Open Stack

On 06/18/2013 05:24 PM, Daniel P. Berrange wrote:
> On Thu, Jun 06, 2013 at 10:33:12AM -0700, Sam Alba wrote:
>> Hi all,
>>
>> I work for dotCloud and I wanted to share our recent work on Nova[1].
>> We've been using LXC containers on our PaaS product for more than 2
>> years now and we recently released the Docker project[2] that you may
>> have heard about already.
>>
>> We also wrote a blog post[3] to explain the work we did and how the
>> Glance can make the glue between Nova and Docker's remote Images
>> index.
> 
> Some people asked offlist what my opinion was on accepting this new
> virt driver, given that we already have Libvirt LXC driver support
> in Nova.
> 
> Superficially this appears to be the same scenario that was recently
> raised wrt supporting a new OpenVZ driver in Nova, vs supporting it
> via the Libvirt OpenVZ capabilities (where we chose the latter).
> 
> "LXC" can mean many things. In particular it can refer to the kernel
> features that have been implemented to support containers on Linux
> or it can refer to a specific userspace toolset implementation that
> uses those kernel features. There is the Libvirt LXC driver or there
> is the sf.net LXC toolset providing separate userspace implementations.
> IIUC, Docker is an application that is built on top of the sf.net
> LXC toolset. Conceptually it looks like it works at a higher level
> than the raw LXC toolset, so cannot be considered to duplicate either
> the Libvirt LXC / sf.net LXC toolset, but rather to complement them.
> 
> As such, I believe this is a different situation to the one that
> recently arose wrt OpenVZ. A "Docker" driver for Nova would be
> providing integration with different capability, than is provided
> for by the Libvirt LXC driver. So I think there could be merit in
> having Docker support in Nova, provided the submitter (or another
> interested party) is prepared to commit to being an active maintainer
> for the code long term, and not just submit it and expect someone
> else to maintain it after merge.

I can buy that. I'd also like to add that I think it would be good to
get patches to ensure this driver is tested. Since it's driving LXC,
there should be no problems in doing testing nested in devstack vms.