Unprivileged containers and co-ordinating user namespaces
Serge E. Hallyn
serge at hallyn.com
Fri Apr 29 15:53:03 UTC 2016
Quoting James Bottomley (James.Bottomley at HansenPartnership.com):
> On Thu, 2016-04-28 at 16:00 -0700, W. Trevor King wrote:
> > On Thu, Apr 28, 2016 at 03:02:08PM -0700, James Bottomley wrote:
> > > /etc/usernamespaces
> > >
> > > and the format be :::
> > >
> > > …
> > >
> > > If this sounds OK to people, I can code up a utility that does this,
> > > which should probably belong in util-linux.
> > This sounds a lot like shadow's newuidmap and newgidmap [1,2,3].
> > Cheers,
> > Trevor
> > : https://github.com/shadow-maint/shadow/commit/673c2a6f9aa6c69588f4c1be08589b8d3475a520
> > : http://man7.org/linux/man-pages/man1/newuidmap.1.html
> > : http://man7.org/linux/man-pages/man5/subuid.5.html
> I think that mostly works. No-one's packaging it yet, which is why I
> didn't notice. It also looks like the build dependencies have vastly
> expanded, so I can't get it to build in the build service yet.
> It looks like the only addition it needs is the setgroups flag for
> newgidmap, which the security people will need, so I can patch that.
> Plus it's trying to install newgidmap/newuidmap as setuid root rather
> than cap_setuid/cap_setgid, but that's fixable in the spec file.
That would prevent it being installed inside user namespaces, until
the user namespaced file capabilities (see separate thread :) hit.
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