Service Subnets - DHCP port creation fails

[John Davidge]

Service Subnets[1] were added in Newton.

The TL;DR is that a subnet can be created/updated with one or more service_types corresponding to a port device owner. If a subnet has one or more service_types, then only ports with a matching device owner can be created on the subnet.

If a service subnet is created with dhcp enabled, automatic dhcp port creation fails, because the port device owner does not match the subnet's service_types.

The port creation is re-attempted over and over, and the subnet remains without dhcp.

Steps to recreate:

NOTE: THIS REQUIRES INSTALLING OPENSTACKCLIENT FROM MASTER

$ openstack network create test-net

$ openstack subnet create test-subnet --subnet-range 10.1.0.0/24 \
  --service-type compute:nova --network test-net

Then take a look in the q-svc logs.

[1] http://docs.openstack.org/draft/networking-guide/config-service-subnets.html

[Carl Baldwin (carl-baldwin)]

Actually, I had this in the back of my mind at one point. I didn't prioritize the issue because the use cases that I had in mind don't require DHCP enabled on the subnet. Then, I forgot to follow up on it. That was my fault.

That's not a good excuse. This should work. The DHCP server needs a port on such a subnet and we need to allow it. It should be a pretty easy fix. Thanks for filing this bug report.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/392183

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/392183
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=1800ae63c2c1b6366f555c2f943e97f361c9ecd4
Submitter: Jenkins
Branch: master

commit 1800ae63c2c1b6366f555c2f943e97f361c9ecd4
Author: John Davidge <email address hidden>
Date: Tue Nov 1 14:36:49 2016 +0000

    Fix DHCP Port Creation on Service Subnets

    This changes the IPAM logic for service subnets to allow DHCP ports
    to be created on subnets of any service type, provided that the subnet
    has DHCP enabled.. This ensures that DHCP ports can still be created
    automatically on 'nova:compute' service subnets, for example.

    DocImpact

    Change-Id: I736262f2a7d3f3d7dfdc5276e2364aca7187d18b
    Closes-Bug: #1636963

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/newton
Review: https://review.openstack.org/412510

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/412510
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=cfac3bc3c9a96be293f5b4e166faff0f9d4328dd
Submitter: Jenkins
Branch: stable/newton

commit cfac3bc3c9a96be293f5b4e166faff0f9d4328dd
Author: John Davidge <email address hidden>
Date: Tue Nov 1 14:36:49 2016 +0000

    Fix DHCP Port Creation on Service Subnets

    This changes the IPAM logic for service subnets to allow DHCP ports
    to be created on subnets of any service type, provided that the subnet
    has DHCP enabled.. This ensures that DHCP ports can still be created
    automatically on 'nova:compute' service subnets, for example.

    DocImpact

    Change-Id: I736262f2a7d3f3d7dfdc5276e2364aca7187d18b
    Closes-Bug: #1636963
    (cherry picked from commit 1800ae63c2c1b6366f555c2f943e97f361c9ecd4)

[Brian Haley (brian-haley)]

This change is already in stable/newton, which is when subnet service types were introduced, so there isn't any other stable branch that needs the fix. I'll remove the backport-potential tag.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 10.0.0.0b3 development milestone.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 9.2.0 release.