[Bug 2126923] Re: [SRU] ovn_dhcp4_global_options doesn't support keys with a list of values
Leah Goldberg
2126923 at bugs.launchpad.net
Fri Mar 20 21:29:18 UTC 2026
********** Verification for Caracal (UCA) **********
##### Before enabling -proposed #####
# current installed package
ubuntu at rs-jammy-caracal:~/regress-stack$ apt-cache policy neutron-server
neutron-server:
Installed: 2:24.1.0-0ubuntu1~cloud0
Candidate: 2:24.1.0-0ubuntu1~cloud0
Version table:
*** 2:24.1.0-0ubuntu1~cloud0 500
500 http://ubuntu-cloud.archive.canonical.com/ubuntu jammy-updates/caracal/main amd64 Packages
100 /var/lib/dpkg/status
2:20.5.0-0ubuntu2.1 500
500 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages
2:20.3.0-0ubuntu1.1 500
500 http://security.ubuntu.com/ubuntu jammy-security/main amd64 Packages
2:20.0.0-0ubuntu3 500
500 http://archive.ubuntu.com/ubuntu jammy/main amd64 Packages
# Changed the value of `ovn_dhcp4_global_options`
# to contain multiple values in the `ml2_conf.ini` file
sudo micro /etc/neutron/plugins/ml2/ml2_conf.ini
ovn_dhcp4_global_options = ntp_server:1.2.3.4,wpad:1.2.3.5;1.2.3.6
# Restart the neutron server
ubuntu at rs-jammy-caracal:~/regress-stack$ sudo systemctl restart neutron-server
ubuntu at rs-jammy-caracal:~/regress-stack$ sudo systemctl daemon-reload
# Create a new network and subnet
ubuntu at rs-jammy-caracal:~/regress-stack$ openstack network create test-network
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | UP |
| availability_zone_hints | |
| availability_zones | |
| created_at | 2026-03-20T21:21:06Z |
| description | |
| dns_domain | |
| id | 9b82342a-7909-4c79-8b90-b656ea416bfd |
| ipv4_address_scope | None |
| ipv6_address_scope | None |
| is_default | False |
| is_vlan_transparent | None |
| l2_adjacency | True |
| mtu | 1442 |
| name | test-network |
| port_security_enabled | True |
| project_id | 24e5244fb4124ef889fff29861533029 |
| provider:network_type | None |
| provider:physical_network | None |
| provider:segmentation_id | None |
| qos_policy_id | None |
| revision_number | 1 |
| router:external | Internal |
| segments | None |
| shared | False |
| status | ACTIVE |
| subnets | |
| tags | |
| tenant_id | 24e5244fb4124ef889fff29861533029 |
| updated_at | 2026-03-20T21:21:06Z |
+---------------------------+--------------------------------------+
ubuntu at rs-jammy-caracal:~/regress-stack$ openstack subnet create --network test-network --subnet-range 192.168.100.0/24 --dhcp test-subnet
+----------------------+--------------------------------------+
| Field | Value |
+----------------------+--------------------------------------+
| allocation_pools | 192.168.100.2-192.168.100.254 |
| cidr | 192.168.100.0/24 |
| created_at | 2026-03-20T21:21:10Z |
| description | |
| dns_nameservers | |
| dns_publish_fixed_ip | None |
| enable_dhcp | True |
| gateway_ip | 192.168.100.1 |
| host_routes | |
| id | 25bca3bd-e768-456f-aed4-79b6de8ea9d3 |
| ip_version | 4 |
| ipv6_address_mode | None |
| ipv6_ra_mode | None |
| name | test-subnet |
| network_id | 9b82342a-7909-4c79-8b90-b656ea416bfd |
| project_id | 24e5244fb4124ef889fff29861533029 |
| revision_number | 0 |
| segment_id | None |
| service_types | |
| subnetpool_id | None |
| tags | |
| updated_at | 2026-03-20T21:21:10Z |
+----------------------+--------------------------------------+
# See that multiple values are parsed incorrectly
ubuntu at rs-jammy-caracal:~/regress-stack$ sudo ovn-nbctl list
DHCP_Options
_uuid : 6808b77f-e72b-4f89-a929-06a8d85a49fc
cidr : "192.168.100.0/24"
external_ids : {"neutron:revision_number"="0", subnet_id="25bca3bd-e768-456f-aed4-79b6de8ea9d3"}
options : {classless_static_route="{169.254.169.254/32,192.168.100.2, 0.0.0.0/0,192.168.100.1}", dns_server="{127.0.0.53}", lease_time="600", mtu="1442", ntp_server="1.2.3.4", router="192.168.100.1", server_id="192.168.100.1", server_mac="fa:16:3e:93:80:89", wpad="1.2.3.5;1.2.3.6"}
*** Note wpad="1.2.3.5;1.2.3.6" (semi-colon) is incorrect
# Delete the network and subnet
ubuntu at rs-jammy-caracal:~/regress-stack$ openstack subnet delete test-subnet
ubuntu at rs-jammy-caracal:~/regress-stack$ openstack network delete test-network
### Enabling -proposed #####
ubuntu at rs-jammy-caracal:~/regress-stack$ sudo add-apt-repository cloud-
