FIP ns created on network node for DVR

[sunzuohua]

I have a devstack with following configuration:
network nodes:
    /etc/neutron/l3_agent.ini
    [default]
    agent_mode = dvr_snat
compute nodes:
    /etc/neutron/l3_agent.ini
    [default]
    agent_mode = dvr_no_external

The reproduction steps
1.Launch VM and assign floating IP to it
2.Check namespace on network nodes.
3.You can see fip namespace on network nodes.

I guess the problem is that DvrLocalRouter is the inherited class of DvrEdgeRouter.
DvrLocalRouter will not create fip namespace only on nodes with "dvr_no_external" mode[1].
[1]https://github.com/openstack/neutron/blob/master/neutron/agent/l3/dvr_local_router.py#L569

Mybe DvrLocalRouter should not create fip namespace on nodes with "dvr_no_external" and "dvr_snat" mode.

[Swaminathan Vasudevan (swaminathan-vasudevan)]

This is as per design. The fip namespace gets created when gateway is enabled. This will be used for floating ip.created on an all in one node.

[sunzuohua (zuohuasun)]

But the fip namespace is not needed on an network only mode.
Before creating the fip namespace, checking the existing of floating ips for this node maybe can distinguish network only node and all in one node.

[Brian Haley (brian-haley)]

The fip namespace is needed for any centralized floating IPs, for example, floating IPs assigned to VMs on the dvr_no_external compute nodes. This is by design as Swami mentioned.

[sunzuohua (zuohuasun)]

In my opinion, the snat namespace is needed for any centralized floating IPs, not the fip namespace.
The fip namespace is needed on all in one node or dvr_no_external compute nodes.
Am I right?

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/512937

[Brian Haley (brian-haley)]

This can be closed as a duplicate of 1723891 right?

[sunzuohua (zuohuasun)]

This is not closed as duplicate of 1723891:
    Fip agent port is created for 1723891.
    Fip ns is created on network node for this.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/520261

[Swaminathan Vasudevan (swaminathan-vasudevan)]

Yes I agree that we can check on the fips host bound to create the fip namespace.
But it would be complex now, since we are creating fip namespaces based on the gateway and not on floatingIP anymore, since we are supporting the Fast path exit.

[OpenStack Infra (hudson-openstack)]

Change abandoned by "Rodolfo Alonso <email address hidden>" on branch: master
Review: https://review.opendev.org/c/openstack/neutron/+/520261