Open Stack

On 18/04/2016 13:51, Sean Dague wrote:
> On 04/18/2016 08:22 AM, Chris Dent wrote:
>> On Mon, 18 Apr 2016, Sean Dague wrote:
>>
>>> So if you have strong feelings and ideas, why not get them out in email
>>> now? That will help in the framing of the conversation.
>>
>> I won't be at summit and I feel pretty strongly about this topic, so
>> I'll throw out my comments:
>>
>> I agree with the basic premise: In the big tent universe co-
>> installability is holding us back and is a huge cost in terms of spent
>> energy. In a world where service isolation is desirable and common
>> (whether by virtualenv, containers, different hosts, etc) targeting an
>> all-in-one install seems only to serve the purposes of all-in-one rpm-
>> or deb-based installations.
>>
>> Many (most?) people won't be doing those kinds of installations. If all-in-
>> one installations are important to the rpm- and deb- based distributions
>> then _they_ should be resolving the dependency issues local to their own
>> infrastructure (or realizing that it is too painful and start
>> containerizing or otherwise as well).
>>
>> I think making these changes will help to improve and strengthen the
>> boundaries and contracts between services. If not technically then
>> at least socially, in the sense that the negotiations that people
>> make to get things to work are about what actually matters in their
>> services, not unwinding python dependencies and the like.
>>
>> A lot of the basics of getting this to work are already in place in
>> devstack. One challenge I've run into the past is when devstack
>> plugin A has made an assumption about having access to a python
>> script provided by devstack plugin B, but it's not on $PATH or its
>> dependencies are not in the site-packages visible to the current
>> context. The solution here is to use full paths _into_ virtenvs.
>
> As Chris said, doing virtualenvs on the Devstack side for services is
> pretty much there. The team looked at doing this last year, then stopped
> due to operator feedback.
>
> One of the things that gets a little weird (when using devstack for
> development) is if you actually want to see the impact of library
> changes on the environment. As you'll need to make sure you loop and
> install those libraries into every venv where they are used. This
> forward reference doesn't really exist. So some tooling there will be
> needed.
>
> Middleware that's pushed from one project into another (like Ceilometer
> -> Swift) is also a funny edge case that I think get funnier here.
>
> Those are mostly implementation details, that probably have work
> arounds, but would need people on them.
>
>
>  From a strategic perspective this would basically make traditional Linux
> Packaging of OpenStack a lot harder. That might be the right call,
> because traditional Linux Packaging definitely suffers from the fact
> that everything on a host needs to be upgraded at the same time. For
> large installs of OpenStack (especially public cloud cases) traditional
> packages are definitely less used.
>
> However Linux Packaging is how a lot of people get exposed to software.
> The power of onboarding with apt-get / yum install is a big one.
>
> I've been through the ups and downs of both approaches so many times now
> in my own head, I no longer have a strong preference beyond the fact
> that we do one approach today, and doing a different one is effort to
> make the transition.
>
> 	-Sean
>

It is also worth noting that according to the OpenStack User Survey [0]
56% of deployments use "Unmodifed packages from the operating system".

Granted it was a small sample size (302 responses to that question)
but it is worth keeping this in mind as we talk about moving the burden
to packagers.

0 - 
https://www.openstack.org/assets/survey/April-2016-User-Survey-Report.pdf (page 
36)