archive:caracal-proposed
ubuntu at rs-jammy-caracal:~/regress-stack$ sudo apt update
ubuntu at rs-jammy-caracal: sudo apt install -y \
neutron-server=2:24.1.0-0ubuntu1.1~cloud0 \
neutron-common=2:24.1.0-0ubuntu1.1~cloud0 \
neutron-plugin-ml2=2:24.1.0-0ubuntu1.1~cloud0 \
python3-neutron=2:24.1.0-0ubuntu1.1~cloud0
##### After enabling -proposed #####
# installed package
ubuntu at rs-jammy-caracal:~/regress-stack$ apt-cache policy neutron-server
neutron-server:
Installed: 2:24.1.0-0ubuntu1.1~cloud0
Candidate: 2:24.1.0-0ubuntu1.1~cloud0
Version table:
*** 2:24.1.0-0ubuntu1.1~cloud0 500
500 http://ubuntu-cloud.archive.canonical.com/ubuntu jammy-proposed/caracal/main amd64 Packages
100 /var/lib/dpkg/status
2:24.1.0-0ubuntu1~cloud0 500
500 http://ubuntu-cloud.archive.canonical.com/ubuntu jammy-updates/caracal/main amd64 Packages
2:20.5.0-0ubuntu2.1 500
500 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages
2:20.3.0-0ubuntu1.1 500
500 http://security.ubuntu.com/ubuntu jammy-security/main amd64 Packages
2:20.0.0-0ubuntu3 500
500 http://archive.ubuntu.com/ubuntu jammy/main amd64 Packages
# Create a new network and subnet again
ubuntu at rs-jammy-caracal:~/regress-stack$ openstack network create test-network
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | UP |
| availability_zone_hints | |
| availability_zones | |
| created_at | 2026-03-20T21:27:38Z |
| description | |
| dns_domain | |
| id | 1f3b06bb-a77b-40f0-bcfc-d399a97d4933 |
| ipv4_address_scope | None |
| ipv6_address_scope | None |
| is_default | False |
| is_vlan_transparent | None |
| l2_adjacency | True |
| mtu | 1442 |
| name | test-network |
| port_security_enabled | True |
| project_id | 24e5244fb4124ef889fff29861533029 |
| provider:network_type | None |
| provider:physical_network | None |
| provider:segmentation_id | None |
| qos_policy_id | None |
| revision_number | 1 |
| router:external | Internal |
| segments | None |
| shared | False |
| status | ACTIVE |
| subnets | |
| tags | |
| tenant_id | 24e5244fb4124ef889fff29861533029 |
| updated_at | 2026-03-20T21:27:38Z |
+---------------------------+--------------------------------------+
ubuntu at rs-jammy-caracal:~/regress-stack$ openstack subnet create --network test-network --subnet-range 192.168.100.0/24 --dhcp test-subnet
+----------------------+--------------------------------------+
| Field | Value |
+----------------------+--------------------------------------+
| allocation_pools | 192.168.100.2-192.168.100.254 |
| cidr | 192.168.100.0/24 |
| created_at | 2026-03-20T21:27:44Z |
| description | |
| dns_nameservers | |
| dns_publish_fixed_ip | None |
| enable_dhcp | True |
| gateway_ip | 192.168.100.1 |
| host_routes | |
| id | 5201d54c-8769-4a37-94a2-945e0eaf909c |
| ip_version | 4 |
| ipv6_address_mode | None |
| ipv6_ra_mode | None |
| name | test-subnet |
| network_id | 1f3b06bb-a77b-40f0-bcfc-d399a97d4933 |
| project_id | 24e5244fb4124ef889fff29861533029 |
| revision_number | 0 |
| segment_id | None |
| service_types | |
| subnetpool_id | None |
| tags | |
| updated_at | 2026-03-20T21:27:44Z |
+----------------------+--------------------------------------+
# See that multiple values are parsed correctly
ubuntu at rs-jammy-caracal:~/regress-stack$ sudo ovn-nbctl list
DHCP_Options
_uuid : 6ecb3b97-1b81-478b-8579-40f8b1633733
cidr : "192.168.100.0/24"
external_ids : {"neutron:revision_number"="0", subnet_id="5201d54c-8769-4a37-94a2-945e0eaf909c"}
options : {classless_static_route="{169.254.169.254/32,192.168.100.2, 0.0.0.0/0,192.168.100.1}", dns_server="{127.0.0.53}", lease_time="600", mtu="1442", ntp_server="1.2.3.4", router="192.168.100.1", server_id="192.168.100.1", server_mac="fa:16:3e:8e:79:55", wpad="{1.2.3.5, 1.2.3.6}"}
*** Note wpad="1.2.3.5,1.2.3.6" (comma) is now correct
# Checking neutron-server status is okay
ubuntu at rs-jammy-caracal:~/regress-stack$ sudo systemctl status neutron-server
● neutron-server.service - OpenStack Neutron Server
Loaded: loaded (/lib/systemd/system/neutron-server.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2026-03-20 17:27:13 EDT; 1min 19s ago
Docs: man:neutron-server(1)
Main PID: 32956 (/usr/bin/python)
Tasks: 6 (limit: 19129)
Memory: 364.6M
CPU: 8.081s
CGroup: /system.slice/neutron-server.service
[...]
