[ovirt-devel] ovirt-provider-ovn - appliance inclusion / default enablement

[Dan Kenigsberg]

On Tue, May 16, 2017 at 6:56 PM, Sandro Bonazzola <sbonazzo at redhat.com> wrote:
>
> Hi,
> with https://gerrit.ovirt.org/76855 it's requested to increase the appliance size by adding ovirt-provider-ovn and its dependencies.
>
> This raise a few questions.
> The support for ovirt-provider-ovn is enabled by default in engine-setup and going to be installed by default in the appliance so we're pushing to use it.
> Why not requiring it at ovirt-engine spec file level?
> Answer given in the commit message of above patch is:
>
> We do not want to have a hard dependency in the
> form of an rpm require.
> OVN and openvswitch are relatively heavy and complex,
> and are still experimental. We would not want to
> force everybody to pull them onto any Engine host.
>
> So why adding it to the appliance, which is the default for hosted engine which is our recommeded way to deploy oVirt, and enable it by default?
>
> How this differs from DWH? ovirt-engine requires ovirt-engine-setup which requires ovirt-engine-dwh setup which requires ovirt-engine-dwh.
> Why can't we just require ovirt-provider-ovn in ovirt-engine instead of tweaking the appliance?
>
> If we decide it's not mandatory, why not make the default to not enabling it in engine-setup and avoid to add it to the appliance?
> Being optional, adding it collides with Bug 1401931 - [RFE] reduce the size of the appliance

Much like with DWH, I can envisage a use case where ovirt-provider-ovn
sits on a remote host, rather than on Engine's. However, the default
use case is to place them on the same host.

I thought that it would be a good idea to include OVN on the
appliance, as a means to showcase this new and exciting feature of
oVirt. However, it is not a must. We can say that we'd like to keep
the appliance small; if someone wants to use OVN with it, let them run
ovirt-engine-setup manually, and pull in the dependencies.

For this we'd need to flip the default, and not install OVN when the
appliance is created, and skip OVN test in the offline test suite.

Regards,
Dan.