Boot a VM with an unaddressed port

[Rodolfo Alonso]

This is the Neutron follow-up for the Nova BP https://blueprints.launchpad.net/nova/+spec/boot-vm-with-unaddressed-port.

DESCRIPTION:
Currently Nova only allows to boot a VM if all ports attached:
- Have an IP assigned.
- The IP allocation is deferred.

But Nova doesn't allow to spawn a VM with a port without an IP assigned. However, some kind of applications (e.g.: routers) need a port which may be receiving traffic for several addresses, already configured in other devices.

At the moment, Neutron permits to create a port, assigned to a network with the corresponding subnetworks and IP pools, without an IP.

RELATED BUGS:
* "[RFE] Port binding event extended information for Nova": https://bugs.launchpad.net/neutron/+bug/1821058

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

This is not a RFE but just the needed Neutron counterpart work needed to make this BP feature work.

[YAMAMOTO Takashi (yamamoto)]

what needs to be done in neutron?

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

Hello Yamamoto:

For example, this: https://review.opendev.org/#/c/678027/. This patch should have been tracked in this bug.

If any other patch is needed for this Nova BP (code changes, testing, etc), this will be tracked in this bug. As I commented, I opened this bug just to track in Neutron launchpad the patches needed in this repo for this BP.

Regards.

[YAMAMOTO Takashi (yamamoto)]

do we (neutron) have the corresponding bp/rfe/etc?

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

No, there is no BP because when I submitted the Nova one, I didn't consider a BP/SPEC/RFE in Neutron was needed, just small fixes submitted under the umbrella of the Nova SPEC.

[YAMAMOTO Takashi (yamamoto)]

i think usually we use separate nova/neutron proposal processes for joint efforts.
i'm not sure how this is different from past efforts like https://blueprints.launchpad.net/neutron/+spec/vm-without-l3-address though.