[lxc-users] Creating a container as non root

[Serge Hallyn]

Sounds good.  It might be worthwhile having a 'lxc-setup-images' command
which requires root and builds the base images.  Then unprileged users
could untar/unsquash those images.

To be clear, I absolutely *can* create and run ubuntu-cloud images
without being root.

-serge

Quoting Cal Leeming [Simplicity Media Ltd] (cal.leeming at simplicitymedialtd.co.uk):
> It's also worth mentioning that fakeroot/fakechroot have some nasty issues
> with debootstrap;
> https://bugs.launchpad.net/ubuntu/+source/fakechroot/+bug/1265857
> 
> One theory I'm exploring is building "base images" on a machine that does
> have root, by running debootstrap on every flavor/arch then using
> mksquashfs to compress it down into an image. You could then use unsquashfs
> to force whatever uid/gid you wanted, then fakechroot/fakeroot to make
> whatever changes you need to the container before launching. The downside
> is that there is no public mirror that offers this at the moment (other
> than the latest 13.x ubuntu, which contains a filesystem.squashfs you can
> extract, but it's 700mb). You could create your own set of base images,
> then wrap scripts around them to create the templates, but this is
> absolutely not going to work out of the box, there is a lot of tedious work
> involved.
> 
> I'm planning on doing a better write up about this (as its something I'm
> actively working on), will update this thread at a later date.
> 
> Hope this helps a bit
> 
> Cal
> 
> 
> 
> 
> On Thu, Jan 9, 2014 at 3:39 PM, Michael H. Warfield <mhw at wittsend.com>wrote:
> 
> > On Thu, 2014-01-09 at 08:08 +0200, Kevin Wilson wrote:
> > > Hello,
> > > I believe that creating a container as non root user should be
> > straight-forward.
> >
> > Sigh...  I'm afraid not...
> >
> > Funny, Serge and I just had a couple of comments in exchange about this
> > very thing with regards to templates.  He's been working on getting
> > containers to run under unprivileged users and I know the Fedora and
> > CentOS templates will not even run under a non-user (they check).  His
> > remark was that most templates will not and can not, including the
> > Ubuntu template.  Problem with the Ubuntu template (and, presumably the
> > Debian template) is the use of debboot which, in turn, uses mknod to
> > create devices for the container - and you're then toast.
> >
> > The problem there is that there are going to be privileged operations
> > (chown, mknod, etc) that are simply going to require privileges in the
> > host which are not available to the non-priv user.
> >
> > I'm not so sure about the busybox template but I wouldn't be optimistic.
> > It does look like it checks to see if it's in a user namespace and uses
> > mknod if not and does something else if it is.  So, it looks like it
> > SHOULD work.  But you have to have user namespaces set up to work.
> >
> > Once a container is created, it should be possible to run it under a
> > non-priv user if you have a recent enough kernel along with the latest
> > lxc tools.  But it seems likely we could ever navigate the morass of
> > creating a template using lxc-create as a non-priv user.
> >
> > > I added a user named "test" and I am trying to create a container (see
> > > below the sequence). I am running latest lxc git
> > > (built from source, as root)  on Fedora 20.
> >
> > > useradd test
> > > su test
> > >
> > > lxc-create -t busybox -n busyboxTest
> > > I get:
> > >
> > > You lack access to /home/test/.local/share/lxc/
> > > I ran;
> > > mkdir -p /home/test/.local/share/lxc/
> > >
> > > Then again:
> > > lxc-create -t busybox -n busyboxTest
> > > lxc-create: Permission denied - failed to create directory
> > '/run/user/0/lock/'
> > >
> > > failed to create lock
> > > System error loading container
> > >
> > > What should I do ?
> > >
> > > Regards,
> > > Kevin
> >
> > Regards,
> > Mike
> > --
> > Michael H. Warfield (AI4NB) | (770) 978-7061 |  mhw at WittsEnd.com
> >    /\/\|=mhw=|\/\/          | (678) 463-0932 |
> > http://www.wittsend.com/mhw/
> >    NIC whois: MHW9          | An optimist believes we live in the best of
> > all
> >  PGP Key: 0x674627FF        | possible worlds.  A pessimist is sure of it!
> >
> >
> > _______________________________________________
> > lxc-users mailing list
> > lxc-users at lists.linuxcontainers.org
> > http://lists.linuxcontainers.org/listinfo/lxc-users
> >

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