Bug 2195931 - DHCP Agent doesn't receive notifications in 16.2.5 deployment
Summary: DHCP Agent doesn't receive notifications in 16.2.5 deployment
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat OpenStack
Classification: Red Hat
Component: documentation
Version: 16.2 (Train)
Hardware: All
OS: Linux
high
high
Target Milestone: z5
: 16.2 (Train on RHEL 8.4)
Assignee: Greg Rakauskas
QA Contact: RHOS Documentation Team
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2023-05-06 16:41 UTC by Siggy Sigwald
Modified: 2023-05-09 21:35 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Release Note
Doc Text:
If your Red Hat OpenStack Platform (RHOSP) deployment uses Cisco ACI or other third-party ML2 mechanism drivers that rely on `neutron-dhcp-agent`, you must add `DhcpAgentNotification: true` to your custom heat templates before updating to RHOSP 16.2.5. + In RHOSP 16.2.5, DHCP agent notification is now disabled by default. This configuration change facilitates easier deployment of RHOSP with the ML2/OVN mechanism driver, because RHOSP ML2/OVN deployments do not use the DHCP agent. The heat templates used in ML2/OVS deployments were also modified to provide uninterrupted use of DHCP services in ML2/OVS deployments. + If your deployment uses the OVN or OVS ML2 mechanism driver, your updated deployment will not be affected. + Some third-party mechanism drivers use DHCP and rely on the DHCP notifications. If your environment uses one of these third-party mechanism drivers and you update to RHOSP 16.2.5 without enabling DHCP notification (`DhcpAgentNotification: true`), your updated RHOSP deployment is subject to the following issues: * Network namespaces and `dnsmasq` processes are not created for new networks and ports. * DHCP and DNS are not served to VM instances on the new networks. * New instances fail to launch on existing networks with an error message that the instance cannot be scheduled.
Clone Of:
Environment:
Last Closed: 2023-05-09 21:32:41 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Github openstack/tripleo-heat-templates/commit/4bac4ec9531c43b83b73360d994daae53ae60cf8 0 None None None 2023-05-06 16:41:58 UTC
Red Hat Issue Tracker OSP-24815 0 None None None 2023-05-06 16:41:25 UTC

Description Siggy Sigwald 2023-05-06 16:41:13 UTC 
Description of problem:
Whenever a new network is created, the DHCP agent should create a network namespace. However, the DHCP agent notifications aren't sent, due to the following change in the upstream tripleo templates:
https://github.com/openstack/tripleo-heat-templates/commit/4bac4ec9531c43b83b73360d994daae53ae60cf8
We're able to work around this by adding this parameter to our deployments and setting explicitly, but in our view, this change probably shouldn't have been merged to stable branches as-is, since it breaks existing deployments.  

Version-Release number of selected component (if applicable):
Red Hat Openstack 16.2.5 

How reproducible:
Every time after update.
Comment 2 Jakub Libosvar 2023-05-08 15:14:53 UTC 
We should update our docs to notify users that in case they use custom templates and they need DHCP agent then they should set DhcpAgentNotification to true.

SME: jlibosva
Note You need to log in before you can comment on or make changes to this bug.