On 04/05/16 15:05 +0000, Amrith Kumar wrote:
I'm emailing the ML on the subject of a review ongoing in the Trove project 
regarding image building[1].

TL;DR

One of the most frequent questions that new users of Trove ask is how and where 
to get guest images with which to experiment with Trove, and how to build these 
images for themselves. While documentation about this exists in multiple places 
(including [2], [3]) this is still something that can do with some improvement.

Trove currently uses diskimage-builder for building images used in testing the 
product and these can serve as a good basis for anyone wishing to build an 
image for their own use of Trove. The review [1] makes the argument for the 
libguestfs based approach to building images and advocates that Trove should 
use this instead of diskimage-builder.

At the summit we discussed the possibility of providing an implementation that
would allow for both DIB and libguestfs to be used but to give priority to DIB.
Since there's no real intention of just switching tools at this point, I believe
it'd be good to amend the spec so that it doesn't mention libguestfs should be
used instead of DiB.

The goal at this stage is to provide both and help these move forward.

I believe that a broader discussion of this is required and I appreciate Greg 
Haynes' proposal at the design summit to have this discussion on the ML. I took 
the action item to bring this discussion to the ML.

Details follow ...

Before going further, I will state my views on these matters.

1. It is important for the Trove project to do things quickly to make it easier 
for end users who wish to use Trove and who wish to build their own images. I 
am not concerned what tool or tools a person will use to build these images.

2. If we provide multiple alternatives to image building as part of the Trove 
project, we should make sure that images built with all sets of tools are 
equivalent and usable interchangeably. Failing to do this will make it harder 
for users to use Trove because we will be providing them with a false choice 
(i.e. the alternatives aren't really alternatives). This is harder than it 
sounds given the combination of tools, operating systems, and the source(s) 
from which you can get database software.

Maintaining both in the long run will be harder especially because, as you
mentioned, the output must be usable interchangeably. However, I think we're at
a point, based on the comments in [1] made by Pino Toscano, Luigi Toscano and
some other folks that it'd be beneficial for us to have this discussion and to
also experiment/test other options.

The Sahara team seems to be going in a direction that differs with the one used
by the infra team and the one we're headed to (although they overlap in some
areas).

3. Trove already has elements for all supported databases using DIB in the 
trove-integration project but these elements are not packaged for customer use. 
Making them usable by customers is a relatively small effort including 
providing a wrapper script (derived from redstack[4]) and providing an element 
to install the guest agent software from a fixed location in addition to the 
development and testing version that is better suited to Trove development [5] 
and [6].

4. My comments on various patch sets in the review[1].

I agree with Monty and Greg Haynes that we should understand the deficiencies if any in 
DIB, and if it is in fact the case that they are "intractable/unsolvable", we 
should switch toolchains. This discussion should include issues faced by the Trove team 
as well as other teams that may have faced problems with DIB (such as the sahara team who 
described some of them in the past).

++

Agreed with the above. I'm think collaboration should be the preferred way. I
don't think I've enough technical insight on this topic to provide a detailed
list of things that are good/bad on either of these tools but I wanted to
mention that I believe providing support for both in the short run is good for
us and it helps to make a better decision on what tool works best for the 
project.

There's someone willing to do the job and spend sometime doing the research.
This same person will provide feedback in addition to the one already provided
in [1].

Sorry for not providing much technical details now but I did want to share the
above. Thanks for starting this thread, I believe this discussion in the ML will
be beneficial.

Flavio

Thanks,

-amrith


[1] https://review.openstack.org/#/c/295274/
[2] http://docs.openstack.org/developer/trove/dev/building_guest_images.html
[3] 
https://git.openstack.org/cgit/openstack/diskimage-builder/tree/README.rst#writing-an-element
[4] 
http://git.openstack.org/cgit/openstack/trove-integration/tree/scripts/redstack
[5] 
http://git.openstack.org/cgit/openstack/trove-integration/tree/scripts/files/trove-guest.systemd.conf
[6] 
http://git.openstack.org/cgit/openstack/trove-integration/tree/scripts/files/trove-guest.upstart.conf

__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

--
@flaper87
Flavio Percoco

Attachment: signature.asc
Description: PGP signature

__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

Reply via email to