Comment 9 for bug 1942794

Reviewed: https://review.opendev.org/c/openstack/neutron/+/813408
Committed: https://opendev.org/openstack/neutron/commit/45f070baa17d06fde1d2ee1b53539f35ca6a9d07
Submitter: "Zuul (22348)"
Branch: stable/xena

commit 45f070baa17d06fde1d2ee1b53539f35ca6a9d07
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Tue Sep 7 08:52:21 2021 +0000

    [OVN] Update the DHCP options when the metadata port is modified

    Always update the DHCP options when the metadata port is created,
    updated or deleted. If the metadata port IP addresses are updated,
    the DHCP options register should be too, modifying the static routes
    defined in "DHCP_Options.options.classless_static_route".

    These static routes will be injected in the VM in the DHCP request.
    The IP address of the metadata port should match with the static
    route redirecting the traffic to the metadata IP address
    "169.254.169.254/32":

      $ ip r
      default via 10.0.0.1 dev eth0
      10.0.0.0/28 dev eth0 scope link src 10.0.0.7
      169.254.169.254 via 10.0.0.2 dev eth0 # 10.0.0.2 is the metadata
                                             # port IP address

    Closes-Bug: #1942794
    Change-Id: Id5d4909caa521a899b97d83bdc1963b010e97dac
    (cherry picked from commit bd0ded15ca21161c0f20679477445f4e31128267)