[lxc-devel] API wishlist

[Dwight Engen]

On Mon, 10 Dec 2012 09:44:26 -0500
Stéphane Graber <stgraber at ubuntu.com> wrote:

> On 12/10/2012 09:30 AM, Dwight Engen wrote:
> > On Fri, 07 Dec 2012 12:47:59 -0500
> > Stéphane Graber <stgraber at ubuntu.com> wrote:
> > 
> >> On 12/07/2012 12:25 PM, Serge Hallyn wrote:
> >>> Quoting Stéphane Graber (stgraber at ubuntu.com):
> >>> ...
> >>>>  - get_version() (not container specific)
> >>>>  - get_lxc_path() (not container specific)
> >>>>    Returns the storage path for the containers.
> >>>>    Defaults to LXCPATH.
> >>>>  - set_lxc_path(path) (not container specific)
> >>>>
> >>>>
> >>>> Looking at my todolist for this cycle, the highest priority ones
> >>>> for me would be:
> >>>>  1) get_lxc_path()
> >>>>  2) set_lxc_path()
> >>>>  3) get_cgroup_item()
> >>>>  4) set_cgroup_item()
> >>>
> >>> How would set_lxc_path() work?  Would all the lxc code be switched
> >>> to check /etc/default/lxc.conf for the value, and autoconf would
> >>> only fill in the value in that file?
> >>
> >> So I think we should split the implementation in two:
> >> 1) Stop hardcoding LXCPATH in all the C code, instead make it
> >> default to LXCPATH and overrideable by the set_lxc_path() call.
> >> 2) Discuss implementing a system wide, not container specific, lxc
> >> configuration file to be used by all distros in a format that's
> >> easily parsable.
> > 
> > For 2, doesn't f0e592fc do that?
> 
> f0e592fc is more of a bare config that's copied over to every new
> container than a lxc system configuration file.
> 
> If we were to add the lxcpath to /etc/lxc/lxc.conf, it'd end up being
> added to every new container's configuration where it'd be rather
> useless.
> 
> I think the naming of /etc/lxc/lxc.conf was rather bad and I should
> have thought of that back then :)
> Essentially our current /etc/lxc/lxc.conf should really be
> /etc/lxc/default.conf, clearly identifying that it's the default
> configuration for new containers.
> Then we could use /etc/lxc/lxc.conf for configuration specific to the
> lxc tools.

Ahh, yes I see the distinction. I think your proposal makes sense.

> If that makes sense to everyone else, I think it'd still be possible
> to change that for alpha2.  I expect it to be mostly difficult for
> Ubuntu users as we've had /etc/lxc/lxc.conf for the past few years,
> but that's nothing we can't magically figure out and transition in
> package maintainer scripts.
> 
> >> Implementing 1) will make it easy for individual commands like
> >> lxc-list to implement an extra argument letting the user override
> >> the lookup path. It'll also make it much easier to deal with lxc
> >> being run as a user at some point in the future.
> >>
> >> Obviously, once we have that, some people will want to change the
> >> default lookup location in one place and have all the commands use
> >> that path. That's where we need 2) so that we can store that kind
> >> of settings in a way that's not distro-specific and have all the
> >> tools in all the different languages to parse that file.
> >>
> >>> -serge
> >>>
> >>
> >>
> > 
> 
>