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

[Yedidyah Bar David]

On Wed, May 17, 2017 at 2:54 PM, Dan Kenigsberg <danken at redhat.com> wrote:
> On Wed, May 17, 2017 at 12:23 PM, Yedidyah Bar David <didi at redhat.com> wrote:
>> On Wed, May 17, 2017 at 11:42 AM, Dan Kenigsberg <danken at redhat.com> wrote:
>>> On Wed, May 17, 2017 at 10:44 AM, Yedidyah Bar David <didi at redhat.com> wrote:
>>>> On Wed, May 17, 2017 at 9:38 AM, Dan Kenigsberg <danken at redhat.com> wrote:
>>>>> 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.
>>>>
>>>> The appliance is assumed to (soon?) be our standard installation flow,
>>>> not a way to showcase things. For the latter, you might want to add ovn
>>>> to ovirt-live or to the ovirt demo tool [1] (not yet released IIUC).
>>>>
>>>> [1] https://trello.com/b/wocfflzf/sales-demo-tool-lago-based
>>>>
>>>>>
>>>>> 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.
>>>>
>>>> +1
>>>
>>> Could you point us to the answer file used for appliance creation?
>>
>> Do you want to keep the default True for non-appliance? My +1 above
>> was also for reverting the default, not only in appliance.
>
> Oh. I still want to have OVN by default for non-appliance. I like this
> feature, and I want to entice people to use it.

I think that Sandro's question above applies equally well to the
non-appliance usecase. If it's good enough to be the default for
non-appliance, might as well be so for the appliance as well. If
it's not good enough for the appliance, perhaps default to No also
for non-appliance.

>
> For appliance I understand that we have a size limitation, so ok, let
> us not bloat it up.

What's the impact on size? For the appliance image and for the
eventually-installed machine?

I do not think the impact on appliance size is the major question here,
but whether we really expect most users to use OVN. But I might be
surprised...

>
> I hope you are also fine with disabling ovn in the following answer file.
>
>>
>> The appliance-supplied answer file seems is:
>>
>> https://gerrit.ovirt.org/gitweb?p=ovirt-appliance.git;a=blob;f=engine-appliance/data/ovirt-engine-answers;h=2881af6563297a7a3d220dfe479d39f88c12ca46;hb=HEAD
>>
>> When hosted-engine --deploy is using the appliance, and if the user
>> asks to run engine-setup automatically, it uses above file,
>> but also adds another file, auto-generated, see here:
>>
>> https://gerrit.ovirt.org/gitweb?p=ovirt-hosted-engine-setup.git;a=blob;f=src/plugins/gr-he-common/vm/cloud_init.py;h=0a20f946d65199423c99769ab51e4fe092465e96;hb=HEAD#l1018
>>
>> None of them has the answer for OVN. Latter has:
>>
>> DIALOG/autoAcceptDefault=bool:True
>>
>> For this, see:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=1270719



-- 
Didi