[one-dev] Docker - OpenNebula - Megam

[Carlo Daffara]

First of all, many thanks to the guys at Megam for their work.
May I propose an intermediate solution? Instead of forcing OpenNebula to handle Docker
directly, it may be easier to use a thin OS designed to run Docker directly in an optimized way.
A good example is CoreOS (http://coreos.com/using-coreos/docker/ ) that does have the advantage that can be managed directly through
the Opennebula infrastructure, and eventually linked to OneFlow for more in-depth integration.
This way it would allow for integrating other thin-OSes like OSv ( http://osv.io/ ) that as an alternative targets specifically Java applications.
regards
carlo daffara
cloudweavers ltd

----- Messaggio originale -----
Da: "Javier Fontan" <jfontan at opennebula.org>
A: "Megam Systems" <gomegam at megam.co.in>
Cc: dev at lists.opennebula.org
Inviato: Mercoledì, 18 giugno 2014 17:50:11
Oggetto: Re: [one-dev] Docker - OpenNebula - Megam

Hi,

I'm happy to find this email as I've been tinkering with Docker and
LXC recently.

There are a lot of discussions these days about Docker. I see it as a
nice way to package and deploy apps but I'm not really sure it fits
into OpenNebula. I really want to be wrong on this.

The second proposal (starting up VMs with docker prepared) is straight
forward. It requires an image with the software prepared and maybe
some context scripts that do some kind of configuration so an external
user can call its docker daemon and start new containers.

The first one is a bit more problematic. Even if creating the drivers
to manage docker instances is relatively easy (but time consuming)
there is a problem I couldn't find a solution. VMs usually can be
reached using ssh or VNC. Containers don't have VNC server and with
the Docker philosophy of one app per container you also lose ssh. In
OpenNebula there is not another way of reaching those containers. The
containers will run and do its duty but when something does not work
as expected you can not attach to it to change something and features
like getting the logs from the app are gone.

It may be possible to add some sort of layer to do this. Maybe an ssh
in some host configured like a git server [1] that starts some docker
command instead of a shell. Anyway, this seemed too far fetched for a
pet project and moved to LXC that is more similar to a VM.

Maybe with a bit more heads on the problem we can find an architecture
that makes Docker right at home in OpenNebula.

Cheers

[1] http://gitolite.com/gitolite/glssh.html#restricting-shell-accessdistinguishing-one-user-from-another

On Wed, Jun 18, 2014 at 3:56 PM, Megam Systems <gomegam at megam.co.in> wrote:
> Dear All,
>
> Docker 1.0 was released recently. Megam is a cloud automation engine,
> and would like to support this feature.  With the latest release Docker
> uses libcontainer.
>
> Our *vision* is to enable and simplify running Docker container images
> using Megam on OpenNebula.
>
> *Terminology:*
>
>   * Docker container image  : A tiny image which can be unwrapped and
>     run by "Docker"
>   * Docker container : An instance that is  created as a result of
>     running the Docker container image.
>   * Docker service : A regular Ubuntu or Wheezy VM spinned off by
>     OpenNebula having the "docker" executable installed.
>
>
> Docker helps to run container images  very quickly.  A Docker container
> image is built by an user. So an user builds the Docker container image
> and stores it in a docker registry (this can be public or private).
>
> An example Docker container image can hold  "apache2" or "postgresql".
> Recommendation by Docker is to run just one process.
>
> There are 2 ways in integrating it to OpenNebula.
>
>  1. Docker as a hypervisor which would spin of the user's container
>     image in the OpenNebula host.
>  2. A Docker service which is stood-up and shared by an user. Multiple
>     Docker container can run inside the stood-up Docker service. The
>     Docker service will  be owned by the user and the user can stand-up
>     multiple Docker container in it.
>
>
> We would like to hear the communities feedback and thoughts in taking it
> forward.
>
> Also how are you using Docker today ? How would like to see it being
> used in OpenNebula or using an orchestrator on top of OpenNebula like Megam.
>
> If you haven't started on using Docker, what are the use cases you are
> exploring its use ? What is your wish list for the above integration  ?
>
>
>
> --
> Cheers,
> Megam Systems; http://www.gomegam.com
> email : gomegam at megam.co.in; twitter: @megamsystems
> web   : http://www.gomegam.com  | try   : https://www.megam.co
> blog  : http://blog.megam.co    | github: https://github.com/megamsys
>
>
> _______________________________________________
> Dev mailing list
> Dev at lists.opennebula.org
> http://lists.opennebula.org/listinfo.cgi/dev-opennebula.org
>



-- 
Javier Fontán Muiños
Developer
OpenNebula - Flexible Enterprise Cloud Made Simple
www.OpenNebula.org | @OpenNebula | github.com/jfontan
_______________________________________________
Dev mailing list
Dev at lists.opennebula.org
http://lists.opennebula.org/listinfo.cgi/dev-opennebula.org