add delete_bgpvpn_precommit

[Steve Ruan]

Here is the case, we need a callback delete_bgpvpn_precommit:

We will bind a bgpvpn to bgpspeaker(implemented in neutron-dynamic-routing project). When bgpvpn is deleted, there are 2 options:
1. check whether it's binding to speaker, if yes, prevent this action.
   For this case, we need delete_bgpvpn_precommit callback.
2. check whether it's binding to speaker, if yes, unbind the association.

Method #1 looks more straight forward, and it's the normal behavior.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/333078

[Mathieu Rohon (mathieu-rohon)]

hi steve,

I don't understand why deleting a bgpvpn would be forbidden when it is bound to a speaker? the option number 2 seems more natural to me, and AFAIU, it could be done thanks to the delete_bgpvpn_postcommit callback.

Am I missing something?

[Thomas Morin (tmmorin-orange)]

I agree with Mathieu: if the API user says 'delete this BGPVPN' it means that whatever was needed to implement it should be dropped as well (here the BGPVPN -- BGPSpeaker association).

[Steve Ruan (ruansx)]

Hi Mathieu,

I am work a feature https://bugs.launchpad.net/neutron/+bug/1509431.
This feature will bind a bgpvpn to bgpspeaker, this binding is manually configured. But when bgppn is deleted, there are 2 options described as above.
From my point, since binding is manually, the unbinding is better also manually.

So I want to prevent the unbinding when delete bgpvpn which is bound to a bgp speaker.

Of course, it can also be implemented as Thomas said "it should be dropped as well (here the BGPVPN -- BGPSpeaker association).".

Thanks.

[OpenStack Infra (hudson-openstack)]

Change abandoned by steve (<email address hidden>) on branch: master
Review: https://review.openstack.org/333078

[Thomas Morin (tmmorin-orange)]

addressed by https://review.openstack.org/#/c/422650/

[Thomas Morin (tmmorin-orange)]

(ignore last, bogus, comment)

[Thomas Morin (tmmorin-orange)]

adressed by: https://review.openstack.org/#/c/435651/