Re: [atomic-devel] Running docker-storage-setup from a UI

[Daniel J Walsh <dwalsh redhat com>]

On 04/12/2016 03:50 PM, Vivek Goyal wrote:
> On Tue, Apr 12, 2016 at 03:09:08PM +0300, Marius Vollmer wrote:
> > Hi,
> >
> > I am working on this:
> >
> >      https://github.com/cockpit-project/cockpit/wiki/Atomic:-Docker-Storage
> >
> > which is basically a UI inside Cockpit for docker-storage-setup.
> >
> > I am not super far along, but I am getting to the point where the UI
> > will need to actually run docker-storage-setup.
> >
> > - My basic idea is to write a new /etc/sysconfig/docker-storage-setup
> >    file and then run docker-storage-setup.  Is that the best approach for
> >    a UI?
> >
> > - Docker-storage-setup needs to run non-interactively, but I think it
> >    can't do that right now, and asks confirmation for various things.
> It already runs non-interactively. It is a service which runs on boot.
>
> >    Would it be acceptable to add a "--force-wipe" option to d-s-s, and
> >    maybe others?  I can do that at the same time as I write the code for
> >    the UI.
> So --force-wipe is a new functionality. What will it do?
>
> > - Just showing the contents of /etc/sysconfig/docker-storage-setup in
> >    the UI as the current state of things is not really correct, since
> >    docker-storage-setup might not have run since it was last changed, or
> >    it might have failed.
> >
> >    So I am thinking there could be something like
> >
> >      # docker-storage-setup status
> >      /dev/vda: ok, shared with OS
> >      /dev/sda: ok
> >      /dev/sdb: Not yet set up!
> >
> >      The Docker storage pool is not fully set up.  Run
> >      "docker-storage-setup" to complete the set up.
> I think first what would be nice is to display current docker
> configuration.
>
> What does "shared with OS" mean? Does it mean, it is in same volume
> group where rootfs is?
>
> >    This would output information about how things should be, and how they
> >    actually are.  (With an option for machine readable output.)  The
> >    above would be for VG="" and DEVS="/dev/sda /dev/sdb" where there was
> >    some sort of problem with /dev/sdb.
> >
> >    The machine readable output could maybe look like
> >
> >      # docker-storage-setup status -M
> >      /dev/vda:root
> What does "root" mean?
>
> >      /dev/sda:
> What does empty string after /dev/sda mean?
>
> Thanks
> Vivek
>
> >      /dev/sdb:error=missing
> >
> >    Or should we go full JSON right away?
> >
> > What do you think?  Am I heading down the wrong path?  If nobody stops
> > me, I'll hopefully make some PRs soon for this, and we can discuss the
> > details there.
Eventually adding a feature to do an `atomic migrate` to move from back 
end to another would be nice

With docker-1.10 you can do an

atomic migrate export

Change the back end

atomic migrate import

And switch from loopback devices to devmapper on physical storage or 
even switch the backends altogether.

From devmapper to overlayfs to btrfs  and back again.