop script seems to be used > > > > > to > > > > > destroy > > > > > the container. For the rewrite in C and the merge with lxc-clone I > > > > > thought > > > > > about > > > > > using a simple snapshot-clone with c->clone() with a random name, > > > > > start > > > > > it > > > > > c->start() and when the container is shutdown destroy it with > > > > > c->destroy(). > > > > > This seems cleaner to me then generating scripts. Are there any > > > > > reasons > > > > > to > > > > > not > > > > > do it this way? And if so what would you prefer? > > > > > > > > If you can do this robustly and cleanly then I prefer this. > > > > > > The reason was that the container could be started backgrounded (-d) in > > > which case lxc-start-ephemeral wasn't around anymore to clean things up > > > when the container exits. > > > > > > The post-stop method ensured that the container would be destroyed > > > whenever it finally dies and regardless of how it was killed (either > > > shutdown from inside the container or lxc-stop/lxc-destroy). > > > > Right, so to do this without post-stop we'd probably have to hack a special > > case into the reboot: loop around container-start. Maybe even hardcode the > > 'transient' case into the lxc_handler struct. Or just have a 'special' > > post-stop hook (doesn't even have to be a script, just a hard-code value > > checked for before we run the script) telling us 'delete this thing'. > > > > It could end up looking nice, or could end up a mess. I reserve final > > judgement until there's code :) > Agreed. Let's see how mess-less I can code this. > > As long as the container is started in foreground mode the container will be > destroyed regardless of whether it was killed by lxc-stop or shutdown from > inside. The only problematic case is when the container is started daemonized. > > I need to think about how to handle that case for a bit. I'd like to code more > than one option I think. Unless there's need for rush. :) Suggestions of > course > welcome. I'm currently in favour of the lxc.hook.post-stop version for daemonized containers. The rest means fiddling with a lot of the api-functions for the a rather special case. But there are two things I would like to have input about:
1) Should we register ephemeral clone-snapshots in the lxc_snapshots file of the original container? (I would think not.) 2) Should we have an additional state TRANSIENT in addition to RUNNING, STARTING, etc.? Christian
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