fixed ip gets assigned when a port is created with no fixed ip

[Sridhar Venkat]

When a neutron port is created with no fixed ip, and bound to a nova instance, a random IP is automatically picked up from subnet pool and assigned.
Port request body :
port_req_body
{'port': {'network_id': u'b3bfb646-5794-44e6-86eb-0f90b18c6d78', 'tenant_id': u'ccfdd1bc5f894ad0a085e3e1d53f9329', 'mac_address': u'fa:f8:86:36:34:20', 'fixed_ips': [], 'admin_state_up': True}}

After it is bound to a nova instance, it gets an ip associated with it. From neutron port-show :
| fixed_ips | {"subnet_id": "90f2afbc-bc64-4a0c-823a-a39d71f1fadd", "ip_address": "10.0.0.5"} |
This appears to be a problem due to changes in newton. This behavior was not there in mitaka.

[Matt Riedemann (mriedem)]

This is most likely not something that Nova is doing, but rather something Neutron is doing when the port is created, based on the type of neutron setup you have.

[Matt Riedemann (mriedem)]

https://review.openstack.org/#/c/299591/ might be helpful here.

[Carl Baldwin (carl-baldwin)]

This is probably a bug. My intention was only to assign fixed_ips on port update if the port was a deferred IP port to begin with (only if fixed_ips is not explicitly passed on port create and the network is a routed network and so IPAM could not be done on create). However, for this to work correctly, we might need this [1] change and possibly a small bug fix.

I'll try to confirm this on Monday. I'll target this for rc-1 just to get it on the radar.

[1] https://review.openstack.org/#/c/361455/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/369062

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/369062
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=ab4ee76c8bdacb0f272328e0b4efefc3b820e5ba
Submitter: Jenkins
Branch: master

commit ab4ee76c8bdacb0f272328e0b4efefc3b820e5ba
Author: Carl Baldwin <email address hidden>
Date: Mon Sep 12 16:09:50 2016 -0600

    Only do deferred ip allocation on deferred ports

    Only do deferred ip allocation on ports that were originally marked as
    deferred IP ports on port create.

    Change-Id: Ia34bc2617f99cca73f58c9e615a8ba78e667c9b3
    Closes-Bug: #1617409

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 9.0.0.0rc1 release candidate.