[systemd-devel] How to use machinectl to get a running centos container?

[Lennart Poettering]

On Sat, 04.03.17 01:38, Daurnimator (quae at daurnimator.com) wrote:

> On 3 March 2017 at 20:58, Lennart Poettering <mzerqung at 0pointer.de> wrote:
> > On Fri, 03.03.17 12:34, Daurnimator (quae at daurnimator.com) wrote:
> >
> >> I'm trying to set up a centos 7 container with machinectl.
> >> I've tried to run:
> >>
> >> machinectl pull-raw --verify=no
> >> http://cloud.centos.org/centos/7/images/CentOS-7-x86_64-GenericCloud-1701.raw.tar.gz
> >
> > Hmm, what is a ".raw.tar.gz" file? That suffix makes no sense to me...
> 
> *shrugs* it's what I saw available for download from
> http://cloud.centos.org/centos/7/images/
> 
> Apparently it's a gziped tar with a single file inside:
> CentOS-7-x86_64-GenericCloud-20170131_01.raw
> This .raw file is a disk image.

That appears a bit redundant, and importd/machinectl pull-raw is not
able to handle this.


> > We support raw disk images and tarballs with OS trees in them, both
> > compressed and non-compressed.
> >
> > There's currently a safety limit against overly large images enforced,
> > of 8GiB. If the indicated image is larger than that, and that's
> > intended we should probably bump this safety limit substantially (32G?
> > 64G?), please file a github issue asking for this if this is the
> > case. Or even better prep a PR, the fix is trivial:
> >
> > https://github.com/systemd/systemd/blob/master/src/import/pull-job.c#L530
> 
> Looks like it's *equal* to the limit.
> 
> Before I make a PR here, am I going about running a centos container
> with machinectl the best way here?
> How are other people doing this?

I don't think many people are using CentOS caontainers with
nspawn... That said, there's a good chance that it works OKish.

Note that "machinectl pull-raw" is just a helper to make downloading
easy. But if you have images in weird formats, you can download them
and place them in /var/lib/machines (with the .raw suffix), and
machined/nspawn is happy. It doesn't really matter how the image gets
there as long as it gets there, and "machinectl pull-raw" is just one
way.

Lennart

-- 
Lennart Poettering, Red Hat