***********************************************
I confirm that neutron-server version 2:24.1.0-0ubuntu1~cloud0
from jammy-proposed/caracal fixes LP: #2126923 on Caracal (UCA).
** Tags removed: verification-caracal-needed
** Tags added: verification-caracal-done
--
You received this bug notification because you are a member of Ubuntu
OpenStack, which is subscribed to Ubuntu Cloud Archive.
https://bugs.launchpad.net/bugs/2126923
Title:
[SRU] ovn_dhcp4_global_options doesn't support keys with a list of
values
Status in Ubuntu Cloud Archive:
Fix Committed
Status in Ubuntu Cloud Archive caracal series:
Fix Committed
Status in Ubuntu Cloud Archive dalmatian series:
Fix Committed
Status in Ubuntu Cloud Archive epoxy series:
Fix Committed
Status in Ubuntu Cloud Archive flamingo series:
Fix Committed
Status in neutron:
Fix Released
Status in neutron package in Ubuntu:
Fix Committed
Status in neutron source package in Noble:
Fix Committed
Status in neutron source package in Questing:
Fix Committed
Bug description:
[ Impact ]
* The Neutron configuration option `ovn_dhcp4_global_options` does not
correctly support multiple values for DHCP keys. When multiple values are
specified the neutron-server fails while parsing the configuration and does
not start.
* Backporting this fix would allow users to list multiple values in the
`ovn_dhcp4_global_options` without requiring configuration workarounds.
* The uploaded fix allows the config file, `ml2_conf.ini`, to correctly handle
multiple values in `ovn_dhcp4_global_options`.
[ UPDATED Test Plan ]
* [0] The following versions of Ubuntu-OpenStack will be tested
- UCA: jammy-caracal
- UCA: noble-dalmatian
- UCA: noble-epoxy
- UCA: noble-flamingo
- ubuntu: noble-caracal
- ubuntu: questing-flamingo
* [1] Deploy an OpenStack environment on the target series using regress-stack
in a multipass VM. For Jammy/Noble, it can be set up following the
instructions on the regress-stack README.md.
For Questing, follow these instructions:
https://github.com/canonical/se-wiki/wiki/Regress-Stack-How-to
* [2] Edit the `ml2_conf.ini` file and change `ovn_dhcp4_global_options` to
contain multiple values like
`ovn_dhcp4_global_options = ntp_server:1.2.3.4,wpad:1.2.3.5;1.2.3.6`
* [3] Restart the neutron server after updating the `ml2_conf.ini` file
Jammy/Noble: sudo systemctl restart neutron-server
Questing: sudo systemctl restart neutron-rpc-server.service
* [4] Create a new network and a subnet on that network
`openstack network create test-network`
`openstack subnet create \
--network test-network \
--subnet-range 192.168.100.0/24 \
--dhcp \
test-subnet`
* [5] Check to see that multiple values are parsed incorrectly in
OVN Northbound database
`sudo ovn-nbctl list DHCP_Options`
Incorrect options will look like wpad="1.2.3.5;1.2.3.6"
(with a semi-colon)
* [6] Delete the network and subnet created
`openstack subnet delete test-subnet`
`openstack network delete test-network`
* [7] Apply the patch
* [8] Create a new network and subnet again
(using same commands from step 4)
* [9] Check to see that multiple values are now parsed correctly in
OVN Northbound database.
Correct options will look like wpad="{1.2.3.5, 1.2.3.6}"
(with a comma)
* [10] Check the status of the neutron server to make sure it is running.
Jammy/Noble: sudo systemctl status neutron-server
Questing: sudo systemctl status neutron-rpc-server.service
[ Where problems could occur ]
* This change modifies how `ovn_dhcp4_global_options` options are parsed. A
regression could possibly cause a failure to apply DHCP options all together
due to an incorrect formatting in options sent to OVN.
[ Other Info ]
* Upstream commit to neutron (master):
https://review.opendev.org/c/openstack/neutron/+/963944
===========================================================
[ Original Bug Description ]
When using `ovn_dhcp4_global_options` under `[ovn]` in `ml2_conf.ini`
it will cause `neutron server` to crash when attempting to parse the
configuration if a key provided contains a list seperated by commas.
For example if setting `domain_search_list` with more than one domain.
```
[ovn]
ovn_dhcp4_global_options = domain_search_list:foo.bar,baz.qux
```
Expected output would be that `neutron server` doesn't crash when
attempting to parse such configuration and correctly applies these
options within `OVN`.
Experienced within OpenStack Epoxy.
Not currently blocking anything as it is possible to patch
`_get_ovn_dhcpv4_opts` in
`neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py` with
the following
```
options['domain_search_list'] = "\"foo.bar,baz.qux\""
```
To manage notifications about this bug go to:
https://bugs.launchpad.net/cloud-archive/+bug/2126923/+subscriptions
More information about the Ubuntu-openstack-bugs
mailing list